#!/usr/bin/env node

/* eslint-disable no-console */

/**
 * Dependencies.
 */

const chalk = require('chalk')
const exists = require('fs').existsSync
const Metalsmith = require('..')
const program = require('commander')
const resolve = require('path').resolve

/**
 * Usage.
 */

program
  .version(require('../package.json').version)
  .option('-c, --config <path>', 'configuration file location', 'metalsmith.json')

/**
 * Examples.
 */

program.on('--help', function(){
  console.log('  Examples:')
  console.log()
  console.log('    # build from metalsmith.json:')
  console.log('    $ metalsmith')
  console.log()
  console.log('    # build from lib/config.json:')
  console.log('    $ metalsmith --config lib/config.json')
  console.log()
})

/**
 * Parse.
 */

program.parse(process.argv)

/**
 * Config.
 */

const dir = process.cwd()
const config = program.config
const path = resolve(dir, config)
if (!exists(path)) fatal('could not find a ' + config + ' configuration file.')

let json
try {
  json = require(path)
} catch (e) {
  fatal('it seems like ' + config + ' is malformed.')
}

/**
 * Metalsmith.
 */

const metalsmith = new Metalsmith(dir)
if (json.source) metalsmith.source(json.source)
if (json.destination) metalsmith.destination(json.destination)
if (json.concurrency) metalsmith.concurrency(json.concurrency)
if (json.metadata) metalsmith.metadata(json.metadata)
if (json.clean != null) metalsmith.clean(json.clean)
if (json.frontmatter != null) metalsmith.frontmatter(json.frontmatter)
if (json.ignore != null) metalsmith.ignore(json.ignore)

/**
 * Plugins.
 */

normalize(json.plugins).forEach(function(plugin){
  for (const name in plugin) {
    const opts = plugin[name]
    let mod

    try {
      const local = resolve(dir, name)
      const npm = resolve(dir, 'node_modules', name)

      if (exists(local) || exists(local + '.js')) {
        mod = require(local)
      } else if (exists(npm)) {
        mod = require(npm)
      } else {
        mod = require(name)
      }
    } catch (e) {
      fatal('failed to require plugin "' + name + '".')
    }

    try {
      metalsmith.use(mod(opts))
    } catch (e) {
      fatal('error using plugin "' + name + '"...', e.message + '\n\n' + e.stack)
    }
  }
})

/**
 * Build.
 */

metalsmith.build(function(err){
  if (err) return fatal(err.message, err.stack)
  log('successfully built to ' + metalsmith.destination())
})

/**
 * Log an error and then exit the process.
 *
 * @param {String} msg
 * @param {String} [stack]  Optional stack trace to print.
 */

function fatal(msg, stack){
  console.error()
  console.error(chalk.red('  Metalsmith') + chalk.gray(' · ') + msg)
  if (stack) {
    console.error()
    console.error(chalk.gray(stack))
  }
  console.error()
  // eslint-disable-next-line no-process-exit
  process.exit(1)
}

/**
 * Log a `message`.
 *
 * @param {String} message
 */

function log(message){
  console.log()
  console.log(chalk.gray('  Metalsmith · ') + message)
  console.log()
}

/**
 * Normalize an `obj` of plugins.
 *
 * @param {Array or Object} obj
 * @return {Array}
 */

function normalize(obj){
  if (obj instanceof Array) return obj
  const ret = []

  for (const key in obj) {
    const plugin = {}
    plugin[key] = obj[key]
    ret.push(plugin)
  }

  return ret
}