'use strict';
// @ts-check
// ==================================================================================
// users.js
// ----------------------------------------------------------------------------------
// Description:   System Information - library
//                for Node.js
// Copyright:     (c) 2014 - 2020
// Author:        Sebastian Hildebrandt
// ----------------------------------------------------------------------------------
// License:       MIT
// ==================================================================================
// 11. Users/Sessions
// ----------------------------------------------------------------------------------

const exec = require('child_process').exec;
const util = require('./util');

let _platform = process.platform;

const _linux = (_platform === 'linux');
const _darwin = (_platform === 'darwin');
const _windows = (_platform === 'win32');
const _freebsd = (_platform === 'freebsd');
const _openbsd = (_platform === 'openbsd');
const _netbsd = (_platform === 'netbsd');
const _sunos = (_platform === 'sunos');

let _winDateFormat = {
  dateFormat: '',
  dateSeperator: '',
  timeFormat: '',
  timeSeperator: '',
  amDesignator: '',
  pmDesignator: ''
};

// --------------------------
// array of users online = sessions

function getWinCulture() {
  return new Promise((resolve) => {
    process.nextTick(() => {
      if (!_winDateFormat.dateFormat) {
        util.powerShell('(get-culture).DateTimeFormat')
          .then(data => {
            let lines = data.toString().split('\r\n');
            _winDateFormat.dateFormat = util.getValue(lines, 'ShortDatePattern', ':');
            _winDateFormat.dateSeperator = util.getValue(lines, 'DateSeparator', ':');
            _winDateFormat.timeFormat = util.getValue(lines, 'ShortTimePattern', ':');
            _winDateFormat.timeSeperator = util.getValue(lines, 'TimeSeparator', ':');
            _winDateFormat.amDesignator = util.getValue(lines, 'AMDesignator', ':');
            _winDateFormat.pmDesignator = util.getValue(lines, 'PMDesignator', ':');

            resolve(_winDateFormat);
          })
          .catch(() => {
            resolve(_winDateFormat);
          });
      } else {
        resolve(_winDateFormat);
      }
    });
  });
}

function parseUsersLinux(lines, phase) {
  let result = [];
  let result_who = [];
  let result_w = {};
  let w_first = true;
  let w_header = [];
  let w_pos = [];
  let who_line = {};

  let is_whopart = true;
  lines.forEach(function (line) {
    if (line === '---') {
      is_whopart = false;
    } else {
      let l = line.replace(/ +/g, ' ').split(' ');

      // who part
      if (is_whopart) {
        result_who.push({
          user: l[0],
          tty: l[1],
          date: l[2],
          time: l[3],
          ip: (l && l.length > 4) ? l[4].replace(/\(/g, '').replace(/\)/g, '') : ''
        });
      } else {
        // w part
        if (w_first) {    // header
          w_header = l;
          w_header.forEach(function (item) {
            w_pos.push(line.indexOf(item));
          });
          w_first = false;
        } else {
          // split by w_pos
          result_w.user = line.substring(w_pos[0], w_pos[1] - 1).trim();
          result_w.tty = line.substring(w_pos[1], w_pos[2] - 1).trim();
          result_w.ip = line.substring(w_pos[2], w_pos[3] - 1).replace(/\(/g, '').replace(/\)/g, '').trim();
          result_w.command = line.substring(w_pos[7], 1000).trim();
          // find corresponding 'who' line
          who_line = result_who.filter(function (obj) {
            return (obj.user.substring(0, 8).trim() === result_w.user && obj.tty === result_w.tty);
          });
          if (who_line.length === 1) {
            result.push({
              user: who_line[0].user,
              tty: who_line[0].tty,
              date: who_line[0].date,
              time: who_line[0].time,
              ip: who_line[0].ip,
              command: result_w.command
            });
          }
        }
      }
    }
  });
  if (result.length === 0 && phase === 2) {
    return result_who;
  } else {
    return result;
  }
}

function parseUsersDarwin(lines) {
  let result = [];
  let result_who = [];
  let result_w = {};
  let who_line = {};

  let is_whopart = true;
  lines.forEach(function (line) {
    if (line === '---') {
      is_whopart = false;
    } else {
      let l = line.replace(/ +/g, ' ').split(' ');

      // who part
      if (is_whopart) {
        result_who.push({
          user: l[0],
          tty: l[1],
          date: ('' + new Date().getFullYear()) + '-' + ('0' + ('JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC'.indexOf(l[2].toUpperCase()) / 3 + 1)).slice(-2) + '-' + ('0' + l[3]).slice(-2),
          time: l[4],
        });
      } else {
        // w part
        // split by w_pos
        result_w.user = l[0];
        result_w.tty = l[1];
        result_w.ip = (l[2] !== '-') ? l[2] : '';
        result_w.command = l.slice(5, 1000).join(' ');
        // find corresponding 'who' line
        who_line = result_who.filter(function (obj) {
          return (obj.user === result_w.user && (obj.tty.substring(3, 1000) === result_w.tty || obj.tty === result_w.tty));
        });
        if (who_line.length === 1) {
          result.push({
            user: who_line[0].user,
            tty: who_line[0].tty,
            date: who_line[0].date,
            time: who_line[0].time,
            ip: result_w.ip,
            command: result_w.command
          });
        }
      }
    }
  });
  return result;
}

function parseUsersWin(lines, culture) {

  let result = [];
  const header = lines[0];
  const headerDelimiter = [];
  if (header) {
    const start = (header[0] === ' ') ? 1 : 0;
    headerDelimiter.push(start - 1);
    let nextSpace = 0;
    for (let i = start + 1; i < header.length; i++) {
      if (header[i] === ' ' && ((header[i - 1] === ' ') || (header[i - 1] === '.'))) {
        nextSpace = i;
      } else {
        if (nextSpace) {
          headerDelimiter.push(nextSpace);
          nextSpace = 0;
        }
      }
    }
    for (let i = 1; i < lines.length; i++) {
      if (lines[i].trim()) {
        const user = lines[i].substring(headerDelimiter[0] + 1, headerDelimiter[1]).trim() || '';
        const tty = lines[i].substring(headerDelimiter[1] + 1, headerDelimiter[2] - 2).trim() || '';
        const dateTime = util.parseDateTime(lines[i].substring(headerDelimiter[5] + 1, 2000).trim(), culture) || '';
        result.push({
          user: user,
          tty: tty,
          date: dateTime.date,
          time: dateTime.time,
          ip: '',
          command: ''
        });
      }
    }
  }
  return result;
}

function users(callback) {

  return new Promise((resolve) => {
    process.nextTick(() => {
      let result = [];

      // linux
      if (_linux) {
        exec('who --ips; echo "---"; w | tail -n +2', function (error, stdout) {
          if (!error) {
            // lines / split
            let lines = stdout.toString().split('\n');
            result = parseUsersLinux(lines, 1);
            if (result.length === 0) {
              exec('who; echo "---"; w | tail -n +2', function (error, stdout) {
                if (!error) {
                  // lines / split
                  lines = stdout.toString().split('\n');
                  result = parseUsersLinux(lines, 2);
                }
                if (callback) { callback(result); }
                resolve(result);
              });
            } else {
              if (callback) { callback(result); }
              resolve(result);
            }
          } else {
            if (callback) { callback(result); }
            resolve(result);
          }
        });
      }
      if (_freebsd || _openbsd || _netbsd) {
        exec('who; echo "---"; w -ih', function (error, stdout) {
          if (!error) {
            // lines / split
            let lines = stdout.toString().split('\n');
            result = parseUsersDarwin(lines);
          }
          if (callback) { callback(result); }
          resolve(result);
        });
      }
      if (_sunos) {
        exec('who; echo "---"; w -h', function (error, stdout) {
          if (!error) {
            // lines / split
            let lines = stdout.toString().split('\n');
            result = parseUsersDarwin(lines);
          }
          if (callback) { callback(result); }
          resolve(result);
        });
      }

      if (_darwin) {
        exec('who; echo "---"; w -ih', function (error, stdout) {
          if (!error) {
            // lines / split
            let lines = stdout.toString().split('\n');
            result = parseUsersDarwin(lines);
          }
          if (callback) { callback(result); }
          resolve(result);
        });
      }
      if (_windows) {
        try {
          exec('query user', util.execOptsWin, function (error, stdout) {
            if (stdout) {
              // lines / split
              let lines = stdout.toString().split('\r\n');
              getWinCulture()
                .then(culture => {
                  result = parseUsersWin(lines, culture);
                  if (callback) { callback(result); }
                  resolve(result);
                });
            } else {
              if (callback) { callback(result); }
              resolve(result);
            }
          });
        } catch (e) {
          if (callback) { callback(result); }
          resolve(result);
        }
      }

    });
  });
}

exports.users = users;