/**
 * @package parse-listing
 * @author Sergi Mansilla <sergi.mansilla@gmail.com>
 * @license https://github.com/sergi/parse-listing/blob/master/LICENSE MIT License
 */

"use strict";

/**
 * this is the regular expression used by Unix Parsers.
 *
 * Permissions:
 *    r   the file is readable
 *    w   the file is writable
 *    x   the file is executable
 *    -   the indicated permission is not granted
 *    L   mandatory locking occurs during access (the set-group-ID bit is
 *        on and the group execution bit is off)
 *    s   the set-user-ID or set-group-ID bit is on, and the corresponding
 *        user or group execution bit is also on
 *    S   undefined bit-state (the set-user-ID bit is on and the user
 *        execution bit is off)
 *    t   the 1000 (octal) bit, or sticky bit, is on [see chmod(1)], and
 *        execution is on
 *    T   the 1000 bit is turned on, and execution is off (undefined bit-
 *        state)
 */

var RE_UnixEntry = new RegExp(
  "([bcdlfmpSs-])"
    + "(((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-])))\\+?\\s+"
    + "(\\d+)\\s+"
    + "(\\S+)\\s+"
    + "(?:(\\S+)\\s+)?"
    + "(\\d+)\\s+"

    //numeric or standard format date
    + "((?:\\d+[-/]\\d+[-/]\\d+)|(?:\\S+\\s+\\S+))\\s+"

    // year (for non-recent standard format)
    // or time (for numeric or recent standard format)
    + "(\\d+(?::\\d+)?)\\s*"

    //+ "(\\S*)(\\s*.*)"
    + "(.*)"
);

// MSDOS format
// 04-27-00  09:09PM       <DIR>          licensed
// 07-18-00  10:16AM       <DIR>          pub
// 04-14-00  03:47PM                  589 readme.htm
var RE_DOSEntry = new RegExp(
  "(\\S+)\\s+(\\S+)\\s+" +
  "(<DIR>)?\\s*" +
  "([0-9]+)?\\s{1,}" +
  "(\\S.*)"
);


// Not used for now
// var RE_VMSEntry = new RegExp(
//     "(.*;[0-9]+)\\s*"
//     + "(\\d+)/\\d+\\s*"
//     + "(\\S+)\\s+(\\S+)\\s+"
//     + "\\[(([0-9$A-Za-z_]+)|([0-9$A-Za-z_]+),([0-9$a-zA-Z_]+))\\]?\\s*"
//     + "\\([a-zA-Z]*,[a-zA-Z]*,[a-zA-Z]*,[a-zA-Z]*\\)"
// );

exports.nodeTypes = {
  FILE_TYPE: 0,
  DIRECTORY_TYPE: 1,
  SYMBOLIC_LINK_TYPE: 2,
  UNKNOWN_TYPE: 3
};

exports.permissions = {
  READ_PERMISSION: 0,
  WRITE_PERMISSION: 1,
  EXECUTE_PERMISSION: 2
};

exports.access = {
  USER_ACCESS: 0,
  GROUP_ACCESS: 1,
  WORLD_ACCESS: 2
};

function splitEntries(entries) {
  if (typeof entries === "string") {
    entries = entries.split(/\r?\n/);
  }
  return entries;
}

var RE_RES = /^(\d\d\d)\s(.*)/;
var RE_MULTI = /^(\d\d\d)-/;
var RE_SERVER_RESPONSE = /^(\d\d\d)(.*)/;

exports.parseFtpEntries = function parseFtpEntries(listing, callback) {
  var t, parsedEntry;
  var i = 0;
  var parsed = [];
  var entries = splitEntries(listing);
  entries.forEach(function(entry, i) {
    // Some servers include an official code-multiline sign at the beginning
    // of every string. We must strip it if that's the case.
    if (RE_MULTI.test(entry)) {
      entry = entry.substr(3);
    }

    entry = entry.trim();

    // Filter file-listing results from 'STAT' command, since they include
    // server responses before and after the file listing.
    // Issue: https://github.com/sergi/jsftp/issues/3
    if (RE_SERVER_RESPONSE.test(entry) ||
      RE_RES.test(entry) || RE_MULTI.test(entry)) {
      return;
    }

    parsedEntry = parseEntry(entry);
    if (parsedEntry === null) {
      if (entries[i + 1]) {
        t = parseEntry(entry + entries[i + 1]);
        if (t !== null) {
          entries[i + 1] = entry + entries[i + 1];
          return;
        }
      }

      if (entries[i - 1] && parsed.length > 0) {
        t = parseEntry(entries[i - 1] + entry);
        if (t !== null) {
          parsed[parsed.length - 1] = t;
        }
      }
    }
    else if (parsedEntry) {
      parsed.push(parsedEntry);
    }
  });

  callback(null, parsed);
};

/**
 * Selects which parser to use depending on the first character of the line to
 * parse.
 *
 * @param entries {Array.<string>|string} FTP file entry line.
 * @param callback {Function} Callback function with error or result.
 */
exports.parseEntries = function(entries, callback) {
  callback(null, splitEntries(entries)
    .map(parseEntry)
    .filter(function(entry) { return !!entry; }));
};

/**
 * Selects which parser to use depending on the first character of the line to
 * parse.
 *
 * @param entry {string} FTP file entry line
 * @returns {Object|null} Parsed object with the file entry properties
 */
var parseEntry = exports.parseEntry = function(entry) {
  var c = entry.charAt(0);

  if ('bcdlps-'.indexOf(c) > -1) {
    return parsers.unix(entry);
  }
  else if ('0123456789'.indexOf(c) > -1) {
    return parsers.msdos(entry);
  }

  return null;
};

var parsers = {
  unix: function(entry) {
    var target, writePerm, readPerm, execPerm;
    var group = entry.match(RE_UnixEntry);

    if (group) {
      var type = group[1];
      //var hardLinks = group[15];
      var usr = group[16];
      var grp = group[17];
      var size = group[18];
      var name = group[21];

      var date;
      // Check whether we are given the time (recent file) or the year
      // (older file) in the file listing.
      if (group[20].indexOf(":") === -1) {
        date = +new Date(group[19] + " " + group[20]).getTime();
      }
      else {
        var currentMonth = new Date().getMonth();
        var month = new Date(group[19]).getMonth();
        var year = new Date().getFullYear() - (currentMonth < month ? 1 : 0);

        date = +new Date(group[19] + " " + group[20] + " " + year);
      }

      // Ignoring '.' and '..' entries for now
      if (name === "." || name === "..") {
        return;
      }

      //var endtoken = group[22];

      switch (type[0]) {
        case 'd':
          type = exports.nodeTypes.DIRECTORY_TYPE;
          break;
        case 'l':
          type = exports.nodeTypes.SYMBOLIC_LINK_TYPE;
          var isLink = /(.*)\s->\s(.*)/.exec(name);
          if (isLink) {
            name = isLink[1];
            target = isLink[2];
          }
          break;
        case 'b':
        case 'c':
        // break; - fall through
        case 'f':
        case '-':
          type = exports.nodeTypes.FILE_TYPE;
          break;
        default:
          type = exports.nodeTypes.UNKNOWN_TYPE;
      }

      var file = {
        name: name,
        type: type,
        time: date,
        size: size,
        owner: usr,
        group: grp
      };

      if (target) file.target = target;

      var g = 4;
      ["user", "group", "other"].forEach(function(access) {
        // Use != '-' to avoid having to check for suid and sticky bits
        readPerm = group[g] !== "-";
        writePerm = group[g + 1] !== "-";

        var execPermStr = group[g + 2];

        file[access + "Permissions"] = {
          read: readPerm,
          write: writePerm,
          exec: (execPermStr !== "-") && !(/[A-Z]/.test(execPermStr[0]))
        };

        g += 4;
      });

      return file;
    }
  },

  msdos: function(entry) {
    var group = entry.match(RE_DOSEntry);
    var type;

    if (!group) {
      return null;
    }

    var replacer = function replacer(str, hour, min, ampm, offset, s) {
      return hour + ":" + min + " " + ampm;
    };

    var time = group[2].replace(/(\d{2}):(\d{2})([AP]M)/, replacer);
    var date = new Date(group[1] + " " + time).getTime();
    var dirString = group[3];
    var size = group[4];
    var name = group[5];

    if (null == name || name === "." || name === "..") {
      return null;
    }

    if (dirString === "<DIR>") {
      type = exports.nodeTypes.DIRECTORY_TYPE;
      size = 0;
    }
    else {
      type = exports.nodeTypes.FILE_TYPE;
    }

    return {
      name: name,
      type: type,
      time: date,
      size: size
    };
  }
};

/*
 * MLSx commands are not being used for now.
 *
 * http://rfc-ref.org/RFC-TEXTS/3659/chapter7.html
 * http://www.rhinosoft.com/newsletter/NewsL2005-07-06.asp?prod=rs
 *
 var reKV = /(.+?)=(.+?);/;
 exports.parseMList = function(line) {
 var ret;
 var result = line.trim().split(reKV);

 if (result && result.length > 0) {
 ret = {};
 if (result.length === 1) {
 ret.name = result[0].trim();
 }
 else {
 var i, k, v, len = result.length;
 for (i = 1; i < len; i += 3) {
 k = result[i];
 v = result[i+1];
 ret[k] = v;
 }
 ret.name = result[result.length-1].trim();
 }
 } else
 ret = line;

 return ret;
 }
 */