HORIZON PROJECT

var baseFlatten = require('./_baseFlatten'),

    map = require('./map'),

    toInteger = require('./toInteger');

/**

 * This method is like `_.flatMap` except that it recursively flattens the

 * mapped results up to `depth` times.

 *

 * @static

 * @memberOf _

 * @since 4.7.0

 * @category Collection

 * @param {Array|Object} collection The collection to iterate over.

 * @param {Function} [iteratee=_.identity] The function invoked per iteration.

 * @param {number} [depth=1] The maximum recursion depth.

 * @returns {Array} Returns the new flattened array.

 * @example

 *

 * function duplicate(n) {

 *   return [[[n, n]]];

 * }

 *

 * _.flatMapDepth([1, 2], duplicate, 2);

 * // => [[1, 1], [2, 2]]

 */

function flatMapDepth(collection, iteratee, depth) {

  depth = depth === undefined ? 1 : toInteger(depth);

  return baseFlatten(map(collection, iteratee), depth);

}

module.exports = flatMapDepth;