server.js

var fs = require('fs');
var URL = require('url');
var path = require('path');
var exec = require('child_process').exec;

var mimes = require('./mime.json');
var $ = require('./helper');
var connect = require('connect');
var libDir = __dirname;
var rootDir = path.join(libDir, '../') + path.sep;
var templateDir = path.join(rootDir, 'template') + path.sep;

var chokidar = require('chokidar');
var md_parser = require('./md_parser');
//session相关
var Cookie = require('cookie');
var parseSignedCookie = connect.utils.parseSignedCookie;
var MemoryStore = connect.middleware.session.MemoryStore;
var Session = connect.middleware.session.Session;
//建立一个memory store的实例
var storeMemory = new MemoryStore({
    reapInterval: 60000 * 10
});
module.exports.start = function(port, pptDir, host, argvObj) {
    port = parseInt(port, 10) || 8080;
    pptDir = (pptDir || path.join(__dirname, '../ppts')) + path.sep;
    try {
        pptDir = fs.realpathSync(pptDir) + path.sep;
    } catch (e) {}

    var app = startApp(port, pptDir, host, argvObj);
    var io = require('socket.io').listen(app, {
        log: false,
        origins: '*:*' //解决同源策略
    });
    //设置session
    io.set('authorization', function(handshakeData, accept) {
        // 通过客户端的cookie字符串来获取其session数据
        var ccc = '';
        if (handshakeData.headers && handshakeData.headers.cookie) {
            ccc = handshakeData.headers.cookie;
        }
        handshakeData.cookie = Cookie.parse(ccc);
        var connect_sid = parseSignedCookie(handshakeData.cookie['connect.sid'], 'wyq');
        if (connect_sid) {
            storeMemory.get(connect_sid, function(error, session) {
                if (error) {
                    // if we cannot grab a session, turn down the connection
                    accept(error.message, false);
                } else {
                    // save the session data and accept the connection
                    handshakeData.session = new Session(handshakeData, session);
                    handshakeData.connect_sid = connect_sid;
                    accept(null, true);
                }
            });
        } else {
            accept('nosession');
        }
    });
    //watcher对应的socket
    var watchSockets = {};
    if (argvObj.watch) {
        //添加watch功能
        var exclude = ["\\/\\.", "node_modules"];

        var watcher = chokidar.watch(pptDir, {
            ignored: new RegExp(exclude.join('|')),
            persistent: true
        });
        watcher.on('change', function() {
            sendChangedNotice();
        });
        io.of('/watcher').on('connection', function(socket) {
            watchSockets[socket.id] = socket;
        });
    }


    //用户双屏通信
    var now = Date.now();

    var sockets = {};
    var userMap = {};


    io.of('/ppt').on('connection', function(socket) {
        //解析cookie中的sid
        var cookie = socket.handshake.headers.cookie;
        cookie = Cookie.parse(cookie || '');
        var uid = cookie['connect.sid'];
        socket.uid = uid;

        sockets[uid] = socket;
        //监听添加map
        socket.on('add client', function(data) {
            var targetUid = socket.targetUid = data.targetUid;
            var otherSocket = sockets[targetUid];
            userMap[targetUid] = uid;
            userMap[uid] = targetUid;

            otherSocket && otherSocket.emit('system', {
                action: 'join',
                joinUid: uid
            });

        });
        //建立消息中转站
        socket.on('repost data', function(data) {
            var uid = socket.uid;
            var targetUid = userMap[uid];
            var otherSocket = sockets[targetUid];
            otherSocket && otherSocket.emit('data from another client', data);
        });
        //将当前分配的uid告知客户端
        socket.emit('UUID', uid);

        socket.on('disconnect', function() {
            var uid = socket.uid;
            var targetUid = userMap[uid];
            var otherSocket = sockets[targetUid];
            otherSocket && otherSocket.emit('system', {
                action: 'leave',
                leaveUid: uid
            });
            delete sockets[uid];
        });
    });


    function sendChangedNotice() {
        if (!Object.keys(watchSockets)) {
            return console.error('[watch-connect]', 'No client connected to socket.io');
        }
        Object.keys(watchSockets).forEach(function(s) {
            if (watchSockets[s] && watchSockets[s].emit) {
                watchSockets[s].emit('file changed');
            }
        });
    }
};

function startApp(port, dir, host, argvObj) {
    host = host || '0.0.0.0';
    var staticDir = path.normalize(path.join(__dirname, '../assets')) + path.sep;
    var nodeModules = path.normalize(path.join(__dirname, '../node_modules')) + path.sep;
    var pptDir = dir;

    var now = Date.now();
    var app = connect(
        connect.cookieParser(),
        connect.session({
            secret: 'wyq',
            store: storeMemory
        }),
        function(req, res) {
            var url = URL.parse(req.url).pathname;
            var dirname = path.dirname(url);
            var realPath, ext;
            if (url === '/') {
                //根目录显示list
                pptlist(res, pptDir, argvObj);
                return;
            } else if (dirname === '/md') {
                //md文件解析
                url = URL.parse(req.url).pathname;
                var basename = path.basename(url);
                try {
                    basename = decodeURIComponent(basename);
                } catch (e) {
                    basename = path.basename(url);
                }
                var queryObj = URL.parse(req.url, true).query;
                realPath = pptDir + basename;
                console.log('markdown', realPath, basename);
                markdown(realPath, basename, res, argvObj, queryObj);
                return;
            } else if (/^\/js\/mathjax/.test(dirname)) {
                //处理mathjax
                realPath = url.replace('/js/', nodeModules);
                ext = path.extname(realPath);
                ext = ext ? ext.slice(1) : 'unknown';

            } else {
                //优先选择pptDir的静态资源
                url = url.indexOf('/') === 0 ? url.substring(1) : url;
                realPath = pptDir + url;
                if (!fs.existsSync(realPath)) {
                    realPath = staticDir + url;
                }
                ext = path.extname(realPath);
                ext = ext ? ext.slice(1) : 'unknown';
            }
            assets(realPath, ext, url, res, argvObj);
        }).listen(port, host);
    return app.on('listening', function() {
        var server = app.address();
        var address = server.address === '0.0.0.0' ? '127.0.0.1' : server.address;
        var url = '  http://' + address + ':' + server.port

        console.log('ppt directory:'.cyan + '           ' + pptDir);
        console.log('assets directory:'.cyan + '        ' + staticDir);
        console.log('nodeppt server started:'.cyan + url.yellow);

        if (process.platform === 'win32') {
            exec('start' + url);
        } else {
            exec('open' + url);
        }
    }).on('error', function(e) {
        if (e.code === 'EADDRINUSE' || e.code === 'EACCES') {
            console.log('ERROR: '.red + 'port ' + port + ' is in use!');
        } else {
            console.log('ERROR: '.red + 'server start ' + host + ':' + port + ' info : ' + e.code);
        }
    });
}

function assets(realPath, ext, url, res, argvObj) {
    //静态资源
    if (fs.existsSync(realPath)) {

        fs.readFile(realPath, 'binary', function(err, file) {
            if (err) {
                res.writeHead(500, {
                    'Powered-By': 'nodePPT',
                    'Content-Type': 'text/plain'
                });
                res.end(err);
            } else {
                res.writeHead(200, {
                    'Powered-By': 'nodePPT',
                    'Content-Type': mimes[ext] || 'text/plain'
                });
                res.write(file, 'binary');
                res.end();
            }

        });

    } else {
        page404(res, url);
    }
}

function page404(res, url) {
    res.writeHead(404, {
        'Powered-By': 'nodePPT',
        'Content-Type': mimes.txt
    });

    res.write('This request URL ' + url + ' was not found on this server.');
    res.end();
}

function markdown(realPath, url, res, argvObj, queryObj) {
    if (fs.existsSync(realPath)) {
        var content = fs.readFileSync(realPath, 'utf-8').toString();
        try {
            var html = md_parser(content, function() {}, argvObj, queryObj);
            //添加socket的html代码
            var extraHtml = '';
            if (argvObj.watch) {
                extraHtml += getWatcherHtml();
            }
            if (extraHtml.trim() !== '') {
                html = html.split('<!--placeholder-->').join(extraHtml);
            }

            res.writeHead(200, {
                'Powered-By': 'nodePPT',
                'Content-Type': mimes.html
            });
            res.write(html);
            res.end();
        } catch (e) {
            res.writeHead(500, {
                'Powered-By': 'nodePPT',
                'Content-Type': 'text/plain'
            });
            res.end(e.toString());
        }

    } else {
        page404(res, url);
    }
}


/**
 * 读取ppt列表
 * @param  {[type]} res [description]
 * @param  {[type]} dir [description]
 * @return {[type]}     [description]
 */

function pptlist(res, dir, argvObj) {
    var staticDir = path.join(__dirname, '../assets') + '/';
    res.writeHead(200, {
        'Powered-By': 'nodePPT',
        'Content-Type': mimes.html
    });

    var curPath = dir;

    var count = 0,
        list = '';
    //遍历html文件
    $.recurse(dir, function(abspath, rootdir, subdir, filename) {
        count++;
        var content = fs.readFileSync(abspath, 'utf-8').toString();
        var title = content.match(/<title>(.*?)<\/title>/) || [];
        if (title[1]) {
            title = title[1];
        } else {
            title = filename;
        }
        var url = filename;
        list += '<li><a class="star" href="' + url + '" target="_blank">' + title + '</a></li>';
    }, '', '', function(filename) {
        return /\.htm[l]?/.test(filename);
    });

    //遍历markdown文件
    $.recurse(dir, function(abspath, rootdir, subdir, filename) {
        count++;
        var content = fs.readFileSync(abspath, 'utf-8').toString();
        //第一个是封面
        var cover = content.split('[slide]').shift();

        var title = md_parser.parseCover(cover).title;

        if (!title) {
            title = filename;
        }
        var url = '/md/' + filename;
        list += '<li><a class="star" href="' + url + '" target="_blank">' + title + '</a>';
        list += (argvObj.controller === 'socket' ? '' : '&nbsp; [<a href="' + url + '?_multiscreen=1" target="_blank" title="多窗口打开">多窗口</a>]&nbsp; [<a href="' + url + '?controller=socket" target="_blank" title="用socket远程控制">远程控制</a>]') + '</li>';
    }, '', '', function(filename) {
        return /\.(md|markdown)$/.test(filename);
    });

    var json = require(path.join(__dirname, '../package.json'));

    var data = {
        version: json.version,
        site: json.site,
        date: Date.now(),
        list: list,
        dir: curPath
    };
    //渲染模板
    var html = $.renderFile(templateDir + 'list.ejs', data);
    res.write(html);
    if (count == 0) {
        //路径不存在ppt
        res.write('This directory ' + curPath + ' was not found html on this server.');
        console.log(('This directory ' + curPath + ' was not found html on this server.').red);
    }
    res.end();
}


function getWatcherHtml() {
    var html = ['<script src="/socket.io/socket.io.js"></script>',
        '<script>',
        '(function(window, document, io){',
        '    var socket = io.connect(location.host+"/watcher");',
        '    socket.on("file changed", reload).on("reconnect", reload);',
        '    function reload() { location.reload(); }',
        '}(window, document, io));',
        '</script>'
    ].join('');
    return html;
}