"use strict";

const report = require("../../utils/report");
const ruleMessages = require("../../utils/ruleMessages");
const styleSearch = require("style-search");
const validateOptions = require("../../utils/validateOptions");

const ruleName = "string-no-newline";

const messages = ruleMessages(ruleName, {
  rejected: "Unexpected newline in string"
});

const rule = function(actual) {
  return (root, result) => {
    const validOptions = validateOptions(result, ruleName, { actual });
    if (!validOptions) {
      return;
    }

    const cssString = root.toString();
    styleSearch(
      {
        source: cssString,
        target: "\n",
        strings: "only"
      },
      match => {
        const charBefore = cssString[match.startIndex - 1];
        let index = match.startIndex;
        if (charBefore === "\\") {
          return;
        }
        if (charBefore === "\r") index -= 1;
        report({
          message: messages.rejected,
          node: root,
          index,
          result,
          ruleName
        });
      }
    );
  };
};

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