/**
 * This module is started with bin/run.sh. It sets up a Express HTTP and a Socket.IO Server. 
 * Static file Requests are answered directly from this module, Socket.IO messages are passed 
 * to MessageHandler and minfied requests are passed to minified.
 */

/*
 * 2011 Peter 'Pita' Martischka (Primary Technology Ltd)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS-IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

var ERR = require("async-stacktrace");
var log4js = require('log4js');
var os = require("os");
var socketio = require('socket.io');
var fs = require('fs');
var settings = require('./utils/Settings');
var db = require('./db/DB');
var async = require('async');
var express = require('express');
var path = require('path');
var minify = require('./utils/Minify');
var formidable = require('formidable');
var apiHandler;
var exportHandler;
var importHandler;
var exporthtml;
var readOnlyManager;
var padManager;
var securityManager;
var socketIORouter;

//try to get the git version
var version = "";
try
{
  var rootPath = path.normalize(__dirname + "/../")
  var ref = fs.readFileSync(rootPath + ".git/HEAD", "utf-8");
  var refPath = rootPath + ".git/" + ref.substring(5, ref.indexOf("\n"));
  version = fs.readFileSync(refPath, "utf-8");
  version = version.substring(0, 7);
  console.log("Your Etherpad Lite git version is " + version);
}
catch(e) 
{
  console.warn("Can't get git version for server header\n" + e.message)
}

console.log("Report bugs at https://github.com/Pita/etherpad-lite/issues")

var serverName = "Etherpad-Lite " + version + " (http://j.mp/ep-lite)";

//cache 6 hours
exports.maxAge = 1000*60*60*6;

//set loglevel
log4js.setGlobalLogLevel(settings.loglevel);

async.waterfall([
  //initalize the database
  function (callback)
  {
    db.init(callback);
  },
  //initalize the http server
  function (callback)
  {
    //create server
    var app = express.createServer();

    app.use(function (req, res, next) {
      res.header("Server", serverName);
      next();
    });

    //load modules that needs a initalized db
    readOnlyManager = require("./db/ReadOnlyManager");
    exporthtml = require("./utils/ExportHtml");
    exportHandler = require('./handler/ExportHandler');
    importHandler = require('./handler/ImportHandler');
    apiHandler = require('./handler/APIHandler');
    padManager = require('./db/PadManager');
    securityManager = require('./db/SecurityManager');
    socketIORouter = require("./handler/SocketIORouter");
    
    //install logging      
    var httpLogger = log4js.getLogger("http");
    app.configure(function() 
    {
      // Activate http basic auth if it has been defined in settings.json
      if(settings.httpAuth != null) app.use(basic_auth);

      // If the log level specified in the config file is WARN or ERROR the application server never starts listening to requests as reported in issue #158.
      // Not installing the log4js connect logger when the log level has a higher severity than INFO since it would not log at that level anyway.
      if (!(settings.loglevel === "WARN" || settings.loglevel == "ERROR"))
        app.use(log4js.connectLogger(httpLogger, { level: log4js.levels.INFO, format: ':status, :method :url'}));
      app.use(express.cookieParser());
    });
    
    app.error(function(err, req, res, next){
      res.send(500);
      console.error(err.stack ? err.stack : err.toString());
      gracefulShutdown();
    });
    
    //serve static files
    app.get('/static/*', function(req, res)
    { 
      var filePath = path.normalize(__dirname + "/.." +
                                    req.url.replace(/\.\./g, '').split("?")[0]);
      res.sendfile(filePath, { maxAge: exports.maxAge });
    });
    
    //serve minified files
    app.get('/minified/:filename', minify.minifyJS);
    
    //checks for padAccess
    function hasPadAccess(req, res, callback)
    {
      securityManager.checkAccess(req.params.pad, req.cookies.sessionid, req.cookies.token, req.cookies.password, function(err, accessObj)
      {
        if(ERR(err, callback)) return;
        
        //there is access, continue
        if(accessObj.accessStatus == "grant")
        {
          callback();
        }
        //no access
        else
        {
          res.send("403 - Can't touch this", 403);
        }
      });
    }

    //checks for basic http auth
    function basic_auth (req, res, next) {
      if (req.headers.authorization && req.headers.authorization.search('Basic ') === 0) {
        // fetch login and password
        if (new Buffer(req.headers.authorization.split(' ')[1], 'base64').toString() == settings.httpAuth) {
          next();
          return;
        }
      }
      
      res.header('WWW-Authenticate', 'Basic realm="Protected Area"');
      if (req.headers.authorization) {
        setTimeout(function () {
          res.send('Authentication required', 401);
        }, 1000);
      } else {
        res.send('Authentication required', 401);
      }
    }
    
    //serve read only pad
    app.get('/ro/:id', function(req, res)
    { 
      var html;
      var padId;
      var pad;
      
      async.series([
        //translate the read only pad to a padId
        function(callback)
        {
          readOnlyManager.getPadId(req.params.id, function(err, _padId)
          {
            if(ERR(err, callback)) return;
            
            padId = _padId;
            
            //we need that to tell hasPadAcess about the pad  
            req.params.pad = padId; 
            
            callback();
          });
        },
        //render the html document
        function(callback)
        {
          //return if the there is no padId
          if(padId == null)
          {
            callback("notfound");
            return;
          }
          
          hasPadAccess(req, res, function()
          {
            //render the html document
            exporthtml.getPadHTMLDocument(padId, null, false, function(err, _html)
            {
              if(ERR(err, callback)) return;
              html = _html;
              callback();
            });
          });
        }
      ], function(err)
      {
        //throw any unexpected error
        if(err && err != "notfound")
          ERR(err);
          
        if(err == "notfound")
          res.send('404 - Not Found', 404);
        else
          res.send(html);
      });
    });
    
    //redirects browser to the pad's sanitized url if needed. otherwise, renders the html
    function goToPad(req, res, render) {
      //ensure the padname is valid and the url doesn't end with a /
      if(!padManager.isValidPadId(req.params.pad) || /\/$/.test(req.url))
      {
        res.send('Such a padname is forbidden', 404);
      }
      else
      {
        padManager.sanitizePadId(req.params.pad, function(padId) {
          //the pad id was sanitized, so we redirect to the sanitized version
          if(padId != req.params.pad)
          {
            var real_path = req.path.replace(/^\/p\/[^\/]+/, '/p/' + padId);
            res.header('Location', real_path);
            res.send('You should be redirected to <a href="' + real_path + '">' + real_path + '</a>', 302);
          }
          //the pad id was fine, so just render it
          else
          {
            render();
          }
        });
      }
    }
    
    //serve pad.html under /p
    app.get('/p/:pad', function(req, res, next)
    {    
      goToPad(req, res, function() {
        var filePath = path.normalize(__dirname + "/../static/pad.html");
        res.sendfile(filePath, { maxAge: exports.maxAge });
      });
    });
    
    //serve timeslider.html under /p/$padname/timeslider
    app.get('/p/:pad/timeslider', function(req, res, next)
    {
      goToPad(req, res, function() {
        var filePath = path.normalize(__dirname + "/../static/timeslider.html");
        res.sendfile(filePath, { maxAge: exports.maxAge });
      });
    });
    
    //serve timeslider.html under /p/$padname/timeslider
    app.get('/p/:pad/:rev?/export/:type', function(req, res, next)
    {
      goToPad(req, res, function() {
        var types = ["pdf", "doc", "txt", "html", "odt", "dokuwiki"];
        //send a 404 if we don't support this filetype
        if(types.indexOf(req.params.type) == -1)
        {
          next();
          return;
        }
        
        //if abiword is disabled, and this is a format we only support with abiword, output a message
        if(settings.abiword == null &&
           ["odt", "pdf", "doc"].indexOf(req.params.type) !== -1)
        {
          res.send("Abiword is not enabled at this Etherpad Lite instance. Set the path to Abiword in settings.json to enable this feature");
          return;
        }
        
        res.header("Access-Control-Allow-Origin", "*");
        
        hasPadAccess(req, res, function()
        {
          exportHandler.doExport(req, res, req.params.pad, req.params.type);
        });
      });
    });
    
    //handle import requests
    app.post('/p/:pad/import', function(req, res, next)
    {
      goToPad(req, res, function() {
        //if abiword is disabled, skip handling this request
        if(settings.abiword == null)
        {
          next();
          return; 
        }
      
        hasPadAccess(req, res, function()
        {
          importHandler.doImport(req, res, req.params.pad);
        });
      });
    });
    
    var apiLogger = log4js.getLogger("API");

    //This is for making an api call, collecting all post information and passing it to the apiHandler
    var apiCaller = function(req, res, fields)
    {
      res.header("Content-Type", "application/json; charset=utf-8");
    
      apiLogger.info("REQUEST, " + req.params.func + ", " + JSON.stringify(fields));
      
      //wrap the send function so we can log the response
      res._send = res.send;
      res.send = function(response)
      {
        response = JSON.stringify(response);
        apiLogger.info("RESPONSE, " + req.params.func + ", " + response);
        
        //is this a jsonp call, if yes, add the function call
        if(req.query.jsonp)
          response = req.query.jsonp + "(" + response + ")";
        
        res._send(response);
      }
      
      //call the api handler
      apiHandler.handle(req.params.func, fields, req, res);
    }
    
    //This is a api GET call, collect all post informations and pass it to the apiHandler
    app.get('/api/1/:func', function(req, res)
    {
      apiCaller(req, res, req.query)
    });

    //This is a api POST call, collect all post informations and pass it to the apiHandler
    app.post('/api/1/:func', function(req, res)
    {
      new formidable.IncomingForm().parse(req, function(err, fields, files) 
      {
        apiCaller(req, res, fields)
      });
    });
    
    //The Etherpad client side sends information about how a disconnect happen
    app.post('/ep/pad/connection-diagnostic-info', function(req, res)
    {
      new formidable.IncomingForm().parse(req, function(err, fields, files) 
      { 
        console.log("DIAGNOSTIC-INFO: " + fields.diagnosticInfo);
        res.end("OK");
      });
    });
    
    //The Etherpad client side sends information about client side javscript errors
    app.post('/jserror', function(req, res)
    {
      new formidable.IncomingForm().parse(req, function(err, fields, files) 
      { 
        console.error("CLIENT SIDE JAVASCRIPT ERROR: " + fields.errorInfo);
        res.end("OK");
      });
    });
    
    //serve index.html under /
    app.get('/', function(req, res)
    {
      var filePath = path.normalize(__dirname + "/../static/index.html");
      res.sendfile(filePath, { maxAge: exports.maxAge });
    });
    
    //serve robots.txt
    app.get('/robots.txt', function(req, res)
    {
      var filePath = path.normalize(__dirname + "/../static/robots.txt");
      res.sendfile(filePath, { maxAge: exports.maxAge });
    });
    
    //serve favicon.ico
    app.get('/favicon.ico', function(req, res)
    {
      var filePath = path.normalize(__dirname + "/../static/custom/favicon.ico");
      res.sendfile(filePath, { maxAge: exports.maxAge }, function(err)
      {
        //there is no custom favicon, send the default favicon
        if(err)
        {
          filePath = path.normalize(__dirname + "/../static/favicon.ico");
          res.sendfile(filePath, { maxAge: exports.maxAge });
        }
      });
    });
    
    //let the server listen
    app.listen(settings.port, settings.ip);
    console.log("Server is listening at " + settings.ip + ":" + settings.port);

    var onShutdown = false;
    var gracefulShutdown = function(err)
    {
      if(err && err.stack)
      {
        console.error(err.stack);
      }
      else if(err)
      {
        console.error(err);
      }
      
      //ensure there is only one graceful shutdown running
      if(onShutdown) return;
      onShutdown = true;
    
      console.log("graceful shutdown...");
      
      //stop the http server
      app.close();

      //do the db shutdown
      db.db.doShutdown(function()
      {
        console.log("db sucessfully closed.");
        
        process.exit(0);
      });
      
      setTimeout(function(){
        process.exit(1);
      }, 3000);
    }

    //connect graceful shutdown with sigint and uncaughtexception
    if(os.type().indexOf("Windows") == -1)
    {
      //sigint is so far not working on windows
      //https://github.com/joyent/node/issues/1553
      process.on('SIGINT', gracefulShutdown);
    }
    
    process.on('uncaughtException', gracefulShutdown);

    //init socket.io and redirect all requests to the MessageHandler
    var io = socketio.listen(app);
    
    //this is only a workaround to ensure it works with all browers behind a proxy
    //we should remove this when the new socket.io version is more stable
    io.set('transports', ['xhr-polling']);
    
    var socketIOLogger = log4js.getLogger("socket.io");
    io.set('logger', {
      debug: function (str)
      {
        socketIOLogger.debug.apply(socketIOLogger, arguments);
      }, 
      info: function (str)
      {
        socketIOLogger.info.apply(socketIOLogger, arguments);
      },
      warn: function (str)
      {
        socketIOLogger.warn.apply(socketIOLogger, arguments);
      },
      error: function (str)
      {
        socketIOLogger.error.apply(socketIOLogger, arguments);
      },
    });
    
    //minify socket.io javascript
    if(settings.minify)
      io.enable('browser client minification');
    
    var padMessageHandler = require("./handler/PadMessageHandler");
    var timesliderMessageHandler = require("./handler/TimesliderMessageHandler");
    
    //Initalize the Socket.IO Router
    socketIORouter.setSocketIO(io);
    socketIORouter.addComponent("pad", padMessageHandler);
    socketIORouter.addComponent("timeslider", timesliderMessageHandler);
    
    callback(null);  
  }
]);