"use strict";

const _ = require("lodash");
const isStandardSyntaxRule = require("../../utils/isStandardSyntaxRule");
const keywordSets = require("../../reference/keywordSets");
const report = require("../../utils/report");
const ruleMessages = require("../../utils/ruleMessages");
const styleSearch = require("style-search");
const validateOptions = require("../../utils/validateOptions");

const ruleName = "selector-pseudo-element-colon-notation";

const messages = ruleMessages(ruleName, {
  expected: q => `Expected ${q} colon pseudo-element notation`
});

const rule = function(expectation) {
  return (root, result) => {
    const validOptions = validateOptions(result, ruleName, {
      actual: expectation,
      possible: ["single", "double"]
    });
    if (!validOptions) {
      return;
    }

    root.walkRules(rule => {
      if (!isStandardSyntaxRule(rule)) {
        return;
      }
      const selector = rule.selector;

      // get out early if no pseudo elements or classes
      if (selector.indexOf(":") === -1) {
        return;
      }

      // match only level 1 and 2 pseudo elements
      const pseudoElementsWithColons = _.toArray(
        keywordSets.levelOneAndTwoPseudoElements
      ).map(x => `:${x}`);
      styleSearch(
        { source: selector.toLowerCase(), target: pseudoElementsWithColons },
        match => {
          const prevCharIsColon = selector[match.startIndex - 1] === ":";

          if (expectation === "single" && !prevCharIsColon) {
            return;
          }
          if (expectation === "double" && prevCharIsColon) {
            return;
          }

          report({
            message: messages.expected(expectation),
            node: rule,
            index: match.startIndex,
            result,
            ruleName
          });
        }
      );
    });
  };
};

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