Todo work

packages/example/src/todos/services/TodosState.ts

@@ -0,0 +1,64 @@
+import { Todo } from "@/domain"
+import { KeyValueStore } from "@effect/platform"
+import { BrowserKeyValueStore } from "@effect/platform-browser"
+import { PlatformError } from "@effect/platform/Error"
+import { Cause, Chunk, Context, Effect, identity, Layer, ParseResult, Ref, Schema, SubscriptionRef } from "effect"
+
+
+export class TodosState extends Context.Tag("TodosState")<TodosState, {
+    readonly todos: SubscriptionRef.SubscriptionRef<Chunk.Chunk<Todo.Todo>>
+
+    readonly readFromLocalStorage: Effect.Effect<void, Cause.NoSuchElementException | PlatformError | ParseResult.ParseError>
+    readonly saveToLocalStorage: Effect.Effect<void, PlatformError | ParseResult.ParseError>
+
+    readonly prepend: (todo: Todo.Todo) => Effect.Effect<void>
+    readonly remove: (index: number) => Effect.Effect<void>
+    // readonly moveUp: (index: number) => Effect.Effect<void, Cause.NoSuchElementException>
+    // readonly moveDown: (index: number) => Effect.Effect<void, Cause.NoSuchElementException>
+}>() {}
+
+
+export const make = (key: string) => Layer.effect(TodosState, Effect.gen(function*() {
+    const todos = yield* SubscriptionRef.make(Chunk.empty<Todo.Todo>())
+
+    const readFromLocalStorage = KeyValueStore.KeyValueStore.pipe(
+        Effect.flatMap(kv => kv.get(key)),
+        Effect.flatMap(identity),
+        Effect.flatMap(Schema.parseJson().pipe(
+            Schema.compose(Schema.Chunk(Todo.TodoFromJson)),
+            Schema.decode,
+        )),
+        Effect.flatMap(v => Ref.set(todos, v)),
+
+        Effect.provide(BrowserKeyValueStore.layerLocalStorage),
+    )
+
+    const saveToLocalStorage = Effect.all([KeyValueStore.KeyValueStore, todos]).pipe(
+        Effect.flatMap(([kv, values]) => values.pipe(
+            Schema.parseJson().pipe(
+                Schema.compose(Schema.Chunk(Todo.TodoFromJson)),
+                Schema.encode,
+            ),
+            Effect.flatMap(v => kv.set(key, v)),
+        )),
+
+        Effect.provide(BrowserKeyValueStore.layerLocalStorage),
+    )
+
+    const prepend = (todo: Todo.Todo) => Ref.update(todos, Chunk.prepend(todo))
+    const remove = (index: number) => Ref.update(todos, Chunk.remove(index))
+
+    // const moveUp = (index: number) => Effect.gen(function*() {
+
+    // })
+
+    yield* readFromLocalStorage
+
+    return {
+        todos,
+        readFromLocalStorage,
+        saveToLocalStorage,
+        prepend,
+        remove,
+    }
+}))