"use strict";

var utils = require("./utils");
var cheerio = require("cheerio");
var log = require("npmlog");

var defaultLogRecordSize = 100;
log.maxRecordSize = defaultLogRecordSize;

function setOptions(globalOptions, options) {
  Object.keys(options).map(function(key) {
    switch (key) {
      case 'logLevel':
        log.level = options.logLevel;
        globalOptions.logLevel = options.logLevel;
        break;
      case 'logRecordSize':
        log.maxRecordSize = options.logRecordSize;
        globalOptions.logRecordSize = options.logRecordSize;
        break;
      case 'selfListen':
        globalOptions.selfListen = options.selfListen;
        break;
      case 'listenEvents':
        globalOptions.listenEvents = options.listenEvents;
        break;
      case 'pageID':
        globalOptions.pageID = options.pageID.toString();
        break;
      case 'updatePresence':
        globalOptions.updatePresence = options.updatePresence;
        break;
      case 'forceLogin':
        globalOptions.forceLogin = options.forceLogin;
        break;
      case 'userAgent':
        globalOptions.userAgent = options.userAgent;
        break;
      case 'autoMarkDelivery':
        globalOptions.autoMarkDelivery = options.autoMarkDelivery;
        break;
      case 'autoMarkRead':
        globalOptions.autoMarkRead = options.autoMarkRead;
        break;
      default:
        log.warn("setOptions", "Unrecognized option given to setOptions: " + key);
        break;
    }
  });
}

function buildAPI(globalOptions, html, jar) {
  var maybeCookie = jar.getCookies("https://www.facebook.com").filter(function(val) {
    return val.cookieString().split("=")[0] === "c_user";
  });

  if(maybeCookie.length === 0) {
    throw {error: "Error retrieving userID. This can be caused by a lot of things, including getting blocked by Facebook for logging in from an unknown location. Try logging in with a browser to verify."};
  }

  var userID = maybeCookie[0].cookieString().split("=")[1].toString();
  log.info("login", "Logged in");

  var clientID = (Math.random() * 2147483648 | 0).toString(16);

  // All data available to api functions
  var ctx = {
    userID: userID,
    jar: jar,
    clientID: clientID,
    globalOptions: globalOptions,
    loggedIn: true,
    access_token: 'NONE',
    clientMutationId: 0
  };

  var api = {
    setOptions: setOptions.bind(null, globalOptions),
    getAppState: function getAppState() {
      return utils.getAppState(jar);
    },
  };

  const apiFuncNames = [
    'addUserToGroup',
    'changeAdminStatus',
    'changeArchivedStatus',
    'changeBlockedStatus',
    'changeGroupImage',
    'changeNickname',
    'changeThreadColor',
    'changeThreadEmoji',
    'createPoll',
    'deleteMessage',
    'deleteThread',
    'forwardAttachment',
    'getCurrentUserID',
    'getEmojiUrl',
    'getFriendsList',
    'getThreadHistory',
    'getThreadInfo',
    'getThreadList',
    'getThreadPictures',
    'getUserID',
    'getUserInfo',
    'handleMessageRequest',
    'listen',
    'listenMqtt',
    'logout',
    'markAsDelivered',
    'markAsRead',
    'markAsReadAll',
    'muteThread',
    'removeUserFromGroup',
    'resolvePhotoUrl',
    'searchForThread',
    'sendMessage',
    'sendTypingIndicator',
    'setMessageReaction',
    'setTitle',
    'threadColors',
    'unsendMessage',

    // Deprecated features
    "getThreadListDeprecated",
    'getThreadHistoryDeprecated',
    'getThreadInfoDeprecated',
  ];

  var defaultFuncs = utils.makeDefaults(html, userID, ctx);

  // Load all api functions in a loop
  apiFuncNames.map(function(v) {
    api[v] = require('./src/' + v)(defaultFuncs, api, ctx);
  });

  return [ctx, defaultFuncs, api];
}

function makeLogin(jar, email, password, loginOptions, callback) {
  return function(res) {
    var html = res.body;
    var $ = cheerio.load(html);
    var arr = [];

    // This will be empty, but just to be sure we leave it
    $("#login_form input").map(function(i, v){
      arr.push({val: $(v).val(), name: $(v).attr("name")});
    });

    arr = arr.filter(function(v) {
      return v.val && v.val.length;
    });

    var form = utils.arrToForm(arr);
    form.lsd = utils.getFrom(html, "[\"LSD\",[],{\"token\":\"", "\"}");
    form.lgndim = Buffer.from("{\"w\":1440,\"h\":900,\"aw\":1440,\"ah\":834,\"c\":24}").toString('base64');
    form.email = email;
    form.pass = password;
    form.default_persistent = '0';
    form.lgnrnd = utils.getFrom(html, "name=\"lgnrnd\" value=\"", "\"");
    form.locale = 'en_US';
    form.timezone = '240';
    form.lgnjs = ~~(Date.now() / 1000);


    // Getting cookies from the HTML page... (kill me now plz)
    // we used to get a bunch of cookies in the headers of the response of the
    // request, but FB changed and they now send those cookies inside the JS.
    // They run the JS which then injects the cookies in the page.
    // The "solution" is to parse through the html and find those cookies
    // which happen to be conveniently indicated with a _js_ in front of their
    // variable name.
    //
    // ---------- Very Hacky Part Starts -----------------
    var willBeCookies = html.split("\"_js_");
    willBeCookies.slice(1).map(function(val) {
      var cookieData = JSON.parse("[\"" + utils.getFrom(val, "", "]") + "]");
      jar.setCookie(utils.formatCookie(cookieData, "facebook"), "https://www.facebook.com");
    });
    // ---------- Very Hacky Part Ends -----------------

    log.info("login", "Logging in...");
    return utils
      .post("https://www.facebook.com/login.php?login_attempt=1&lwv=110", jar, form, loginOptions)
      .then(utils.saveCookies(jar))
      .then(function(res) {
        var headers = res.headers;
        if (!headers.location) {
          throw {error: "Wrong username/password."};
        }

        // This means the account has login approvals turned on.
        if (headers.location.indexOf('https://www.facebook.com/checkpoint/') > -1) {
          log.info("login", "You have login approvals turned on.");
          var nextURL = 'https://www.facebook.com/checkpoint/?next=https%3A%2F%2Fwww.facebook.com%2Fhome.php';

          return utils
            .get(headers.location, jar, null, loginOptions)
            .then(utils.saveCookies(jar))
            .then(function(res) {
              var html = res.body;
              // Make the form in advance which will contain the fb_dtsg and nh
              var $ = cheerio.load(html);
              var arr = [];
              $("form input").map(function(i, v){
                arr.push({val: $(v).val(), name: $(v).attr("name")});
              });

              arr = arr.filter(function(v) {
                return v.val && v.val.length;
              });

              var form = utils.arrToForm(arr);
              if (html.indexOf("checkpoint/?next") > -1) {
                throw {
                  error: 'login-approval',
                  continue: function(code) {
                    form.approvals_code = code;
                    form['submit[Continue]'] = 'Continue';
                    return utils
                      .post(nextURL, jar, form, loginOptions)
                      .then(utils.saveCookies(jar))
                      .then(function() {
                        // Use the same form (safe I hope)
                        form.name_action_selected = 'save_device';

                        return utils
                          .post(nextURL, jar, form, loginOptions)
                          .then(utils.saveCookies(jar));
                      })
                      .then(function(res) {
                        var headers = res.headers;
                        if (!headers.location && res.body.indexOf('Review Recent Login') > -1) {
                          throw {error: "Something went wrong with login approvals."};
                        }

                        var appState = utils.getAppState(jar);

                        // Simply call loginHelper because all it needs is the jar
                        // and will then complete the login process
                        return loginHelper(appState, email, password, loginOptions, callback);
                      })
                      .catch(function(err) {
                        callback(err);
                      });
                  }
                };
              } else {
                if (!loginOptions.forceLogin) {
                  throw {error: "Couldn't login. Facebook might have blocked this account. Please login with a browser or enable the option 'forceLogin' and try again."};
                }
                if (html.indexOf("Suspicious Login Attempt") > -1) {
                  form['submit[This was me]'] = "This was me";
                } else {
                  form['submit[This Is Okay]'] = "This Is Okay";
                }

                return utils
                  .post(nextURL, jar, form, loginOptions)
                  .then(utils.saveCookies(jar))
                  .then(function() {
                    // Use the same form (safe I hope)
                    form.name_action_selected = 'save_device';

                    return utils
                      .post(nextURL, jar, form, loginOptions)
                      .then(utils.saveCookies(jar));
                  })
                  .then(function(res) {
                    var headers = res.headers;

                    if (!headers.location && res.body.indexOf('Review Recent Login') > -1) {
                      throw {error: "Something went wrong with review recent login."};
                    }

                    var appState = utils.getAppState(jar);

                    // Simply call loginHelper because all it needs is the jar
                    // and will then complete the login process
                    return loginHelper(appState, email, password, loginOptions, callback);
                  })
                  .catch(function(e) {
                    callback(e);
                  });
              }
            });
        }

        return utils
          .get('https://www.facebook.com/', jar, null, loginOptions)
          .then(utils.saveCookies(jar));
      });
  };
}

// Helps the login
function loginHelper(appState, email, password, globalOptions, callback) {
  var mainPromise = null;
  var jar = utils.getJar();

  // If we're given an appState we loop through it and save each cookie
  // back into the jar.
  if(appState) {
    appState.map(function(c) {
      var str = c.key + "=" + c.value + "; expires=" + c.expires + "; domain=" + c.domain + "; path=" + c.path + ";";
      jar.setCookie(str, "http://" + c.domain);
    });

    // Load the main page.
    mainPromise = utils
      .get('https://www.facebook.com/', jar, null, globalOptions)
      .then(utils.saveCookies(jar));
  } else {
    // Open the main page, then we login with the given credentials and finally
    // load the main page again (it'll give us some IDs that we need)
    mainPromise = utils
      .get("https://www.facebook.com/", null, null, globalOptions)
      .then(utils.saveCookies(jar))
      .then(makeLogin(jar, email, password, globalOptions, callback))
      .then(function() {
        return utils
          .get('https://www.facebook.com/', jar, null, globalOptions)
          .then(utils.saveCookies(jar));
      });
  }

  var ctx = null;
  var defaultFuncs = null;
  var api = null;

  mainPromise = mainPromise
    .then(function(res) {
      // Hacky check for the redirection that happens on some ISPs, which doesn't return statusCode 3xx
      var reg = /<meta http-equiv="refresh" content="0;url=([^"]+)[^>]+>/;
      var redirect = reg.exec(res.body);
      if (redirect && redirect[1]) {
        return utils
          .get(redirect[1], jar, null, globalOptions)
          .then(utils.saveCookies(jar));
      }
      return res;
    })
    .then(function(res) {
      var html = res.body;
      var stuff = buildAPI(globalOptions, html, jar);
      ctx = stuff[0];
      defaultFuncs = stuff[1];
      api = stuff[2];
      return res;
    })
    .then(function() {
      var form = {
        reason: 6
      };
      log.info("login", 'Request to reconnect');
      return defaultFuncs
        .get("https://www.facebook.com/ajax/presence/reconnect.php", ctx.jar, form)
        .then(utils.saveCookies(ctx.jar));
    })
    .then(function(_res) {
      log.info("login", 'Request to pull 1');
      var form = {
        channel : 'p_' + ctx.userID,
        seq : 0,
        partition : -2,
        clientid : ctx.clientID,
        viewer_uid : ctx.userID,
        uid : ctx.userID,
        state : 'active',
        idle : 0,
        cap : 8,
        msgs_recv: 0
      };
      var presence = utils.generatePresence(ctx.userID);
      ctx.jar.setCookie("presence=" + presence + "; path=/; domain=.facebook.com; secure", "https://www.facebook.com");
      ctx.jar.setCookie("presence=" + presence + "; path=/; domain=.messenger.com; secure", "https://www.messenger.com");
      ctx.jar.setCookie("locale=en_US; path=/; domain=.facebook.com; secure", "https://www.facebook.com");
      ctx.jar.setCookie("locale=en_US; path=/; domain=.messenger.com; secure", "https://www.messenger.com");
      ctx.jar.setCookie("a11y=" + utils.generateAccessiblityCookie() + "; path=/; domain=.facebook.com; secure", "https://www.facebook.com");

      return utils
        .get("https://0-edge-chat.facebook.com/pull", ctx.jar, form, globalOptions)
        .then(utils.saveCookies(ctx.jar))
        .then(function(res) {
          var ret = null;
          try {
            ret = JSON.parse(utils.makeParsable(res.body));
          } catch(e) {
            throw {error: "Error inside first pull request. Received HTML instead of JSON. Logging in inside a browser might help fix this."};
          }

          return ret;
        });
    })
    .then(function(resData) {
      if (resData.t !== 'lb') throw {error: "Bad response from pull 1"};

      var form = {
        channel : 'p_' + ctx.userID,
        seq : 0,
        partition : -2,
        clientid : ctx.clientID,
        viewer_uid : ctx.userID,
        uid : ctx.userID,
        state : 'active',
        idle : 0,
        cap : 8,
        msgs_recv:0,
        sticky_token: resData.lb_info.sticky,
        sticky_pool: resData.lb_info.pool,
      };

      log.info("login", "Request to pull 2");
      return utils
        .get("https://0-edge-chat.facebook.com/pull", ctx.jar, form, globalOptions)
        .then(utils.saveCookies(ctx.jar));
    })
    .then(function() {
      var form = {
        'client' : 'mercury',
        'folders[0]': 'inbox',
        'last_action_timestamp' : '0'
      };
      log.info("login", "Request to thread_sync");

      return defaultFuncs
        .post("https://www.facebook.com/ajax/mercury/thread_sync.php", ctx.jar, form, globalOptions)
        .then(utils.saveCookies(ctx.jar));
    });

  // given a pageID we log in as a page
  if (globalOptions.pageID) {
    mainPromise = mainPromise
      .then(function() {
        return utils
          .get('https://www.facebook.com/' + ctx.globalOptions.pageID + '/messages/?section=messages&subsection=inbox', ctx.jar, null, globalOptions);
      })
      .then(function(resData) {
        var url = utils.getFrom(resData.body, 'window.location.replace("https:\\/\\/www.facebook.com\\', '");').split('\\').join('');
        url = url.substring(0, url.length - 1);

        return utils
          .get('https://www.facebook.com' + url, ctx.jar, null, globalOptions);
      });
  }

  // At the end we call the callback or catch an exception
  mainPromise
    .then(function() {
      log.info("login", 'Done logging in.');
      return callback(null, api);
    })
    .catch(function(e) {
      log.error("login", e.error || e);
      callback(e);
    });
}

function login(loginData, options, callback) {
  if(utils.getType(options) === 'Function' || utils.getType(options) === 'AsyncFunction') {
    callback = options;
    options = {};
  }

  var globalOptions = {
    selfListen: false,
    listenEvents: false,
    updatePresence: false,
    forceLogin: false,
    autoMarkDelivery: true,
    autoMarkRead: false,
    logRecordSize: defaultLogRecordSize,
    userAgent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_2) AppleWebKit/600.3.18 (KHTML, like Gecko) Version/8.0.3 Safari/600.3.18"
  };

  setOptions(globalOptions, options);

  loginHelper(loginData.appState, loginData.email, loginData.password, globalOptions, callback);
}

module.exports = login;