/* @flow */
"use strict"

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