/**
 * Plugin developed to save html forms data to LocalStorage to restore them after browser crashes, tabs closings
 * and other disasters.
 *
 * @author Alexander Kaupanin <kaupanin@gmail.com>
 */

(function ($) {

	function getElementIdentifier(el) {
		return '[id=' + el.attr("id") + '][name=' + el.attr("name") + ']';
	}

	$.fn.sisyphus = function (options) {
		var identifier = $.map(this, function (obj) {
			return getElementIdentifier($(obj));
		}).join();

		var sisyphus = Sisyphus.getInstance(identifier);
		sisyphus.protect(this, options);
		return sisyphus;
	};

	var browserStorage = {};

	/**
	 * Check if local storage or other browser storage is available
	 *
	 * @return boolean
	 * @since Kunena
	 */
	browserStorage.isAvailable = function () {
		if (typeof $.jStorage === "object") {
			return true;
		}

		try {
			return localStorage.getItem;
		}
		catch (e) {
			return false;
		}
	};

	/**
	 * Set data to browser storage
	 *
	 * @param [String] key
	 * @param [String] value
	 *
	 * @return boolean
	 * @since Kunena
	 */
	browserStorage.set = function (key, value) {
		if (typeof $.jStorage === "object") {
			$.jStorage.set(key, value + "");
		}
		else {
			try {
				localStorage.setItem(key, value + "");
			}
			catch (e) {
				//QUOTA_EXCEEDED_ERR
			}
		}
	};

	/**
	 * Get data from browser storage by specified key
	 *
	 * @param [String] key
	 *
	 * @return string
	 * @since Kunena
	 */
	browserStorage.get = function (key) {
		if (typeof $.jStorage === "object") {
			var result = $.jStorage.get(key);
			return result ? result.toString() : result;
		}
		else {
			return localStorage.getItem(key);
		}
	};

	/**
	 * Delete data from browser storage by specified key
	 *
	 * @param [String] key
	 *
	 * @return void
	 * @since Kunena
	 */
	browserStorage.remove = function (key) {
		if (typeof $.jStorage === "object") {
			$.jStorage.deleteKey(key);
		}
		else {
			localStorage.removeItem(key);
		}
	};

	Sisyphus = (function () {
		var params = {
			instantiated: [],
			started: []
		};
		var CKEDITOR = window.CKEDITOR;

		function init() {

			return {
				setInstanceIdentifier: function (identifier) {
					this.identifier = identifier;
				},

				getInstanceIdentifier: function () {
					return this.identifier;
				},

				/**
				 * Set plugin initial options
				 *
				 * @param [Object] options
				 *
				 * @return void
				 */
				setInitialOptions: function (options) {
					var defaults = {
						excludeFields: [],
						customKeySuffix: "",
						locationBased: false,
						timeout: 0,
						autoRelease: true,
						onBeforeSave: function () {
						},
						onSave: function () {
						},
						onBeforeRestore: function () {
						},
						onRestore: function () {
						},
						onRelease: function () {
						}
					};
					this.options = this.options || $.extend(defaults, options);
					this.browserStorage = browserStorage;
				},

				/**
				 * Set plugin options
				 *
				 * @param [Object] options
				 *
				 * @return void
				 */
				setOptions: function (options) {
					this.options = this.options || this.setInitialOptions(options);
					this.options = $.extend(this.options, options);
				},

				/**
				 * Protect specified forms, store it's fields data to local storage and restore them on page load
				 *
				 * @param [Object] targets        forms object(s), result of jQuery selector
				 * @param Object options            plugin options
				 *
				 * @return void
				 */
				protect: function (targets, options) {
					this.setOptions(options);
					targets = targets || {};
					var self = this;
					this.targets = this.targets || [];
					if (self.options.name) {
						this.href = self.options.name;
					}
					else {
						this.href = location.hostname + location.pathname + location.search + location.hash;
					}

					this.targets = $.merge(this.targets, targets);
					this.targets = $.unique(this.targets);
					this.targets = $(this.targets);
					if (!this.browserStorage.isAvailable()) {
						return false;
					}

					var callback_result = self.options.onBeforeRestore.call(self);
					if (callback_result === undefined || callback_result) {
						self.restoreAllData();
					}

					if (this.options.autoRelease) {
						self.bindReleaseData();
					}

					if (!params.started[this.getInstanceIdentifier()]) {
						if (self.isCKEditorPresent()) {
							var intervalId = setInterval(function () {
								if (CKEDITOR.isLoaded) {
									clearInterval(intervalId);
									self.bindSaveData();
									params.started[self.getInstanceIdentifier()] = true;
								}
							}, 100);
						}
						else {
							self.bindSaveData();
							params.started[self.getInstanceIdentifier()] = true;
						}
					}
				},

				isCKEditorPresent: function () {
					if (this.isCKEditorExists()) {
						CKEDITOR.isLoaded = false;
						CKEDITOR.on('instanceReady', function () {
							CKEDITOR.isLoaded = true;
						});
						return true;
					}
					else {
						return false;
					}
				},

				isCKEditorExists: function () {
					return typeof CKEDITOR !== "undefined";
				},

				findFieldsToProtect: function (target) {
					return target.find(":input").not(":submit").not(":reset").not(":button").not(":file").not(":password").not(":disabled").not("[readonly]");
				},

				/**
				 * Bind saving data
				 *
				 * @return void
				 */
				bindSaveData: function () {
					var self = this;

					if (self.options.timeout) {
						self.saveDataByTimeout();
					}

					self.targets.each(function () {
						var targetFormIdAndName = getElementIdentifier($(this));
						self.findFieldsToProtect($(this)).each(function () {
							if ($.inArray(this, self.options.excludeFields) !== -1) {
								// Returning non-false is the same as a continue statement in a for loop; it will skip immediately to the next iteration.
								return true;
							}

							var field = $(this);
							var prefix = (self.options.locationBased ? self.href : "") + targetFormIdAndName + getElementIdentifier(field) + self.options.customKeySuffix;
							if (field.is(":text") || field.is("textarea")) {
								if (!self.options.timeout) {
									self.bindSaveDataImmediately(field, prefix);
								}
							}

							self.bindSaveDataOnChange(field);
						});
					});
				},

				/**
				 * Save all protected forms data to Local Storage.
				 * Common method, necessary to not lead astray user firing 'data is saved' when select/checkbox/radio
				 * is changed and saved, while text field data is saved only by timeout
				 *
				 * @return void
				 */
				saveAllData: function () {
					var self = this;
					self.targets.each(function () {
						var targetFormIdAndName = getElementIdentifier($(this));
						var multiCheckboxCache = {};

						self.findFieldsToProtect($(this)).each(function () {
							var field = $(this);
							if ($.inArray(this, self.options.excludeFields) !== -1 || (field.attr("name") === undefined && field.attr("id") === undefined)) {
								// Returning non-false is the same as a continue statement in a for loop; it will skip immediately to the next iteration.
								return true;
							}

							var prefix = (self.options.locationBased ? self.href : "") + targetFormIdAndName + getElementIdentifier(field) + self.options.customKeySuffix;
							var value = field.val();

							if (field.is(":checkbox")) {
								var name = field.attr("name");
								if (name !== undefined && name.indexOf("[") !== -1) {
									if (multiCheckboxCache[name] === true) {
										return;
									}

									value = [];
									$("[name='" + name + "']:checked").each(function () {
										value.push($(this).val());
									});
									multiCheckboxCache[name] = true;
								}
								else {
									value = field.is(":checked");
								}

								self.saveToBrowserStorage(prefix, value, false);
							}
							else if (field.is(":radio")) {
								if (field.is(":checked")) {
									value = field.val();
									self.saveToBrowserStorage(prefix, value, false);
								}
							}
							else {
								if (self.isCKEditorExists()) {
									var editor = CKEDITOR.instances[field.attr("name")] || CKEDITOR.instances[field.attr("id")];
									if (editor) {
										editor.updateElement();
										self.saveToBrowserStorage(prefix, field.val(), false);
									}
									else {
										self.saveToBrowserStorage(prefix, value, false);
									}
								}
								else {
									self.saveToBrowserStorage(prefix, value, false);
								}
							}
						});
					});
					self.options.onSave.call(self);
				},

				/**
				 * Restore forms data from Local Storage
				 *
				 * @return void
				 */
				restoreAllData: function () {
					var self = this;
					var restored = false;

					self.targets.each(function () {
						var target = $(this);
						var targetFormIdAndName = getElementIdentifier($(this));

						self.findFieldsToProtect(target).each(function () {
							if ($.inArray(this, self.options.excludeFields) !== -1) {
								// Returning non-false is the same as a continue statement in a for loop; it will skip immediately to the next iteration.
								return true;
							}

							var field = $(this);
							var prefix = (self.options.locationBased ? self.href : "") + targetFormIdAndName + getElementIdentifier(field) + self.options.customKeySuffix;
							var resque = self.browserStorage.get(prefix);
							if (resque !== null) {
								self.restoreFieldsData(field, resque);
								restored = true;
							}
						});
					});

					if (restored) {
						self.options.onRestore.call(self);
					}
				},

				/**
				 * Restore form field data from local storage
				 *
				 * @param Object field        jQuery form element object
				 * @param String resque     previously stored fields data
				 *
				 * @return void
				 */
				restoreFieldsData: function (field, resque) {
					if (field.attr("name") === undefined && field.attr("id") === undefined) {
						return false;
					}

					var name = field.attr("name");
					if (field.is(":checkbox") && resque !== "false" && (name === undefined || name.indexOf("[") === -1)) {
						// If we aren't named by name (e.g. id) or we aren't in a multiple element field
						field.prop("checked", true);
					}
					else if (field.is(":checkbox") && resque === "false" && (name === undefined || name.indexOf("[") === -1)) {
						// If we aren't named by name (e.g. id) or we aren't in a multiple element field
						field.prop("checked", false);
					}
					else if (field.is(":radio")) {
						if (field.val() === resque) {
							field.prop("checked", true);
						}
					}
					else if (name === undefined || name.indexOf("[") === -1) {
						// If we aren't named by name (e.g. id) or we aren't in a multiple element field
						field.val(resque);
					}
					else {
						resque = resque.split(",");
						field.val(resque);
					}
				},

				/**
				 * Bind immediate saving (on typing/checking/changing) field data to local storage when user fills it
				 *
				 * @param Object field        jQuery form element object
				 * @param String prefix     prefix used as key to store data in local storage
				 *
				 * @return void
				 */
				bindSaveDataImmediately: function (field, prefix) {
					var self = this;
					if ('onpropertychange' in field) {
						field.get(0).onpropertychange = function () {
							self.saveToBrowserStorage(prefix, field.val());
						};
					}
					else {
						field.get(0).oninput = function () {
							self.saveToBrowserStorage(prefix, field.val());
						};
					}

					if (this.isCKEditorExists()) {
						var editor = CKEDITOR.instances[field.attr("name")] || CKEDITOR.instances[field.attr("id")];
						if (editor) {
							editor.document.on('keyup', function () {
								editor.updateElement();
								self.saveToBrowserStorage(prefix, field.val());
							});
						}
					}
				},

				/**
				 * Save data to Local Storage and fire callback if defined
				 *
				 * @param String key
				 * @param String value
				 * @param Boolean [true] fireCallback
				 *
				 * @return void
				 */
				saveToBrowserStorage: function (key, value, fireCallback) {
					var self = this;

					var callback_result = self.options.onBeforeSave.call(self);
					if (callback_result !== undefined && callback_result === false) {
						return;
					}

					// if fireCallback is undefined it should be true
					fireCallback = fireCallback === undefined ? true : fireCallback;
					this.browserStorage.set(key, value);
					if (fireCallback && value !== "") {
						this.options.onSave.call(this);
					}
				},

				/**
				 * Bind saving field data on change
				 *
				 * @param Object field        jQuery form element object
				 *
				 * @return void
				 */
				bindSaveDataOnChange: function (field) {
					var self = this;
					field.change(function () {
						self.saveAllData();
					});
				},

				/**
				 * Saving (by timeout) field data to local storage when user fills it
				 *
				 * @return void
				 */
				saveDataByTimeout: function () {
					var self = this;
					var targetForms = self.targets;
					setTimeout((function () {
						function timeout() {
							self.saveAllData();
							setTimeout(timeout, self.options.timeout * 1000);
						}

						return timeout;
					})(targetForms), self.options.timeout * 1000);
				},

				/**
				 * Bind release form fields data from local storage on submit/reset form
				 *
				 * @return void
				 */
				bindReleaseData: function () {
					var self = this;
					self.targets.each(function () {
						var target = $(this);
						var formIdAndName = getElementIdentifier(target);
						$(this).bind("submit reset", function () {
							self.releaseData(formIdAndName, self.findFieldsToProtect(target));
						});
					});
				},

				/**
				 * Manually release form fields
				 *
				 * @return void
				 */
				manuallyReleaseData: function () {
					var self = this;
					self.targets.each(function () {
						var target = $(this);
						var formIdAndName = getElementIdentifier(target);
						self.releaseData(formIdAndName, self.findFieldsToProtect(target));
					});
				},

				/**
				 * Bind release form fields data from local storage on submit/resett form
				 *
				 * @param String targetFormIdAndName    a form identifier consists of its id and name glued
				 * @param Object fieldsToProtect        jQuery object contains form fields to protect
				 *
				 * @return void
				 */
				releaseData: function (targetFormIdAndName, fieldsToProtect) {
					var released = false;
					var self = this;

					// Released form, are not started anymore. Fix for ajax loaded forms.
					params.started[self.getInstanceIdentifier()] = false;

					fieldsToProtect.each(function () {
						if ($.inArray(this, self.options.excludeFields) !== -1) {
							// Returning non-false is the same as a continue statement in a for loop; it will skip immediately to the next iteration.
							return true;
						}

						var field = $(this);
						var prefix = (self.options.locationBased ? self.href : "") + targetFormIdAndName + getElementIdentifier(field) + self.options.customKeySuffix;
						self.browserStorage.remove(prefix);
						released = true;
					});

					if (released) {
						self.options.onRelease.call(self);
					}
				}

			};
		}

		return {
			getInstance: function (identifier) {
				if (!params.instantiated[identifier]) {
					params.instantiated[identifier] = init();
					params.instantiated[identifier].setInstanceIdentifier(identifier);
					params.instantiated[identifier].setInitialOptions();
				}

				if (identifier) {
					return params.instantiated[identifier];
				}

				return params.instantiated[identifier];
			},

			free: function () {
				params = {
					instantiated: [],
					started: []
				};
				return null;
			},
			version: '1.1.2'
		};
	})();
})(jQuery);