"use strict";

const beforeBlockString = require("../../utils/beforeBlockString");
const blockString = require("../../utils/blockString");
const hasBlock = require("../../utils/hasBlock");
const hasEmptyBlock = require("../../utils/hasEmptyBlock");
const report = require("../../utils/report");
const ruleMessages = require("../../utils/ruleMessages");
const validateOptions = require("../../utils/validateOptions");
const whitespaceChecker = require("../../utils/whitespaceChecker");

const ruleName = "block-opening-brace-space-after";

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

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",
        "always-multi-line",
        "never-multi-line"
      ]
    });

    if (!validOptions) {
      return;
    }

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

    function check(statement) {
      // Return early if blockless or has an empty block
      if (!hasBlock(statement) || hasEmptyBlock(statement)) {
        return;
      }

      checker.after({
        source: blockString(statement),
        index: 0,
        err: m => {
          if (context.fix) {
            if (expectation.indexOf("always") === 0) {
              statement.first.raws.before = " ";

              return;
            } else if (expectation.indexOf("never") === 0) {
              statement.first.raws.before = "";

              return;
            }
          }

          report({
            message: m,
            node: statement,
            index:
              beforeBlockString(statement, { noRawBefore: true }).length + 1,
            result,
            ruleName
          });
        }
      });
    }
  };
};

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