import { ApiGatewayManagementApiClient, PostToConnectionCommand } from "@aws-sdk/client-apigatewaymanagementapi";
import { APIGatewayProxyHandlerV2 } from "aws-lambda";

export const main: APIGatewayProxyHandlerV2 = async (event) => {
  const body = event.body;
  const {domainName, stage, connectionId, routeKey} = event.requestContext;

  const apiGateway = new ApiGatewayManagementApiClient({
    endpoint: `https://${domainName}/${stage}`,
  });

  try {
    switch (routeKey) {
      case '$connect':
        return { statusCode: 200, body: 'Connected' };

      case '$disconnect':
        return { statusCode: 200, body: 'Disconnected' };

      default:
        console.log(`Received message: ${body}`);
      await sendMessageToClient(apiGateway, connectionId, `Echo: ${body}`);
      return { statusCode: 200, body: `Echoed: ${body}` };
    }
  } catch (error) {
    console.error('Error: ', error);
    return { statusCode: 500, body: 'Error processing request' };
  }
};

// メッセージをクライアントに送信する関数（修正済み）
const sendMessageToClient = async (apiGateway, connectionId, message) => {
  try {
    const command = new PostToConnectionCommand({
      ConnectionId: connectionId,
      Data: Buffer.from(message),
    });

    await apiGateway.send(command);
    console.log(`Sent message to ${connectionId}: ${message}`);
  } catch (error) {
    console.error(`Failed to send message to ${connectionId}:`, error);
  }
};