+const Model = {
+ createTask: function (timestamp: string, description: string) {
+ const task = document.createElement("div");
+ task.appendChild(document.createTextNode(description));
+ task.setAttribute("class", "task");
+ task.setAttribute("tabindex", "0");
+ task.setAttribute("data-created", timestamp);
+ return task;
+ },
+
+ addTask: function (timestamp: string, description: string) {
+ document.body.appendChild(this.createTask(timestamp, description)).focus();
+ },
+
+ getTask: function (createTimestamp: string) {
+ for (const task of document.getElementsByClassName("task")) {
+ if (task.getAttribute("data-created") === createTimestamp) {
+ return task;
+ }
+ }
+ },
+
+ destroyTask: function (createTimestamp: string) {
+ const task = this.getTask(createTimestamp);
+ task!.parentElement!.removeChild(task!);
+ },
+};
+
+const Log = (function () {
+ var next_log_index = 0;
+ return {
+ apply: function (entry: string) {
+ const [timestamp, command, data] = splitN(entry, " ", 2);
+ if (command == "Create") {
+ Model.addTask(timestamp, data);
+ }
+ if (command == "Destroy") {
+ Model.destroyTask(data.split(" ", 1)[0]);
+ }
+ },
+
+ record: function (entry: string) {
+ window.localStorage.setItem(`${next_log_index++}`, entry);
+ },
+
+ recordAndApply: function (entry: string) {
+ this.record(entry);
+ this.apply(entry);
+ },
+
+ replay: function () {
+ while (true) {
+ const entry = window.localStorage.getItem(`${next_log_index}`);
+ if (entry === null) {
+ break;
+ }
+ this.apply(entry);
+ next_log_index++;
+ }
+ },
+ };
+})();
+
+const UI = {
+ addTask: function (description: string) {
+ Log.recordAndApply(`${Date.now()} Create ${description}`);
+ },
+ destroyTask: function (createTimestamp: string) {
+ Log.recordAndApply(`${Date.now()} Destroy ${createTimestamp} ${Model.getTask(createTimestamp)?.textContent}`);
+ },
+};
+
+const BrowserUI = {
+ addTask: function (form: any) {
+ if (form.taskName.value) {
+ UI.addTask(form.taskName.value);
+ form.taskName.value = "";
+ }
+ return false;
+ },
+
+ destroyTask: function () {
+ const createTimestamp = document.activeElement?.getAttribute("data-created");
+ this.moveCursor(1) || this.moveCursor(-1);
+ return UI.destroyTask(createTimestamp!);
+ },
+
+ focusTaskNameInput: function (event: any) {
+ document.getElementById("taskName")!.focus();
+ event.preventDefault();
+ },
+
+ moveCursor: function (offset: number): boolean {
+ var active = document.activeElement;
+ if (offset === 1 && active) {
+ active = active.nextElementSibling;
+ }
+ if (offset === -1 && active) {
+ active = active.previousElementSibling;
+ }
+ if (active && active instanceof HTMLElement) {
+ active.focus();
+ return true;
+ }
+ return false;
+ },
+};