helix-engage-server/src/messaging/messaging.controller.ts

import { Controller, Post, Get, Body, Param, Res, Logger } from '@nestjs/common';
import type { Response } from 'express';
import { MessagingProvider } from './providers/messaging-provider.interface';
import { MessagingService } from './messaging.service';
import { QrService } from './qr.service';

@Controller('api/messaging')
export class MessagingController {
    private readonly logger = new Logger(MessagingController.name);

    constructor(
        private readonly provider: MessagingProvider,
        private readonly messaging: MessagingService,
        private readonly qr: QrService,
    ) {}

    @Post('webhook')
    async webhook(@Body() body: any) {
        this.logger.log(`[WA-WEBHOOK] Received: ${JSON.stringify(body).substring(0, 500)}`);

        if (!this.provider.validateWebhook(body)) {
            this.logger.warn('[WA-WEBHOOK] Validation failed — ignoring');
            return { status: 'ignored', reason: 'validation failed' };
        }

        const message = this.provider.parseInbound(body);
        if (!message) {
            this.logger.log('[WA-WEBHOOK] Non-message event — skipped');
            return { status: 'ok', type: body?.type ?? 'unknown' };
        }

        // Handle async — don't block webhook response
        this.messaging.handleInbound(message).catch(err => {
            this.logger.error(`[WA-WEBHOOK] handleInbound failed: ${err.message}`);
        });

        return { status: 'ok' };
    }

    // Serve QR code images — Gupshup needs a public URL to send images
    @Get('qr/:appointmentId')
    async serveQr(@Param('appointmentId') appointmentId: string, @Res() res: Response) {
        const png = this.qr.get(appointmentId);
        if (!png) {
            res.status(404).json({ error: 'QR code not found or expired' });
            return;
        }
        res.set('Content-Type', 'image/png');
        res.set('Cache-Control', 'public, max-age=86400');
        res.send(png);
    }
}