'use strict'

const log = require('debug')('interactor:client')
const fs = require('fs')
const path = require('path')
const rpc = require('pm2-axon-rpc')
const axon = require('pm2-axon')
const chalk = require('chalk')
const os = require('os')
const constants = require('../constants')
const childProcess = require('child_process')

const printError = function (msg) {
  if (process.env.PM2_SILENT || process.env.PM2_PROGRAMMATIC) return false
  if (msg instanceof Error) return console.error(msg.message)
  return console.error.apply(console, arguments)
}
const printOut = function (msg) {
  if (process.env.PM2_SILENT || process.env.PM2_PROGRAMMATIC) return false
  return console.log.apply(console, arguments)
}

module.exports = class InteractorDaemonizer {
  /**
   * Ping the Interactor to see if its online
   * @param {Object} opts global constants
   * @param {String} opts.INTERACTOR_RPC_PORT path used to connect to the interactor
   * @param {Function} cb invoked with <err, result>
   */
  static ping (opts, cb) {
    if (typeof cb !== 'function') {
      throw new Error('Missing parameters')
    } else if (typeof opts !== 'object' || !opts || !opts.INTERACTOR_RPC_PORT) {
      return cb(new Error('Missing parameters'))
    }
    const req = axon.socket('req')
    const client = new rpc.Client(req)

    log('[PING INTERACTOR] Trying to connect to Interactor daemon')

    client.sock.once('reconnect attempt', _ => {
      client.sock.close()
      log('Interactor Daemon not launched')
      return cb(null, false)
    })

    client.sock.once('connect', _ => {
      client.sock.once('close', _ => {
        return cb(null, true)
      })
      client.sock.close()
      log('Interactor Daemon alive')
    })

    client.sock.once('error', (e) => {
      if (e.code === 'EACCES') {
        fs.stat(opts.INTERACTOR_RPC_PORT, (e, stats) => {
          if (stats.uid === 0) {
            console.error('Permission denied, activate current user')
            return process.exit(1)
          }
        })
      } else {
        console.error('unexpected error')
        console.error(e)
      }
    })

    req.connect(opts.INTERACTOR_RPC_PORT)
  }

  /**
   * Try to kill the interactor daemon via RPC
   * @param {Object} conf global constants
   * @param {String} conf.INTERACTOR_RPC_PORT path used to connect to the interactor
   * @param {Function} cb invoked with <err>
   */
  static killInteractorDaemon (conf, cb) {
    process.env.PM2_INTERACTOR_PROCESSING = true

    log('Killing interactor #1 ping')
    this.ping(conf, (err, online) => {
      log(`Interactor is ${!online || err ? 'offline' : 'online'}`)

      if (!online || err) {
        return cb ? err ? cb(err) : cb(new Error('Interactor not launched')) : printError('Interactor not launched')
      }

      this.launchRPC(conf, (err, data) => {
        if (err) {
          setTimeout(_ => {
            this.disconnectRPC(cb)
          }, 100)
          return false
        }
        this.rpc.kill((err) => {
          if (err) printError(err)
          setTimeout(_ => {
            this.disconnectRPC(cb)
          }, 100)
        })
        return false
      })
      return false
    })
  }

  /**
   * Start a RPC client that connect to the InteractorDaemon
   * @param {Object} conf global constants
   * @param {Function} cb invoked with <err>
   */
  static launchRPC (conf, cb) {
    const req = axon.socket('req')
    this.rpc = {}
    this.client = new rpc.Client(req)

    log('Generating Interactor methods of RPC client')

    // attach known methods to RPC client
    const generateMethods = (cb) => {
      this.client.methods((err, methods) => {
        if (err) return cb(err)
        Object.keys(methods).forEach((key) => {
          let method = methods[key]
          log('+ Adding %s method to interactor RPC client', method.name);
          ((name) => {
            let self = this
            this.rpc[name] = function () {
              let args = Array.prototype.slice.call(arguments)
              args.unshift(name)
              self.client.call.apply(self.client, args)
            }
          })(method.name)
        })
        return cb()
      })
    }

    this.client.sock.once('reconnect attempt', (err) => {
      this.client.sock.removeAllListeners()
      return cb(err, { success: false, msg: 'reconnect attempt' })
    })

    this.client.sock.once('error', (err) => {
      log('-- Error in error catch all on Interactor --', err)
      return cb(err, { success: false, msg: 'reconnect attempt' })
    })

    this.client.sock.once('connect', () => {
      this.client.sock.removeAllListeners()
      generateMethods(_ => {
        log('Methods of RPC client for Interaction ready.')
        return cb(null, { success: true })
      })
    })

    this.client_sock = req.connect(conf.INTERACTOR_RPC_PORT)
  }

  /**
   * Start or Restart the Interaction Daemon depending if its online or not
   * @private
   * @param {Object} conf global constants
   * @param {Object} infos data used to start the interactor [can be recovered from FS]
   * @param {String} infos.secret_key the secret key used to cipher data
   * @param {String} infos.public_key the public key used identify the user
   * @param {String} infos.machine_name [optional] override name of the machine
   * @param {Function} cb invoked with <err, msg, process>
   */
  static daemonize (cst, conf, cb) {
    const InteractorJS = path.resolve(path.dirname(module.filename), 'InteractorDaemon.js')
    const PM2Path = require.main.filename

    // Redirect PM2 internal err and out
    // to STDERR STDOUT when running with Travis
    const testEnv = process.env.TRAVIS || (process.env.NODE_ENV && process.env.NODE_ENV.match(/test/))
    const out = testEnv ? 1 : fs.openSync(constants.INTERACTOR_LOG_FILE_PATH, 'a')
    const err = testEnv ? 2 : fs.openSync(constants.INTERACTOR_LOG_FILE_PATH, 'a')

    let binary = process.execPath
    if (binary.indexOf('node') === -1) {
      binary = 'node'
    }
    if (process.env.NODEJS_EXECUTABLE) {
      binary = process.env.NODEJS_EXECUTABLE
    }

    const child = childProcess.spawn(binary, [InteractorJS], {
      silent: false,
      detached: true,
      cwd: process.cwd(),
      env: Object.assign({
        PM2_HOME: cst.PM2_HOME,
        PM2_MACHINE_NAME: conf.machine_name,
        PM2_SECRET_KEY: conf.secret_key,
        PM2_PUBLIC_KEY: conf.public_key,
        PM2_REVERSE_INTERACT: conf.reverse_interact,
        PM2_BINARY_PATH: PM2Path,
        KEYMETRICS_NODE: conf.info_node,
        PM2_VERSION: conf.pm2_version,
        DEBUG: process.env.DEBUG || 'interactor:*,-interactor:axon,-interactor:websocket,-interactor:pm2:client,-interactor:push'
      }, process.env),
      stdio: ['ipc', out, err]
    })

    try {
      let prevPid = fs.readFileSync(constants.INTERACTOR_PID_PATH)
      prevPid = parseInt(prevPid)
      process.kill(prevPid)
    } catch (e) {
    }

    let pid = ''

    if (child.pid)
      pid = child.pid.toString()

    fs.writeFileSync(cst.INTERACTOR_PID_PATH, pid)

    child.on('close', (status) => {
      if (status === constants.ERROR_EXIT) {
        return cb(new Error('Agent has shutdown for unknown reason'))
      }
      return cb()
    })

    child.once('error', (err) => {
      log('Error when launching Interactor, please check the agent logs')
      return cb(err)
    })

    child.unref()

    const timeout = setTimeout(_ => {
      printOut(`${chalk.yellow('[PM2.IO][WARNING]')} Not managed to connect to PM2 Plus, retrying in background.`)
      child.removeAllListeners()
      child.disconnect()
      return cb(null, {}, child)
    }, 7000)

    child.once('message', (msg) => {
      clearTimeout(timeout)
      log('Interactor daemon launched :', msg)

      if (msg.log) {
        return cb(null, msg, child)
      }

      child.removeAllListeners('error')
      child.disconnect()

      // Handle and show to user the different error message that can happen
      if (msg.km_data && msg.km_data.error === true) {
        if (!process.env.PM2_SILENT) {
          console.log(chalk.red('[PM2.IO][ERROR]'), msg.km_data.msg)
          console.log(chalk.cyan('[PM2.IO]') + ' Contact support contact@keymetrics.io and send us the error message')
        }
        return cb(msg)
      } else if (msg.km_data && msg.km_data.disabled === true) {
        if (!process.env.PM2_SILENT) {
          console.log(chalk.cyan('[PM2.IO]') + ' Server DISABLED BY ADMINISTRATION contact support contact@keymetrics.io with reference to your public and secret keys)')
        }
        return cb(msg)
      } else if (msg.km_data && msg.km_data.error === true) {
        if (!process.env.PM2_SILENT) {
          console.log('%s %s (Public: %s) (Secret: %s) (Machine name: %s)', chalk.red('[PM2.IO][ERROR]'),
            msg.km_data.msg, msg.public_key, msg.secret_key, msg.machine_name)
        }
        return cb(msg)
      } else if (msg.km_data && msg.km_data.active === false && msg.km_data.pending === true) {
        if (!process.env.PM2_SILENT) {
          console.log('%s You must upgrade your bucket in order to monitor more servers.', chalk.red('[PM2.IO]'))
        }
        return cb(msg)
      }

      return cb(null, msg, child)
    })
  }

  /**
   * Start or Restart the Interaction Daemon depending if its online or not
   * @private
   * @param {Object} conf global constants
   * @param {Object} infos data used to start the interactor [can be recovered from FS]
   * @param {String} infos.secret_key the secret key used to cipher data
   * @param {String} infos.public_key the public key used identify the user
   * @param {String} infos.machine_name [optional] override name of the machine
   * @param {Function} cb invoked with <err, msg, process>
   */
  static launchOrAttach (conf, infos, cb) {
    this.ping(conf, (err, online) => {
      if (!err && online) {
        log('Interactor online, restarting it...')
        this.launchRPC(conf, _ => {
          this.rpc.kill((ignoredErr) => {
            this.daemonize(conf, infos, cb)
          })
        })
      } else {
        log('Interactor offline, launching it...')
        this.daemonize(conf, infos, cb)
      }
    })
  }

  /**
   * Restart the Interactor Daemon
   * @param {Object} conf global constants
   * @param {Function} cb invoked with <err, msg>
   */
  static update (conf, cb) {
    this.ping(conf, (err, online) => {
      if (err || !online) {
        return cb ? cb(new Error('Interactor not launched')) : printError('Interactor not launched')
      }
      this.launchRPC(conf, _ => {
        this.rpc.kill((err) => {
          if (err) {
            return cb ? cb(err) : printError(err)
          }
          printOut('Interactor successfully killed')
          setTimeout(_ => {
            this.launchAndInteract(conf, {}, _ => {
              return cb(null, { msg: 'Daemon launched' })
            })
          }, 500)
        })
      })
    })
  }

  /**
   * Retrieve Interactor configuration from env, params and filesystem.
   * @param {Object} cst global constants
   * @param {Object} infos data used to start the interactor [optional]
   * @param {String} infos.secret_key the secret key used to cipher data [optional]
   * @param {String} infos.public_key the public key used identify the user [optional]
   * @param {String} infos.machine_name override name of the machine [optional]
   * @param {Function} cb invoked with <err, configuration>
   */
  static getOrSetConf (cst, infos, cb) {
    infos = infos || {}
    let configuration = {
      version_management: {
        active: true
      }
    }
    let confFS = {}

    // Try loading configuration file on FS
    try {
      let fileContent = fs.readFileSync(cst.INTERACTION_CONF).toString()
      // Handle old configuration with json5
      fileContent = fileContent.replace(/\s(\w+):/g, '"$1":')
      // parse
      confFS = JSON.parse(fileContent)

      if (confFS.version_management) {
        configuration.version_management.active = confFS.version_management.active
      }
    } catch (e) {
      log('Interaction file does not exists')
    }

    // load the configration (first have priority)
    //    -> from env variable
    //    -> from params (eg. CLI)
    //    -> from configuration on FS
    configuration.public_key = process.env.PM2_PUBLIC_KEY || process.env.KEYMETRICS_PUBLIC || infos.public_key || confFS.public_key
    configuration.secret_key = process.env.PM2_SECRET_KEY || process.env.KEYMETRICS_SECRET || infos.secret_key || confFS.secret_key
    configuration.machine_name = process.env.PM2_MACHINE_NAME || process.env.INSTANCE_NAME || infos.machine_name || confFS.machine_name || `${os.hostname()}-${require('crypto').randomBytes(2).toString('hex')}`
    configuration.pm2_version = process.env.PM2_VERSION || infos.pm2_version || confFS.pm2_version
    configuration.reverse_interact = confFS.reverse_interact || true
    // is setup empty ? use the one provided in env OR root OTHERWISE get the one on FS conf OR fallback on root
    configuration.info_node = process.env.KEYMETRICS_NODE || infos.info_node || confFS.info_node || cst.KEYMETRICS_ROOT_URL


    if (!configuration.secret_key) {
      log('Secret key is not defined in configuration', configuration)
      return cb(new Error('secret key is not defined'))
    }
    if (!configuration.public_key) {
      log('Public key is not defined in configuration', configuration)
      return cb(new Error('public key is not defined'))
    }

    // write configuration on FS
    try {
      fs.writeFileSync(cst.INTERACTION_CONF, JSON.stringify(configuration, null, 4))
    } catch (e) {
      console.error('Error when writting configuration file %s', cst.INTERACTION_CONF)
      return cb(e)
    }
    if (configuration.info_node.indexOf('http') === -1) { // handle old file
      configuration.info_node = `https://${configuration.info_node}`
    }
    return cb(null, configuration)
  }

  /**
   * Disconnect the RPC client from Interactor Daemon
   * @param {Function} cb invoked with <err, msg>
   */
  static disconnectRPC (cb) {
    log('Disconnect RPC')
    if (!this.client_sock || !this.client_sock.close) {
      log('RPC not launched')
      return cb(null, {
        success: false,
        msg: 'RPC connection to Interactor Daemon is not launched'
      })
    }

    if (this.client_sock.closing === true) {
      log('RPC already closed')
      return cb(null, {
        success: false,
        msg: 'RPC closed'
      })
    }

    try {
      let timer

      log('Closing RPC INTERACTOR')

      this.client_sock.once('close', _ => {
        log('RPC INTERACTOR cleanly closed')
        clearTimeout(timer)
        return cb ? cb(null, { success: true }) : false
      })

      timer = setTimeout(_ => {
        if (this.client_sock.destroy) {
          this.client_sock.destroy()
        }
        return cb ? cb(null, { success: true }) : false
      }, 200)

      this.client_sock.close()
    } catch (err) {
      log('Error while closing RPC INTERACTOR : %s', err.message || err)
      return cb ? cb(err) : false
    }
  }

  /**
   * Start the Interactor Daemon
   * @param {Object} cst global constants
   * @param {Object} infos data used to start the interactor [can be recovered from FS]
   * @param {String} infos.secret_key the secret key used to cipher data
   * @param {String} infos.public_key the public key used identify the user
   * @param {String} infos.machine_name [optional] override name of the machine
   * @param {Function} cb invoked with <err, msg, process>
   */
  static launchAndInteract (cst, opts, cb) {
    // For Watchdog
    if (process.env.PM2_AGENT_ONLINE) {
      return cb()
    }

    process.env.PM2_INTERACTOR_PROCESSING = true

    this.getOrSetConf(Object.assign(cst, constants), opts, (err, conf) => {
      if (err || !conf) return cb(err || new Error('Cant retrieve configuration'))

      if (!process.env.PM2_SILENT) {
        console.log(chalk.cyan('[PM2 I/O]') + ' Using: Public key: %s | Private key: %s | Machine name: %s', conf.public_key, conf.secret_key, conf.machine_name)
      }
      return this.launchOrAttach(cst, conf, cb)
    })
  }

  /**
   * Retrieve configuration used by the Interaction Daemon
   * @param {Object} cst global constants
   * @param {Function} cb invoked with <err, data>
   */
  static getInteractInfo (cst, cb) {
    log('Getting interaction info')
    if (process.env.PM2_NO_INTERACTION) return cb(new Error('PM2_NO_INTERACTION set'))

    this.ping(cst, (err, online) => {
      if (err || !online) return cb(new Error('Interactor is offline'))

      this.launchRPC(cst, _ => {
        this.rpc.getInfos((err, infos) => {
          if (err) return cb(err)

          // Avoid general CLI to interfere with Keymetrics CLI commands
          if (process.env.PM2_INTERACTOR_PROCESSING) return cb(null, infos)

          this.disconnectRPC(() => {
            return cb(null, infos)
          })
        })
      })
    })
  }
}