#!/usr/bin/env node
'use strict';
var os = require('os');
var fs = require('fs');
var meow = require('meow');
var indentString = require('indent-string');
var stdin = require('get-stdin');
var css = require('css');
var _ = require('lodash');
var inlineCritical = require('./');
var ok;

var help = [
  'Usage: inline-critical <input> [<option>]',
  '',
  'Options:',
  '   -c, --css       Path to CSS file',
  '   -h, --html      Path to HTML file',
  '   -i, --ignore    Skip matching stylesheets',
  '   -m, --minify    Minify the styles before inlining',
  '   -e, --extract   Remove the inlined styles from any stylesheets referenced in the HTML',
  '   -b, --base      Is used when extracting styles to find the files references by `href` attributes',
  '   -s, --selector  Optionally defines the element used by loadCSS as a reference for inlining'
];

var cli = meow({
  help: help
}, {
  alias: {
    c: 'css',
    h: 'html',
    i: 'ignore',
    m: 'minify',
    b: 'base',
    e: 'extract',
    s: 'selector'
  }
});

// cleanup cli flags
cli.flags = _.reduce(cli.flags, function (res, val, key) {
  if (key.length <= 1) {
    return res;
  }

  switch (key) {
    case 'css':
    case 'html':
      try {
        res[key] = read(val)
      } catch (err) {
      }
      break;
    case 'base':
      res.basePath = val;
      break;
    case 'ignore':
      if (_.isString(val) || _.isRegExp(val)) {
        val = [val];
      }
      res.ignore = _.map(val || [], function (ignore) {
        // check regex
        var match = ignore.match(/^\/(.*)\/([igmy]+)?$/);

        if (match) {
          return new RegExp(_.escapeRegExp(match[1]), match[2]);
        }
        return ignore;
      });
      break;
    default:
      res[key] = val;
      break;
  }

  return res;
}, {});

function error(err) {
  process.stderr.write(indentString(err.message || err, '   Error: '));
  process.stderr.write(os.EOL);
  process.stderr.write(indentString(help.join(os.EOL), '   '));
  process.exit(1);
}

function read(file) {
  try {
    return fs.readFileSync(file, 'utf8');
  } catch (err) {
    error(err);
  }
}


function run(data) {
  var opts = _.defaults(cli.flags, {basePath: process.cwd()});
  ok = true;

  if (data) {
    // detect html
    try {
      css.parse(data);
      opts.css = data;
    } catch (err) {
      opts.html = data;
    }
  }

  _.forEach(cli.input, function (file) {
    var tmp = read(file);
    try {
      css.parse(tmp);
      opts.css = tmp;
    } catch (err) {
      opts.html = tmp;
    }
  });

  if (!opts.html || !opts.css) {
    cli.showHelp();
  }

  try {
    var out = inlineCritical(opts.html, opts.css, opts);
    console.log(out.toString());
  } catch (err) {
    error(err);
  }
}

// get stdin
stdin().then(run);
setTimeout(function () {
  if (ok) {
    return;
  }
  run();
}, 100);