/**
 * Copyright 2013 the PM2 project authors. All rights reserved.
 * Use of this source code is governed by a license that
 * can be found in the LICENSE file.
 */
var debug  = require('debug')('pm2:cli:startup');
var chalk  = require('chalk');
var path   = require('path');
var fs     = require('fs');
var async  = require('async');
var exec   = require('child_process').exec;
var Common = require('../Common.js');
var cst    = require('../../constants.js');
var spawn    = require('child_process').spawn;
var shelljs  = require('shelljs');

module.exports = function(CLI) {
  /**
   * If command is launched without root right
   * Display helper
   */
  function isNotRoot(platform, opts, cb) {
    if (opts.user) {
      console.log(cst.PREFIX_MSG + 'You have to run this command as root. Execute the following command:');
      console.log('sudo env PATH=$PATH:' + path.dirname(process.execPath) + ' pm2 startup ' + platform + ' -u ' + opts.user + ' --hp ' + process.env.HOME);
      return cb(new Error('You have to run this with elevated rights'));
    }
    return exec('whoami', function(err, stdout, stderr) {
      console.log(cst.PREFIX_MSG + 'You have to run this command as root. Execute the following command:');
      console.log('sudo env PATH=$PATH:' + path.dirname(process.execPath) + ' ' + require.main.filename + ' startup ' + platform + ' -u ' + stdout.trim() + ' --hp ' + process.env.HOME);
      return cb(new Error('You have to run this with elevated rights'));
    });
  }

  /**
   * Detect running init system
   */
  function detectInitSystem() {
    var hash_map = {
      'systemctl'  : 'systemd',
      'update-rc.d': 'upstart',
      'launchctl'  : 'launchd',
      'chkconfig'  : 'rcd'
    };
    var init_systems = Object.keys(hash_map);

    for (var i = 0; i < init_systems.length; i++) {
      if (shelljs.which(init_systems[i]) != null) {
        break;
      }
    }

    if (i >= init_systems.length) {
      Common.printError(cst.PREFIX_MSG_ERR + 'Init system not found');
      return null;
    }
    Common.printOut(cst.PREFIX_MSG + 'Init System found: ' + chalk.bold(hash_map[init_systems[i]]));
    return hash_map[init_systems[i]];
  }

  CLI.prototype.uninstallStartup = function(platform, cb) {
    var commands;
    var that = this;

    if (!platform)
      platform = detectInitSystem();

    if (!cb) {
      cb = function(err, data) {
        if (err)
          return that.exitCli(cst.ERROR_EXIT);
        return that.exitCli(cst.SUCCESS_EXIT);
      }
    }

    if (process.getuid() != 0) {
      console.log('sudo env PATH=$PATH:' + path.dirname(process.execPath) + ' ' + require.main.filename + ' unstartup ' + platform);
      return cb();
    }

    if (fs.existsSync('/etc/init.d/pm2-init.sh')) {
      platform = 'oldsystem';
    }

    switch(platform) {
    case 'systemd':
      commands = [
        'systemctl stop pm2',
        'systemctl disable pm2',
        'systemctl status pm2',
        'rm /etc/systemd/system/pm2.service'
      ];
      break;
    case 'oldsystem':
      Common.printOut(cst.PREFIX_MSG + 'Disabling and deleting old startup system');
      commands = [
        'update-rc.d pm2-init.sh disable',
        'update-rc.d -f pm2-init.sh remove',
        'rm /etc/init.d/pm2-init.sh'
      ];
      break;
    case 'upstart':
      commands = [
        'update-rc.d pm2 disable',
        'update-rc.d -f pm2 remove',
        'rm /etc/init.d/pm2'
      ];
      break;
    case 'launchd':
      var destination = path.join(process.env.HOME, 'Library/LaunchAgents/PM2.plist');
      commands = [
        'launchctl remove com.PM2',
        'rm ' + destination
      ];
    };

    shelljs.exec(commands.join('; '), function(code, stdout, stderr) {
      console.log(stdout);
      console.log(stderr);
      if (code == 0) {
        Common.printOut(cst.PREFIX_MSG + chalk.bold('Init file disabled.'));
      }
      cb(null, {
        commands : commands,
        platform : platform
      });
    });
  };

  /**
   * Startup script generation
   * @method startup
   * @param {string} platform type (centos|redhat|amazon|gentoo|systemd)
   */
  CLI.prototype.startup = function(platform, opts, cb) {
    var that = this;

    if (!platform)
      if ((platform = detectInitSystem()) == null)
        throw new Error('Init system not found');

    if (!cb) {
      cb = function(err, data) {
        if (err)
          return that.exitCli(cst.ERROR_EXIT);
        return that.exitCli(cst.SUCCESS_EXIT);
      }
    }

    if (process.getuid() != 0) {
      return isNotRoot(platform, opts, cb);
    }

    var destination;
    var commands;
    var template;

    function getTemplate(type) {
      return fs.readFileSync(path.join(__dirname, '..', 'templates/init-scripts', type + '.tpl'), {encoding: 'utf8'});
    }

    switch(platform) {
    case 'ubuntu':
    case 'centos':
    case 'arch':
    case 'oracle':
    case 'systemd':
      template = getTemplate('systemd');
      destination = '/etc/systemd/system/pm2.service';
      commands = [
        'chmod +x ' + destination,
        'systemctl enable pm2',
        'systemctl start pm2',
        'systemctl daemon-reload',
        'systemctl status pm2'
      ];
      break;
    case 'ubuntu14':
    case 'ubuntu12':
    case 'upstart':
      template = getTemplate('upstart');
      destination = '/etc/init.d/pm2';
      commands = [
        'chmod +x ' + destination,
        'touch /var/lock/subsys/pm2',
        'update-rc.d pm2 defaults',
        'service pm2 start',
        'initctl list'
      ];
      break;
    case 'macos':
    case 'darwin':
    case 'launchd':
      // https://nathangrigg.com/2012/07/schedule-jobs-using-launchd#launchctl
      template = getTemplate('launchd');
      destination = path.join(process.env.HOME, 'Library/LaunchAgents/PM2.plist');
      commands = [
        'chmod +x ' + destination,
        'launchctl load ' + destination,
        'launchctl start ' + destination,
        'launchctl list'
      ]
      break;
    case 'freebsd':
    case 'rcd':
      template = getTemplate('rcd');
      destination = '/etc/rc.d/pm2';
      commands = [
        'chmod +x ' + destination,
        'echo "pm2_enable=YES" > /etc/rc.conf'
      ];
      break;
    default:
      throw new Error('Unknown platform / init system name');
    }

    /**
     * 4# Replace template variable value
     */
    template = template.replace(/%PM2_PATH%/g, process.mainModule.filename)
      .replace(/%NODE_PATH%/g, path.dirname(process.execPath))
      .replace(/%USER%/g, opts.user || process.env.USER)
      .replace(/%HOME_PATH%/g, opts.hp ? path.resolve(opts.hp, '.pm2') : cst.PM2_ROOT_PATH);

    console.log(chalk.bold('Platform'), platform);
    console.log(chalk.bold('Template'));
    console.log(template);
    console.log(chalk.bold('Target path'));
    console.log(destination);
    console.log(chalk.bold('Command list'));
    console.log(commands);

    Common.printOut(cst.PREFIX_MSG + 'Writing init configuration in ' + destination);
    try {
      fs.writeFileSync(destination, template);
    } catch (e) {
      console.error(cst.PREFIX_MSG_ERR + 'Failure when trying to write startup script');
      console.error(e.message || e);
      return cb(e);
    }

    Common.printOut(cst.PREFIX_MSG + 'Making script booting at startup...');

    async.forEachLimit(commands, 1, function(command, next) {
      console.log(chalk.bold('>>> Executing %s'), command);
      shelljs.exec(command, function(err, stdout) {
        console.log(chalk.bold('[DONE] '));
        next();
      })
    }, function() {
      console.log(chalk.bold.blue('+---------------------------------------+'));
      Common.printOut(chalk.bold.blue((cst.PREFIX_MSG + 'Freeze a process list on reboot via:' )));
      Common.printOut(chalk.bold('$ pm2 save'));
      console.log('');
      Common.printOut(chalk.bold.blue(cst.PREFIX_MSG + 'Remove init script via:'));
      Common.printOut(chalk.bold('$ pm2 unstartup ' + platform));

      return cb(null, {
        destination  : destination,
        template : template
      });
    });
  };

  /**
   * Dump current processes managed by pm2 into DUMP_FILE_PATH file
   * @method dump
   * @param {} cb
   * @return
   */
  CLI.prototype.dump = function(cb) {
    var env_arr = [];
    var that = this;


    Common.printOut(cst.PREFIX_MSG + 'Saving current process list...');

    that.Client.executeRemote('getMonitorData', {}, function(err, list) {
      if (err) {
        Common.printError('Error retrieving process list: ' + err);
        return cb ? cb(Common.retErr(err)) : that.exitCli(cst.ERROR_EXIT);
      }

      /**
       * Description
       * @method fin
       * @param {} err
       * @return
       */
      function fin(err) {
        try {
          fs.writeFileSync(cst.DUMP_FILE_PATH, JSON.stringify(env_arr, '', 2));
        } catch (e) {
          console.error(e.stack || e);
          Common.printOut(cst.PREFIX_MSG_ERR + 'Failed to save dump file in %s', cst.DUMP_FILE_PATH);
          return that.exitCli(cst.ERROR_EXIT);
        }
        if (cb) return cb(null, {success:true});

        Common.printOut(cst.PREFIX_MSG + 'Successfully saved in %s', cst.DUMP_FILE_PATH);
        return that.exitCli(cst.SUCCESS_EXIT);
      }

      (function ex(apps) {
        if (!apps[0]) return fin(null);
        delete apps[0].pm2_env.instances;
        delete apps[0].pm2_env.pm_id;
        if (!apps[0].pm2_env.pmx_module)
          env_arr.push(apps[0].pm2_env);
        apps.shift();
        return ex(apps);
      })(list);
    });
  };

  /**
   * Resurrect processes
   * @method resurrect
   * @param {} cb
   * @return
   */
  CLI.prototype.resurrect = function(cb) {
    var apps = {};
    var that = this;

    Common.printOut(cst.PREFIX_MSG + 'Restoring processes located in %s', cst.DUMP_FILE_PATH);

    try {
      apps = fs.readFileSync(cst.DUMP_FILE_PATH);
    } catch(e) {
      Common.printError(cst.PREFIX_MSG_ERR + 'No processes saved; DUMP file doesn\'t exist');
      // if (cb) return cb(Common.retErr(e));
      // else return that.exitCli(cst.ERROR_EXIT);
      return that.speedList();
    }

    var processes = Common.parseConfig(apps, 'none');

    that.Client.executeRemote('getMonitorData', {}, function(err, list) {
      if (err) {
        Common.printError(err);
        return that.exitCli(1);
      }

      var current = [];
      var target = [];

      list.forEach(function(app) {
        if (!current[app.name])
          current[app.name] = 0;
        current[app.name]++;
      });

      processes.forEach(function(app) {
        if (!target[app.name])
          target[app.name] = 0;
        target[app.name]++;
      });

      var tostart = Object.keys(target).filter(function(i) {
        return Object.keys(current).indexOf(i) < 0;
      })

      async.eachLimit(processes, cst.CONCURRENT_ACTIONS, function(app, next) {
        if (tostart.indexOf(app.name) == -1)
          return next();
        that.Client.executeRemote('prepare', app, function(err, dt) {
          if (err)
            Common.printError(err);
          else
            Common.printOut(cst.PREFIX_MSG + 'Process %s restored', app.pm_exec_path);
          next();
        });
      }, function(err) {
        return cb ? cb(null, apps) : that.speedList();
      });
    });
  };

}