/* @flow */
"use strict";

const balancedMatch = require("balanced-match");
const styleSearch = require("style-search");

/**
 * Search a CSS string for functions by name.
 * For every match, invoke the callback, passing the function's
 * "argument(s) string" (whatever is inside the parentheses)
 * as an argument.
 *
 * Callback will be called once for every matching function found,
 * with the function's "argument(s) string" and its starting index
 * as the arguments.
 */
module.exports = function(
  source /*: string*/,
  functionName /*: string*/,
  callback /*: Function*/
) {
  styleSearch(
    {
      source,
      target: functionName,
      functionNames: "check"
    },
    match => {
      if (source[match.endIndex] !== "(") {
        return;
      }

      const parensMatch = balancedMatch(
        "(",
        ")",
        source.substr(match.startIndex)
      );

      callback(parensMatch.body, match.endIndex + 1);
    }
  );
};