"use strict";

const _ = require("lodash");
const atRuleParamIndex = require("../../utils/atRuleParamIndex");
const report = require("../../utils/report");
const ruleMessages = require("../../utils/ruleMessages");
const validateOptions = require("../../utils/validateOptions");
const valueParser = require("postcss-value-parser");

const ruleName = "media-feature-parentheses-space-inside";

const messages = ruleMessages(ruleName, {
  expectedOpening: 'Expected single space after "("',
  rejectedOpening: 'Unexpected whitespace after "("',
  expectedClosing: 'Expected single space before ")"',
  rejectedClosing: 'Unexpected whitespace before ")"'
});

const rule = function(expectation, options, context) {
  return (root, result) => {
    const validOptions = validateOptions(result, ruleName, {
      actual: expectation,
      possible: ["always", "never"]
    });

    if (!validOptions) {
      return;
    }

    root.walkAtRules(/^media$/i, atRule => {
      // If there are comments in the params, the complete string
      // will be at atRule.raws.params.raw
      const params = _.get(atRule, "raws.params.raw", atRule.params);
      const indexBoost = atRuleParamIndex(atRule);
      const violations = [];

      const parsedParams = valueParser(params).walk(node => {
        if (node.type === "function") {
          const len = valueParser.stringify(node).length;

          if (expectation === "never") {
            if (node.before === " ") {
              if (context.fix) node.before = "";

              violations.push({
                message: messages.rejectedOpening,
                index: node.sourceIndex + 1 + indexBoost
              });
            }

            if (node.after === " ") {
              if (context.fix) node.after = "";

              violations.push({
                message: messages.rejectedClosing,
                index: node.sourceIndex - 2 + len + indexBoost
              });
            }
          } else if (expectation === "always") {
            if (node.before === "") {
              if (context.fix) node.before = " ";

              violations.push({
                message: messages.expectedOpening,
                index: node.sourceIndex + 1 + indexBoost
              });
            }

            if (node.after === "") {
              if (context.fix) node.after = " ";

              violations.push({
                message: messages.expectedClosing,
                index: node.sourceIndex - 2 + len + indexBoost
              });
            }
          }
        }
      });

      if (violations.length) {
        if (context.fix) {
          atRule.params = parsedParams.toString();

          return;
        }

        violations.forEach(err => {
          report({
            message: err.message,
            node: atRule,
            index: err.index,
            result,
            ruleName
          });
        });
      }
    });
  };
};

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