"use strict";

const _ = require("lodash");
const beforeBlockString = require("../../utils/beforeBlockString");
const hasEmptyBlock = require("../../utils/hasEmptyBlock");
const optionsMatches = require("../../utils/optionsMatches");
const report = require("../../utils/report");
const ruleMessages = require("../../utils/ruleMessages");
const validateOptions = require("../../utils/validateOptions");

const ruleName = "block-no-empty";

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

const rule = function(primary, options = {}) {
  return (root, result) => {
    const validOptions = validateOptions(
      result,
      ruleName,
      {
        actual: primary,
        possible: _.isBoolean
      },
      {
        actual: options,
        possible: {
          ignore: ["comments"]
        },
        optional: true
      }
    );

    if (!validOptions) {
      return;
    }

    const ignoreComments = optionsMatches(options, "ignore", "comments");

    // Check both kinds of statements: rules and at-rules
    root.walkRules(check);
    root.walkAtRules(check);

    function check(statement) {
      if (!hasEmptyBlock(statement) && !ignoreComments) {
        return;
      }

      const hasCommentsOnly = statement.nodes.every(
        node => node.type === "comment"
      );

      if (!hasCommentsOnly) {
        return;
      }

      let index = beforeBlockString(statement, { noRawBefore: true }).length;

      // For empty blocks when using SugarSS parser
      if (statement.raws.between === undefined) {
        index--;
      }

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

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