////////// Requires //////////

var fs = require("fs");
var path = require("path");


var files = require('./files.js');
var library = require('./library.js');
var watch = require('./watch.js');
var project = require('./project.js');
var updater = require('./updater.js');
var bundler = require('./bundler.js');
var Builder = require('./builder.js');
var buildmessage = require('./buildmessage.js');
var mongo_runner = require('./mongo_runner.js');
var mongoExitCodes = require('./mongo_exit_codes.js');
var warehouse = require("./warehouse.js");
var unipackage = require('./unipackage.js');

var _ = require('underscore');
var inFiber = require('./fiber-helpers.js').inFiber;
var Future = require('fibers/future');

////////// Globals //////////
//XXX: Refactor to not have globals anymore?

// list of log objects from the child process.
var serverLog = [];

var Status = {
  running: false, // is server running now?
  crashing: false, // does server crash whenever we start it?
  listening: false, // do we expect the server to be listening now.
  counter: 0, // how many crashes in rapid succession
  code: 0, // exit code last returned
  shouldRestart: true, // true if we should be restarting the server
  shuttingDown: false, // true if we're on the way to shutting down the server

  exitNow: function () {
    var self = this;
    logToClients({'exit': "Your application is exiting."});
    self.shuttingDown = true;

    self.mongoHandle && self.mongoHandle.stop(function (err) {
      if (err)
        process.stdout.write(err.reason + "\n");
      process.exit(self.code);
    });
  },
  reset: function () {
    this.crashing = false;
    this.counter = 0;
  },

  hardCrashed: function (complaint) {
    complaint = complaint || "is crashing";

    var self = this;
    if (!self.shouldRestart) {
      self.exitNow();
      return;
    }
    logToClients({'exit': "=> Your application " + complaint +
                  ". Waiting for file change."});
    this.crashing = true;
  },

  softCrashed: function () {
    var self = this;
    if (!self.shouldRestart) {
      self.exitNow();
      return;
    }
    if (this.counter === 0)
      setTimeout(function () {
        this.counter = 0;
      }, 2000);

    this.counter++;

    if (this.counter > 2) {
      Status.hardCrashed("is crashing");
    }
  }
};

// Parse out s as if it were a bash command line.
var bashParse = function (s) {
  if (s.search("\"") !== -1 || s.search("'") !== -1) {
    throw new Error("Meteor cannot currently handle quoted NODE_OPTIONS");
  }
  return _.without(s.split(/\s+/), '');
};

var getNodeOptionsFromEnvironment = function () {
  return bashParse(process.env.NODE_OPTIONS || "");
};

// List of queued requests. Each item in the list is a function to run
// when the inner app is ready to receive connections.
var requestQueue = [];

////////// Outer Proxy Server //////////
//
// calls callback once proxy is actively listening on outer and
// proxying to inner.

var startProxy = function (outerPort, innerPort, callback) {
  callback = callback || function () {};

  var http = require('http');
  // Note: this uses the pre-release 1.0.0 API.
  var httpProxy = require('http-proxy');

  var proxy = httpProxy.createProxyServer({
    // agent is required to handle keep-alive, and http-proxy 1.0 is a little
    // buggy without it: https://github.com/nodejitsu/node-http-proxy/pull/488
    agent: new http.Agent({maxSockets: 100})
  });

  var server = http.createServer(function (req, res) {
    if (Status.crashing) {
      // sad face. send error logs.
      // XXX formatting! text/plain is bad
      res.writeHead(200, {'Content-Type': 'text/plain'});

      res.write("Your app is crashing. Here's the latest log.\n\n");

      _.each(serverLog, function(log) {
        _.each(log, function(val, key) {
          if (val)
            res.write(val);
          res.write("\n");
        });
      });

      res.end();
      return;
    }
    var proxyIt = function () {
      proxy.web(req, res, {target: 'http://127.0.0.1:' + innerPort});
    };
    if (Status.listening) {
      // server is listening. things are hunky dory!
      proxyIt();
    } else {
      requestQueue.push(proxyIt);
    }
  });

  // Proxy websocket requests using same buffering logic as for regular HTTP
  // requests
  server.on('upgrade', function(req, socket, head) {
    var proxyIt = function () {
      proxy.ws(req, socket, head, { target: 'http://127.0.0.1:' + innerPort});
    };
    if (Status.listening) {
      // server is listening. things are hunky dory!
      proxyIt();
    } else {
      // Not listening yet. Queue up request.
      requestQueue.push(proxyIt);
    }
  });

  server.on('error', function (err) {
    if (err.code == 'EADDRINUSE') {
      process.stderr.write("Can't listen on port " + outerPort
                           + ". Perhaps another Meteor is running?\n");
      process.stderr.write("\n");
      process.stderr.write("Running two copies of Meteor in the same application directory\n");
      process.stderr.write("will not work. If something else is using port " + outerPort + ", you can\n");
      process.stderr.write("specify an alternative port with --port <port>.\n");
    } else {
      process.stderr.write(err + "\n");
    }

    process.exit(1);
  });

  // don't crash if the app doesn't respond. instead return an error
  // immediately. This shouldn't happen much since we try to not send requests
  // if the app is down.
  proxy.ee.on('http-proxy:outgoing:web:error', function (err, req, res) {
    res.writeHead(503, {
      'Content-Type': 'text/plain'
    });
    res.end('Unexpected error.');
  });
  proxy.ee.on('http-proxy:outgoing:ws:error', function (err, req, socket) {
    socket.end();
  });

  server.listen(outerPort, callback);
};

var saveLog = function (msg) {
  serverLog.push(msg);
  if (serverLog.length > 100) {
    serverLog.shift();
  }
};

var logToClients = function (msg) {
  saveLog(msg);

  _.each(msg, function (val, key) {
    if (key === "stdout")
      process.stdout.write(val + "\n");
    else if (key === "stderr")
      process.stderr.write(val + "\n");
    else
      console.log(val);
  });
};


////////// Launch server process //////////
// Takes options:
// bundlePath
// outerPort
// innerPort
// mongoUrl
// library
// onExit
// [program]
// [onListen]
// [nodeOptions]
// [settings]


var startServer = function (options) {
  // environment
  options = _.extend({
    nodeOptions: []
  }, options);

  var env = {};
  for (var k in process.env)
    env[k] = process.env[k];

  env.PORT = options.innerPort;
  env.MONGO_URL = options.mongoUrl;
  env.ROOT_URL = options.rootUrl;
  if (options.settings)
    env.METEOR_SETTINGS = options.settings;
  else
    delete env.METEOR_SETTINGS;
  // Display errors from (eg) the NPM connect module over the network.
  env.NODE_ENV = 'development';

  if (! options.program) {
    var nodeOptions = _.clone(options.nodeOptions);
    nodeOptions.push(path.join(options.bundlePath, 'main.js'));
    nodeOptions.push('--keepalive');

    var child_process = require('child_process');
    var proc = child_process.spawn(process.execPath, nodeOptions,
                                   {env: env});
  } else {
    var starJson = JSON.parse(
      fs.readFileSync(path.join(options.bundlePath, 'star.json'), 'utf8'));
    var programPath = null;

    var archinfo = require('./archinfo.js');
    _.each(starJson.programs, function (p) {
      // XXX should actually use archinfo.mostSpecificMatch instead of
      // taking the first match
      if (p.name !== options.program)
        return;
      if (! archinfo.matches(archinfo.host(), p.arch))
        return; // can't run here
      programPath = path.join(options.bundlePath, p.path);
    });

    if (! programPath) {
      // XXX probably not the correct error handling
      process.stderr.write("Program '" + options.program + "' not found.\n");
      process.exit(1);
    }

    var child_process = require('child_process');
    var proc = child_process.spawn(programPath, [], {env: env});
  }

  // XXX deal with test server logging differently?!

  var Log = unipackage.load({
    library: options.library,
    packages: ['logging']
  }).logging.Log;

  // Since no other process will be listening to stdout and parsing it,
  // print directly in the same format as log messages from other apps
  Log.outputFormat = 'colored-text';

  var eachline = require('eachline');
  eachline(proc.stdout, 'utf8', function (line) {
    if (!line) return;
    // string must match server.js
    if (line.match(/^LISTENING\s*$/)) {
      options.onListen && options.onListen();
      return;
    }

    if (options.rawLogs) {
      console.log(line);
      saveLog({stdout: line});
    } else {
      var obj = Log.parse(line) || Log.objFromText(line);
      console.log(Log.format(obj, { color:true }));
      saveLog({stdout: Log.format(obj)});
    }
  });

  eachline(proc.stderr, 'utf8', function (line) {
    if (!line) return;
    if (options.rawLogs) {
      console.error(line);
      saveLog({stderr: line});
    } else {
      var obj = Log.objFromText(line, { level: 'warn', stderr: true });
      console.log(Log.format(obj, { color: true }));
      saveLog({stderr: Log.format(obj)});
    }
  });

  proc.on('close', function (code, signal) {
    if (signal) {
      logToClients({'exit': '=> Exited from signal: ' + signal});
    } else {
      logToClients({'exit': '=> Exited with code: ' + code});
    }

    options.onExit(code);
  });

  // this happens sometimes when we write a keepalive after the app is
  // dead. If we don't register a handler, we get a top level exception
  // and the whole app dies.
  // http://stackoverflow.com/questions/2893458/uncatchable-errors-in-node-js
  proc.stdin.on('error', function () {});

  // Keepalive so server can detect when we die
  var timer = setInterval(function () {
    try {
      if (proc && proc.pid && proc.stdin && proc.stdin.write)
        proc.stdin.write('k');
    } catch (e) {
      // do nothing. this fails when the process dies.
    }
  }, 2000);

  return {
    proc: proc,
    timer: timer
  };
};

var killServer = function (handle) {
  if (handle.proc.pid) {
    handle.proc.removeAllListeners('close');
    handle.proc.kill();
  }
  clearInterval(handle.timer);
};

///////////////////////////////////////////////////////////////////////////////

// Also used by "meteor deploy" in meteor.js.

exports.getSettings = function (filename, watchSet) {
  var absPath = path.resolve(filename);
  var buffer = watch.readAndWatchFile(watchSet, absPath);
  if (!buffer)
    throw new Error("Could not find settings file " + filename);
  if (buffer.length > 0x10000)
    throw new Error("Settings file must be less than 64 KB long");

  var str = buffer.toString('utf8');

  // Ensure that the string is parseable in JSON, but there's no reason to use
  // the object value of it yet.
  if (str.match(/\S/)) {
    JSON.parse(str);
    return str;
  } else {
    return "";
  }
};

// XXX leave a pidfile and check if we are already running

// This function never returns and will call process.exit() if it
// can't continue. If you change this, remember to call
// watcher.stop() as appropriate.
//
// context is as created in meteor.js.
// options include: port, minify, once, settingsFile, testPackages,
// banner, program
//
//
// banner can be used to replace the application path that is normally
// printed on startup (context.appDir) with an arbitrary string, for
// example if you autogenerated an app in a temp file to run tests
exports.run = function (context, options) {
  var outerPort = options.port || 3000;
  var innerPort = outerPort + 1;
  var mongoPort = outerPort + 2;
  var bundlePath = path.join(context.appDir, '.meteor', 'local', 'build');
  // Allow override and use of external mongo. Matches code in launch_mongo.
  var mongoUrl = process.env.MONGO_URL ||
        ("mongodb://127.0.0.1:" + mongoPort + "/meteor");
  var firstRun = true;

  var serverHandle;
  var watcher;

  var lastThingThatPrintedWasRestartMessage = false;
  var silentRuns = 0;

  // Hijack process.stdout and process.stderr so that whenever anything is
  // written to one of them, if the last thing we printed as the "Meteor server
  // restarted" message with no newline, we (a) print that newline and (b)
  // remember that *something* was printed (and so we shouldn't try to erase and
  // rewrite the line on the next restart).
  var realStdoutWrite = process.stdout.write;
  var realStderrWrite = process.stderr.write;
  // Call this function before printing anything to stdout or stderr.
  var onStdio = function () {
    if (lastThingThatPrintedWasRestartMessage) {
      realStdoutWrite.call(process.stdout, "\n");
      lastThingThatPrintedWasRestartMessage = false;
      silentRuns = 0;
    }
  };
  process.stdout.write = function () {
    onStdio();
    return realStdoutWrite.apply(process.stdout, arguments);
  };
  process.stderr.write = function () {
    onStdio();
    return realStderrWrite.apply(process.stderr, arguments);
  };


  if (options.once) {
    Status.shouldRestart = false;
  }

  var bundleOpts = {
    nodeModulesMode: 'symlink',
    minify: options.minify,
    testPackages: options.testPackages,
    releaseStamp: context.releaseVersion,
    library: context.library
  };

  var startWatching = function (watchSet) {
    if (process.env.METEOR_DEBUG_WATCHSET)
      console.log(JSON.stringify(watchSet, null, 2));

    if (!Status.shouldRestart)
      return;

    if (watcher)
      watcher.stop();

    watcher = new watch.Watcher({
      watchSet: watchSet,
      onChange: function () {
        if (Status.crashing)
          logToClients({'system': "=> Modified -- restarting."});
        Status.reset();
        context.library.refresh(true); // pick up changes to packages
        restartServer();
      }
    });
  };

  // Using `inFiber` since bundling can yield when loading a manifest
  // file from warehouse.meteor.com.
  var restartServer = inFiber(function () {
    Status.running = false;
    Status.listening = false;
    if (watcher) {
      watcher.stop();
      watcher = null;
    }
    if (serverHandle) {
      killServer(serverHandle);
      serverHandle = null;
    }

    // If the user did not specify a --release on the command line, and
    // simultaneously runs `meteor update` during this run, just exit and let
    // them restart the run. (We can do something fancy like allowing this to
    // work if the tools version didn't change, or even springboarding if the
    // tools version does change, but this (which prevents weird errors) is a
    // start.)
    // (Make sure that we don't hit this test for "meteor test-packages",
    // though; there's not a real app to update there!)
    if (files.usesWarehouse() && !context.userReleaseOverride &&
        !options.testPackages) {
      var newAppRelease = project.getMeteorReleaseVersion(context.appDir) ||
            warehouse.latestRelease();
      if (newAppRelease !== context.appReleaseVersion) {
        console.error("Your app has been updated to Meteor %s from " +
                      "Meteor %s.\nRestart meteor to use the new release.",
                      newAppRelease,
                      context.appReleaseVersion);
        process.exit(1);
      }
    }

    serverLog = [];

    // Bundle up the app
    var bundleResult = bundler.bundle(context.appDir, bundlePath, bundleOpts);
    var watchSet = bundleResult.watchSet;
    if (bundleResult.errors) {
      logToClients({stdout: "=> Errors prevented startup:\n\n" +
                    bundleResult.errors.formatMessages()});
      // Ensure that if we are running under --once, we exit with a non-0 code.
      Status.code = 1;
      Status.hardCrashed("has errors");
      startWatching(watchSet);
      return;
    }

    // Read the settings file, if any
    var settings = null;
    if (options.settingsFile)
      settings = exports.getSettings(options.settingsFile, watchSet);

    // Start the server
    Status.running = true;


    var rootUrl = process.env.ROOT_URL ||
          ('http://localhost:' + outerPort + '/');
    if (firstRun) {
      process.stdout.write("=> Meteor server running on: " + rootUrl + "\n");
      firstRun = false;
      lastThingThatPrintedWasRestartMessage = false;
    } else {
      if (lastThingThatPrintedWasRestartMessage) {
        // The last run was not the "Running on: " run, and it didn't print
        // anything. So the last thing that printed was the restart message.
        // Overwrite it.
        realStdoutWrite.call(process.stdout, '\r');
      }
      realStdoutWrite.call(process.stdout, "=> Meteor server restarted");
      if (lastThingThatPrintedWasRestartMessage) {
        ++silentRuns;
        realStdoutWrite.call(process.stdout, " (x" + (silentRuns+1) + ")");
      }
      lastThingThatPrintedWasRestartMessage = true;
    }

    serverHandle = startServer({
      bundlePath: bundlePath,
      outerPort: outerPort,
      innerPort: innerPort,
      mongoUrl: mongoUrl,
      rootUrl: rootUrl,
      library: context.library,
      rawLogs: options.rawLogs,
      onExit: function (code) {
        // on server exit
        Status.running = false;
        Status.listening = false;
        Status.code = code;
        Status.softCrashed();
        if (!Status.crashing)
          restartServer();
      },
      onListen: function () {
        // on listen
        Status.listening = true;
        _.each(requestQueue, function (f) { f(); });
        requestQueue = [];
      },
      nodeOptions: getNodeOptionsFromEnvironment(),
      settings: settings,
      program: options.program
    });

    // Start watching for changes for files. There's no hurry to call
    // this, since watchSet contains a snapshot of the state of
    // the world at the time of bundling, in the form of hashes and
    // lists of matching files in each directory.
    startWatching(watchSet);
  });

  var mongoErrorCount = 0;
  var mongoErrorTimer;
  var mongoStartupPrintTimer;
  var launch = function () {
    Status.mongoHandle = mongo_runner.launch_mongo(
      context.appDir,
      mongoPort,
      function () { // On Mongo startup complete
        // don't print mongo startup is slow warning.
        if (mongoStartupPrintTimer) {
          clearTimeout(mongoStartupPrintTimer);
          mongoStartupPrintTimer = null;
        }
        restartServer();
      },
      function (code, signal, stderr) { // On Mongo dead
        if (Status.shuttingDown) {
          return;
        }

        // Print only last 20 lines of stderr.
        stderr = stderr.split('\n').slice(-20).join('\n');

        console.log(stderr + "Unexpected mongo exit code " + code + ". Restarting.\n");

        // if mongo dies 3 times with less than 5 seconds between each,
        // declare it failed and die.
        mongoErrorCount += 1;
        if (mongoErrorCount >= 3) {
          var explanation = mongoExitCodes.Codes[code];
          console.log("Can't start mongod\n");
          if (explanation)
            console.log(explanation.longText);
          if (explanation === mongoExitCodes.EXIT_NET_ERROR)
            console.log("\nCheck for other processes listening on port " + mongoPort +
                        "\nor other meteors running in the same project.");
          if (!explanation && /GLIBC/i.test(stderr))
            console.log("\nLooks like you are trying to run Meteor on an old Linux " +
                        "distribution. Meteor on Linux only supports Linux with glibc " +
                        "version 2.9 and above. Try upgrading your distribution " +
                        "to the latest version.");
          process.exit(1);
        }
        if (mongoErrorTimer)
          clearTimeout(mongoErrorTimer);
        mongoErrorTimer = setTimeout(function () {
          mongoErrorCount = 0;
          mongoErrorTimer = null;
        }, 5000);

        // Wait a sec to restart.
        setTimeout(launch, 1000);
      });
  };

  startProxy(outerPort, innerPort, function () {
    var banner = options.banner || files.pretty_path(context.appDir);
    process.stdout.write("[[[[[ " + banner + " ]]]]]\n\n");

    mongoStartupPrintTimer = setTimeout(function () {
      process.stdout.write("Initializing mongo database... this may take a moment.\n");
    }, 3000);

    updater.startUpdateChecks(context);
    launch();
  });
};