"use strict";

const report = require("../../utils/report");
const ruleMessages = require("../../utils/ruleMessages");
const validateOptions = require("../../utils/validateOptions");

const ruleName = "no-empty-first-line";
const noEmptyFirstLineTest = /^\s*[\r\n]/;

const messages = ruleMessages(ruleName, {
  rejected: "Unexpected empty line"
});

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

    if (
      !validOptions ||
      root.source.inline ||
      root.source.lang === "object-literal"
    ) {
      return;
    }

    const rootString = context.fix ? root.toString() : root.source.input.css;

    if (!rootString.trim()) {
      return;
    }

    if (noEmptyFirstLineTest.test(rootString)) {
      if (context.fix) {
        root.nodes[0].raws.before = root.first.raws.before.trimLeft();

        return;
      }

      report({
        message: messages.rejected,
        node: root,
        result,
        ruleName
      });
    }
  };
};

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