#!/usr/bin/env node
var fs = require('fs')
var path = require('path')
var updateNotifier = require('update-notifier')
var _db = require('underscore-db')
var yargs = require('yargs')
var chalk = require('chalk')
var got = require('got')
var pkg = require('../package.json')
var jsonServer = require('../src')
var jsMockGenerator = null

updateNotifier({packageName: pkg.name, packageVersion: pkg.version}).notify()

// Parse arguments
var argv = yargs
    .usage('$0 [options] <source>')
    .options({
      port: {
        alias: 'p',
        description: 'Set port',
        default: 3000
      },
      host: {
        alias: 'H',
        description: 'Set host',
        default: '0.0.0.0'
      },
      watch: {
        alias: 'w',
        description: 'Reload database on JSON file change'
      },
      routes: {
        alias: 'r',
        description: 'Load routes file'
      },
      id: {
        description: 'Set database id property (e.g. _id)',
        default: 'id'
      }
    })
    .boolean('watch')
    .help('help').alias('help', 'h')
    .version(pkg.version).alias('version', 'v')
    .example('$0 db.json', '')
    .example('$0 file.js', '')
    .example('$0 http://example.com/db.json', '')
    .epilog('https://github.com/typicode/json-server')
    .require(1, 'Missing <source> argument')
    .argv

function showResources (hostname, port, object) {
  for (var prop in object) {
    console.log(chalk.gray('  http://' + hostname + ':' + port + '/') + chalk.cyan(prop))
  }
}

function start (object, filename) {
  var port = process.env.PORT || argv.port
  var hostname = argv.host === '0.0.0.0' ? 'localhost' : argv.host

  console.log()
  showResources(hostname, port, object)
  console.log()
  console.log(
      'You can now go to ' + chalk.gray('http://' + hostname + ':' + port)
  )
  console.log()
  console.log(
      'Enter ' + chalk.cyan('s') + ' at any time to create a snapshot of the db'
  )

  // Snapshot
  process.stdin.resume()
  process.stdin.setEncoding('utf8')
  process.stdin.on('data', function (chunk) {
    if (chunk.trim().toLowerCase() === 's') {
      var file = 'db-' + Date.now() + '.json'
      _db.save(object, file)
      console.log('Saved snapshot to ' + chalk.cyan(file) + '\n')
    }
  })

  // Router
  var router = jsonServer.router(filename ? filename : object)

  // Watcher
  if (argv.watch) {
    console.log('Watching', chalk.cyan(source))

    var db = router.db
    var watchedDir = path.dirname(filename)
    var watchedFile = path.basename(filename)

    fs.watch(watchedDir, function (event, changedFile) {
      // lowdb generates 'rename' event on watchedFile
      // using it to know if file has been modified by the user
      if ((event === 'change' || event === 'rename') && (changedFile === watchedFile || changedFile === source)) {
        console.log(chalk.cyan(source), 'has changed, reloading database')

        try {
          if (filename) {
            db.object = JSON.parse(fs.readFileSync(filename))
          } else {
            require.cache[jsMockGenerator] = null
            db.object = require(jsMockGenerator)()
          }
          showResources(hostname, port, db.object)
        } catch (e) {
          console.log('Can\'t parse', chalk.cyan(source))
          console.log(e.message)
        }

        console.log()
      }
    })
  }
  console.log()

  var server = jsonServer.create()
  server.use(jsonServer.defaults)

  // Rewriter
  if (argv.routes) {
    var routes = JSON.parse(fs.readFileSync(process.cwd() + '/' + argv.routes))
    var rewriter = jsonServer.rewriter(routes)
    server.use(rewriter)
  }

  server.use(router)

  // Custom id
  router.db._.id = argv.id

  server.listen(port, argv.host)
}

// Set file and port
var source = argv._[0]

// Say hi, load file and start server
console.log(chalk.cyan('  {^_^} Hi!\n'))
console.log('Loading database from ' + chalk.cyan(source))

// Remote source
if (/^(http|https):/.test(source)) {
  got(source, function (err, data) {
    if (err) {
      console.log('Error', err)
      process.exit(1)
    }
    var object = JSON.parse(data)
    start(object)
  })
// JSON file
} else if (/\.json$/.test(source)) {
  var filename = process.cwd() + '/' + source
  var object = require(filename)
  start(object, filename)
// JS file
} else if (/\.js$/.test(source)) {
  jsMockGenerator = process.cwd() + '/' + source
  var object = require(jsMockGenerator)()
  start(object)
}