/* @flow */
"use strict";

const normalizeRuleSettings = require("../normalizeRuleSettings");
const Result = require("postcss/lib/result");
const rules = require("../rules");

// Useful for third-party code (e.g. plugins) to run a PostCSS Root
// against a specific rule and do something with the warnings
module.exports = function(
  options /*: {
    ruleName: string,
    ruleSettings: stylelint$configRuleSettings,
    root: Object,
  }*/,
  callback /*: Function*/
) {
  if (!options)
    throw new Error(
      "checkAgainstRule requires an options object with 'ruleName', 'ruleSettings', and 'root' properties"
    );
  if (!callback) throw new Error("checkAgainstRule requires a callback");
  if (!options.ruleName)
    throw new Error("checkAgainstRule requires a 'ruleName' option");
  if (!rules[options.ruleName])
    throw new Error(`Rule '${options.ruleName}' does not exist`);
  if (!options.ruleSettings)
    throw new Error("checkAgainstRule requires a 'ruleSettings' option");
  if (!options.root)
    throw new Error("checkAgainstRule requires a 'root' option");

  const settings = normalizeRuleSettings(
    options.ruleSettings,
    options.ruleName
  );
  if (!settings) {
    return;
  }

  const tmpPostcssResult = new Result();
  rules[options.ruleName](settings[0], settings[1], {})(
    options.root,
    tmpPostcssResult
  );
  tmpPostcssResult.warnings().forEach(callback);
};
