/*
 * react pattern engine for patternlab-node - v0.1.0 - 2016
 *
 * Geoffrey Pursell, Brian Muenzenmeyer, and the web community.
 * Licensed under the MIT license.
 *
 * Many thanks to Brad Frost and Dave Olsen for inspiration, encouragement, and advice.
 *
 */
'use strict';

const fs = require('fs');
const path = require('path');
const React = require('react');
const ReactDOMServer = require('react-dom/server');
const Babel = require('babel-core');
const Hogan = require('hogan');
const beautify = require('js-beautify');
const cheerio = require('cheerio');
const _require = require;

var errorStyling = `
<style>
  .plError {
    background: linear-gradient(to bottom, #f1f1f1 0%,#ffffff 60%);
    color: #444;
    padding: 30px;
  }
  .plError h1 {
    font-size: 16pt;
    color: #733;
    background: #fcfcfc;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    padding: 17px 30px;
    margin: -30px -30px 0 -30px;
  }
  .plError dt { font-weight: bold; }
</style>
`;

// This holds the config from from core. The core has to call
// usePatternLabConfig() at load time for this to be populated.
let patternLabConfig = {};

let enableRuntimeCode = true;

const outputTemplate = Hogan.compile(
  fs.readFileSync(path.join(__dirname, './outputTemplate.mustache'), 'utf8')
);

let registeredComponents = {
  byPatternPartial: {},
};

function moduleCodeString(pattern) {
  return pattern.template || pattern.extendedTemplate;
}

function babelTransform(pattern) {
  let transpiledModule = Babel.transform(moduleCodeString(pattern), {
    presets: [require('babel-preset-react')],
    plugins: [require('babel-plugin-transform-es2015-modules-commonjs')],
  });

  // eval() module code in this little scope that injects our
  // custom wrap of require();
  (require => {
    /* eslint-disable no-eval */
    transpiledModule = eval(transpiledModule.code);
  })(customRequire);

  return transpiledModule;
}

function customRequire(id) {
  const registeredPattern = registeredComponents.byPatternPartial[id];

  if (registeredPattern) {
    return babelTransform(registeredPattern);
  } else {
    return _require(id);
  }
}

var engine_react = {
  engine: React,
  engineName: 'react',
  engineFileExtension: ['.jsx', '.js'],

  // hell no
  expandPartials: false,

  // regexes, stored here so they're only compiled once
  findPartialsRE: /import .* from '[^']+'/g,
  findPartialsWithStyleModifiersRE: null,
  findPartialsWithPatternParametersRE: null,
  findListItemsRE: null,
  findPartialRE: /from '([^']+)'/,

  // render it
  renderPattern(pattern, data, partials) {
    let renderedHTML = '';
    const transpiledModule = babelTransform(pattern);

    const staticMarkup = ReactDOMServer.renderToStaticMarkup(
      React.createFactory(transpiledModule)(data)
    );

    renderedHTML = outputTemplate.render({
      htmlOutput: staticMarkup,
    });

    return Promise.resolve(renderedHTML).catch(e => {
      var errorMessage = `Error rendering React pattern "${
        pattern.patternName
      }" (${pattern.relPath}): [${e.toString()}]`;
      console.log(errorMessage);
      renderedHTML = `${errorStyling} <div class="plError">
          <h1>Error rendering React pattern "${pattern.patternName}"</h1>
          <dl>
            <dt>Message</dt><dd>${e.toString()}</dd>
            <dt>Partial name</dt><dd>${pattern.patternName}</dd>
            <dt>Template path</dt><dd>${pattern.relPath}</dd>
          </dl>
          </div>
        `;
    });
  },

  registerPartial(pattern) {
    // add to registry
    registeredComponents.byPatternPartial[pattern.patternPartial] = pattern;
  },

  /**
   * Find regex matches within both pattern strings and pattern objects.
   *
   * @param {string|object} pattern Either a string or a pattern object.
   * @param {object} regex A JavaScript RegExp object.
   * @returns {array|null} An array if a match is found, null if not.
   */
  patternMatcher(pattern, regex) {
    var matches;
    if (typeof pattern === 'string') {
      matches = pattern.match(regex);
    } else if (
      typeof pattern === 'object' &&
      typeof pattern.template === 'string'
    ) {
      matches = pattern.template.match(regex);
    }
    return matches;
  },

  // find and return any `import X from 'template-name'` within pattern
  findPartials(pattern) {
    const self = this;
    const matches = pattern.template.match(this.findPartialsRE);
    if (!matches) {
      return [];
    }

    // Remove unregistered imports from the matches
    matches.map(m => {
      const key = self.findPartial(m);
      if (!registeredComponents.byPatternPartial[key]) {
        const i = matches.indexOf(m);
        if (i > -1) {
          matches.splice(i, 1);
        }
      }
    });

    return matches;
  },

  findPartialsWithStyleModifiers(pattern) {
    return [];
  },

  // returns any patterns that match {{> value(foo:'bar') }} or {{>
  // value:mod(foo:'bar') }} within the pattern
  findPartialsWithPatternParameters(pattern) {
    return [];
  },
  findListItems(pattern) {
    return [];
  },

  // given a pattern, and a partial string, tease out the "pattern key" and
  // return it.
  findPartial(partialString) {
    let partial = partialString.match(this.findPartialRE)[1];
    return partial;
  },

  rawTemplateCodeFormatter(unformattedString) {
    return beautify(unformattedString, { e4x: true, indent_size: 2 });
  },

  renderedCodeFormatter(unformattedString) {
    return unformattedString;
  },

  markupOnlyCodeFormatter(unformattedString, pattern) {
    // const $ = cheerio.load(unformattedString);
    // return beautify.html($('.reactPatternContainer').html(), {indent_size: 2});
    return unformattedString;
  },

  /**
   * Add custom output files to the pattern output
   * @param {object} patternlab - the global state object
   * @returns {(object|object[])} - an object or array of objects,
   * each with two properties: path, and content
   */
  addOutputFiles(paths, patternlab) {
    return [];
  },

  /**
   * Accept a Pattern Lab config object from the core and put it in
   * this module's closure scope so we can configure engine behavior.
   *
   * @param {object} config - the global config object from core
   */
  usePatternLabConfig: function(config) {
    patternLabConfig = config;

    try {
      enableRuntimeCode = patternLabConfig.engines.react.enableRuntimeCode;
    } catch (error) {
      console.log(
        'You’re missing the engines.react.enableRuntimeCode setting in your config file.'
      );
    }
  },
};

module.exports = engine_react;