window_message.ts

import type { Message, MessageConnect, MessageSend, RuntimeMessageSender, TMessage } from "./types";
import { uuidv4 } from "@App/pkg/utils/uuid";
import EventEmitter from "eventemitter3";

// 通过 window.postMessage/onmessage 实现通信

export interface PostMessage {
  postMessage<T = any>(message: T): void;
}

class WindowPostMessage implements PostMessage {
  constructor(private target: Window) {}

  postMessage<T = any>(message: T): void {
    this.target.postMessage(message, "*");
  }
}

// 消息体
export type WindowMessageBody<T = any> = {
  messageId: string; // 消息id
  type: "sendMessage" | "respMessage" | "connect" | "disconnect" | "connectMessage"; // 消息类型
  data: T | null; // 消息数据
};

export class WindowMessage implements Message {
  EE = new EventEmitter<string, any>();

  // source: Window 消息来源
  // target: Window 消息目标
  constructor(
    private source: Window,
    private target: Window,
    private serviceWorker?: boolean
  ) {
    // 监听消息
    this.source.addEventListener("message", (e) => {
      if (e.source === this.target || e.source === this.source) {
        this.messageHandle(e.data, new WindowPostMessage(this.target));
      }
    });
    // 是否监听serviceWorker消息
    if (this.serviceWorker) {
      navigator.serviceWorker.addEventListener("message", (e) => {
        if (e.source) {
          this.messageHandle(e.data, e.source as Window);
        }
      });
    }
  }

  messageHandle(data: WindowMessageBody, target: PostMessage) {
    // 处理消息
    if (data.type === "sendMessage") {
      // 接收到消息
      this.EE.emit("message", data.data, (resp: any) => {
        // 发送响应消息
        // 无消息id则不发送响应消息
        if (!data.messageId) {
          return;
        }
        const body: WindowMessageBody = {
          messageId: data.messageId,
          type: "respMessage",
          data: resp,
        };
        target.postMessage(body);
      });
    } else if (data.type === "respMessage") {
      // 接收到响应消息
      this.EE.emit(`response:${data.messageId}`, data);
    } else if (data.type === "connect") {
      this.EE.emit("connect", data.data, new WindowMessageConnect(data.messageId, this.EE, target));
    } else if (data.type === "disconnect") {
      this.EE.emit(`disconnect:${data.messageId}`);
    } else if (data.type === "connectMessage") {
      this.EE.emit(`connectMessage:${data.messageId}`, data.data);
    }
  }

  onConnect(callback: (data: TMessage, con: MessageConnect) => void): void {
    this.EE.addListener("connect", callback);
  }

  connect(data: TMessage): Promise<MessageConnect> {
    return new Promise((resolve) => {
      const body: WindowMessageBody<TMessage> = {
        messageId: uuidv4(),
        type: "connect",
        data,
      };
      this.target.postMessage(body, "*");
      resolve(new WindowMessageConnect(body.messageId, this.EE, this.target));
    });
  }

  onMessage(
    callback: (data: TMessage, sendResponse: (data: any) => void, sender: RuntimeMessageSender) => boolean | void
  ): void {
    this.EE.addListener("message", callback);
  }

  // 发送消息 注意不进行回调的内存泄漏
  sendMessage<T = any>(data: TMessage): Promise<T> {
    return new Promise((resolve: ((value: T) => void) | null) => {
      const messageId = uuidv4();
      const body: WindowMessageBody<TMessage> = {
        messageId,
        type: "sendMessage",
        data,
      };
      const eventId = `response:${messageId}`;
      this.EE.addListener(eventId, (body: WindowMessageBody<TMessage>) => {
        this.EE.removeAllListeners(eventId);
        resolve!(body.data as T);
        resolve = null; // 设为 null 提醒JS引擎可以GC
      });
      this.target.postMessage(body, "*");
    });
  }
}

export class WindowMessageConnect implements MessageConnect {
  constructor(
    private messageId: string,
    private EE: EventEmitter<string, any>,
    private target: PostMessage
  ) {
    this.onDisconnect(() => {
      // 移除所有监听
      this.EE.removeAllListeners("connectMessage:" + this.messageId);
      this.EE.removeAllListeners("disconnect:" + this.messageId);
    });
  }

  sendMessage(data: TMessage) {
    const body: WindowMessageBody<TMessage> = {
      messageId: this.messageId,
      type: "connectMessage",
      data,
    };
    this.target.postMessage(body);
  }

  onMessage(callback: (data: TMessage) => void) {
    this.EE.addListener(`connectMessage:${this.messageId}`, callback);
  }

  disconnect() {
    const body: WindowMessageBody<TMessage> = {
      messageId: this.messageId,
      type: "disconnect",
      data: null,
    };
    this.target.postMessage(body);
  }

  onDisconnect(callback: () => void) {
    this.EE.addListener(`disconnect:${this.messageId}`, callback);
  }
}

// service_worker和offscreen同时监听消息,会导致消息被两边同时接收,但是返回结果时会产生问题,导致报错
// 不进行监听的话又无法从service_worker主动发送消息
// 所以service_worker与offscreen使用ServiceWorker的方式进行通信
export class ServiceWorkerMessageSend implements MessageSend {
  EE = new EventEmitter<string, any>();

  private target: PostMessage | undefined = undefined;

  constructor() {}

  listened: boolean = false;

  async init() {
    if (!this.target && self.clients) {
      if (!this.listened) {
        this.listened = true;
        self.addEventListener("message", (e) => {
          this.messageHandle(e.data);
        });
      }
      const list = await self.clients.matchAll({ includeUncontrolled: true, type: "window" });
      // 找到offscreen.html窗口
      this.target = list.find((client) => client.url == chrome.runtime.getURL("src/offscreen.html")) as PostMessage;
    }
  }

  messageHandle(data: WindowMessageBody) {
    // 处理消息
    if (data.type === "respMessage") {
      // 接收到响应消息
      this.EE.emit(`response:${data.messageId}`, data);
    } else if (data.type === "disconnect") {
      this.EE.emit(`disconnect:${data.messageId}`);
    } else if (data.type === "connectMessage") {
      this.EE.emit(`connectMessage:${data.messageId}`, data.data);
    }
  }

  async connect(data: TMessage): Promise<MessageConnect> {
    await this.init();
    const body: WindowMessageBody<TMessage> = {
      messageId: uuidv4(),
      type: "connect",
      data,
    };
    this.target!.postMessage(body);
    return new WindowMessageConnect(body.messageId, this.EE, this.target!);
  }

  // 发送消息 注意不进行回调的内存泄漏
  async sendMessage<T = any>(data: TMessage): Promise<T> {
    await this.init();
    return new Promise((resolve: ((value: T) => void) | null) => {
      const messageId = uuidv4();
      const body: WindowMessageBody<TMessage> = {
        messageId,
        type: "sendMessage",
        data,
      };
      const eventId = `response:${messageId}`;
      this.EE.addListener(eventId, (body: WindowMessageBody<TMessage>) => {
        this.EE.removeAllListeners(eventId);
        resolve!(body.data as T);
        resolve = null; // 设为 null 提醒JS引擎可以GC
      });
      this.target!.postMessage(body);
    });
  }
}