import { escapeRegExp, expandVariantGroup } from '@unocss/core';

function transformerCompileClass(options = {}) {
  const {
    trigger = ":uno:",
    classPrefix = "uno-",
    hashFn = hash,
    keepUnknown = true
  } = options;
  const regex = new RegExp(`(["'\`])${escapeRegExp(trigger)}\\s([^\\1]*?)\\1`, "g");
  return {
    name: "compile-class",
    enforce: "pre",
    async transform(s, _, { uno, tokens }) {
      const matches = [...s.original.matchAll(regex)];
      if (!matches.length)
        return;
      for (const match of matches) {
        let body = expandVariantGroup(match[2].trim());
        const start = match.index;
        const replacements = [];
        if (keepUnknown) {
          const result = await Promise.all(body.split(/\s+/).filter(Boolean).map(async (i) => [i, !!await uno.parseToken(i)]));
          const known = result.filter(([, matched]) => matched).map(([i]) => i);
          const unknown = result.filter(([, matched]) => !matched).map(([i]) => i);
          replacements.push(...unknown);
          body = known.join(" ");
        }
        if (body) {
          const hash2 = hashFn(body);
          const className = `${classPrefix}${hash2}`;
          replacements.unshift(className);
          if (options.layer)
            uno.config.shortcuts.push([className, body, { layer: options.layer }]);
          else
            uno.config.shortcuts.push([className, body]);
          tokens.add(className);
        }
        s.overwrite(start + 1, start + match[0].length - 1, replacements.join(" "));
      }
    }
  };
}
function hash(str) {
  let i;
  let l;
  let hval = 2166136261;
  for (i = 0, l = str.length; i < l; i++) {
    hval ^= str.charCodeAt(i);
    hval += (hval << 1) + (hval << 4) + (hval << 7) + (hval << 8) + (hval << 24);
  }
  return `00000${(hval >>> 0).toString(36)}`.slice(-6);
}

export { transformerCompileClass as default };