const bluebird = require("bluebird");
var request = bluebird.promisify(require("request").defaults({ jar: true }));
const fs = require("fs");
const cheerio = require("cheerio");

var jar = request.jar();

function getHeaders(url, options) {
    var headers = {
      "Content-Type": "application/x-www-form-urlencoded",
      Referer: "https://www.facebook.com/",
      Host: url.replace("https://", "").split("/")[0],
      Origin: "https://www.facebook.com",
      "User-Agent": options.userAgent,
      Connection: "keep-alive"
    };
  
    return headers;
}

function saveCookies(jar) {
  return function(res) {
    var cookies = res.headers["set-cookie"] || [];
    cookies.forEach(function(c) {
      if (c.indexOf(".facebook.com") > -1) {
        jar.setCookie(c, "https://www.facebook.com");
      }
      var c2 = c.replace(/domain=\.facebook\.com/, "domain=.messenger.com");
      jar.setCookie(c2, "https://www.messenger.com");
    });
    return res;
  };
}

function getType(obj) {
    return Object.prototype.toString.call(obj).slice(8, -1);
}

function getFrom(str, startToken, endToken) {
  var start = str.indexOf(startToken) + startToken.length;
  if (start < startToken.length) return "";

  var lastHalf = str.substring(start);
  var end = lastHalf.indexOf(endToken);
  if (end === -1) {
    throw Error(
      "Could not find endTime `" + endToken + "` in the given string."
    );
  }
  return lastHalf.substring(0, end);
}

function arrayToObject(arr, getKey, getValue) {
  return arr.reduce(function(acc, val) {
    acc[getKey(val)] = getValue(val);
    return acc;
  }, {});
}

function formatCookie(arr, url) {
  return (
    arr[0] + "=" + arr[1] + "; Path=" + arr[3] + "; Domain=" + url + ".com"
  );
}

function arrToForm(form) {
  return arrayToObject(
    form,
    function(v) {
      return v.name;
    },
    function(v) {
      return v.val;
    }
  );
}

const globalOption = { selfListen: false,
    listenEvents: false,
    updatePresence: false,
    forceLogin: false,
    logRecordSize: 100,
    userAgent:
    ' Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:59.0) Gecko/20100101 Firefox/59.0' }

function get(url, jar, qs, options) {
    // I'm still confused about this
    if (getType(qs) === "Object") {
      for (var prop in qs) {
        if (qs.hasOwnProperty(prop) && getType(qs[prop]) === "Object") {
          qs[prop] = JSON.stringify(qs[prop]);
        }
      }
    }
    var op = {
      headers: getHeaders(url, options),
      timeout: 60000,
      qs: qs,
      url: url,
      method: "GET",
      jar: jar,
      gzip: true
    };
    return request(op).then(function(res) {
      return res;
    });
} 

function post(url, jar, form, options) {
  var op = {
    headers: getHeaders(url, options),
    timeout: 60000,
    url: url,
    method: "POST",
    form: form,
    jar: jar,
    gzip: true
  };
  return request(op).then(function(res) {
    return res;
  });
}

function getAppState(jar) {
    return jar
      .getCookies("https://www.facebook.com")
      .concat(jar.getCookies("https://facebook.com"))
      .concat(jar.getCookies("https://www.messenger.com"));
}
function getData(){
    
}
const login = function(account){
  return new Promise((resolve,reject) => {
      get('https://www.facebook.com/', null, null, globalOption).then(saveCookies(jar)).then((res) => {
          let email = account.email
          let password = account.password
          var html = res.body;
          var $ = cheerio.load(html);
          var arr = [];
          $("#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 = arrToForm(arr);
          form.lsd = getFrom(html, "[\"LSD\",[],{\"token\":\"", "\"}");
          form.lgndim = new 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 = getFrom(html, "name=\"lgnrnd\" value=\"", "\"");
          form.locale = 'en_US';
          form.timezone = '240';
          form.lgnjs = ~~(Date.now() / 1000);
          var willBeCookies = html.split("\"_js_");
              willBeCookies.slice(1).map(function(val) {
              var cookieData = JSON.parse("[\"" + getFrom(val, "", "]") + "]");
              jar.setCookie(formatCookie(cookieData, "facebook"), "https://www.facebook.com");
              });
              let apps = false;
              if (fs.existsSync("./session.json")) {
                    apps = JSON.parse(fs.readFileSync("session.json","utf-8"));
                    apps.map(function(c) {
                      var str = c.key + "=" + c.value + "; expires=" + c.expires + "; domain=" + c.domain + "; path=" + c.path + ";";
                      jar.setCookie(str, "http://" + c.domain);
                    });
                    get('https://www.facebook.com/', jar, null, globalOption)
                    .then(saveCookies(jar)).then(function(res) {
                        var html = res.body;
                        var fb_dtsg = getFrom(html, 'name="fb_dtsg" value="', '"');
                        var revision = getFrom(html, 'revision":', ",");
                        let cookie = "";
                        jar.getCookies("https://www.facebook.com").forEach(el => {
                        el = el.toString();
                        let data = el.slice(0,el.indexOf(";"));
                        cookie+=(data+";")
                        });
                        var ttstamp = "2";
                        for (var i = 0; i < fb_dtsg.length; i++) {
                            ttstamp += fb_dtsg.charCodeAt(i);
                        }
                        resolve({fb_dtsg,revision,cookie,ttstamp});
                    });    
              } else { 
                post("https://www.facebook.com/login.php?login_attempt=1&lwv=110", jar, form, globalOption)
                .then(saveCookies(jar))
                .then(function(res) {
                    console.log("[WARN] đang tạo file cookie");
                    var headers = res.headers;
                    if (!headers.location) {
                      throw {error: "Sai tên tài khoản hoặc mật khẩu :("};
                    }
                    else if (headers.location.indexOf('https://www.facebook.com/checkpoint/') > -1) {
                      console.log("Checkpoint cmnr, :>.");
                      var nextURL = 'https://www.facebook.com/checkpoint/?next=https%3A%2F%2Fwww.facebook.com%2Fhome.php';
                    }
                    else {
                      fs.writeFileSync("session.json",JSON.stringify(getAppState(jar)));
                      let inter = setInterval(()=> {
                        login(account).then(resolve);
                        clearInterval(inter);
                      },1000);
                    } 
                })
              }
          })
  });

}

module.exports = login;