"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = _default;
var _queue = _interopRequireDefault(require("./queue.js"));
var _Heap = _interopRequireDefault(require("./internal/Heap.js"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
/**
 * The same as [async.queue]{@link module:ControlFlow.queue} only tasks are assigned a priority and
 * completed in ascending priority order.
 *
 * @name priorityQueue
 * @static
 * @memberOf module:ControlFlow
 * @method
 * @see [async.queue]{@link module:ControlFlow.queue}
 * @category Control Flow
 * @param {AsyncFunction} worker - An async function for processing a queued task.
 * If you want to handle errors from an individual task, pass a callback to
 * `q.push()`.
 * Invoked with (task, callback).
 * @param {number} concurrency - An `integer` for determining how many `worker`
 * functions should be run in parallel.  If omitted, the concurrency defaults to
 * `1`.  If the concurrency is `0`, an error is thrown.
 * @returns {module:ControlFlow.QueueObject} A priorityQueue object to manage the tasks. There are three
 * differences between `queue` and `priorityQueue` objects:
 * * `push(task, priority, [callback])` - `priority` should be a number. If an
 *   array of `tasks` is given, all tasks will be assigned the same priority.
 * * `pushAsync(task, priority, [callback])` - the same as `priorityQueue.push`,
 *   except this returns a promise that rejects if an error occurs.
 * * The `unshift` and `unshiftAsync` methods were removed.
 */
function _default(worker, concurrency) {
  // Start with a normal queue
  var q = (0, _queue.default)(worker, concurrency);
  var {
    push,
    pushAsync
  } = q;
  q._tasks = new _Heap.default();
  q._createTaskItem = ({
    data,
    priority
  }, callback) => {
    return {
      data,
      priority,
      callback
    };
  };
  function createDataItems(tasks, priority) {
    if (!Array.isArray(tasks)) {
      return {
        data: tasks,
        priority
      };
    }
    return tasks.map(data => {
      return {
        data,
        priority
      };
    });
  }

  // Override push to accept second parameter representing priority
  q.push = function (data, priority = 0, callback) {
    return push(createDataItems(data, priority), callback);
  };
  q.pushAsync = function (data, priority = 0, callback) {
    return pushAsync(createDataItems(data, priority), callback);
  };

  // Remove unshift functions
  delete q.unshift;
  delete q.unshiftAsync;
  return q;
}
module.exports = exports.default;