Todo.ts

/*!
 * Copyright (c) Microsoft Corporation and contributors. All rights reserved.
 * Licensed under the MIT License.
 */

import { DataObject, DataObjectFactory } from "@fluidframework/aqueduct";
import { IFluidHandle } from "@fluidframework/core-interfaces";
import { ISharedMap, SharedMap } from "@fluidframework/map";
import { SharedString } from "@fluidframework/sequence";
import { v4 as uuid } from "uuid";
import { ITodoItemInitialState, TodoItem, TodoItemFactory } from "../TodoItem";

export const TodoName = "Todo";

const todoItemsKey = "todo-items";
const todoTitleKey = "todo-title";

/**
 * Todo data object.
 * Contains the following:
 * - Title
 * - List of todo items
 */
export class Todo extends DataObject {
    private _todoItemsMap: ISharedMap | undefined;
    private get todoItemsMap(): ISharedMap {
        if (this._todoItemsMap === undefined) {
            throw new Error("Attempted to access todoItemsMap before initialized");
        }
        return this._todoItemsMap;
    }

    /**
     * Create the map for todo items and a string for the title
     */
    protected async initializingFirstTime() {
        const map = SharedMap.create(this.runtime);
        this.root.set(todoItemsKey, map.handle);

        const text = SharedString.create(this.runtime);
        text.insertText(0, "Title");
        this.root.set(todoTitleKey, text.handle);
    }

    protected async hasInitialized() {
        const todoItemsHandle = this.root.get<IFluidHandle<ISharedMap>>(todoItemsKey);
        if (todoItemsHandle === undefined) {
            throw new Error("Todo items ISharedMap missing");
        }
        this._todoItemsMap = await todoItemsHandle.get();
        // Hide the DDS eventing used by the model, expose a model-specific event interface.
        this.todoItemsMap.on("valueChanged", (changed, local) => {
            if (!local) {
                this.emit("todoItemsChanged");
            }
        });
    }

    // start public API surface for the Todo model, used by the view

    // Would prefer not to hand this out, and instead give back a title object?
    public async getTodoTitleString() {
        const todoTitleHandle = this.root.get<IFluidHandle<SharedString>>(todoTitleKey);
        if (todoTitleHandle === undefined) {
            throw new Error("Todo title SharedString missing");
        }
        return todoTitleHandle.get();
    }

    public async addTodoItem(props?: ITodoItemInitialState) {
        // Create a new todo item
        const todoItem = await TodoItemFactory.createChildInstance(this.context, props);

        // Generate an ID that we can sort on later, and store the handle.
        const id = `${Date.now()}-${uuid()}`;

        this.todoItemsMap.set(
            id,
            todoItem.handle,
        );

        this.emit("todoItemsChanged");
    }

    public async getTodoItems(): Promise<[string, TodoItem][]> {
        const todoItemsEntries: [string, IFluidHandle<TodoItem>][] = [...this.todoItemsMap.entries()];
        const todoItemsEntriesResolvedP = todoItemsEntries.map(
            async ([key, todoItemHandle]): Promise<[string, TodoItem]> => {
                const todoItem = await todoItemHandle.get();
                return [key, todoItem];
            },
        );
        const todoItemsEntriesResolved = await Promise.all(todoItemsEntriesResolvedP);
        todoItemsEntriesResolved.sort((entryA, entryB) => {
            // Sort on keys as strings
            return entryA[0].localeCompare(entryB[0]);
        });
        return todoItemsEntriesResolved;
    }

    public async getTodoItem(id: string) {
        const maybeHandle: IFluidHandle<TodoItem> | undefined = this.todoItemsMap.get(id);
        if (maybeHandle !== undefined) {
            return maybeHandle.get();
        }
    }

    public deleteTodoItem(id: string) {
        if (this.todoItemsMap.delete(id)) {
            this.emit("todoItemsChanged");
        }
    }

    // end public API surface for the Todo model, used by the view
}

export const TodoFactory = new DataObjectFactory(
    TodoName,
    Todo,
    [
        SharedMap.getFactory(),
        SharedString.getFactory(),
    ],
    {},
    new Map([
        TodoItemFactory.registryEntry,
    ]),
);