Persist the list

import { DateTime, Effect, Layer, Context, Schema } from "effect";
import { Fx } from "@typed/fx";
import * as Router from "@typed/router";
import * as App from "./application.js";
import * as Domain from "./domain.js";

const TODOS_STORAGE_KEY = `@typed/todomvc/todos`;

const TodoListJson = Schema.fromJsonString(Schema.toCodecJson(Domain.TodoList));
const decodeTodoList = Schema.decodeEffect(TodoListJson);
const encodeTodoList = Schema.encodeEffect(TodoListJson);

class Todos extends Context.Service<
  Todos,
  {
    readonly load: Effect.Effect<Domain.TodoList, unknown>;
    readonly save: (todos: Domain.TodoList) => Effect.Effect<void, unknown>;
  }
>()("TodosService") {
  static readonly get = Todos.pipe(
    Effect.flatMap((service) => service.load),
    Effect.catchCause(() => Effect.succeed([])),
  );

  static readonly set = (todos: Domain.TodoList) =>
    Effect.flatMap(Todos, (service) => service.save(todos)).pipe(
      Effect.catchCause((cause) =>
        Effect.logError("Failed to write todos to key value store", cause),
      ),
    );

  static readonly replicateToStorage = App.TodoList.pipe(Fx.observeLayer(Todos.set));

  static readonly local = Layer.succeed(Todos, {
    load: Effect.try(() => localStorage.getItem(TODOS_STORAGE_KEY)).pipe(
      Effect.flatMap((value) =>
        value === null ? Effect.succeed<Domain.TodoList>([]) : decodeTodoList(value),
      ),
    ),
    save: (todos) =>
      encodeTodoList(todos).pipe(
        Effect.flatMap((value) => Effect.try(() => localStorage.setItem(TODOS_STORAGE_KEY, value))),
      ),
  });
}

const FilterState = Router.match(Router.Slash, "all")
  .match(Router.Parse("active"), "active")
  .match(Router.Parse("completed"), "completed")
  .redirectTo("/")
  .pipe(
    Fx.catchCause(() => Fx.succeed("all" as const)),
  );

const Model = Layer.mergeAll(
  App.TodoList.make(Todos.get),
  App.FilterState.make(FilterState),
  App.TodoText.make(""),
);

const CreateTodo = Layer.sync(
  App.CreateTodo,
  () => (text: string) =>
    Effect.sync((): Domain.Todo => ({
      id: Domain.TodoId.make(crypto.randomUUID()),
      text,
      completed: false,
      timestamp: DateTime.makeUnsafe(new Date()),
    })),
);

export const makeServices = (router = Router.BrowserRouter()) =>
  Layer.mergeAll(CreateTodo, Todos.replicateToStorage).pipe(
    Layer.provideMerge(Model),
    Layer.provideMerge([Todos.local, router]),
  );

export const Services = makeServices();

import * as Effect from "effect/Effect";
import * as Option from "effect/Option";
import * as Context from "effect/Context";
import { RefArray, RefSubject } from "@typed/fx";
import * as Domain from "./domain.js";

export class CreateTodo extends Context.Service<
  CreateTodo,
  (text: string) => Effect.Effect<Domain.Todo>
>()("CreateTodo") {
  static readonly call = (text: string) =>
    Effect.flatMap(CreateTodo, (createTodo) => createTodo(text));
}

export class TodoList extends RefSubject.Service<TodoList, Domain.TodoList>()("TodoList") {}

export class FilterState extends RefSubject.Service<FilterState, Domain.FilterState>()(
  "FilterState",
) {}

export class TodoText extends RefSubject.Service<TodoText, string>()("TodoText") {}

export const Todos: RefSubject.Computed<Domain.TodoList, never, TodoList | FilterState> =
  RefSubject.map(
    RefSubject.struct({
      list: TodoList,
      state: FilterState,
    }),
    Domain.filterTodoList,
  );

export const ActiveCount: RefSubject.Computed<number, never, TodoList> = RefSubject.map(
  TodoList,
  Domain.activeCount,
);

export const SomeAreCompleted: RefSubject.Computed<boolean, never, TodoList> = RefSubject.map(
  TodoList,
  Domain.someAreCompleted,
);

export const AllAreCompleted: RefSubject.Computed<boolean, never, TodoList> = RefSubject.map(
  TodoList,
  Domain.allAreCompleted,
);

export const createTodo: Effect.Effect<
  Option.Option<Domain.Todo>,
  never,
  CreateTodo | TodoList | TodoText
> = Effect.flatMap(TodoText, (text: string) =>
  text.trim() === ""
    ? Effect.succeed(Option.none<Domain.Todo>())
    : CreateTodo.call(text).pipe(
        Effect.tap((todo) => RefArray.prepend(TodoList, todo)),
        Effect.tap(() => RefSubject.set(TodoText, "")),
        Effect.asSome,
      ),
);

export const editTodo = (
  id: Domain.TodoId,
  text: string,
): Effect.Effect<Domain.TodoList, never, TodoList> =>
  text.trim() === "" ? deleteTodo(id) : RefSubject.update(TodoList, Domain.editText(id, text));

export const toggleTodoCompleted: (
  id: Domain.TodoId,
) => Effect.Effect<Domain.TodoList, never, TodoList> = (id) =>
  RefSubject.update(TodoList, Domain.toggleCompleted(id));

export const deleteTodo: (id: Domain.TodoId) => Effect.Effect<Domain.TodoList, never, TodoList> = (
  id,
) => RefSubject.update(TodoList, Domain.deleteTodo(id));

export const clearCompletedTodos: Effect.Effect<Domain.TodoList, never, TodoList> =
  RefSubject.update(TodoList, Domain.clearCompleted);

export const toggleAllCompleted: Effect.Effect<Domain.TodoList, never, TodoList> =
  RefSubject.update(TodoList, Domain.toggleAllCompleted);

// oxlint-disable require-yield
import { Effect } from "effect";
import { Fx, RefSubject } from "@typed/fx";
import { component, EventHandler, html, many } from "@typed/template";
import * as App from "./application.js";
import * as Domain from "./domain.js";
import { Link } from "@typed/ui/Link";

const HasTodos = RefSubject.map(App.TodoList, (list) => list.length > 0).pipe(Fx.skipRepeats);

const TodoItem = component(function* (todo: RefSubject.RefSubject<Domain.Todo>, id: Domain.TodoId) {
  const editing = yield* RefSubject.make(false);
  const draft = yield* RefSubject.make("");

  const text = RefSubject.map(todo, (value) => value.text);
  const completed = RefSubject.map(todo, (value) => value.completed);

  const begin = text.pipe(
    Effect.flatMap((value) => RefSubject.set(draft, value)),
    Effect.flatMap(() => RefSubject.set(editing, true)),
  );
  const cancel = RefSubject.set(editing, false);
  const save = draft.pipe(
    Effect.flatMap((value) => App.editTodo(id, value)),
    Effect.flatMap(() => cancel),
  );

  return html`<li
    class="${Fx.when(completed, { onTrue: "completed", onFalse: "" })} ${Fx.when(editing, { onTrue: "editing", onFalse: "" })}"
  >
    <div class="view">
      <input
        class="toggle"
        type="checkbox"
        aria-label="Complete ${text}"
        ?checked=${completed}
        onchange=${App.toggleTodoCompleted(id)}
      />
      <label ondblclick=${begin}>${text}</label>
      <button
        class="destroy"
        type="button"
        aria-label="Delete ${text}"
        onclick=${App.deleteTodo(id)}
      ></button>
    </div>
    <input
      class="edit"
      aria-label="Edit todo"
      .value=${draft}
      oninput=${EventHandler.make((event: InputEvent & { target: HTMLInputElement }) =>
        RefSubject.set(draft, event.target.value),
      )}
      onblur=${EventHandler.make(
        () => Effect.flatMap(editing, (isEditing) => (isEditing ? save : Effect.void)),
        { capture: true },
      )}
      onkeydown=${EventHandler.make((event: KeyboardEvent) => {
        if (event.key === "Escape") return cancel;
        if (event.key === "Enter") return save;

        return undefined;
      })}
    />
  </li>`;
});

const onInput = EventHandler.make((event: InputEvent & { target: HTMLInputElement }) =>
  RefSubject.set(App.TodoText, event.target.value),
);

const onNewTodoKeydown = EventHandler.make((event: KeyboardEvent) =>
  event.key === "Enter" ? App.createTodo : undefined,
);

export const TodoApp = html`<section class="todoapp">
  <header class="header">
    <h1>todos</h1>
    <input
      class="new-todo"
      aria-label="New todo"
      autofocus
      autocomplete="off"
      .value=${App.TodoText}
      oninput=${onInput}
      onkeydown=${onNewTodoKeydown}
      placeholder="What needs to be done?"
    />
  </header>
  ${Fx.if(HasTodos, {
    onTrue: html`<section class="main">
      <input
        id="toggle-all"
        class="toggle-all"
        type="checkbox"
        ?checked=${App.AllAreCompleted}
        onchange=${App.toggleAllCompleted}
      />
      <label for="toggle-all">Mark all as complete</label>
      <ul class="todo-list">
        ${many(App.Todos, (todo) => todo.id, TodoItem)}
      </ul>
    </section>
    <footer class="footer">
      <span class="todo-count"><strong>${App.ActiveCount}</strong>
        ${RefSubject.map(App.ActiveCount, (count) => (count === 1 ? " item" : " items"))} left</span>
      <ul class="filters">
        ${Domain.FilterState.literals.map(
          (filter) =>
            html`<li>
              ${Link({
                href: filter === "all" ? "/" : "/" + filter,
                content: filter[0]!.toUpperCase() + filter.slice(1),
                props: {
                  class: Fx.when(
                    RefSubject.map(App.FilterState, (current) => current === filter),
                    { onTrue: "selected", onFalse: "" },
                  ),
                },
              })}
            </li>`,
        )}
      </ul>
      ${Fx.if(App.SomeAreCompleted, {
        onTrue: html`<button
          class="clear-completed"
          type="button"
          onclick=${App.clearCompletedTodos}
        >
          Clear completed
        </button>`,
        onFalse: Fx.null,
      })}
    </footer>`,
    onFalse: Fx.null,
  })}
</section>
<footer class="info">
  <p>Double-click to edit a todo</p>
  <p>Part of <a href="http://todomvc.com">TodoMVC</a></p>
</footer>`;

import { Fx } from "@typed/fx";
import { ServerRouter } from "@typed/router";
import { TodoApp } from "./presentation.js";
import { makeServices } from "./infrastructure.js";

// Only the runtime router changes when this example is embedded in the website.
export const Preview = TodoApp.pipe(
  Fx.provide(makeServices(ServerRouter({ url: "https://tutorial.local/" }))),
);