/**
 * This module is included by serve.js, which bin/run.sh invokes. 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 ref = fs.readFileSync("../.git/HEAD", "utf-8");
  var refPath = "../.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);

function setupDb(callback){
  db.init(callback);
}

function padAccessCombinator(securityManager, req, res, callback, errorback){
  function checkback(err, accessObj){
    if(err) return errorback(err);
    if("grant" == accessObj.accessStatus) return callback();
    return res.send("403 - Can't touch this", 403);
  }
  //works great for one session
  //but what if there are multiple?
  //if(!("sessionIDs" in req.cookies))
  return securityManager.checkAccess(
    req.params.pad,
    req.cookies.sessionid,
    req.cookies.token,
    req.cookies.password,
    checkback
  );
  /*sessIds = JSON.parse(req.cookies.sessionIDs);
  var tasks = [];
  function createTask(sid){
    return function(cb){
      return securityManager.checkAccess(
        req.params.pad,
        sid,
        req.cookies.token,
        req.cookies.password,
        cb//function(err, accessObj){return cb(err, accessObj);}
      );
    }
  }
  for(var i = 0; i < sessIds.length; i++)
    tasks[i] = createTasks(sessIds[i]);
  return async.parallel(
    tasks,
    function(err, obs){
      if(err) return errorback(err);
      for(var i = 0; i < obs.length; i++)
        if("grant" == obs[i].accessStatus) return callback(null);
      return res.send("none of those IDs worked", 403);
    }
  )*/
}
function getStatic(req, res){
  res.header("Server", serverName);
  var filePath = path.normalize(
    __dirname + "/.." +
      req.url.replace(/\.\./g, '').split("?")[0]
  );
  res.sendfile(filePath, { maxAge: exports.maxAge });
}
function getMinified(req, res, next)
{
  res.header("Server", serverName);
  
  var id = req.params.id;
  
  if(id == "pad.js" || id == "timeslider.js")
  {
    minify.minifyJS(req,res,id);
  }
  else
  {
    next();
  }
}
function checkPadName(padManager, req, res, callback){
  //ensure the padname is valid and the url doesn't end with a /
  if(!padManager.isValidPadId(req.params.pad) || /\/$/.test(req.url))
    return res.send("Such a padname is forbidden", 404);
  return callback();
}
function setupIo(socketio, log4js, settings, socketIORouter, app){
  //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);
  return io;
}
function setupShutdown(db, app){
  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);
  }
  
  return process.on('uncaughtException', gracefulShutdown);
}
function sendStatic(path, res, filename, callback){
  if("function" != typeof callback) callback = function(){};
  res.header("Server", serverName);
  var filePath = path.normalize(__dirname + "/../static/" + filename);
  return res.sendfile(filePath, { maxAge: exports.maxAge }, callback);
}
function translateRoCombinator(managers, req, ERR){
  return function translateRo(callback){
    function padBack(err, padId){
      if(ERR(err, callback)) return;
      //we need that to tell hasPadAccess about the pad
      req.params.pad = padId;
      return callback(err, padId);
    }
    return managers.ro.getPadID(req.params.id, padBack);
  };
}
function roAsyncOutCombinator(ERR, callback){
  return function(err, data){
    if(ERR(err, callback)) return;
    return callback(err, data);
  }
}
function roAccessbackCombinator(exporthtml, padId, callback){
  return function accessBack(){
    return exporthtml.getPadHTMLDocument(padId, null, false, callback);
  }
}
function roRenderCombinator(padAccessp, req, res, exporthtml, ERR){
  return function(padId, callback){
    if(null == padId)
     return callback("notfound");
    return padAccessp(
      req, res,
      roAccessbackCombinator(
        exporthtml, padId,
        roAsyncOutCombinator(
          ERR, callback
        )
      )
    );
  }
}
function roBindSendBackCombinator(res){
  return function(html, callback){
   res.send(html);
   return callback(null);
  }
}
function roErrBackCombinator(ERR, res){
  return function(err){
    if(!err) return
    if("notfound" == err)
	return res.send("404 - Not Found", 404);
    return ERR(err);
  }
}
function getRoCombinator(serverName, managers, padAccessp, ERR, exporthtml){
  return function(req, res){
    res.header("Server", serverName);
    return async.waterfall(
      [
        translateRoCombinator(managers),
          roRenderCombinator(padAccessp, req, res, exporthtml, ERR),
        roBindSendBackCombinator(res)
      ],
      roErrBackCombinator(ERR, res))
    )
  }
}
function sendStaticIfPad(goToPad, padManager, path, filename){
  return function staticSender(req, res, next){
    return goToPad(
      req, res,
      function goBack(){
        return sendStatic(path, res, filename);
      }
    );
  };
}
function getExportPadCombinator(goToPad, settings, hasPadAccess, exportHandler, serverName){
  return function getExportPad(req, res, next){
    goToPad(req, res, function padback() {
      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", "*");
      res.header("Server", serverName);
      
      hasPadAccess(req, res, function()
      {
        exportHandler.doExport(req, res, req.params.pad, req.params.type);
      });
    });
  }
}

function postImportPadCombinator(goToPad, settings, serverName, hasPadAccess, importHandler){
  return function postImportPad(req, res, next){
    goToPad(req, res, function padback() {
      //if abiword is disabled, skip handling this request
      if(settings.abiword == null)
      {
        next();
        return; 
      }
    
      res.header("Server", serverName);
      
      hasPadAccess(req, res, function()
      {
        importHandler.doImport(req, res, req.params.pad);
      });
    });
  }
}
function apiCallerCombinator(serverName, apiLogger, apiHandler){
  return function apiCaller(req, res, fields){
      res.header("Server", serverName);
      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);
  }
}
function logOkPostCombinator(prefix, consoleFn, field){
  return function(req, res){
    new formidable.IncomingForm().parse(
      req,
      function(err, fields, files){
	  console[consoleFn](prefix + ": " + fields[field]);
	  res.end("OK");
      }
    );
  }
}

function configureCombinator(app, settings, basic_auth, log4js, httpLogger){
  return function configBack() 
  {
    // 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());
  };
}

//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);
  }
}

function gotoPadCombinator(checkPadName, padManager){
  return function gotoPad(req, res, render){
    return checkPadName(
      padManager, req, res,
      function callback(){
        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();
          }
        });
      }
    );
  }
}

function init(additionalSetup){
 if("function" != typeof additionalSetup)
  additionalSetup = function(){};
 async.waterfall([
  //initalize the database
  setupDb,
  //initalize the http server
  function (callback)
  {
    //create server
    var app = express.createServer();


    //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");

    var managers = {
      ro: readOnlyManager,
      security: securityManager
    };
    var handlers = {
      "export": exportHandler,
      "import": importHandler,
      api: apiHandler
    };

    //install logging      
    var httpLogger = log4js.getLogger("http");
    var apiLogger = log4js.getLogger("API");


    //checks for padAccess
    function hasPadAccess(req, res, callback)
    {
      return padAccessCombinator(
        securityManager, req, res,
        callback,
        function errorback(err, accessObj){
           return ERR(err, callback);
        }
      );
    }
    //redirects browser to the pad's sanitized url if needed. otherwise, renders the html
      var goToPad = gotoPadCombinator(checkPadName, padManager);
    //This is for making an api call, collecting all post information and passing it to the apiHandler
    var apiCaller = apiCallerCombinator(serverName, apiLogger, apiHandler);



    app.configure(configureCombinator(app, settings, basic_auth, log4js, httpLogger));
    
    app.error(function(err, req, res, next){
      res.send(500);
      console.error(err.stack ? err.stack : err.toString());
      gracefulShutdown();
    });



    var gets = {
      '/static/*': getStatic,
      '/minified/:id': getMinified,
      '/ro/:id': getRoCombinator(
        serverName,
        {ro: readOnlyManager},
        hasPadAccess,
        ERR,
        exporthtml
      ),
      '/p/:pad': sendStaticIfPad(
        goToPad,
        padManager,
        path,
        "pad.html"
      )
      '/p/:pad/timeslider': sendStaticIfPad(
        goToPad, padManager, path, "timeslider.html"
      ),
      '/p/:pad/:rev?/export/:type': getExportPadCombinator(
        goToPad, settings, hasPadAccess, exportHandler, serverName
      '/api/1/:func': function(req, res)
      {
        apiCaller(req, res, req.query)
      },
      '/': function(req, res)
      {
        return sendStatic(path, res, "index.html");
      },
      '/robots.txt': function(req, res)
      {
        return sendStatic(path, res, "robots.txt");
      },
      '/favicon.ico': function(req, res)
      {
        return sendStatic(path, res, "custom/favicon.ico",
          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 });
            }
          });
      }
    };

    var posts = {
      '/p/:pad/import': postImportPadCombinator(
        goToPad, settings, serverName, hasPadAccess, importHandler
      ),
      '/api/1/:func': function(req, res){
        new formidable.IncomingForm().parse(
          req,
          function(err, fields, files) 
          {
            apiCaller(req, res, fields)
          });
      },
      '/ep/pad/connection-diagnostic-info': logOkPostCombinator(
        "DIAGNOSTIC-INFO", "log", "diagnosticInfo"
      ),
      '/jserror': logOkPostCombinator(        
        "CLIENT SIDE JAVASCRIPT ERROR", "error", "errorInfo"
      )
    };
 
   

    additionalSetup(app, gets, posts, managers, handlers, db);

    
    for(var key in gets) app.get(key, gets[key]);
    for(var key in posts) app.post(key, posts[key]);

    //let the server listen
    app.listen(settings.port, settings.ip);
    console.log("Server is listening at " + settings.ip + ":" + settings.port);

    setupShutdown(db, app);

    var io = setupIo(socketio, log4js, settings, socketIORouter, app);
    
    callback(null);  
  }
 ]);

}


init(function(app, gets, posts, managers, handlers, db){});