/**
 * session.js 0.4.1
 * (c) 2012 Iain, CodeJoust
 * session.js is freely distributable under the MIT license.
 * Portions of session.js are inspired or borrowed from Underscore.js, and quirksmode.org demo javascript.
 * This version uses google's jsapi library for location services.
 * For details, see: https://github.com/codejoust/session.js
 */
(function(win, doc, nav){
  // Changing the API Version invalidates olde cookies with previous api version tags.
  var API_VERSION = 0.4;
  
  // Settings: defaults
  var options = {
    // Use the HTML5 Geolocation API
    // this ONLY returns lat & long, no city/address
    use_html5_location: false,
    // Attempts to use IPInfoDB if provided a valid key
    // Get a key at http://ipinfodb.com/register.php
    ipinfodb_key: false,
    // Leaving true allows for fallback for both
    // the HTML5 location and the IPInfoDB
    gapi_location: true,
    // Name of the location cookie (set blank to disable cookie)
    //   - WARNING: different providers use the same cookie
    //   - if switching providers, remember to use another cookie or provide checks for old cookies
    location_cookie: "location",
    // Location cookie expiration in hours
    location_cookie_timeout: 5,
    // Session expiration in days
    session_timeout: 32,
    // Session cookie name (set blank to disable cookie)
    session_cookie: "first_session"
  };
  
  // Session object
  var SessionRunner = function(){
    // Helper for querying.
    // Usage: session.current_session.referrer_info.hostname.contains(['github.com','news.ycombinator.com'])
    String.prototype.contains = function(other_str){
      if (typeof(other_str) === 'string'){
        return (this.indexOf(other_str) !== -1); }
      for (var i = 0; i < other_str.length; i++){
        if (this.indexOf(other_str[i]) !== -1){ return true; } }
      return false; }
    // Merge options
    if (win.session && win.session.options) {
      for (option in win.session.options){
        options[option] = win.session.options[option]; }
    }
    // Modules to run
    // If the module has arguments,
    //   it _needs_ to return a callback function.
    var unloaded_modules = {
      api_version: API_VERSION,
      locale: modules.locale(),
      current_session: modules.session(),
      original_session: modules.session(
        options.session_cookie,
        options.session_timeout * 24 * 60 * 60 * 1000),
      browser: modules.browser(),
      plugins: modules.plugins(),
      time: modules.time(),
      device: modules.device()
    };
    // Location switch
    if (options.use_html5_location){
      unloaded_modules.location = modules.html5_location();
    } else if (options.ipinfodb_key){
      unloaded_modules.location = modules.ipinfodb_location(options.ipinfodb_key);
    } else if (options.gapi_location){
      unloaded_modules.location = modules.gapi_location();
    }
    // Cache win.session.start
    if (win.session && win.session.start){
      var start = win.session.start;
    }
    // Set up checking, if all modules are ready
    var asynchs = 0, module, result,
    check_asynch = function(){
      if (asynchs === 0){
        // Run start calback
        if (start){ start(win.session); }
      }
    };
    win.session = {};
    // Run asynchronous methods
    for (var name in unloaded_modules){
      module = unloaded_modules[name];
      if (typeof module === "function"){
        try {
          module(function(data){
            win.session[name] = data;
            asynchs--;
            check_asynch();
          });
          asynchs++;
        } catch(err){
          if (win.console && typeof(console.log) === "function"){
            console.log(err); }
        }
      } else {
        win.session[name] = module;
      } }
    check_asynch();
  };
  
  
  // Browser (and OS) detection
  var browser = {
    detect: function(){
      return {
        browser: this.search(this.data.browser),
        version: this.search(nav.userAgent) || this.search(nav.appVersion),
        os: this.search(this.data.os)
    } },
    search: function(data) {
      if (typeof data === "object"){
        // search for string match
        for(var i = 0; i < data.length; i++) {
          var dataString = data[i].string,
              dataProp   = data[i].prop;
          this.version_string = data[i].versionSearch || data[i].identity;
          if (dataString){
            if (dataString.indexOf(data[i].subString) != -1){
              return data[i].identity;
            }
          } else if (dataProp){
            return data[i].identity;
          }
        }
      } else {
        // search for version number
        var index = data.indexOf(this.version_string);
        if (index == -1) return;
        return parseFloat(data.substr(index + this.version_string.length + 1));
      }
    },
    data: {
      browser: [
        { string: nav.userAgent, subString: "Chrome", identity: "Chrome" },
        { string: nav.userAgent, subString: "OmniWeb", versionSearch: "OmniWeb/", identity: "OmniWeb" },
        { string: nav.vendor, subString: "Apple", identity: "Safari", versionSearch: "Version" },
        { prop:   win.opera, identity: "Opera", versionSearch: "Version" },
        { string: nav.vendor, subString: "iCab",identity: "iCab" },
        { string: nav.vendor, subString: "KDE", identity: "Konqueror" },
        { string: nav.userAgent, subString: "Firefox", identity: "Firefox" },
        { string: nav.vendor, subString: "Camino", identity: "Camino" },
        { string: nav.userAgent, subString: "Netscape", identity: "Netscape" },
        { string: nav.userAgent, subString: "MSIE", identity: "Explorer", versionSearch: "MSIE" },
        { string: nav.userAgent, subString: "Gecko", identity: "Mozilla", versionSearch: "rv" },
        { string: nav.userAgent, subString: "Mozilla", identity: "Netscape", versionSearch: "Mozilla" }
      ],
      os: [
        { string: nav.platform, subString: "Win", identity: "Windows" },
        { string: nav.platform, subString: "Mac", identity: "Mac" },
        { string: nav.userAgent, subString: "iPhone", identity: "iPhone/iPod" },
        { string: nav.userAgent, subString: "iPad", identitiy: "iPad" },
        { string: nav.platform, subString: "Linux", identity: "Linux" },
        { string: nav.userAgent, subString: "Android", identity: "Android" }
      ]}
  };
  
  var modules = {
    browser: function(){
      return browser.detect();
    },
    time: function(){
      // split date and grab timezone estimation.
      // timezone estimation: http://www.onlineaspect.com/2007/06/08/auto-detect-a-time-zone-with-javascript/
      var d1 = new Date(), d2 = new Date();
      d1.setMonth(0); d1.setDate(1); d2.setMonth(6); d2.setDate(1);
      return({tz_offset: -(new Date().getTimezoneOffset()) / 60, observes_dst: (d1.getTimezoneOffset() !== d2.getTimezoneOffset()) });
      // Gives a browser estimation, not guaranteed to be correct.
    },
    locale: function() {
      var lang = (
        nav.language        ||
        nav.browserLanguage ||
        nav.systemLanguage  ||
        nav.userLanguage
      ).split("-");
      if (lang.length == 2){
        return { country: lang[1].toLowerCase(), lang: lang[0].toLowerCase() };
      } else if (lang) {
        return {lang: lang[0].toLowerCase(), country: null };
      } else { return{lang: null, country: null }; }
    },
    device: function() {
      var device = {
        screen: {
          width: screen.width,
          height: screen.height
        }
      };
      var html = doc.documentElement,
          body = doc.getElementsByTagName("body")[0];
      device.viewport = {
        width:  win.innerWidth  || html.clientWidth  || body.clientWidth,
        height: win.innerHeight || html.clientHeight || body.clientHeight
      };
      device.is_tablet = !!nav.userAgent.match(/(iPad|SCH-I800|xoom|kindle)/i);
      device.is_phone = !device.isTablet && !!nav.userAgent.match(/(iPhone|iPod|blackberry|android 0.5|htc|lg|midp|mmp|mobile|nokia|opera mini|palm|pocket|psp|sgh|smartphone|symbian|treo mini|Playstation Portable|SonyEricsson|Samsung|MobileExplorer|PalmSource|Benq|Windows Phone|Windows Mobile|IEMobile|Windows CE|Nintendo Wii)/i);
      device.is_mobile = (device.is_tablet || device.is_phone);
      return device;
    },
    plugins: function(){
      var check_plugin = function(name){
        if (nav.plugins){
          var plugin, i = 0, length = nav.plugins.length;
          for (; i < length; i++ ){
            plugin = nav.plugins[i];
            if (plugin && plugin.name && plugin.name.toLowerCase().indexOf(name) !== -1){
              return true;
            } }
          return false;
        } return false;
      }
      return {
        flash:       check_plugin("flash"),
        silverlight: check_plugin("silverlight"),
        java:        check_plugin("java"),
        quicktime:   check_plugin("quicktime")
      }; 
    },
    session: function (cookie, expires){
      var session = util.get_obj(cookie);
      if (session == null){
        session = {
          visits: 1,
          start: new Date().getTime(), last_visit: new Date().getTime(),
          url: win.location.href, path: win.location.pathname,
          referrer: doc.referrer, referrer_info: util.parse_url(doc.referrer),
          search: { engine: null, query: null }
        };
        var search_engines = [
          { name: "Google", host: "google", query: "q" },
          { name: "Bing", host: "bing.com", query: "q" },
          { name: "Yahoo", host: "search.yahoo", query: "p" },
          { name: "AOL", host: "search.aol", query: "q" },
          { name: "Ask", host: "ask.com", query: "q" },
          { name: "Baidu", host: "baidu.com", query: "wd" }
        ], length = search_engines.length,
           engine, match, i = 0,
           fallbacks = 'q query term p wd query text'.split(' ');
        for (i = 0; i < length; i++){
          engine = search_engines[i];
          if (session.referrer_info.host.indexOf(engine.host) !== -1){
            session.search.engine = engine.name;
            session.search.query  = session.referrer_info.query[engine.query];
            session.search.terms  = session.search.query ? session.search.query.split(" ") : null;
            break;
          }
        }
        if (session.search.engine === null && session.referrer_info.search.length > 1){
          for (i = 0; i < fallbacks.length; i++){
            var terms = session.referrer_info.query[fallbacks[i]];
            if (terms){
              session.search.engine = "Unknown";
              session.search.query  = terms; session.search.terms  = terms.split(" ");
              break;
            }
          } 
        }
      } else {
        session.last_visit = new Date().getTime();
        session.visits++;
      }
      util.set_cookie(cookie, util.package_obj(session), expires);
      return session;
    },
    html5_location: function(){
      return function(callback){
        nav.geolocation.getCurrentPosition(function(pos){
          pos.source = 'html5';
          callback(pos);
        }, function(err) {
          if (options.gapi_location){
            modules.gapi_location()(callback);
          } else {
            callback({error: true, source: 'html5'}); }
        });
      };
    },
    gapi_location: function(){
      return function(callback){
        var location = util.get_obj(options.location_cookie);
        if (!location || location.source !== 'google'){
          win.gloader_ready = function() {
            if ("google" in win){
              if (win.google.loader.ClientLocation){
                win.google.loader.ClientLocation.source = "google";
                callback(win.google.loader.ClientLocation);
              } else {
                callback({error: true, source: "google"});
              }
              util.set_cookie(
                options.location_cookie,
                util.package_obj(win.google.loader.ClientLocation),
                options.location_cookie_timeout * 60 * 60 * 1000);
            }}
          util.embed_script("https://www.google.com/jsapi?callback=gloader_ready");
        } else {
          callback(location);
        }}
    },
    ipinfodb_location: function(api_key){
      return function (callback){
        var location_cookie = util.get_obj(options.location_cookie);
        if (location_cookie && location_cookie.source === 'ipinfodb'){ callback(location_cookie); }
        win.ipinfocb = function(data){
          if (data.statusCode === "OK"){
            data.source = "ipinfodb";
            util.set_cookie(
              options.location_cookie,
              util.package_obj(data),
              options.location_cookie * 60 * 60 * 1000);
            callback(data);
          } else {
            if (options.gapi_location){ return modules.gapi_location()(callback); }
            else { callback({error: true, source: "ipinfodb", message: data.statusMessage}); }
          }}
        util.embed_script("http://api.ipinfodb.com/v3/ip-city/?key=" + api_key + "&format=json&callback=ipinfocb");
      }}
  };
  
  // Utilities
  var util = {
    parse_url: function(url_str){
      var a = doc.createElement("a"), query = {};
      a.href = url_str; query_str = a.search.substr(1);
      // Disassemble query string
      if (query_str != ''){
        var pairs = query_str.split("&"), i = 0,
            length = pairs.length, parts;
        for (; i < length; i++){
          parts = pairs[i].split("=");
          if (parts.length === 2){
            query[parts[0]] = decodeURI(parts[1]); }
        }
      }
      return {
        host:     a.host,
        path:     a.pathname,
        protocol: a.protocol,
        port:     a.port === '' ? 80 : a.port,
        search:   a.search,
        query:    query }
    },
    set_cookie: function(cname, value, expires, options){ // from jquery.cookie.js
      if (!doc.cookie || !cname || !value){ return null; }
      if (!options){ var options = {}; }
      if (value === null || value === undefined){ expires = -1; }
      if (expires){ options.expires = (new Date().getTime()) + expires; }
      return (document.cookie = [
          encodeURIComponent(cname), '=',
          encodeURIComponent(String(value)),
          options.expires ? '; expires=' + new Date(options.expires).toUTCString() : '', // use expires attribute, max-age is not supported by IE
          options.path ? '; path=' + options.path : '',
          options.domain ? '; domain=' + options.domain : '',
          (win.location && win.location.protocol === 'https:') ? '; secure' : ''
      ].join(''));
    },
    get_cookie: function(cookie_name, result){ // from jquery.cookie.js
      return (result = new RegExp('(?:^|; )' + encodeURIComponent(cookie_name) + '=([^;]*)').exec(document.cookie)) ? decodeURIComponent(result[1]) : null;
    },
    embed_script: function(url){
      var element  = doc.createElement("script");
      element.type = "text/javascript";
      element.src  = url;
      doc.getElementsByTagName("body")[0].appendChild(element);
    },
    package_obj: function (obj){
      obj.version = API_VERSION;
      var ret = JSON.stringify(obj);
      delete obj.version; return ret;
    },
    get_obj: function(cookie_name){
      var obj;
      try { obj = JSON.parse(util.get_cookie(cookie_name)); } catch(e){};
      if (obj && obj.version == API_VERSION){
        delete obj.version; return obj;
      }
    }
  };
  
  // JSON
  var JSON = {
    parse: (win.JSON && win.JSON.parse) || function(data){
        if (typeof data !== "string" || !data){ return null; }
        return (new Function("return " + data))();
    },
    stringify: (win.JSON && win.JSON.stringify) || function(object){
      var type = typeof object;
      if (type !== "object" || object === null) {
        if (type === "string"){ return '"' + object + '"'; }
      } else {
        var k, v, json = [],
            isArray = (object && object.constructor === Array);
        for (k in object ) {
          v = object[k]; type = typeof v;
          if (type === "string")
            v = '"' + v + '"';
          else if (type === "object" && v !== null)
            v = this.stringify(v);
          json.push((isArray ? "" : '"' + k + '":') + v);
        }
        return (isArray ? "[" : "{") + json.join(",") + (isArray ? "]" : "}");
      } } };

  // Initialize SessionRunner
  SessionRunner();

})(window, document, navigator);