"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = minifyCss;
var _helpers = require("../helpers.cjs");
const postcssOptions = {
  // Prevent the following warning from being shown:
  // > Without `from` option PostCSS could generate wrong source map and will not find Browserslist config.
  // > Set it to CSS file path or to `undefined` to prevent this warning.
  from: undefined
};

/** Minify CSS with cssnano */
async function minifyCss(tree, options, cssnanoOptions) {
  const cssnano = await (0, _helpers.optionalImport)('cssnano');
  const postcss = await (0, _helpers.optionalImport)('postcss');
  if (!cssnano || !postcss) {
    return tree;
  }
  let promises = [];
  tree.walk(node => {
    // Skip SRI, reasons are documented in "minifyJs" module
    if (node.attrs && 'integrity' in node.attrs) {
      return node;
    }
    if ((0, _helpers.isStyleNode)(node)) {
      promises.push(processStyleNode(node, cssnanoOptions, cssnano, postcss));
    } else if (node.attrs && node.attrs.style) {
      promises.push(processStyleAttr(node, cssnanoOptions, cssnano, postcss));
    }
    return node;
  });
  return Promise.all(promises).then(() => tree);
}
function processStyleNode(styleNode, cssnanoOptions, cssnano, postcss) {
  let css = (0, _helpers.extractCssFromStyleNode)(styleNode);

  // Improve performance by avoiding calling stripCdata again and again
  let isCdataWrapped = false;
  if (css.includes('CDATA')) {
    const strippedCss = stripCdata(css);
    isCdataWrapped = css !== strippedCss;
    css = strippedCss;
  }
  return postcss([cssnano(cssnanoOptions)]).process(css, postcssOptions).then(result => {
    if (isCdataWrapped) {
      return styleNode.content = ['<![CDATA[' + result + ']]>'];
    }
    return styleNode.content = [result.css];
  });
}
function processStyleAttr(node, cssnanoOptions, cssnano, postcss) {
  // CSS "color: red;" is invalid. Therefore it should be wrapped inside some selector:
  // a{color: red;}
  const wrapperStart = 'a{';
  const wrapperEnd = '}';
  const wrappedStyle = wrapperStart + (node.attrs.style || '') + wrapperEnd;
  return postcss([cssnano(cssnanoOptions)]).process(wrappedStyle, postcssOptions).then(result => {
    const minifiedCss = result.css;
    // Remove wrapperStart at the start and wrapperEnd at the end of minifiedCss
    node.attrs.style = minifiedCss.substring(wrapperStart.length, minifiedCss.length - wrapperEnd.length);
  });
}
function stripCdata(css) {
  const leftStrippedCss = css.replace('<![CDATA[', '');
  if (leftStrippedCss === css) {
    return css;
  }
  const strippedCss = leftStrippedCss.replace(']]>', '');
  return leftStrippedCss === strippedCss ? css : strippedCss;
}