/**
 * Copyright (c) 2019-present Tomek Wójcik <contact@bthlabs.pl>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

const crypto = require('crypto');
const fs = require('fs');
const path = require('path');

const glob = require('glob');
const Mustache = require('mustache');
const {PNG} = require('pngjs');
const URI = require('urijs');

const DEFAULT_OPTIONS = {
  files: [],
  output: 'sprite/',
  urlPrefix: '/'
};

const spritemaker = (options) => {
  options = Object.assign({}, DEFAULT_OPTIONS, options);
  const images = [];
  const bounds = {
    width: 0,
    height: 0
  };
  const spriteMap = [];

  options.files.forEach((pattern, index) => {
    glob.sync(pattern).forEach((imagePath, index) => {
      const data = fs.readFileSync(imagePath);
      const image = PNG.sync.read(data);

      bounds.height += image.height;
      if (image.width > bounds.width) {
        bounds.width = image.width;
      }

      images.push([imagePath, image]);
    });
  });

  const outputImage = new PNG({
    height: bounds.height,
    width: bounds.width
  });

  let currentDeltaY = 0;
  images.forEach(([imagePath, image], index) => {
    PNG.bitblt(
      image, outputImage,
      0, 0, image.width, image.height,
      0, currentDeltaY
    );

    spriteMap.push({
      name: path.basename(imagePath, '.png'),
      rect: {
        x: 0,
        y: currentDeltaY * -1,
        width: image.width,
        height: image.height
      }
    });

    currentDeltaY += image.height;
  });

  const hash = crypto.Hash('md5');
  hash.update(outputImage.data);

  const outputBasename = `sprite`;
  const outputName = `${outputBasename}-${hash.digest('hex')}.png`;
  const outbutBuffer = PNG.sync.write(outputImage, {
    colorType: 6
  });
  fs.writeFileSync(
    path.resolve(options.output, outputName), outbutBuffer
  );

  const template = fs.readFileSync(
    path.resolve(__dirname, 'scss.mustache'), {encoding: 'utf-8'}
  );
  const context = {
    bounds: bounds,
    images: spriteMap,
    url: path.join(options.urlPrefix, outputName)
  };
  const scss = Mustache.render(template, context);

  const scssName = `${outputBasename}.scss`;
  fs.writeFileSync(
    path.resolve(options.output, scssName), scss
  );

  return [outputName, scssName];
};

module.exports = {
  spritemaker: spritemaker
};