import { Controller, Get, Post, Query, Body, HttpCode, HttpStatus, Logger, Res } from '@nestjs/common';
import { Response } from 'express';
import { InstagramService } from './instagram.service';

@Controller('webhook')
export class InstagramController {
  private readonly logger = new Logger(InstagramController.name);

  constructor(private readonly instagramService: InstagramService) {}

  /**
   * Webhook verification endpoint required by Meta.
   * Responds to the GET request with the hub.challenge if verify_token matches.
   */
  @Get()
  verifyWebhook(
    @Query('hub.mode') mode: string,
    @Query('hub.verify_token') verifyToken: string,
    @Query('hub.challenge') challenge: string,
    @Res() res: Response
  ) {
    const localVerifyToken = process.env.META_VERIFY_TOKEN || 'kodelyx_verify_token_2026';
    
    this.logger.log(`Received Meta verification request: token=${verifyToken}, mode=${mode}`);

    if (mode === 'subscribe' && verifyToken === localVerifyToken) {
      this.logger.log('Webhook successfully verified!');
      return res.status(HttpStatus.OK).send(challenge);
    } else {
      this.logger.warn('Webhook verification failed: token mismatch');
      return res.status(HttpStatus.FORBIDDEN).send('Verification failed');
    }
  }

  /**
   * Receives events from Instagram (comments, messages, mentions).
   */
  @Post()
  @HttpCode(HttpStatus.OK)
  async handleWebhookEvents(@Body() body: any) {
    this.logger.log('Received webhook event from Meta');

    // Make sure it is an instagram object
    if (body.object !== 'instagram') {
      this.logger.warn(`Ignored event: object type is ${body.object}`);
      return { status: 'ignored' };
    }

    try {
      const entries = body.entry || [];

      for (const entry of entries) {
        const instagramId = entry.id; // Instagram Business Account ID
        const changes = entry.changes || [];

        for (const change of changes) {
          // Check if the change is a comment event
          if (change.field === 'comments') {
            const commentVal = change.value;
            const commentId = commentVal.id;
            const commentText = commentVal.text;
            const senderId = commentVal.from?.id;

            if (commentId && commentText && senderId) {
              this.logger.log(
                `Processing comment trigger from Instagram user ID ${senderId}: "${commentText}"`
              );
              
              // Run the background trigger processing
              this.instagramService.processCommentWebhook(
                instagramId,
                commentId,
                commentText,
                senderId
              ).catch((err) => {
                this.logger.error(`Error in webhook processing async handler: ${err.message}`);
              });
            }
          }
        }
      }

      return { status: 'processed' };
    } catch (error: any) {
      this.logger.error(`Failed to handle webhook POST request: ${error.message}`);
      return { status: 'error', message: error.message };
    }
  }
}