viz.py

# pylint: disable=C,R,W
"""This module contains the 'Viz' objects

These objects represent the backend of all the visualizations that
Superset can render.
"""
from collections import defaultdict, OrderedDict
import copy
from datetime import datetime, timedelta
from functools import reduce
import hashlib
import inspect
from itertools import product
import logging
import math
import pickle as pkl
import re
import traceback
import uuid

from dateutil import relativedelta as rdelta
from flask import request
from flask_babel import lazy_gettext as _
import geohash
from geopy.point import Point
from markdown import markdown
import numpy as np
import pandas as pd
from pandas.tseries.frequencies import to_offset
from past.builtins import basestring
import polyline
import simplejson as json

from superset import app, cache, get_css_manifest_files
from superset.exceptions import NullValueException, SpatialException
from superset.utils import core as utils
from superset.utils.core import (
    DTTM_ALIAS,
    JS_MAX_INTEGER,
    merge_extra_filters,
    to_adhoc,
)


config = app.config
stats_logger = config.get('STATS_LOGGER')

METRIC_KEYS = [
    'metric', 'metrics', 'percent_metrics', 'metric_2', 'secondary_metric',
    'x', 'y', 'size',
]


class BaseViz(object):

    """All visualizations derive this base class"""

    viz_type = None
    verbose_name = 'Base Viz'
    credits = ''
    is_timeseries = False
    default_fillna = 0
    cache_type = 'df'
    enforce_numerical_metrics = True

    def __init__(self, datasource, form_data, force=False):
        if not datasource:
            raise Exception(_('Viz is missing a datasource'))

        self.datasource = datasource
        self.request = request
        self.viz_type = form_data.get('viz_type')
        self.form_data = form_data

        self.query = ''
        self.token = self.form_data.get(
            'token', 'token_' + uuid.uuid4().hex[:8])

        self.groupby = self.form_data.get('groupby') or []
        self.time_shift = timedelta()

        self.status = None
        self.error_message = None
        self.force = force

        # Keeping track of whether some data came from cache
        # this is useful to trigger the <CachedLabel /> when
        # in the cases where visualization have many queries
        # (FilterBox for instance)
        self._some_from_cache = False
        self._any_cache_key = None
        self._any_cached_dttm = None
        self._extra_chart_data = []

        self.process_metrics()

    def process_metrics(self):
        # metrics in TableViz is order sensitive, so metric_dict should be
        # OrderedDict
        self.metric_dict = OrderedDict()
        fd = self.form_data
        for mkey in METRIC_KEYS:
            val = fd.get(mkey)
            if val:
                if not isinstance(val, list):
                    val = [val]
                for o in val:
                    label = self.get_metric_label(o)
                    if isinstance(o, dict):
                        o['label'] = label
                    self.metric_dict[label] = o

        # Cast to list needed to return serializable object in py3
        self.all_metrics = list(self.metric_dict.values())
        self.metric_labels = list(self.metric_dict.keys())

    def get_metric_label(self, metric):
        if isinstance(metric, str):
            return metric

        if isinstance(metric, dict):
            metric = metric.get('label')

        if self.datasource.type == 'table':
            db_engine_spec = self.datasource.database.db_engine_spec
            metric = db_engine_spec.mutate_expression_label(metric)
        return metric

    @staticmethod
    def handle_js_int_overflow(data):
        for d in data.get('records', dict()):
            for k, v in list(d.items()):
                if isinstance(v, int):
                    # if an int is too big for Java Script to handle
                    # convert it to a string
                    if abs(v) > JS_MAX_INTEGER:
                        d[k] = str(v)
        return data

    def run_extra_queries(self):
        """Lifecycle method to use when more than one query is needed

        In rare-ish cases, a visualization may need to execute multiple
        queries. That is the case for FilterBox or for time comparison
        in Line chart for instance.

        In those cases, we need to make sure these queries run before the
        main `get_payload` method gets called, so that the overall caching
        metadata can be right. The way it works here is that if any of
        the previous `get_df_payload` calls hit the cache, the main
        payload's metadata will reflect that.

        The multi-query support may need more work to become a first class
        use case in the framework, and for the UI to reflect the subtleties
        (show that only some of the queries were served from cache for
        instance). In the meantime, since multi-query is rare, we treat
        it with a bit of a hack. Note that the hack became necessary
        when moving from caching the visualization's data itself, to caching
        the underlying query(ies).
        """
        pass

    def handle_nulls(self, df):
        fillna = self.get_fillna_for_columns(df.columns)
        return df.fillna(fillna)

    def get_fillna_for_col(self, col):
        """Returns the value to use as filler for a specific Column.type"""
        if col:
            if col.is_string:
                return ' NULL'
        return self.default_fillna

    def get_fillna_for_columns(self, columns=None):
        """Returns a dict or scalar that can be passed to DataFrame.fillna"""
        if columns is None:
            return self.default_fillna
        columns_dict = {col.column_name: col for col in self.datasource.columns}
        fillna = {
            c: self.get_fillna_for_col(columns_dict.get(c))
            for c in columns
        }
        return fillna

    def get_samples(self):
        query_obj = self.query_obj()
        query_obj.update({
            'groupby': [],
            'metrics': [],
            'row_limit': 1000,
            'columns': [o.column_name for o in self.datasource.columns],
        })
        df = self.get_df(query_obj)
        return df.to_dict(orient='records')

    def get_df(self, query_obj=None):
        """Returns a pandas dataframe based on the query object"""
        if not query_obj:
            query_obj = self.query_obj()
        if not query_obj:
            return None

        self.error_msg = ''

        timestamp_format = None
        if self.datasource.type == 'table':
            dttm_col = self.datasource.get_col(query_obj['granularity'])
            if dttm_col:
                timestamp_format = dttm_col.python_date_format

        # The datasource here can be different backend but the interface is common
        self.results = self.datasource.query(query_obj)
        self.query = self.results.query
        self.status = self.results.status
        self.error_message = self.results.error_message

        df = self.results.df
        # Transform the timestamp we received from database to pandas supported
        # datetime format. If no python_date_format is specified, the pattern will
        # be considered as the default ISO date format
        # If the datetime format is unix, the parse will use the corresponding
        # parsing logic.
        if df is not None and not df.empty:
            if DTTM_ALIAS in df.columns:
                if timestamp_format in ('epoch_s', 'epoch_ms'):
                    # Column has already been formatted as a timestamp.
                    df[DTTM_ALIAS] = df[DTTM_ALIAS].apply(pd.Timestamp)
                else:
                    df[DTTM_ALIAS] = pd.to_datetime(
                        df[DTTM_ALIAS], utc=False, format=timestamp_format)
                if self.datasource.offset:
                    df[DTTM_ALIAS] += timedelta(hours=self.datasource.offset)
                df[DTTM_ALIAS] += self.time_shift

            if self.enforce_numerical_metrics:
                self.df_metrics_to_num(df)

            df.replace([np.inf, -np.inf], np.nan)
            df = self.handle_nulls(df)
        return df

    def df_metrics_to_num(self, df):
        """Converting metrics to numeric when pandas.read_sql cannot"""
        metrics = self.metric_labels
        for col, dtype in df.dtypes.items():
            if dtype.type == np.object_ and col in metrics:
                df[col] = pd.to_numeric(df[col], errors='coerce')

    def process_query_filters(self):
        utils.convert_legacy_filters_into_adhoc(self.form_data)
        merge_extra_filters(self.form_data)
        utils.split_adhoc_filters_into_base_filters(self.form_data)

    def query_obj(self):
        """Building a query object"""
        form_data = self.form_data
        self.process_query_filters()
        gb = form_data.get('groupby') or []
        metrics = self.all_metrics or []
        columns = form_data.get('columns') or []
        groupby = []
        for o in gb + columns:
            if o not in groupby:
                groupby.append(o)

        is_timeseries = self.is_timeseries
        if DTTM_ALIAS in groupby:
            groupby.remove(DTTM_ALIAS)
            is_timeseries = True

        granularity = (
            form_data.get('granularity') or
            form_data.get('granularity_sqla')
        )
        limit = int(form_data.get('limit') or 0)
        timeseries_limit_metric = form_data.get('timeseries_limit_metric')
        row_limit = int(form_data.get('row_limit') or config.get('ROW_LIMIT'))

        # default order direction
        order_desc = form_data.get('order_desc', True)

        since, until = utils.get_since_until(form_data.get('time_range'),
                                             form_data.get('since'),
                                             form_data.get('until'))
        time_shift = form_data.get('time_shift', '')
        self.time_shift = utils.parse_human_timedelta(time_shift)
        from_dttm = None if since is None else (since - self.time_shift)
        to_dttm = None if until is None else (until - self.time_shift)
        if from_dttm and to_dttm and from_dttm > to_dttm:
            raise Exception(_('From date cannot be larger than to date'))

        self.from_dttm = from_dttm
        self.to_dttm = to_dttm

        # extras are used to query elements specific to a datasource type
        # for instance the extra where clause that applies only to Tables
        extras = {
            'where': form_data.get('where', ''),
            'having': form_data.get('having', ''),
            'having_druid': form_data.get('having_filters', []),
            'time_grain_sqla': form_data.get('time_grain_sqla', ''),
            'druid_time_origin': form_data.get('druid_time_origin', ''),
        }

        d = {
            'granularity': granularity,
            'from_dttm': from_dttm,
            'to_dttm': to_dttm,
            'is_timeseries': is_timeseries,
            'groupby': groupby,
            'metrics': metrics,
            'row_limit': row_limit,
            'filter': self.form_data.get('filters', []),
            'timeseries_limit': limit,
            'extras': extras,
            'timeseries_limit_metric': timeseries_limit_metric,
            'order_desc': order_desc,
            'prequeries': [],
            'is_prequery': False,
        }
        return d

    @property
    def cache_timeout(self):
        if self.form_data.get('cache_timeout') is not None:
            return int(self.form_data.get('cache_timeout'))
        if self.datasource.cache_timeout is not None:
            return self.datasource.cache_timeout
        if (
                hasattr(self.datasource, 'database') and
                self.datasource.database.cache_timeout) is not None:
            return self.datasource.database.cache_timeout
        return config.get('CACHE_DEFAULT_TIMEOUT')

    def get_json(self):
        return json.dumps(
            self.get_payload(),
            default=utils.json_int_dttm_ser, ignore_nan=True)

    def cache_key(self, query_obj, **extra):
        """
        The cache key is made out of the key/values in `query_obj`, plus any
        other key/values in `extra`.

        We remove datetime bounds that are hard values, and replace them with
        the use-provided inputs to bounds, which may be time-relative (as in
        "5 days ago" or "now").

        The `extra` arguments are currently used by time shift queries, since
        different time shifts wil differ only in the `from_dttm` and `to_dttm`
        values which are stripped.
        """
        cache_dict = copy.copy(query_obj)
        cache_dict.update(extra)

        for k in ['from_dttm', 'to_dttm']:
            del cache_dict[k]

        cache_dict['time_range'] = self.form_data.get('time_range')
        cache_dict['datasource'] = self.datasource.uid
        json_data = self.json_dumps(cache_dict, sort_keys=True)
        return hashlib.md5(json_data.encode('utf-8')).hexdigest()

    def get_payload(self, query_obj=None):
        """Returns a payload of metadata and data"""
        self.run_extra_queries()
        payload = self.get_df_payload(query_obj)

        df = payload.get('df')
        if self.status != utils.QueryStatus.FAILED:
            if df is not None and df.empty:
                payload['error'] = 'No data'
            else:
                payload['data'] = self.get_data(df)
        if 'df' in payload:
            del payload['df']
        return payload

    def get_df_payload(self, query_obj=None, **kwargs):
        """Handles caching around the df payload retrieval"""
        if not query_obj:
            query_obj = self.query_obj()
        cache_key = self.cache_key(query_obj, **kwargs) if query_obj else None
        logging.info('Cache key: {}'.format(cache_key))
        is_loaded = False
        stacktrace = None
        df = None
        cached_dttm = datetime.utcnow().isoformat().split('.')[0]
        if cache_key and cache and not self.force:
            cache_value = cache.get(cache_key)
            if cache_value:
                stats_logger.incr('loaded_from_cache')
                try:
                    cache_value = pkl.loads(cache_value)
                    df = cache_value['df']
                    self.query = cache_value['query']
                    self._any_cached_dttm = cache_value['dttm']
                    self._any_cache_key = cache_key
                    self.status = utils.QueryStatus.SUCCESS
                    is_loaded = True
                except Exception as e:
                    logging.exception(e)
                    logging.error('Error reading cache: ' +
                                  utils.error_msg_from_exception(e))
                logging.info('Serving from cache')

        if query_obj and not is_loaded:
            try:
                df = self.get_df(query_obj)
                if self.status != utils.QueryStatus.FAILED:
                    stats_logger.incr('loaded_from_source')
                    is_loaded = True
            except Exception as e:
                logging.exception(e)
                if not self.error_message:
                    self.error_message = '{}'.format(e)
                self.status = utils.QueryStatus.FAILED
                stacktrace = traceback.format_exc()

            if (
                    is_loaded and
                    cache_key and
                    cache and
                    self.status != utils.QueryStatus.FAILED):
                try:
                    cache_value = dict(
                        dttm=cached_dttm,
                        df=df if df is not None else None,
                        query=self.query,
                    )
                    cache_value = pkl.dumps(
                        cache_value, protocol=pkl.HIGHEST_PROTOCOL)

                    logging.info('Caching {} chars at key {}'.format(
                        len(cache_value), cache_key))

                    stats_logger.incr('set_cache_key')
                    cache.set(
                        cache_key,
                        cache_value,
                        timeout=self.cache_timeout)
                except Exception as e:
                    # cache.set call can fail if the backend is down or if
                    # the key is too large or whatever other reasons
                    logging.warning('Could not cache key {}'.format(cache_key))
                    logging.exception(e)
                    cache.delete(cache_key)
        return {
            'cache_key': self._any_cache_key,
            'cached_dttm': self._any_cached_dttm,
            'cache_timeout': self.cache_timeout,
            'df': df,
            'error': self.error_message,
            'form_data': self.form_data,
            'is_cached': self._any_cache_key is not None,
            'query': self.query,
            'status': self.status,
            'stacktrace': stacktrace,
            'rowcount': len(df.index) if df is not None else 0,
        }

    def json_dumps(self, obj, sort_keys=False):
        return json.dumps(
            obj,
            default=utils.json_int_dttm_ser,
            ignore_nan=True,
            sort_keys=sort_keys,
        )

    def payload_json_and_has_error(self, payload):
        has_error = payload.get('status') == utils.QueryStatus.FAILED or \
            payload.get('error') is not None
        return self.json_dumps(payload), has_error

    @property
    def data(self):
        """This is the data object serialized to the js layer"""
        content = {
            'form_data': self.form_data,
            'token': self.token,
            'viz_name': self.viz_type,
            'filter_select_enabled': self.datasource.filter_select_enabled,
        }
        return content

    def get_csv(self):
        df = self.get_df()
        include_index = not isinstance(df.index, pd.RangeIndex)
        return df.to_csv(index=include_index, **config.get('CSV_EXPORT'))

    def get_data(self, df):
        return df.to_dict(orient='records')

    @property
    def json_data(self):
        return json.dumps(self.data)


class TableViz(BaseViz):

    """A basic html table that is sortable and searchable"""

    viz_type = 'table'
    verbose_name = _('Table View')
    credits = 'a <a href="https://github.com/airbnb/superset">Superset</a> original'
    is_timeseries = False
    enforce_numerical_metrics = False

    def should_be_timeseries(self):
        fd = self.form_data
        # TODO handle datasource-type-specific code in datasource
        conditions_met = (
            (fd.get('granularity') and fd.get('granularity') != 'all') or
            (fd.get('granularity_sqla') and fd.get('time_grain_sqla'))
        )
        if fd.get('include_time') and not conditions_met:
            raise Exception(_(
                'Pick a granularity in the Time section or '
                "uncheck 'Include Time'"))
        return fd.get('include_time')

    def query_obj(self):
        d = super(TableViz, self).query_obj()
        fd = self.form_data

        if fd.get('all_columns') and (fd.get('groupby') or fd.get('metrics')):
            raise Exception(_(
                'Choose either fields to [Group By] and [Metrics] or '
                '[Columns], not both'))

        sort_by = fd.get('timeseries_limit_metric')
        if fd.get('all_columns'):
            d['columns'] = fd.get('all_columns')
            d['groupby'] = []
            order_by_cols = fd.get('order_by_cols') or []
            d['orderby'] = [json.loads(t) for t in order_by_cols]
        elif sort_by:
            sort_by_label = utils.get_metric_name(sort_by)
            if sort_by_label not in utils.get_metric_names(d['metrics']):
                d['metrics'] += [sort_by]
            d['orderby'] = [(sort_by, not fd.get('order_desc', True))]

        # Add all percent metrics that are not already in the list
        if 'percent_metrics' in fd:
            d['metrics'] = d['metrics'] + list(filter(
                lambda m: m not in d['metrics'],
                fd['percent_metrics'] or [],
            ))

        d['is_timeseries'] = self.should_be_timeseries()
        return d

    def get_data(self, df):
        fd = self.form_data
        if (
                not self.should_be_timeseries() and
                df is not None and
                DTTM_ALIAS in df
        ):
            del df[DTTM_ALIAS]

        # Sum up and compute percentages for all percent metrics
        percent_metrics = fd.get('percent_metrics') or []
        percent_metrics = [self.get_metric_label(m) for m in percent_metrics]

        if len(percent_metrics):
            percent_metrics = list(filter(lambda m: m in df, percent_metrics))
            metric_sums = {
                m: reduce(lambda a, b: a + b, df[m])
                for m in percent_metrics
            }
            metric_percents = {
                m: list(map(
                    lambda a: None if metric_sums[m] == 0 else a / metric_sums[m], df[m]))
                for m in percent_metrics
            }
            for m in percent_metrics:
                m_name = '%' + m
                df[m_name] = pd.Series(metric_percents[m], name=m_name)
            # Remove metrics that are not in the main metrics list
            metrics = fd.get('metrics') or []
            metrics = [self.get_metric_label(m) for m in metrics]
            for m in filter(
                lambda m: m not in metrics and m in df.columns,
                percent_metrics,
            ):
                del df[m]

        data = self.handle_js_int_overflow(
            dict(
                records=df.to_dict(orient='records'),
                columns=list(df.columns),
            ))

        return data

    def json_dumps(self, obj, sort_keys=False):
        if self.form_data.get('all_columns'):
            return json.dumps(
                obj,
                default=utils.json_iso_dttm_ser,
                sort_keys=sort_keys,
                ignore_nan=True)
        else:
            return super(TableViz, self).json_dumps(obj)


class TimeTableViz(BaseViz):

    """A data table with rich time-series related columns"""

    viz_type = 'time_table'
    verbose_name = _('Time Table View')
    credits = 'a <a href="https://github.com/airbnb/superset">Superset</a> original'
    is_timeseries = True

    def query_obj(self):
        d = super(TimeTableViz, self).query_obj()
        fd = self.form_data

        if not fd.get('metrics'):
            raise Exception(_('Pick at least one metric'))

        if fd.get('groupby') and len(fd.get('metrics')) > 1:
            raise Exception(_(
                "When using 'Group By' you are limited to use a single metric"))
        return d

    def get_data(self, df):
        fd = self.form_data
        columns = None
        values = self.metric_labels
        if fd.get('groupby'):
            values = self.metric_labels[0]
            columns = fd.get('groupby')
        pt = df.pivot_table(
            index=DTTM_ALIAS,
            columns=columns,
            values=values)
        pt.index = pt.index.map(str)
        pt = pt.sort_index()
        return dict(
            records=pt.to_dict(orient='index'),
            columns=list(pt.columns),
            is_group_by=len(fd.get('groupby')) > 0,
        )


class PivotTableViz(BaseViz):

    """A pivot table view, define your rows, columns and metrics"""

    viz_type = 'pivot_table'
    verbose_name = _('Pivot Table')
    credits = 'a <a href="https://github.com/airbnb/superset">Superset</a> original'
    is_timeseries = False

    def query_obj(self):
        d = super(PivotTableViz, self).query_obj()
        groupby = self.form_data.get('groupby')
        columns = self.form_data.get('columns')
        metrics = self.form_data.get('metrics')
        if not columns:
            columns = []
        if not groupby:
            groupby = []
        if not groupby:
            raise Exception(_("Please choose at least one 'Group by' field "))
        if not metrics:
            raise Exception(_('Please choose at least one metric'))
        if (
                any(v in groupby for v in columns) or
                any(v in columns for v in groupby)):
            raise Exception(_("Group By' and 'Columns' can't overlap"))
        return d

    def get_data(self, df):
        if (
                self.form_data.get('granularity') == 'all' and
                DTTM_ALIAS in df):
            del df[DTTM_ALIAS]
        df = df.pivot_table(
            index=self.form_data.get('groupby'),
            columns=self.form_data.get('columns'),
            values=[self.get_metric_label(m) for m in self.form_data.get('metrics')],
            aggfunc=self.form_data.get('pandas_aggfunc'),
            margins=self.form_data.get('pivot_margins'),
        )
        # Display metrics side by side with each column
        if self.form_data.get('combine_metric'):
            df = df.stack(0).unstack()
        return dict(
            columns=list(df.columns),
            html=df.to_html(
                na_rep='',
                classes=(
                    'dataframe table table-striped table-bordered '
                    'table-condensed table-hover').split(' ')),
        )


class MarkupViz(BaseViz):

    """Use html or markdown to create a free form widget"""

    viz_type = 'markup'
    verbose_name = _('Markup')
    is_timeseries = False

    def query_obj(self):
        return None

    def get_df(self, query_obj=None):
        return None

    def get_data(self, df):
        markup_type = self.form_data.get('markup_type')
        code = self.form_data.get('code', '')
        if markup_type == 'markdown':
            code = markdown(code)
        return dict(html=code, theme_css=get_css_manifest_files('theme'))


class SeparatorViz(MarkupViz):

    """Use to create section headers in a dashboard, similar to `Markup`"""

    viz_type = 'separator'
    verbose_name = _('Separator')


class WordCloudViz(BaseViz):

    """Build a colorful word cloud

    Uses the nice library at:
    https://github.com/jasondavies/d3-cloud
    """

    viz_type = 'word_cloud'
    verbose_name = _('Word Cloud')
    is_timeseries = False

    def query_obj(self):
        d = super(WordCloudViz, self).query_obj()
        d['groupby'] = [self.form_data.get('series')]
        return d


class TreemapViz(BaseViz):

    """Tree map visualisation for hierarchical data."""

    viz_type = 'treemap'
    verbose_name = _('Treemap')
    credits = '<a href="https://d3js.org">d3.js</a>'
    is_timeseries = False

    def _nest(self, metric, df):
        nlevels = df.index.nlevels
        if nlevels == 1:
            result = [{'name': n, 'value': v}
                      for n, v in zip(df.index, df[metric])]
        else:
            result = [{'name': l, 'children': self._nest(metric, df.loc[l])}
                      for l in df.index.levels[0]]
        return result

    def get_data(self, df):
        df = df.set_index(self.form_data.get('groupby'))
        chart_data = [{'name': metric, 'children': self._nest(metric, df)}
                      for metric in df.columns]
        return chart_data


class CalHeatmapViz(BaseViz):

    """Calendar heatmap."""

    viz_type = 'cal_heatmap'
    verbose_name = _('Calendar Heatmap')
    credits = (
        '<a href=https://github.com/wa0x6e/cal-heatmap>cal-heatmap</a>')
    is_timeseries = True

    def get_data(self, df):
        form_data = self.form_data

        data = {}
        records = df.to_dict('records')
        for metric in self.metric_labels:
            values = {}
            for obj in records:
                v = obj[DTTM_ALIAS]
                if hasattr(v, 'value'):
                    v = v.value
                values[str(v / 10**9)] = obj.get(metric)
            data[metric] = values

        start, end = utils.get_since_until(form_data.get('time_range'),
                                           form_data.get('since'),
                                           form_data.get('until'))
        if not start or not end:
            raise Exception('Please provide both time bounds (Since and Until)')
        domain = form_data.get('domain_granularity')
        diff_delta = rdelta.relativedelta(end, start)
        diff_secs = (end - start).total_seconds()

        if domain == 'year':
            range_ = diff_delta.years + 1
        elif domain == 'month':
            range_ = diff_delta.years * 12 + diff_delta.months + 1
        elif domain == 'week':
            range_ = diff_delta.years * 53 + diff_delta.weeks + 1
        elif domain == 'day':
            range_ = diff_secs // (24 * 60 * 60) + 1
        else:
            range_ = diff_secs // (60 * 60) + 1

        return {
            'data': data,
            'start': start,
            'domain': domain,
            'subdomain': form_data.get('subdomain_granularity'),
            'range': range_,
        }

    def query_obj(self):
        d = super(CalHeatmapViz, self).query_obj()
        fd = self.form_data
        d['metrics'] = fd.get('metrics')
        return d


class NVD3Viz(BaseViz):

    """Base class for all nvd3 vizs"""

    credits = '<a href="http://nvd3.org/">NVD3.org</a>'
    viz_type = None
    verbose_name = 'Base NVD3 Viz'
    is_timeseries = False


class BoxPlotViz(NVD3Viz):

    """Box plot viz from ND3"""

    viz_type = 'box_plot'
    verbose_name = _('Box Plot')
    sort_series = False
    is_timeseries = True

    def to_series(self, df, classed='', title_suffix=''):
        label_sep = ' - '
        chart_data = []
        for index_value, row in zip(df.index, df.to_dict(orient='records')):
            if isinstance(index_value, tuple):
                index_value = label_sep.join(index_value)
            boxes = defaultdict(dict)
            for (label, key), value in row.items():
                if key == 'median':
                    key = 'Q2'
                boxes[label][key] = value
            for label, box in boxes.items():
                if len(self.form_data.get('metrics')) > 1:
                    # need to render data labels with metrics
                    chart_label = label_sep.join([index_value, label])
                else:
                    chart_label = index_value
                chart_data.append({
                    'label': chart_label,
                    'values': box,
                })
        return chart_data

    def get_data(self, df):
        form_data = self.form_data
        df = df.fillna(0)

        # conform to NVD3 names
        def Q1(series):  # need to be named functions - can't use lambdas
            return np.percentile(series, 25)

        def Q3(series):
            return np.percentile(series, 75)

        whisker_type = form_data.get('whisker_options')
        if whisker_type == 'Tukey':

            def whisker_high(series):
                upper_outer_lim = Q3(series) + 1.5 * (Q3(series) - Q1(series))
                series = series[series <= upper_outer_lim]
                return series[np.abs(series - upper_outer_lim).argmin()]

            def whisker_low(series):
                lower_outer_lim = Q1(series) - 1.5 * (Q3(series) - Q1(series))
                # find the closest value above the lower outer limit
                series = series[series >= lower_outer_lim]
                return series[np.abs(series - lower_outer_lim).argmin()]

        elif whisker_type == 'Min/max (no outliers)':

            def whisker_high(series):
                return series.max()

            def whisker_low(series):
                return series.min()

        elif ' percentiles' in whisker_type:
            low, high = whisker_type.replace(' percentiles', '').split('/')

            def whisker_high(series):
                return np.percentile(series, int(high))

            def whisker_low(series):
                return np.percentile(series, int(low))

        else:
            raise ValueError('Unknown whisker type: {}'.format(whisker_type))

        def outliers(series):
            above = series[series > whisker_high(series)]
            below = series[series < whisker_low(series)]
            # pandas sometimes doesn't like getting lists back here
            return set(above.tolist() + below.tolist())

        aggregate = [Q1, np.median, Q3, whisker_high, whisker_low, outliers]
        df = df.groupby(form_data.get('groupby')).agg(aggregate)
        chart_data = self.to_series(df)
        return chart_data


class BubbleViz(NVD3Viz):

    """Based on the NVD3 bubble chart"""

    viz_type = 'bubble'
    verbose_name = _('Bubble Chart')
    is_timeseries = False

    def query_obj(self):
        form_data = self.form_data
        d = super(BubbleViz, self).query_obj()
        d['groupby'] = [
            form_data.get('entity'),
        ]
        if form_data.get('series'):
            d['groupby'].append(form_data.get('series'))
        self.x_metric = form_data.get('x')
        self.y_metric = form_data.get('y')
        self.z_metric = form_data.get('size')
        self.entity = form_data.get('entity')
        self.series = form_data.get('series') or self.entity
        d['row_limit'] = form_data.get('limit')

        d['metrics'] = [
            self.z_metric,
            self.x_metric,
            self.y_metric,
        ]
        if not all(d['metrics'] + [self.entity]):
            raise Exception(_('Pick a metric for x, y and size'))
        return d

    def get_data(self, df):
        df['x'] = df[[utils.get_metric_name(self.x_metric)]]
        df['y'] = df[[utils.get_metric_name(self.y_metric)]]
        df['size'] = df[[utils.get_metric_name(self.z_metric)]]
        df['shape'] = 'circle'
        df['group'] = df[[self.series]]

        series = defaultdict(list)
        for row in df.to_dict(orient='records'):
            series[row['group']].append(row)
        chart_data = []
        for k, v in series.items():
            chart_data.append({
                'key': k,
                'values': v})
        return chart_data


class BulletViz(NVD3Viz):

    """Based on the NVD3 bullet chart"""

    viz_type = 'bullet'
    verbose_name = _('Bullet Chart')
    is_timeseries = False

    def query_obj(self):
        form_data = self.form_data
        d = super(BulletViz, self).query_obj()
        self.metric = form_data.get('metric')

        def as_strings(field):
            value = form_data.get(field)
            return value.split(',') if value else []

        def as_floats(field):
            return [float(x) for x in as_strings(field)]

        self.ranges = as_floats('ranges')
        self.range_labels = as_strings('range_labels')
        self.markers = as_floats('markers')
        self.marker_labels = as_strings('marker_labels')
        self.marker_lines = as_floats('marker_lines')
        self.marker_line_labels = as_strings('marker_line_labels')

        d['metrics'] = [
            self.metric,
        ]
        if not self.metric:
            raise Exception(_('Pick a metric to display'))
        return d

    def get_data(self, df):
        df = df.fillna(0)
        df['metric'] = df[[self.get_metric_label(self.metric)]]
        values = df['metric'].values
        return {
            'measures': values.tolist(),
            'ranges': self.ranges or [0, values.max() * 1.1],
            'rangeLabels': self.range_labels or None,
            'markers': self.markers or None,
            'markerLabels': self.marker_labels or None,
            'markerLines': self.marker_lines or None,
            'markerLineLabels': self.marker_line_labels or None,
        }


class BigNumberViz(BaseViz):

    """Put emphasis on a single metric with this big number viz"""

    viz_type = 'big_number'
    verbose_name = _('Big Number with Trendline')
    credits = 'a <a href="https://github.com/airbnb/superset">Superset</a> original'
    is_timeseries = True

    def query_obj(self):
        d = super(BigNumberViz, self).query_obj()
        metric = self.form_data.get('metric')
        if not metric:
            raise Exception(_('Pick a metric!'))
        d['metrics'] = [self.form_data.get('metric')]
        self.form_data['metric'] = metric
        return d


class BigNumberTotalViz(BaseViz):

    """Put emphasis on a single metric with this big number viz"""

    viz_type = 'big_number_total'
    verbose_name = _('Big Number')
    credits = 'a <a href="https://github.com/airbnb/superset">Superset</a> original'
    is_timeseries = False

    def query_obj(self):
        d = super(BigNumberTotalViz, self).query_obj()
        metric = self.form_data.get('metric')
        if not metric:
            raise Exception(_('Pick a metric!'))
        d['metrics'] = [self.form_data.get('metric')]
        self.form_data['metric'] = metric
        return d


class NVD3TimeSeriesViz(NVD3Viz):

    """A rich line chart component with tons of options"""

    viz_type = 'line'
    verbose_name = _('Time Series - Line Chart')
    sort_series = False
    is_timeseries = True

    def to_series(self, df, classed='', title_suffix=''):
        cols = []
        for col in df.columns:
            if col == '':
                cols.append('N/A')
            elif col is None:
                cols.append('NULL')
            else:
                cols.append(col)
        df.columns = cols
        series = df.to_dict('series')

        chart_data = []
        for name in df.T.index.tolist():
            ys = series[name]
            if df[name].dtype.kind not in 'biufc':
                continue
            if isinstance(name, list):
                series_title = [str(title) for title in name]
            elif isinstance(name, tuple):
                series_title = tuple(str(title) for title in name)
            else:
                series_title = str(name)
            if (
                    isinstance(series_title, (list, tuple)) and
                    len(series_title) > 1 and
                    len(self.metric_labels) == 1):
                # Removing metric from series name if only one metric
                series_title = series_title[1:]
            if title_suffix:
                if isinstance(series_title, str):
                    series_title = (series_title, title_suffix)
                elif isinstance(series_title, (list, tuple)):
                    series_title = series_title + (title_suffix,)

            values = []
            for ds in df.index:
                if ds in ys:
                    d = {
                        'x': ds,
                        'y': ys[ds],
                    }
                else:
                    d = {}
                values.append(d)

            d = {
                'key': series_title,
                'values': values,
            }
            if classed:
                d['classed'] = classed
            chart_data.append(d)
        return chart_data

    def process_data(self, df, aggregate=False):
        fd = self.form_data
        df = df.fillna(0)
        if fd.get('granularity') == 'all':
            raise Exception(_('Pick a time granularity for your time series'))
        if not aggregate:
            df = df.pivot_table(
                index=DTTM_ALIAS,
                columns=fd.get('groupby'),
                values=self.metric_labels)
        else:
            df = df.pivot_table(
                index=DTTM_ALIAS,
                columns=fd.get('groupby'),
                values=self.metric_labels,
                fill_value=0,
                aggfunc=sum)

        fm = fd.get('resample_fillmethod')
        if not fm:
            fm = None
        how = fd.get('resample_how')
        rule = fd.get('resample_rule')
        if how and rule:
            df = df.resample(rule, how=how, fill_method=fm)
            if not fm:
                df = df.fillna(0)

        if self.sort_series:
            dfs = df.sum()
            dfs.sort_values(ascending=False, inplace=True)
            df = df[dfs.index]

        if fd.get('contribution'):
            dft = df.T
            df = (dft / dft.sum()).T

        rolling_type = fd.get('rolling_type')
        rolling_periods = int(fd.get('rolling_periods') or 0)
        min_periods = int(fd.get('min_periods') or 0)

        if rolling_type in ('mean', 'std', 'sum') and rolling_periods:
            kwargs = dict(
                window=rolling_periods,
                min_periods=min_periods)
            if rolling_type == 'mean':
                df = df.rolling(**kwargs).mean()
            elif rolling_type == 'std':
                df = df.rolling(**kwargs).std()
            elif rolling_type == 'sum':
                df = df.rolling(**kwargs).sum()
        elif rolling_type == 'cumsum':
            df = df.cumsum()
        if min_periods:
            df = df[min_periods:]

        return df

    def run_extra_queries(self):
        fd = self.form_data

        time_compare = fd.get('time_compare') or []
        # backwards compatibility
        if not isinstance(time_compare, list):
            time_compare = [time_compare]

        for option in time_compare:
            query_object = self.query_obj()
            delta = utils.parse_human_timedelta(option)
            query_object['inner_from_dttm'] = query_object['from_dttm']
            query_object['inner_to_dttm'] = query_object['to_dttm']

            if not query_object['from_dttm'] or not query_object['to_dttm']:
                raise Exception(_(
                    '`Since` and `Until` time bounds should be specified '
                    'when using the `Time Shift` feature.'))
            query_object['from_dttm'] -= delta
            query_object['to_dttm'] -= delta

            df2 = self.get_df_payload(query_object, time_compare=option).get('df')
            if df2 is not None and DTTM_ALIAS in df2:
                label = '{} offset'. format(option)
                df2[DTTM_ALIAS] += delta
                df2 = self.process_data(df2)
                self._extra_chart_data.append((label, df2))

    def get_data(self, df):
        fd = self.form_data
        comparison_type = fd.get('comparison_type') or 'values'
        df = self.process_data(df)

        if comparison_type == 'values':
            chart_data = self.to_series(df)
            for i, (label, df2) in enumerate(self._extra_chart_data):
                chart_data.extend(
                    self.to_series(
                        df2, classed='time-shift-{}'.format(i), title_suffix=label))
        else:
            chart_data = []
            for i, (label, df2) in enumerate(self._extra_chart_data):
                # reindex df2 into the df2 index
                combined_index = df.index.union(df2.index)
                df2 = df2.reindex(combined_index) \
                    .interpolate(method='time') \
                    .reindex(df.index)

                if comparison_type == 'absolute':
                    diff = df - df2
                elif comparison_type == 'percentage':
                    diff = (df - df2) / df2
                elif comparison_type == 'ratio':
                    diff = df / df2
                else:
                    raise Exception(
                        'Invalid `comparison_type`: {0}'.format(comparison_type))

                # remove leading/trailing NaNs from the time shift difference
                diff = diff[diff.first_valid_index():diff.last_valid_index()]

                chart_data.extend(
                    self.to_series(
                        diff, classed='time-shift-{}'.format(i), title_suffix=label))

        return sorted(chart_data, key=lambda x: tuple(x['key']))


class MultiLineViz(NVD3Viz):

    """Pile on multiple line charts"""

    viz_type = 'line_multi'
    verbose_name = _('Time Series - Multiple Line Charts')

    is_timeseries = True

    def query_obj(self):
        return None

    def get_data(self, df):
        fd = self.form_data
        # Late imports to avoid circular import issues
        from superset.models.core import Slice
        from superset import db
        slice_ids1 = fd.get('line_charts')
        slices1 = db.session.query(Slice).filter(Slice.id.in_(slice_ids1)).all()
        slice_ids2 = fd.get('line_charts_2')
        slices2 = db.session.query(Slice).filter(Slice.id.in_(slice_ids2)).all()
        return {
            'slices': {
                'axis1': [slc.data for slc in slices1],
                'axis2': [slc.data for slc in slices2],
            },
        }


class NVD3DualLineViz(NVD3Viz):

    """A rich line chart with dual axis"""

    viz_type = 'dual_line'
    verbose_name = _('Time Series - Dual Axis Line Chart')
    sort_series = False
    is_timeseries = True

    def query_obj(self):
        d = super(NVD3DualLineViz, self).query_obj()
        m1 = self.form_data.get('metric')
        m2 = self.form_data.get('metric_2')
        d['metrics'] = [m1, m2]
        if not m1:
            raise Exception(_('Pick a metric for left axis!'))
        if not m2:
            raise Exception(_('Pick a metric for right axis!'))
        if m1 == m2:
            raise Exception(_('Please choose different metrics'
                            ' on left and right axis'))
        return d

    def to_series(self, df, classed=''):
        cols = []
        for col in df.columns:
            if col == '':
                cols.append('N/A')
            elif col is None:
                cols.append('NULL')
            else:
                cols.append(col)
        df.columns = cols
        series = df.to_dict('series')
        chart_data = []
        metrics = [
            self.form_data.get('metric'),
            self.form_data.get('metric_2'),
        ]
        for i, m in enumerate(metrics):
            m = utils.get_metric_name(m)
            ys = series[m]
            if df[m].dtype.kind not in 'biufc':
                continue
            series_title = m
            d = {
                'key': series_title,
                'classed': classed,
                'values': [
                    {'x': ds, 'y': ys[ds] if ds in ys else None}
                    for ds in df.index
                ],
                'yAxis': i + 1,
                'type': 'line',
            }
            chart_data.append(d)
        return chart_data

    def get_data(self, df):
        fd = self.form_data
        df = df.fillna(0)

        if self.form_data.get('granularity') == 'all':
            raise Exception(_('Pick a time granularity for your time series'))

        metric = self.get_metric_label(fd.get('metric'))
        metric_2 = self.get_metric_label(fd.get('metric_2'))
        df = df.pivot_table(
            index=DTTM_ALIAS,
            values=[metric, metric_2])

        chart_data = self.to_series(df)
        return chart_data


class NVD3TimeSeriesBarViz(NVD3TimeSeriesViz):

    """A bar chart where the x axis is time"""

    viz_type = 'bar'
    sort_series = True
    verbose_name = _('Time Series - Bar Chart')


class NVD3TimePivotViz(NVD3TimeSeriesViz):

    """Time Series - Periodicity Pivot"""

    viz_type = 'time_pivot'
    sort_series = True
    verbose_name = _('Time Series - Period Pivot')

    def query_obj(self):
        d = super(NVD3TimePivotViz, self).query_obj()
        d['metrics'] = [self.form_data.get('metric')]
        return d

    def get_data(self, df):
        fd = self.form_data
        df = self.process_data(df)
        freq = to_offset(fd.get('freq'))
        freq.normalize = True
        df[DTTM_ALIAS] = df.index.map(freq.rollback)
        df['ranked'] = df[DTTM_ALIAS].rank(method='dense', ascending=False) - 1
        df.ranked = df.ranked.map(int)
        df['series'] = '-' + df.ranked.map(str)
        df['series'] = df['series'].str.replace('-0', 'current')
        rank_lookup = {
            row['series']: row['ranked']
            for row in df.to_dict(orient='records')
        }
        max_ts = df[DTTM_ALIAS].max()
        max_rank = df['ranked'].max()
        df[DTTM_ALIAS] = df.index + (max_ts - df[DTTM_ALIAS])
        df = df.pivot_table(
            index=DTTM_ALIAS,
            columns='series',
            values=self.get_metric_label(fd.get('metric')))
        chart_data = self.to_series(df)
        for serie in chart_data:
            serie['rank'] = rank_lookup[serie['key']]
            serie['perc'] = 1 - (serie['rank'] / (max_rank + 1))
        return chart_data


class NVD3CompareTimeSeriesViz(NVD3TimeSeriesViz):

    """A line chart component where you can compare the % change over time"""

    viz_type = 'compare'
    verbose_name = _('Time Series - Percent Change')


class NVD3TimeSeriesStackedViz(NVD3TimeSeriesViz):

    """A rich stack area chart"""

    viz_type = 'area'
    verbose_name = _('Time Series - Stacked')
    sort_series = True


class DistributionPieViz(NVD3Viz):

    """Annoy visualization snobs with this controversial pie chart"""

    viz_type = 'pie'
    verbose_name = _('Distribution - NVD3 - Pie Chart')
    is_timeseries = False

    def get_data(self, df):
        metric = self.metric_labels[0]
        df = df.pivot_table(
            index=self.groupby,
            values=[metric])
        df.sort_values(by=metric, ascending=False, inplace=True)
        df = df.reset_index()
        df.columns = ['x', 'y']
        return df.to_dict(orient='records')


class HistogramViz(BaseViz):

    """Histogram"""

    viz_type = 'histogram'
    verbose_name = _('Histogram')
    is_timeseries = False

    def query_obj(self):
        """Returns the query object for this visualization"""
        d = super(HistogramViz, self).query_obj()
        d['row_limit'] = self.form_data.get(
            'row_limit', int(config.get('VIZ_ROW_LIMIT')))
        numeric_columns = self.form_data.get('all_columns_x')
        if numeric_columns is None:
            raise Exception(_('Must have at least one numeric column specified'))
        self.columns = numeric_columns
        d['columns'] = numeric_columns + self.groupby
        # override groupby entry to avoid aggregation
        d['groupby'] = []
        return d

    def labelify(self, keys, column):
        if isinstance(keys, str):
            keys = (keys,)
        # removing undesirable characters
        labels = [re.sub(r'\W+', r'_', k) for k in keys]
        if len(self.columns) > 1 or not self.groupby:
            # Only show numeric column in label if there are many
            labels = [column] + labels
        return '__'.join(labels)

    def get_data(self, df):
        """Returns the chart data"""
        chart_data = []
        if len(self.groupby) > 0:
            groups = df.groupby(self.groupby)
        else:
            groups = [((), df)]
        for keys, data in groups:
            chart_data.extend([{
                'key': self.labelify(keys, column),
                'values': data[column].tolist()}
                for column in self.columns])
        return chart_data


class DistributionBarViz(DistributionPieViz):

    """A good old bar chart"""

    viz_type = 'dist_bar'
    verbose_name = _('Distribution - Bar Chart')
    is_timeseries = False

    def query_obj(self):
        d = super(DistributionBarViz, self).query_obj()  # noqa
        fd = self.form_data
        if (
            len(d['groupby']) <
            len(fd.get('groupby') or []) + len(fd.get('columns') or [])
        ):
            raise Exception(
                _("Can't have overlap between Series and Breakdowns"))
        if not fd.get('metrics'):
            raise Exception(_('Pick at least one metric'))
        if not fd.get('groupby'):
            raise Exception(_('Pick at least one field for [Series]'))
        return d

    def get_data(self, df):
        fd = self.form_data
        metrics = self.metric_labels

        row = df.groupby(self.groupby).sum()[metrics[0]].copy()
        row.sort_values(ascending=False, inplace=True)
        columns = fd.get('columns') or []
        pt = df.pivot_table(
            index=self.groupby,
            columns=columns,
            values=metrics)
        if fd.get('contribution'):
            pt = pt.fillna(0)
            pt = pt.T
            pt = (pt / pt.sum()).T
        pt = pt.reindex(row.index)
        chart_data = []
        for name, ys in pt.items():
            if pt[name].dtype.kind not in 'biufc' or name in self.groupby:
                continue
            if isinstance(name, str):
                series_title = name
            else:
                offset = 0 if len(metrics) > 1 else 1
                series_title = ', '.join([str(s) for s in name[offset:]])
            values = []
            for i, v in ys.items():
                x = i
                if isinstance(x, (tuple, list)):
                    x = ', '.join([str(s) for s in x])
                else:
                    x = str(x)
                values.append({
                    'x': x,
                    'y': v,
                })
            d = {
                'key': series_title,
                'values': values,
            }
            chart_data.append(d)
        return chart_data


class SunburstViz(BaseViz):

    """A multi level sunburst chart"""

    viz_type = 'sunburst'
    verbose_name = _('Sunburst')
    is_timeseries = False
    credits = (
        'Kerry Rodden '
        '@<a href="https://bl.ocks.org/kerryrodden/7090426">bl.ocks.org</a>')

    def get_data(self, df):
        fd = self.form_data
        cols = fd.get('groupby')
        metric = self.get_metric_label(fd.get('metric'))
        secondary_metric = self.get_metric_label(fd.get('secondary_metric'))
        if metric == secondary_metric or secondary_metric is None:
            df.columns = cols + ['m1']
            df['m2'] = df['m1']
        return json.loads(df.to_json(orient='values'))

    def query_obj(self):
        qry = super(SunburstViz, self).query_obj()
        fd = self.form_data
        qry['metrics'] = [fd['metric']]
        secondary_metric = fd.get('secondary_metric')
        if secondary_metric and secondary_metric != fd['metric']:
            qry['metrics'].append(secondary_metric)
        return qry


class SankeyViz(BaseViz):

    """A Sankey diagram that requires a parent-child dataset"""

    viz_type = 'sankey'
    verbose_name = _('Sankey')
    is_timeseries = False
    credits = '<a href="https://www.npmjs.com/package/d3-sankey">d3-sankey on npm</a>'

    def query_obj(self):
        qry = super(SankeyViz, self).query_obj()
        if len(qry['groupby']) != 2:
            raise Exception(_('Pick exactly 2 columns as [Source / Target]'))
        qry['metrics'] = [
            self.form_data['metric']]
        return qry

    def get_data(self, df):
        df.columns = ['source', 'target', 'value']
        df['source'] = df['source'].astype(basestring)
        df['target'] = df['target'].astype(basestring)
        recs = df.to_dict(orient='records')

        hierarchy = defaultdict(set)
        for row in recs:
            hierarchy[row['source']].add(row['target'])

        def find_cycle(g):
            """Whether there's a cycle in a directed graph"""
            path = set()

            def visit(vertex):
                path.add(vertex)
                for neighbour in g.get(vertex, ()):
                    if neighbour in path or visit(neighbour):
                        return (vertex, neighbour)
                path.remove(vertex)

            for v in g:
                cycle = visit(v)
                if cycle:
                    return cycle

        cycle = find_cycle(hierarchy)
        if cycle:
            raise Exception(_(
                "There's a loop in your Sankey, please provide a tree. "
                "Here's a faulty link: {}").format(cycle))
        return recs


class DirectedForceViz(BaseViz):

    """An animated directed force layout graph visualization"""

    viz_type = 'directed_force'
    verbose_name = _('Directed Force Layout')
    credits = 'd3noob @<a href="http://bl.ocks.org/d3noob/5141278">bl.ocks.org</a>'
    is_timeseries = False

    def query_obj(self):
        qry = super(DirectedForceViz, self).query_obj()
        if len(self.form_data['groupby']) != 2:
            raise Exception(_("Pick exactly 2 columns to 'Group By'"))
        qry['metrics'] = [self.form_data['metric']]
        return qry

    def get_data(self, df):
        df.columns = ['source', 'target', 'value']
        return df.to_dict(orient='records')


class ChordViz(BaseViz):

    """A Chord diagram"""

    viz_type = 'chord'
    verbose_name = _('Directed Force Layout')
    credits = '<a href="https://github.com/d3/d3-chord">Bostock</a>'
    is_timeseries = False

    def query_obj(self):
        qry = super(ChordViz, self).query_obj()
        fd = self.form_data
        qry['groupby'] = [fd.get('groupby'), fd.get('columns')]
        qry['metrics'] = [self.get_metric_label(fd.get('metric'))]
        return qry

    def get_data(self, df):
        df.columns = ['source', 'target', 'value']

        # Preparing a symetrical matrix like d3.chords calls for
        nodes = list(set(df['source']) | set(df['target']))
        matrix = {}
        for source, target in product(nodes, nodes):
            matrix[(source, target)] = 0
        for source, target, value in df.to_records(index=False):
            matrix[(source, target)] = value
        m = [[matrix[(n1, n2)] for n1 in nodes] for n2 in nodes]
        return {
            'nodes': list(nodes),
            'matrix': m,
        }


class CountryMapViz(BaseViz):

    """A country centric"""

    viz_type = 'country_map'
    verbose_name = _('Country Map')
    is_timeseries = False
    credits = 'From bl.ocks.org By john-guerra'

    def query_obj(self):
        qry = super(CountryMapViz, self).query_obj()
        qry['metrics'] = [
            self.form_data['metric']]
        qry['groupby'] = [self.form_data['entity']]
        return qry

    def get_data(self, df):
        fd = self.form_data
        cols = [fd.get('entity')]
        metric = self.metric_labels[0]
        cols += [metric]
        ndf = df[cols]
        df = ndf
        df.columns = ['country_id', 'metric']
        d = df.to_dict(orient='records')
        return d


class WorldMapViz(BaseViz):

    """A country centric world map"""

    viz_type = 'world_map'
    verbose_name = _('World Map')
    is_timeseries = False
    credits = 'datamaps on <a href="https://www.npmjs.com/package/datamaps">npm</a>'

    def query_obj(self):
        qry = super(WorldMapViz, self).query_obj()
        qry['groupby'] = [self.form_data['entity']]
        return qry

    def get_data(self, df):
        from superset.data import countries
        fd = self.form_data
        cols = [fd.get('entity')]
        metric = self.get_metric_label(fd.get('metric'))
        secondary_metric = self.get_metric_label(fd.get('secondary_metric'))
        columns = ['country', 'm1', 'm2']
        if metric == secondary_metric:
            ndf = df[cols]
            # df[metric] will be a DataFrame
            # because there are duplicate column names
            ndf['m1'] = df[metric].iloc[:, 0]
            ndf['m2'] = ndf['m1']
        else:
            if secondary_metric:
                cols += [metric, secondary_metric]
            else:
                cols += [metric]
                columns = ['country', 'm1']
            ndf = df[cols]
        df = ndf
        df.columns = columns
        d = df.to_dict(orient='records')
        for row in d:
            country = None
            if isinstance(row['country'], str):
                country = countries.get(
                    fd.get('country_fieldtype'), row['country'])

            if country:
                row['country'] = country['cca3']
                row['latitude'] = country['lat']
                row['longitude'] = country['lng']
                row['name'] = country['name']
            else:
                row['country'] = 'XXX'
        return d


class FilterBoxViz(BaseViz):

    """A multi filter, multi-choice filter box to make dashboards interactive"""

    viz_type = 'filter_box'
    verbose_name = _('Filters')
    is_timeseries = False
    credits = 'a <a href="https://github.com/airbnb/superset">Superset</a> original'
    cache_type = 'get_data'

    def query_obj(self):
        return None

    def run_extra_queries(self):
        qry = self.filter_query_obj()
        filters = [g for g in self.form_data['groupby']]
        self.dataframes = {}
        for flt in filters:
            qry['groupby'] = [flt]
            df = self.get_df_payload(query_obj=qry).get('df')
            self.dataframes[flt] = df

    def filter_query_obj(self):
        qry = super(FilterBoxViz, self).query_obj()
        groupby = self.form_data.get('groupby')
        if len(groupby) < 1 and not self.form_data.get('date_filter'):
            raise Exception(_('Pick at least one filter field'))
        qry['metrics'] = [
            self.form_data['metric']]
        return qry

    def get_data(self, df):
        d = {}
        filters = [g for g in self.form_data['groupby']]
        for flt in filters:
            df = self.dataframes[flt]
            d[flt] = [{
                'id': row[0],
                'text': row[0],
                'filter': flt,
                'metric': row[1]}
                for row in df.itertuples(index=False)
            ]
        return d


class IFrameViz(BaseViz):

    """You can squeeze just about anything in this iFrame component"""

    viz_type = 'iframe'
    verbose_name = _('iFrame')
    credits = 'a <a href="https://github.com/airbnb/superset">Superset</a> original'
    is_timeseries = False

    def query_obj(self):
        return None

    def get_df(self, query_obj=None):
        return None

    def get_data(self, df):
        return {}


class ParallelCoordinatesViz(BaseViz):

    """Interactive parallel coordinate implementation

    Uses this amazing javascript library
    https://github.com/syntagmatic/parallel-coordinates
    """

    viz_type = 'para'
    verbose_name = _('Parallel Coordinates')
    credits = (
        '<a href="https://syntagmatic.github.io/parallel-coordinates/">'
        "Syntagmatic's library</a>")
    is_timeseries = False

    def query_obj(self):
        d = super(ParallelCoordinatesViz, self).query_obj()
        fd = self.form_data
        d['groupby'] = [fd.get('series')]
        return d

    def get_data(self, df):
        return df.to_dict(orient='records')


class HeatmapViz(BaseViz):

    """A nice heatmap visualization that support high density through canvas"""

    viz_type = 'heatmap'
    verbose_name = _('Heatmap')
    is_timeseries = False
    credits = (
        'inspired from mbostock @<a href="http://bl.ocks.org/mbostock/3074470">'
        'bl.ocks.org</a>')

    def query_obj(self):
        d = super(HeatmapViz, self).query_obj()
        fd = self.form_data
        d['metrics'] = [fd.get('metric')]
        d['groupby'] = [fd.get('all_columns_x'), fd.get('all_columns_y')]
        return d

    def get_data(self, df):
        fd = self.form_data
        x = fd.get('all_columns_x')
        y = fd.get('all_columns_y')
        v = self.metric_labels[0]
        if x == y:
            df.columns = ['x', 'y', 'v']
        else:
            df = df[[x, y, v]]
            df.columns = ['x', 'y', 'v']
        norm = fd.get('normalize_across')
        overall = False
        max_ = df.v.max()
        min_ = df.v.min()
        if norm == 'heatmap':
            overall = True
        else:
            gb = df.groupby(norm, group_keys=False)
            if len(gb) <= 1:
                overall = True
            else:
                df['perc'] = (
                    gb.apply(
                        lambda x: (x.v - x.v.min()) / (x.v.max() - x.v.min()))
                )
                df['rank'] = gb.apply(lambda x: x.v.rank(pct=True))
        if overall:
            df['perc'] = (df.v - min_) / (max_ - min_)
            df['rank'] = df.v.rank(pct=True)
        return {
            'records': df.to_dict(orient='records'),
            'extents': [min_, max_],
        }


class HorizonViz(NVD3TimeSeriesViz):

    """Horizon chart

    https://www.npmjs.com/package/d3-horizon-chart
    """

    viz_type = 'horizon'
    verbose_name = _('Horizon Charts')
    credits = (
        '<a href="https://www.npmjs.com/package/d3-horizon-chart">'
        'd3-horizon-chart</a>')


class MapboxViz(BaseViz):

    """Rich maps made with Mapbox"""

    viz_type = 'mapbox'
    verbose_name = _('Mapbox')
    is_timeseries = False
    credits = (
        '<a href=https://www.mapbox.com/mapbox-gl-js/api/>Mapbox GL JS</a>')

    def query_obj(self):
        d = super(MapboxViz, self).query_obj()
        fd = self.form_data
        label_col = fd.get('mapbox_label')

        if not fd.get('groupby'):
            d['columns'] = [fd.get('all_columns_x'), fd.get('all_columns_y')]

            if label_col and len(label_col) >= 1:
                if label_col[0] == 'count':
                    raise Exception(_(
                        "Must have a [Group By] column to have 'count' as the [Label]"))
                d['columns'].append(label_col[0])

            if fd.get('point_radius') != 'Auto':
                d['columns'].append(fd.get('point_radius'))

            d['columns'] = list(set(d['columns']))
        else:
            # Ensuring columns chosen are all in group by
            if (label_col and len(label_col) >= 1 and
                    label_col[0] != 'count' and
                    label_col[0] not in fd.get('groupby')):
                raise Exception(_(
                    'Choice of [Label] must be present in [Group By]'))

            if (fd.get('point_radius') != 'Auto' and
                    fd.get('point_radius') not in fd.get('groupby')):
                raise Exception(_(
                    'Choice of [Point Radius] must be present in [Group By]'))

            if (fd.get('all_columns_x') not in fd.get('groupby') or
                    fd.get('all_columns_y') not in fd.get('groupby')):
                raise Exception(_(
                    '[Longitude] and [Latitude] columns must be present in [Group By]'))
        return d

    def get_data(self, df):
        if df is None:
            return None
        fd = self.form_data
        label_col = fd.get('mapbox_label')
        has_custom_metric = label_col is not None and len(label_col) > 0
        metric_col = [None] * len(df.index)
        if has_custom_metric:
            if label_col[0] == fd.get('all_columns_x'):
                metric_col = df[fd.get('all_columns_x')]
            elif label_col[0] == fd.get('all_columns_y'):
                metric_col = df[fd.get('all_columns_y')]
            else:
                metric_col = df[label_col[0]]
        point_radius_col = (
            [None] * len(df.index)
            if fd.get('point_radius') == 'Auto'
            else df[fd.get('point_radius')])

        # using geoJSON formatting
        geo_json = {
            'type': 'FeatureCollection',
            'features': [
                {
                    'type': 'Feature',
                    'properties': {
                        'metric': metric,
                        'radius': point_radius,
                    },
                    'geometry': {
                        'type': 'Point',
                        'coordinates': [lon, lat],
                    },
                }
                for lon, lat, metric, point_radius
                in zip(
                    df[fd.get('all_columns_x')],
                    df[fd.get('all_columns_y')],
                    metric_col, point_radius_col)
            ],
        }

        x_series, y_series = df[fd.get('all_columns_x')], df[fd.get('all_columns_y')]
        south_west = [x_series.min(), y_series.min()]
        north_east = [x_series.max(), y_series.max()]

        return {
            'geoJSON': geo_json,
            'hasCustomMetric': has_custom_metric,
            'mapboxApiKey': config.get('MAPBOX_API_KEY'),
            'mapStyle': fd.get('mapbox_style'),
            'aggregatorName': fd.get('pandas_aggfunc'),
            'clusteringRadius': fd.get('clustering_radius'),
            'pointRadiusUnit': fd.get('point_radius_unit'),
            'globalOpacity': fd.get('global_opacity'),
            'bounds': [south_west, north_east],
            'renderWhileDragging': fd.get('render_while_dragging'),
            'tooltip': fd.get('rich_tooltip'),
            'color': fd.get('mapbox_color'),
        }


class DeckGLMultiLayer(BaseViz):

    """Pile on multiple DeckGL layers"""

    viz_type = 'deck_multi'
    verbose_name = _('Deck.gl - Multiple Layers')

    is_timeseries = False
    credits = '<a href="https://uber.github.io/deck.gl/">deck.gl</a>'

    def query_obj(self):
        return None

    def get_data(self, df):
        fd = self.form_data
        # Late imports to avoid circular import issues
        from superset.models.core import Slice
        from superset import db
        slice_ids = fd.get('deck_slices')
        slices = db.session.query(Slice).filter(Slice.id.in_(slice_ids)).all()
        return {
            'mapboxApiKey': config.get('MAPBOX_API_KEY'),
            'slices': [slc.data for slc in slices],
        }


class BaseDeckGLViz(BaseViz):

    """Base class for deck.gl visualizations"""

    is_timeseries = False
    credits = '<a href="https://uber.github.io/deck.gl/">deck.gl</a>'
    spatial_control_keys = []

    def handle_nulls(self, df):
        return df

    def get_metrics(self):
        self.metric = self.form_data.get('size')
        return [self.metric] if self.metric else []

    def process_spatial_query_obj(self, key, group_by):
        group_by.extend(self.get_spatial_columns(key))

    def get_spatial_columns(self, key):
        spatial = self.form_data.get(key)
        if spatial is None:
            raise ValueError(_('Bad spatial key'))

        if spatial.get('type') == 'latlong':
            return [spatial.get('lonCol'), spatial.get('latCol')]
        elif spatial.get('type') == 'delimited':
            return [spatial.get('lonlatCol')]
        elif spatial.get('type') == 'geohash':
            return [spatial.get('geohashCol')]

    @staticmethod
    def parse_coordinates(s):
        if not s:
            return None
        try:
            p = Point(s)
        except Exception:
            raise SpatialException(
                _('Invalid spatial point encountered: %s' % s))
        return (p.latitude, p.longitude)

    @staticmethod
    def reverse_geohash_decode(geohash_code):
        lat, lng = geohash.decode(geohash_code)
        return (lng, lat)

    @staticmethod
    def reverse_latlong(df, key):
        df[key] = [
            tuple(reversed(o))
            for o in df[key]
            if isinstance(o, (list, tuple))
        ]

    def process_spatial_data_obj(self, key, df):
        spatial = self.form_data.get(key)
        if spatial is None:
            raise ValueError(_('Bad spatial key'))

        if spatial.get('type') == 'latlong':
            df[key] = list(zip(
                pd.to_numeric(df[spatial.get('lonCol')], errors='coerce'),
                pd.to_numeric(df[spatial.get('latCol')], errors='coerce'),
            ))
        elif spatial.get('type') == 'delimited':
            lon_lat_col = spatial.get('lonlatCol')
            df[key] = df[lon_lat_col].apply(self.parse_coordinates)
            del df[lon_lat_col]
        elif spatial.get('type') == 'geohash':
            df[key] = df[spatial.get('geohashCol')].map(self.reverse_geohash_decode)
            del df[spatial.get('geohashCol')]

        if spatial.get('reverseCheckbox'):
            self.reverse_latlong(df, key)

        if df.get(key) is None:
            raise NullValueException(_('Encountered invalid NULL spatial entry, \
                                       please consider filtering those out'))
        return df

    def add_null_filters(self):
        fd = self.form_data
        spatial_columns = set()
        for key in self.spatial_control_keys:
            for column in self.get_spatial_columns(key):
                spatial_columns.add(column)

        if fd.get('adhoc_filters') is None:
            fd['adhoc_filters'] = []

        line_column = fd.get('line_column')
        if line_column:
            spatial_columns.add(line_column)

        for column in sorted(spatial_columns):
            filter_ = to_adhoc({
                'col': column,
                'op': 'IS NOT NULL',
                'val': '',
            })
            fd['adhoc_filters'].append(filter_)

    def query_obj(self):
        fd = self.form_data

        # add NULL filters
        if fd.get('filter_nulls', True):
            self.add_null_filters()

        d = super(BaseDeckGLViz, self).query_obj()
        gb = []

        for key in self.spatial_control_keys:
            self.process_spatial_query_obj(key, gb)

        if fd.get('dimension'):
            gb += [fd.get('dimension')]

        if fd.get('js_columns'):
            gb += fd.get('js_columns')
        metrics = self.get_metrics()
        gb = list(set(gb))
        if metrics:
            d['groupby'] = gb
            d['metrics'] = metrics
            d['columns'] = []
        else:
            d['columns'] = gb
        return d

    def get_js_columns(self, d):
        cols = self.form_data.get('js_columns') or []
        return {col: d.get(col) for col in cols}

    def get_data(self, df):
        if df is None:
            return None

        # Processing spatial info
        for key in self.spatial_control_keys:
            df = self.process_spatial_data_obj(key, df)

        features = []
        for d in df.to_dict(orient='records'):
            feature = self.get_properties(d)
            extra_props = self.get_js_columns(d)
            if extra_props:
                feature['extraProps'] = extra_props
            features.append(feature)

        return {
            'features': features,
            'mapboxApiKey': config.get('MAPBOX_API_KEY'),
            'metricLabels': self.metric_labels,
        }

    def get_properties(self, d):
        raise NotImplementedError()


class DeckScatterViz(BaseDeckGLViz):

    """deck.gl's ScatterLayer"""

    viz_type = 'deck_scatter'
    verbose_name = _('Deck.gl - Scatter plot')
    spatial_control_keys = ['spatial']
    is_timeseries = True

    def query_obj(self):
        fd = self.form_data
        self.is_timeseries = bool(
            fd.get('time_grain_sqla') or fd.get('granularity'))
        self.point_radius_fixed = (
            fd.get('point_radius_fixed') or {'type': 'fix', 'value': 500})
        return super(DeckScatterViz, self).query_obj()

    def get_metrics(self):
        self.metric = None
        if self.point_radius_fixed.get('type') == 'metric':
            self.metric = self.point_radius_fixed.get('value')
            return [self.metric]
        return None

    def get_properties(self, d):
        return {
            'metric': d.get(self.metric_label),
            'radius': self.fixed_value if self.fixed_value else d.get(self.metric_label),
            'cat_color': d.get(self.dim) if self.dim else None,
            'position': d.get('spatial'),
            DTTM_ALIAS: d.get(DTTM_ALIAS),
        }

    def get_data(self, df):
        fd = self.form_data
        self.metric_label = \
            self.get_metric_label(self.metric) if self.metric else None
        self.point_radius_fixed = fd.get('point_radius_fixed')
        self.fixed_value = None
        self.dim = self.form_data.get('dimension')
        if self.point_radius_fixed.get('type') != 'metric':
            self.fixed_value = self.point_radius_fixed.get('value')
        return super(DeckScatterViz, self).get_data(df)


class DeckScreengrid(BaseDeckGLViz):

    """deck.gl's ScreenGridLayer"""

    viz_type = 'deck_screengrid'
    verbose_name = _('Deck.gl - Screen Grid')
    spatial_control_keys = ['spatial']
    is_timeseries = True

    def query_obj(self):
        fd = self.form_data
        self.is_timeseries = fd.get('time_grain_sqla') or fd.get('granularity')
        return super(DeckScreengrid, self).query_obj()

    def get_properties(self, d):
        return {
            'position': d.get('spatial'),
            'weight': d.get(self.metric_label) or 1,
            '__timestamp': d.get(DTTM_ALIAS) or d.get('__time'),
        }

    def get_data(self, df):
        self.metric_label = self.get_metric_label(self.metric)
        return super(DeckScreengrid, self).get_data(df)


class DeckGrid(BaseDeckGLViz):

    """deck.gl's DeckLayer"""

    viz_type = 'deck_grid'
    verbose_name = _('Deck.gl - 3D Grid')
    spatial_control_keys = ['spatial']

    def get_properties(self, d):
        return {
            'position': d.get('spatial'),
            'weight': d.get(self.metric_label) or 1,
        }

    def get_data(self, df):
        self.metric_label = self.get_metric_label(self.metric)
        return super(DeckGrid, self).get_data(df)


def geohash_to_json(geohash_code):
    p = geohash.bbox(geohash_code)
    return [
        [p.get('w'), p.get('n')],
        [p.get('e'), p.get('n')],
        [p.get('e'), p.get('s')],
        [p.get('w'), p.get('s')],
        [p.get('w'), p.get('n')],
    ]


class DeckPathViz(BaseDeckGLViz):

    """deck.gl's PathLayer"""

    viz_type = 'deck_path'
    verbose_name = _('Deck.gl - Paths')
    deck_viz_key = 'path'
    is_timeseries = True
    deser_map = {
        'json': json.loads,
        'polyline': polyline.decode,
        'geohash': geohash_to_json,
    }

    def query_obj(self):
        fd = self.form_data
        self.is_timeseries = fd.get('time_grain_sqla') or fd.get('granularity')
        d = super(DeckPathViz, self).query_obj()
        self.metric = fd.get('metric')
        line_col = fd.get('line_column')
        if d['metrics']:
            self.has_metrics = True
            d['groupby'].append(line_col)
        else:
            self.has_metrics = False
            d['columns'].append(line_col)
        return d

    def get_properties(self, d):
        fd = self.form_data
        line_type = fd.get('line_type')
        deser = self.deser_map[line_type]
        line_column = fd.get('line_column')
        path = deser(d[line_column])
        if fd.get('reverse_long_lat'):
            path = [(o[1], o[0]) for o in path]
        d[self.deck_viz_key] = path
        if line_type != 'geohash':
            del d[line_column]
        d['__timestamp'] = d.get(DTTM_ALIAS) or d.get('__time')
        return d

    def get_data(self, df):
        self.metric_label = self.get_metric_label(self.metric)
        return super(DeckPathViz, self).get_data(df)


class DeckPolygon(DeckPathViz):

    """deck.gl's Polygon Layer"""

    viz_type = 'deck_polygon'
    deck_viz_key = 'polygon'
    verbose_name = _('Deck.gl - Polygon')

    def query_obj(self):
        fd = self.form_data
        self.elevation = (
            fd.get('point_radius_fixed') or {'type': 'fix', 'value': 500})
        return super(DeckPolygon, self).query_obj()

    def get_metrics(self):
        metrics = [self.form_data.get('metric')]
        if self.elevation.get('type') == 'metric':
            metrics.append(self.elevation.get('value'))
        return [metric for metric in metrics if metric]

    def get_properties(self, d):
        super(DeckPolygon, self).get_properties(d)
        fd = self.form_data
        elevation = fd['point_radius_fixed']['value']
        type_ = fd['point_radius_fixed']['type']
        d['elevation'] = d.get(elevation) if type_ == 'metric' else elevation
        return d


class DeckHex(BaseDeckGLViz):

    """deck.gl's DeckLayer"""

    viz_type = 'deck_hex'
    verbose_name = _('Deck.gl - 3D HEX')
    spatial_control_keys = ['spatial']

    def get_properties(self, d):
        return {
            'position': d.get('spatial'),
            'weight': d.get(self.metric_label) or 1,
        }

    def get_data(self, df):
        self.metric_label = self.get_metric_label(self.metric)
        return super(DeckHex, self).get_data(df)


class DeckGeoJson(BaseDeckGLViz):

    """deck.gl's GeoJSONLayer"""

    viz_type = 'deck_geojson'
    verbose_name = _('Deck.gl - GeoJSON')

    def query_obj(self):
        d = super(DeckGeoJson, self).query_obj()
        d['columns'] += [self.form_data.get('geojson')]
        d['metrics'] = []
        d['groupby'] = []
        return d

    def get_properties(self, d):
        geojson = d.get(self.form_data.get('geojson'))
        return json.loads(geojson)


class DeckArc(BaseDeckGLViz):

    """deck.gl's Arc Layer"""

    viz_type = 'deck_arc'
    verbose_name = _('Deck.gl - Arc')
    spatial_control_keys = ['start_spatial', 'end_spatial']
    is_timeseries = True

    def query_obj(self):
        fd = self.form_data
        self.is_timeseries = bool(
            fd.get('time_grain_sqla') or fd.get('granularity'))
        return super(DeckArc, self).query_obj()

    def get_properties(self, d):
        dim = self.form_data.get('dimension')
        return {
            'sourcePosition': d.get('start_spatial'),
            'targetPosition': d.get('end_spatial'),
            'cat_color': d.get(dim) if dim else None,
            DTTM_ALIAS: d.get(DTTM_ALIAS),
        }

    def get_data(self, df):
        d = super(DeckArc, self).get_data(df)

        return {
            'features': d['features'],
            'mapboxApiKey': config.get('MAPBOX_API_KEY'),
        }


class EventFlowViz(BaseViz):

    """A visualization to explore patterns in event sequences"""

    viz_type = 'event_flow'
    verbose_name = _('Event flow')
    credits = 'from <a href="https://github.com/williaster/data-ui">@data-ui</a>'
    is_timeseries = True

    def query_obj(self):
        query = super(EventFlowViz, self).query_obj()
        form_data = self.form_data

        event_key = form_data.get('all_columns_x')
        entity_key = form_data.get('entity')
        meta_keys = [
            col for col in form_data.get('all_columns')
            if col != event_key and col != entity_key
        ]

        query['columns'] = [event_key, entity_key] + meta_keys

        if form_data['order_by_entity']:
            query['orderby'] = [(entity_key, True)]

        return query

    def get_data(self, df):
        return df.to_dict(orient='records')


class PairedTTestViz(BaseViz):

    """A table displaying paired t-test values"""

    viz_type = 'paired_ttest'
    verbose_name = _('Time Series - Paired t-test')
    sort_series = False
    is_timeseries = True

    def get_data(self, df):
        """
        Transform received data frame into an object of the form:
        {
            'metric1': [
                {
                    groups: ('groupA', ... ),
                    values: [ {x, y}, ... ],
                }, ...
            ], ...
        }
        """
        fd = self.form_data
        groups = fd.get('groupby')
        metrics = fd.get('metrics')
        df.fillna(0)
        df = df.pivot_table(
            index=DTTM_ALIAS,
            columns=groups,
            values=metrics)
        cols = []
        # Be rid of falsey keys
        for col in df.columns:
            if col == '':
                cols.append('N/A')
            elif col is None:
                cols.append('NULL')
            else:
                cols.append(col)
        df.columns = cols
        data = {}
        series = df.to_dict('series')
        for nameSet in df.columns:
            # If no groups are defined, nameSet will be the metric name
            hasGroup = not isinstance(nameSet, str)
            Y = series[nameSet]
            d = {
                'group': nameSet[1:] if hasGroup else 'All',
                'values': [
                    {'x': t, 'y': Y[t] if t in Y else None}
                    for t in df.index
                ],
            }
            key = nameSet[0] if hasGroup else nameSet
            if key in data:
                data[key].append(d)
            else:
                data[key] = [d]
        return data


class RoseViz(NVD3TimeSeriesViz):

    viz_type = 'rose'
    verbose_name = _('Time Series - Nightingale Rose Chart')
    sort_series = False
    is_timeseries = True

    def get_data(self, df):
        data = super(RoseViz, self).get_data(df)
        result = {}
        for datum in data:
            key = datum['key']
            for val in datum['values']:
                timestamp = val['x'].value
                if not result.get(timestamp):
                    result[timestamp] = []
                value = 0 if math.isnan(val['y']) else val['y']
                result[timestamp].append({
                    'key': key,
                    'value': value,
                    'name': ', '.join(key) if isinstance(key, list) else key,
                    'time': val['x'],
                })
        return result


class PartitionViz(NVD3TimeSeriesViz):

    """
    A hierarchical data visualization with support for time series.
    """

    viz_type = 'partition'
    verbose_name = _('Partition Diagram')

    def query_obj(self):
        query_obj = super(PartitionViz, self).query_obj()
        time_op = self.form_data.get('time_series_option', 'not_time')
        # Return time series data if the user specifies so
        query_obj['is_timeseries'] = time_op != 'not_time'
        return query_obj

    def levels_for(self, time_op, groups, df):
        """
        Compute the partition at each `level` from the dataframe.
        """
        levels = {}
        for i in range(0, len(groups) + 1):
            agg_df = df.groupby(groups[:i]) if i else df
            levels[i] = (
                agg_df.mean() if time_op == 'agg_mean'
                else agg_df.sum(numeric_only=True))
        return levels

    def levels_for_diff(self, time_op, groups, df):
        # Obtain a unique list of the time grains
        times = list(set(df[DTTM_ALIAS]))
        times.sort()
        until = times[len(times) - 1]
        since = times[0]
        # Function describing how to calculate the difference
        func = {
            'point_diff': [
                pd.Series.sub,
                lambda a, b, fill_value: a - b,
            ],
            'point_factor': [
                pd.Series.div,
                lambda a, b, fill_value: a / float(b),
            ],
            'point_percent': [
                lambda a, b, fill_value=0: a.div(b, fill_value=fill_value) - 1,
                lambda a, b, fill_value: a / float(b) - 1,
            ],
        }[time_op]
        agg_df = df.groupby(DTTM_ALIAS).sum()
        levels = {0: pd.Series({
            m: func[1](agg_df[m][until], agg_df[m][since], 0)
            for m in agg_df.columns})}
        for i in range(1, len(groups) + 1):
            agg_df = df.groupby([DTTM_ALIAS] + groups[:i]).sum()
            levels[i] = pd.DataFrame({
                m: func[0](agg_df[m][until], agg_df[m][since], fill_value=0)
                for m in agg_df.columns})
        return levels

    def levels_for_time(self, groups, df):
        procs = {}
        for i in range(0, len(groups) + 1):
            self.form_data['groupby'] = groups[:i]
            df_drop = df.drop(groups[i:], 1)
            procs[i] = self.process_data(df_drop, aggregate=True).fillna(0)
        self.form_data['groupby'] = groups
        return procs

    def nest_values(self, levels, level=0, metric=None, dims=()):
        """
        Nest values at each level on the back-end with
        access and setting, instead of summing from the bottom.
        """
        if not level:
            return [{
                'name': m,
                'val': levels[0][m],
                'children': self.nest_values(levels, 1, m),
            } for m in levels[0].index]
        if level == 1:
            return [{
                'name': i,
                'val': levels[1][metric][i],
                'children': self.nest_values(levels, 2, metric, (i,)),
            } for i in levels[1][metric].index]
        if level >= len(levels):
            return []
        return [{
            'name': i,
            'val': levels[level][metric][dims][i],
            'children': self.nest_values(
                levels, level + 1, metric, dims + (i,),
            ),
        } for i in levels[level][metric][dims].index]

    def nest_procs(self, procs, level=-1, dims=(), time=None):
        if level == -1:
            return [{
                'name': m,
                'children': self.nest_procs(procs, 0, (m,)),
            } for m in procs[0].columns]
        if not level:
            return [{
                'name': t,
                'val': procs[0][dims[0]][t],
                'children': self.nest_procs(procs, 1, dims, t),
            } for t in procs[0].index]
        if level >= len(procs):
            return []
        return [{
            'name': i,
            'val': procs[level][dims][i][time],
            'children': self.nest_procs(procs, level + 1, dims + (i,), time),
        } for i in procs[level][dims].columns]

    def get_data(self, df):
        fd = self.form_data
        groups = fd.get('groupby', [])
        time_op = fd.get('time_series_option', 'not_time')
        if not len(groups):
            raise ValueError('Please choose at least one groupby')
        if time_op == 'not_time':
            levels = self.levels_for('agg_sum', groups, df)
        elif time_op in ['agg_sum', 'agg_mean']:
            levels = self.levels_for(time_op, groups, df)
        elif time_op in ['point_diff', 'point_factor', 'point_percent']:
            levels = self.levels_for_diff(time_op, groups, df)
        elif time_op == 'adv_anal':
            procs = self.levels_for_time(groups, df)
            return self.nest_procs(procs)
        else:
            levels = self.levels_for('agg_sum', [DTTM_ALIAS] + groups, df)
        return self.nest_values(levels)


viz_types = {
    o.viz_type: o for o in globals().values()
    if (
        inspect.isclass(o) and
        issubclass(o, BaseViz) and
        o.viz_type not in config.get('VIZ_TYPE_BLACKLIST'))}