"use strict";

const _ = require("lodash");
const atRuleParamIndex = require("../../utils/atRuleParamIndex");
const declarationValueIndex = require("../../utils/declarationValueIndex");
const getUnitFromValueNode = require("../../utils/getUnitFromValueNode");
const mediaParser = require("postcss-media-query-parser").default;
const optionsMatches = require("../../utils/optionsMatches");
const report = require("../../utils/report");
const ruleMessages = require("../../utils/ruleMessages");
const validateObjectWithStringArrayProps = require("../../utils/validateObjectWithStringArrayProps");
const validateOptions = require("../../utils/validateOptions");
const valueParser = require("postcss-value-parser");

const ruleName = "unit-blacklist";

const messages = ruleMessages(ruleName, {
  rejected: unit => `Unexpected unit "${unit}"`
});

// a function to retrieve only the media feature name
// could be externalized in an utils function if needed in other code
const getMediaFeatureName = mediaFeatureNode => {
  const value = mediaFeatureNode.value.toLowerCase();

  return /((-?\w*)*)/i.exec(value)[1];
};

const rule = function(blacklistInput, options) {
  const blacklist = [].concat(blacklistInput);
  return (root, result) => {
    const validOptions = validateOptions(
      result,
      ruleName,
      {
        actual: blacklist,
        possible: [_.isString]
      },
      {
        optional: true,
        actual: options,
        possible: {
          ignoreProperties: validateObjectWithStringArrayProps,
          ignoreMediaFeatureNames: validateObjectWithStringArrayProps
        }
      }
    );
    if (!validOptions) {
      return;
    }

    function check(node, nodeIndex, valueNode, input, option) {
      const unit = getUnitFromValueNode(valueNode);

      // There is not unit or it is not configured as a violation
      if (!unit || (unit && blacklist.indexOf(unit.toLowerCase()) === -1)) {
        return;
      }

      // The unit has an ignore option for the specific input
      if (optionsMatches(option, unit.toLowerCase(), input)) {
        return;
      }

      report({
        index: nodeIndex + valueNode.sourceIndex,
        message: messages.rejected(unit),
        node,
        result,
        ruleName
      });
    }

    function checkMedia(node, value, getIndex) {
      mediaParser(node.params).walk(/^media-feature$/i, mediaFeatureNode => {
        const mediaName = getMediaFeatureName(mediaFeatureNode),
          parentValue = mediaFeatureNode.parent.value;

        valueParser(value).walk(function(valueNode) {
          // Ignore all non-word valueNode and
          // the values not included in the parentValue string
          if (
            valueNode.type !== "word" ||
            !parentValue.includes(valueNode.value)
          ) {
            return;
          }
          check(
            node,
            getIndex(node),
            valueNode,
            mediaName,
            options ? options.ignoreMediaFeatureNames : {}
          );
        });
        return;
      });
    }

    function checkDecl(node, value, getIndex) {
      // make sure multiplication operations (*) are divided - not handled
      // by postcss-value-parser
      value = value.replace(/\*/g, ",");

      valueParser(value).walk(function(valueNode) {
        // Ignore wrong units within `url` function
        if (
          valueNode.type === "function" &&
          valueNode.value.toLowerCase() === "url"
        ) {
          return false;
        }
        check(
          node,
          getIndex(node),
          valueNode,
          node.prop,
          options ? options.ignoreProperties : {}
        );
      });
    }

    root.walkAtRules(/^media$/i, atRule =>
      checkMedia(atRule, atRule.params, atRuleParamIndex)
    );
    root.walkDecls(decl => checkDecl(decl, decl.value, declarationValueIndex));
  };
};

rule.primaryOptionArray = true;

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