#!/usr/bin/env node

'use strict'

// dependencies
let cache = require('mako-cache')
let config = require('mako-config')
let logger = require('mako-logger')
let mako = require('mako')
let pkg = require('../package.json')
let program = require('commander')
let Promise = require('bluebird')
let utils = require('mako-utils')
let Watcher = require('mako-watch')

require('bluebird-co')

// cli configuration
program
  .version(pkg.version)
  .usage('[options] [entries...]')
  .option('-C, --cache', 'turn on caching')
  .option('-q, --quiet', 'only log errors')
  .option('-v, --verbose', 'turn on verbose logging')
  .option('-w, --watch', 'rebuild when changes occur')
  .parse(process.argv)

// set the log output level
if (program.verbose) {
  logger.setLevel('verbose')
} else if (program.quiet) {
  logger.setLevel('error')
}

// run!
Promise.coroutine(main)().catch(err => logger.fatal(err))

/**
 * The primary behavior for this script.
 */
function * main () {
  let conf = yield config({ overrides: program.args })
  logger.verbose('config loaded')

  let tree = program.cache ? yield cache.load(conf.root) : null
  if (tree) logger.verbose('cache loaded')

  let builder = mako({
    tree: tree,
    root: conf.root,
    plugins: conf.plugins
  })

  yield runBuild(builder, conf.entries)

  if (program.watch) {
    logger.info('watch starting')
    let watcher = new Watcher(builder.tree)

    watcher.on('add', file => {
      logger.info('add detected: %s (reloading config)', utils.relative(file))
      config({ overrides: program.args }).then((config) => conf = config)
    })

    watcher.on('remove', file => {
      logger.info('remove detected: %s (reloading config)', utils.relative(file))
      config({ overrides: program.args }).then((config) => conf = config)
    })

    watcher.on('change', (file, tree) => {
      logger.info('change detected: %s', utils.relative(file.path))
      Promise.coroutine(runBuild)(builder, conf.entries)
    })
  }
}

/**
 * Runs a build for the given builder/entries.
 *
 * @param {Runner} builder  The mako builder/runner.
 * @param {Array} entries   The entries to build.
 */
function * runBuild (builder, entries) {
  logger.verbose('build starting')
  entries.forEach(entry => logger.info('building %s', utils.relative(entry)))
  let build = yield builder.build(entries)
  if (program.cache) {
    yield cache.save(builder.tree)
    logger.verbose('cache saved')
  }
  build.tree.getFiles().forEach(file => logger.info('built %s', utils.relative(file.path)))
  logger.info('build complete')
}