"use strict";

const atRuleParamIndex = require("../../utils/atRuleParamIndex");
const mediaQueryListCommaWhitespaceChecker = require("../mediaQueryListCommaWhitespaceChecker");
const ruleMessages = require("../../utils/ruleMessages");
const validateOptions = require("../../utils/validateOptions");
const whitespaceChecker = require("../../utils/whitespaceChecker");

const ruleName = "media-query-list-comma-space-after";

const messages = ruleMessages(ruleName, {
  expectedAfter: () => 'Expected single space after ","',
  rejectedAfter: () => 'Unexpected whitespace after ","',
  expectedAfterSingleLine: () =>
    'Expected single space after "," in a single-line list',
  rejectedAfterSingleLine: () =>
    'Unexpected whitespace after "," in a single-line list'
});

const rule = function(expectation, options, context) {
  const checker = whitespaceChecker("space", expectation, messages);

  return (root, result) => {
    const validOptions = validateOptions(result, ruleName, {
      actual: expectation,
      possible: ["always", "never", "always-single-line", "never-single-line"]
    });

    if (!validOptions) {
      return;
    }

    let fixData;

    mediaQueryListCommaWhitespaceChecker({
      root,
      result,
      locationChecker: checker.after,
      checkedRuleName: ruleName,
      fix: context.fix
        ? (atRule, index) => {
            const paramCommaIndex = index - atRuleParamIndex(atRule);

            fixData = fixData || new Map();
            const commaIndices = fixData.get(atRule) || [];

            commaIndices.push(paramCommaIndex);
            fixData.set(atRule, commaIndices);

            return true;
          }
        : null
    });

    if (fixData) {
      fixData.forEach((commaIndices, atRule) => {
        let params = atRule.raws.params
          ? atRule.raws.params.raw
          : atRule.params;

        commaIndices
          .sort((a, b) => b - a)
          .forEach(index => {
            const beforeComma = params.slice(0, index + 1);
            const afterComma = params.slice(index + 1);

            if (expectation.indexOf("always") === 0) {
              params = beforeComma + afterComma.replace(/^\s*/, " ");
            } else if (expectation.indexOf("never") === 0) {
              params = beforeComma + afterComma.replace(/^\s*/, "");
            }
          });

        if (atRule.raws.params) {
          atRule.raws.params.raw = params;
        } else {
          atRule.params = params;
        }
      });
    }
  };
};

rule.ruleName = ruleName;
rule.messages = messages;
module.exports = rule;