/*
 * Copyright (C) 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import {FunctionUtils} from 'common/function_utils';
import {OnBugreportReceived, RemoteBugreportReceiver} from 'interfaces/remote_bugreport_receiver';
import {OnTimestampReceived, RemoteTimestampReceiver} from 'interfaces/remote_timestamp_receiver';
import {RemoteTimestampSender} from 'interfaces/remote_timestamp_sender';
import {RealTimestamp} from 'trace/timestamp';
import {Message, MessageBugReport, MessagePong, MessageTimestamp, MessageType} from './messages';
import {OriginAllowList} from './origin_allow_list';

class RemoteTool {
  constructor(readonly window: Window, readonly origin: string) {}
}

export class CrossToolProtocol
  implements RemoteBugreportReceiver, RemoteTimestampReceiver, RemoteTimestampSender
{
  private remoteTool?: RemoteTool;
  private onBugreportReceived: OnBugreportReceived = FunctionUtils.DO_NOTHING_ASYNC;
  private onTimestampReceived: OnTimestampReceived = FunctionUtils.DO_NOTHING_ASYNC;

  constructor() {
    window.addEventListener('message', async (event) => {
      await this.onMessageReceived(event);
    });
  }

  setOnBugreportReceived(callback: OnBugreportReceived) {
    this.onBugreportReceived = callback;
  }

  setOnTimestampReceived(callback: OnTimestampReceived) {
    this.onTimestampReceived = callback;
  }

  sendTimestamp(timestamp: RealTimestamp) {
    if (!this.remoteTool) {
      return;
    }

    const message = new MessageTimestamp(timestamp.getValueNs());
    this.remoteTool.window.postMessage(message, this.remoteTool.origin);
    console.log('Cross-tool protocol sent timestamp message:', message);
  }

  private async onMessageReceived(event: MessageEvent) {
    if (!OriginAllowList.isAllowed(event.origin)) {
      console.log(
        'Cross-tool protocol ignoring message from non-allowed origin.',
        'Origin:',
        event.origin,
        'Message:',
        event.data
      );
      return;
    }

    const message = event.data as Message;
    if (message.type === undefined) {
      return;
    }

    if (!this.remoteTool) {
      this.remoteTool = new RemoteTool(event.source as Window, event.origin);
    }

    switch (message.type) {
      case MessageType.PING:
        console.log('Cross-tool protocol received ping message:', message);
        (event.source as Window).postMessage(new MessagePong(), event.origin);
        break;
      case MessageType.PONG:
        console.log('Cross-tool protocol received unexpected pong message:', message);
        break;
      case MessageType.BUGREPORT:
        console.log('Cross-tool protocol received bugreport message:', message);
        await this.onMessageBugreportReceived(message as MessageBugReport);
        console.log('Cross-tool protocol processes bugreport message:', message);
        break;
      case MessageType.TIMESTAMP:
        console.log('Cross-tool protocol received timestamp message:', message);
        await this.onMessageTimestampReceived(message as MessageTimestamp);
        console.log('Cross-tool protocol processed timestamp message:', message);
        break;
      case MessageType.FILES:
        console.log('Cross-tool protocol received unexpected files message', message);
        break;
      default:
        console.log('Cross-tool protocol received unsupported message type:', message);
        break;
    }
  }

  private async onMessageBugreportReceived(message: MessageBugReport) {
    const timestamp =
      message.timestampNs !== undefined ? new RealTimestamp(message.timestampNs) : undefined;
    await this.onBugreportReceived(message.file, timestamp);
  }

  private async onMessageTimestampReceived(message: MessageTimestamp) {
    const timestamp = new RealTimestamp(message.timestampNs);
    await this.onTimestampReceived(timestamp);
  }
}