const postcss = require("postcss");
const postcssLightningcss = require("postcss-lightningcss");

postcss([postcssLightningcss(/* pluginOptions */)]).process(
  YOUR_CSS /*, processOptions */
);

const postcssLightningcss = require("postcss-lightningcss");

postcssLightningcss({
  // Use a browserslist query that will inform which browsers are supported
  // Will add or remove vendor prefixes that are needed or not anymore
  browsers: ">= .25%",
  // Auto set lightningcssOptions.cssModules, possible values:
  // - auto - enable CSS modules for all files matching `/\.module(s)?\.\w+$/i.test(filename)`
  // - RegExp - enable CSS modules for all files matching `/RegExp/i.test(filename)`
  // - boolean - true enable css modules for all files
  // Will be overwrite by the lightningcssOptions cssModules(boolean) option
  cssModules: /\.module\.css/,

  // Callback containing the transformed class names for cssModules
  // this runs only if cssModules is enabled
  cssModulesJSON(cssFileName: string, json: object, outputFileName: string): {},
  // Will pass all options to lightningcss
  // Check out their documentation for details:
  // https://www.npmjs.com/package/lightningcss#user-content-documentation
  lightningcssOptions: {
    // Enable minification (default: true)
    minify: true,

    // Enable source maps (default: true)
    sourceMap: true,

    // Compile as cssModules (default: undefined)
    cssModules: false,

    // For which browsers to compile (default: undefined)
    // Can be omitted if you set the `browsers` option
    targets: {
      safari: (13 << 16) | (2 << 8), // represents Safari 13.2.0
    },

    // Individually enable various drafts
    drafts: {
      // Enable css nesting (default: undefined)
      nesting: false,
    },
  },
});

const path = require("path");
const fs = require("fs");

postcssLightningcss({
  cssModules: /\.module\.css/,
  cssModulesJSON(cssFileName, json, outputFileName) {
    const cssName = path.basename(cssFileName, ".css");
    const jsonFileName = path.resolve("./build/" + cssName + ".json");
    fs.writeFileSync(jsonFileName, JSON.stringify(json));
  },
});

postcssLightningcss({
  cssModulesJSON(cssFileName, json, outputFileName) {
    // Your export function here
  },
  lightningcssOptions: {
    cssModules: {
      pattern: "my-company-[name]-[hash]-[local]",
    },
  },
});