text: var AdmZip = require('adm-zip');
  var parseString = require('xml2js').parseString;
  var parseUrl = require('url').parse;
  var util = require('./util');
  
  function getMetaAttrs(meta) {
    meta = meta && meta.Session;
    if (!meta) {
      return {};
    }
    var result = meta.SessionTimers && meta.SessionTimers[0];
    result = result && result.$ || {};
    var SessionFlag = meta.SessionFlags && meta.SessionFlags[0] && meta.SessionFlags[0].SessionFlag;
    if (Array.isArray(SessionFlag)) {
      SessionFlag.forEach(function(flag) {
        flag = flag && flag.$;
        if (!flag || typeof flag.N !== 'string') {
          return;
        }
        result[flag.N] = flag.V || '';
      });
    }
    return result;
  }
  
  function parseMetaInfo(result) {
    var req = result.req;
    if (!req) {
      return false;
    }
    var port;
    if (/^[^:/]+:\/\//.test(req.url)) {
      var options = parseUrl(req.url);
      if (!req.headers.host) {
        req.headers.host = options.host;
      }
      req.isHttps = /^https:/i.test(req.url);
      port = options.port || (req.isHttps ? 443 : 80);
      req.url = options.path;
    } else if (typeof req.headers.host !== 'string') {
      req.headers.host = '';
    }
  
    var meta = getMetaAttrs(result.meta);
    var startTime = result.startTime = new Date(meta.ClientConnected).getTime() || 0;
    if (meta.DNSTime >= 0) {
      startTime = result.dnsTime = +startTime + (+meta.DNSTime);
    }
    if (meta.ClientDoneRequest) {
      var requestTime = new Date(meta.ClientDoneRequest).getTime() || 0;
      startTime = result.requestTime = Math.max(startTime, requestTime);
    }
    if (meta.ClientBeginResponse) {
      var responseTime = new Date(meta.ClientBeginResponse).getTime() || 0;
      startTime = result.responseTime = Math.max(startTime, responseTime);
    }
    if (meta.ClientDoneResponse) {
      var endTime = new Date(meta.ClientDoneResponse).getTime() || 0;
      result.endTime = Math.max(endTime, startTime);
    }
    result.rules = result.rules || {};
    var res = result.res = result.res || {};
    result.hostIp = res.ip = util.removeIPV6Prefix(meta['x-hostip']);
    res.port = port;
    result.clientIp = req.ip = util.removeIPV6Prefix(meta['x-clientip']);
    var clientPort = meta['x-clientport'];
    if (clientPort) {
      req.port = clientPort;
    }
    var size = meta['x-transfer-size'] || meta['x-responsebodytransferlength'];
    if (typeof size === 'string') {
      size = parseInt(size.replace(/\s*,\s*/g, ''), 10);
    }
    if (size > -1) {
      res.size = size;
    }
    if (req.method === 'CONNECT') {
      result.url = req.url;
      result.isHttps = true;
    } else {
      result.url = 'http' + (req.isHttps ? 's' : '') +'://' + req.headers.host + req.url;
      if (/\bwebsocket\b/i.test(req.headers.upgrade)) {
        result.url = result.url.replace(/^http/, 'ws');
      }
    }
  }
  
  module.exports = function(buffer, cb) {
    var zip = new AdmZip(buffer);
    var zipEntries = zip.getEntries();
    var sessions = {};
    var count = 0;
    var execCallback = function() {
      if (count <= 0) {
        var result = [];
        var wsLen = 0;
        Object.keys(sessions).forEach(function(key) {
          var session = sessions[key];
          if (session.req && session.meta) {
            if (parseMetaInfo(session) !== false) {
              result.push(session);
            }
          }
          if (session.trailers && session.res) {
            session.res.trailers = session.trailers;
            session.res.rawTrailerNames = session.rawTrailerNames;
            delete session.trailers;
            delete session.rawTrailerNames;
          }
          var framesData = session.framesData;
          if (framesData) {
            delete session.framesData;
            ++wsLen;
            util.parseFrames(session.res, framesData, function(frames) {
              session.frames = frames;
              if (--wsLen === 0) {
                cb(result);
              }
            });
          }
        });
        !wsLen && cb(result);
      }
    };
    zipEntries.forEach(function(entry) {
      if (entry.isDirectory) {
        return;
      }
      var entryName = entry.entryName;
      var filename = entryName.substring(4);
      var dashIndex = filename.lastIndexOf('_');
      if (dashIndex <= 0) {
        return;
      }
      var index = filename.substring(0, dashIndex);
      filename = filename.substring(dashIndex + 1).toLowerCase();
      if (['c.txt', 'm.xml', 's.txt', 'w.txt', 'whistle.json'].indexOf(filename) === -1) {
        return;
      }
      var content = zip.readFile(entryName);
      if (!content) {
        return;
      }
      var result = sessions[index] = sessions[index] || {};
      ++count;
      if (filename === 'c.txt') {
        util.getReq(content, function(req) {
          setImmediate(function() {
            result.req = req;
            --count;
            execCallback();
          });
        });
      } else if (filename === 'm.xml') {
        parseString(content, function(err, meta) {
          setImmediate(function() {
            result.meta = meta;
            --count;
            execCallback();
          });
        });
      } else if (filename === 'whistle.json') {
        setImmediate(function() {
          --count;
          var data = util.parseJSON(String(content));
          if (data) {
            if (typeof data.realUrl === 'string') {
              result.realUrl = data.realUrl;
            }
            if (data.rules) {
              result.rules = data.rules;
            }
            if (data.frames) {
              result.frames = data.frames;
            }
            if (data.fwdHost) {
              result.fwdHost = data.fwdHost;
            }
            if (data.useHttp) {
              result.useHttp = true;
            }
            if (data.httpsTime > 0) {
              result.httpsTime = data.httpsTime;
            }
            if (data.useH2) {
              result.useH2 = true;
            }
            if (data.mark) {
              result.mark = true;
            }
            result.trailers = data.trailers;
            result.rawTrailerNames = data.rawTrailerNames;
          }
          execCallback();
        });
      } else if (filename === 'w.txt') {
        setImmediate(function() {
          result.framesData = content;
          --count;
          execCallback();
        });
      } else {
        util.getRes(content, function(res) {
          setImmediate(function() {
            result.res = res;
            --count;
            execCallback();
          });
        });
      }
    });
    execCallback();
  };
  