"use strict";

const generateValidator = require("./generate-validator");
const guardedSet = require("./guarded-collections/set");
const guardedMap = require("./guarded-collections/map");
const guardedArray = require("./guarded-collections/array");

module.exports = function generateDescriptor(rule, key, allowSlot = false) {
	if (rule._isTypeRule === true) {
		let validator = generateValidator(rule, key);

		if (rule._collectionType != null) {
			let guardedCollectionFactory;

			if (rule._collectionType === "set") {
				guardedCollectionFactory = guardedSet;
			} else if (rule._collectionType === "map") {
				guardedCollectionFactory = guardedMap;
			} else if (rule._collectionType === "array") {
				guardedCollectionFactory = guardedArray;
			} else {
				throw new Error(`Unknown collection type: ${rule._collectionType}`);
			}

			let valueGuard = generateValidator(rule._itemType);
			let keyGuard = (rule._keyType != null) ? generateValidator(rule._keyType) : null;

			return [key, {
				enumerable: true,
				get: function () {
					return this._data[key];
				},
				set: function (value) {
					if (allowSlot && value != null && value._isSlotRule === true) {
						this._data[key] = value;
					} else {
						let validationResult = validator.call(this, value);

						if (validationResult === true) {
							if (value == null) {
								this._data[key] = value;
							} else {
								this._data[key] = guardedCollectionFactory(value, valueGuard, keyGuard, this);
							}
						} else if (validationResult._default !== undefined) {
							this._data[key] = guardedCollectionFactory(validationResult._default, valueGuard, keyGuard, this);
						} else {
							throw validationResult;
						}
					}
				}
			}];
		} else {
			return [key, {
				enumerable: true,
				get: function () {
					return this._data[key];
				},
				set: function (value) {
					if (allowSlot && value != null && value._isSlotRule === true) {
						this._data[key] = value;
					} else {
						let validationResult = validator.call(this, value);

						if (validationResult === true) {
							this._data[key] = value;
						} else if (validationResult._default !== undefined) {
							this._data[key] = validationResult._default;
						} else {
							throw validationResult;
						}
					}
				}
			}];
		}
	} else {
		/* TODO: Does this cause a slowdown compared to merging in these props with Object.assign later? */
		return [key, {
			value: rule
		}];
	}
};