generate-exports.py

#!/usr/bin/env python

from operator import attrgetter
from optparse import OptionParser
import re
import sys


def simplerepr(obj):
    keys = sorted(key for key in obj.__dict__.keys() if not key.startswith('_'))
    attrs = ''.join(' %s=%r' % (key, obj.__dict__[key]) for key in keys)
    return '<%s%s>' % (obj.__class__.__name__, attrs)


class Exportable(object):

    def __init__(self, name):
        self.name = name

    __repr__ = simplerepr

    def export(self):
        return ''

    def extern(self):
        return ''

    def typedef(self):
        return ''


class ObjectLiteral(Exportable):

    def __init__(self, name, objects):
        Exportable.__init__(self, name)
        self.prop_types = {}
        self.objects = objects

    __repr__ = simplerepr

    def extern(self):
        lines = []
        lines.append('\n\n\n')
        lines.append('/**\n')
        lines.append(' * @interface\n')
        lines.append(' */\n')
        lines.append('%s = function() {};\n' % (self.extern_name(),))
        for prop in sorted(self.prop_types.keys()):
            lines.append('\n\n')
            lines.append('/**\n')
            prop_types = self.prop_types[prop].split('|')
            for i, t in enumerate(prop_types):
                if t in self.objects and isinstance(self.objects[t], ObjectLiteral):
                    prop_types[i] = self.objects[t].extern_name()
            prop_types = '|'.join(prop_types)
            lines.append(' * @type {%s}\n' % (prop_types,))
            lines.append(' */\n')
            lines.append('%s.prototype.%s;\n' % (self.extern_name(), prop))
        return ''.join(lines)

    def extern_name(self):
        return re.sub(r'(olx\.\S+)', r'\1Extern', self.name)

    def extern_namespace(self):
        return '.'.join(self.extern_name().split('.')[:-1]) or None

    def provide(self):
        return 'goog.provide(\'%s\');\n' % (self.name,)

    def typedef(self):
        lines = []
        lines.append('\n\n')
        lines.append('/**\n')
        for i, prop in enumerate(sorted(self.prop_types.keys())):
            prefix =  ' * @typedef {{' if i == 0 else ' *            '
            suffix = '}}' if i == len(self.prop_types) - 1 else ','
            type = self.prop_types[prop]
            if '|' in type:
                type = '(%s)' % (type,)
            lines.append('%s%s: %s%s\n' % (prefix, prop, type, suffix))
        lines.append(' */\n')
        lines.append('%s;\n' % (self.name,))
        return ''.join(lines)


class Symbol(Exportable):

    def __init__(self, name, export_symbol):
        Exportable.__init__(self, name)
        self.export_symbol = export_symbol
        self.props = set()

    __repr__ = simplerepr

    def export(self):
        lines = []
        if self.export_symbol:
            lines.append('\n\ngoog.exportSymbol(\n    \'%s\',\n    %s);\n' % (self.name, self.name))
        lines.extend('goog.exportProperty(\n    %s,\n    \'%s\',\n    %s.%s);\n' % (self.name, prop, self.name, prop) for prop in sorted(self.props))
        return ''.join(lines)


def main(argv):

    option_parser = OptionParser()
    option_parser.add_option('--exports', action='store_true')
    option_parser.add_option('--externs', action='store_true')
    option_parser.add_option('--typedef', action='store_true')
    options, args = option_parser.parse_args(argv[1:])

    objects = {}
    requires = set()
    for arg in args:
        in_comment = False
        object_literal = None
        for line in open(arg, 'rU'):
            line = line.strip()
            if not line:
                continue
            if line == '/**':
                assert not in_comment
                in_comment = True
                continue
            if line == '*/':
                assert in_comment
                in_comment = False
                object_literal = None
                continue
            if in_comment:
                if not line.startswith('*'):
                    raise RuntimeError(line)  # malformed comment
                m = re.match(r'\*\s*@typedef\s*\{Object\}\s*(?P<name>\S+)', line)
                if m:
                    assert object_literal is None
                    name = m.group('name')
                    if name in objects:
                        raise RuntimeError(line)  # Name already defined
                    object_literal = ObjectLiteral(name, objects)
                    objects[name] = object_literal
                    continue
                m = re.match(r'\*\s*@property\s*{(?P<type>.*?)}\s*(?P<prop>\S+)', line)
                if m:
                    assert object_literal is not None
                    prop = m.group('prop')
                    if prop in object_literal.prop_types:
                        raise RuntimeError(line)  # Duplicate property
                    type = m.group('type')
                    object_literal.prop_types[prop] = type
                    continue
                continue
            m = re.match(r'@exportProperty\s+(?P<prop>\S+)\Z', line)
            if m:
                components = m.group('prop').split('.')
                if components[-2] == 'prototype':
                    requires.add('.'.join(components[:-2]))
                else:
                    requires.add('.'.join(components[:-1]))
                name = '.'.join(components[:-1]) 
                prop = components[-1]
                if name in objects:
                    symbol = objects[name]
                else:
                    symbol = Symbol(name, False)
                    objects[name] = symbol
                symbol.props.add(prop)
                continue
            m = re.match(r'@exportSymbol\s+(?P<name>\S+)\Z', line)
            if m:
                name = m.group('name')
                if name in objects:
                    raise RuntimeError(line)  # Name already defined
                symbol = Symbol(name, True)
                objects[name] = symbol
                components = m.group('name').split('.')
                if re.match(r'[A-Z]', components[-1]):
                    requires.add(name)
                else:
                    requires.add('.'.join(components[:-1]))
                continue
            raise RuntimeError(line)

    objects = sorted(objects.values(), key=attrgetter('name'))

    if options.exports:
        if requires:
            for require in sorted(requires):
                sys.stdout.write('goog.require(\'%s\');\n' % (require,))
        for obj in objects:
            sys.stdout.write(obj.export())

    if options.externs:
        object_literals = [obj for obj in objects if isinstance(obj, ObjectLiteral)]
        sys.stdout.write('/**\n')
        sys.stdout.write(' * @externs\n')
        sys.stdout.write(' */\n')
        namespaces = sorted(set(filter(None, (object_literal.extern_namespace() for object_literal in object_literals))))
        for namespace in namespaces:
            sys.stdout.write('\n\n')
            sys.stdout.write('/**\n')
            sys.stdout.write(' * @type {Object}\n')
            sys.stdout.write(' */\n')
            if '.' in namespace:
                sys.stdout.write('%s = {};\n' % (namespace,))
            else:
                sys.stdout.write('var %s;\n' % (namespace,))
        for object_literal in object_literals:
            sys.stdout.write(object_literal.typedef())
            sys.stdout.write(object_literal.extern())

    if options.typedef:
        object_literals = [obj for obj in objects if isinstance(obj, ObjectLiteral)]
        for object_literal in object_literals:
            sys.stdout.write(object_literal.provide())
        for object_literal in object_literals:
            sys.stdout.write(object_literal.typedef())


if __name__ == '__main__':
    sys.exit(main(sys.argv))