#!/usr/bin/env node

/**
 * Dependencies.
 */

var chalk = require('chalk');
var exists = require('fs').existsSync;
var Metalsmith = require('..');
var program = require('commander');
var 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.
 */

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

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

/**
 * Metalsmith.
 */

var 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);

/**
 * Plugins.
 */

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

    try {
      var local = resolve(dir, name);
      var 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();
  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;
  var ret = [];

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

  return ret;
}