import { Controller, Post, Get, Body, Query, Logger, HttpException } from '@nestjs/common';
import { WidgetService } from './widget.service';
import { createHmac } from 'crypto';

@Controller('api/webhook')
export class WebhooksController {
    private readonly logger = new Logger(WebhooksController.name);
    private readonly googleWebhookKey: string;
    private readonly fbVerifyToken: string;

    constructor(private readonly widget: WidgetService) {
        this.googleWebhookKey = process.env.GOOGLE_WEBHOOK_KEY ?? '';
        this.fbVerifyToken = process.env.FB_VERIFY_TOKEN ?? 'helix-engage-verify';
    }

    // ─── Facebook / Instagram Lead Ads ───

    // Webhook verification (Meta sends GET to verify endpoint)
    @Get('facebook')
    verifyFacebook(
        @Query('hub.mode') mode: string,
        @Query('hub.verify_token') token: string,
        @Query('hub.challenge') challenge: string,
    ) {
        if (mode === 'subscribe' && token === this.fbVerifyToken) {
            this.logger.log('[FB] Webhook verified');
            return challenge;
        }
        throw new HttpException('Verification failed', 403);
    }

    // Receive leads from Facebook/Instagram
    @Post('facebook')
    async facebookLead(@Body() body: any) {
        this.logger.log(`[FB] Webhook received: ${JSON.stringify(body).substring(0, 200)}`);

        if (body.object !== 'page') {
            return { status: 'ignored', reason: 'not a page event' };
        }

        let leadsCreated = 0;

        for (const entry of body.entry ?? []) {
            for (const change of entry.changes ?? []) {
                if (change.field !== 'leadgen') continue;

                const leadData = change.value;
                const leadgenId = leadData.leadgen_id;
                const formId = leadData.form_id;
                const pageId = leadData.page_id;

                this.logger.log(`[FB] Lead received: leadgen_id=${leadgenId} form_id=${formId} page_id=${pageId}`);

                // Fetch full lead data from Meta Graph API
                const lead = await this.fetchFacebookLead(leadgenId);
                if (!lead) {
                    this.logger.warn(`[FB] Could not fetch lead data for ${leadgenId}`);
                    continue;
                }

                const name = this.extractFbField(lead, 'full_name') ?? 'Facebook Lead';
                const phone = this.extractFbField(lead, 'phone_number') ?? '';
                const email = this.extractFbField(lead, 'email') ?? '';

                try {
                    await this.widget.createLead({
                        name,
                        phone: phone.replace(/[^0-9+]/g, ''),
                        interest: `Facebook Ad (form: ${formId})`,
                        message: email ? `Email: ${email}` : undefined,
                        captchaToken: 'webhook-bypass',
                    });
                    leadsCreated++;
                    this.logger.log(`[FB] Lead created: ${name} (${phone})`);
                } catch (err: any) {
                    this.logger.error(`[FB] Lead creation failed: ${err.message}`);
                }
            }
        }

        return { status: 'ok', leadsCreated };
    }

    private async fetchFacebookLead(leadgenId: string): Promise<any | null> {
        const accessToken = process.env.FB_PAGE_ACCESS_TOKEN;
        if (!accessToken) {
            this.logger.warn('[FB] FB_PAGE_ACCESS_TOKEN not set — cannot fetch lead details');
            return null;
        }

        try {
            const res = await fetch(`https://graph.facebook.com/v21.0/${leadgenId}?access_token=${accessToken}`);
            if (!res.ok) return null;
            return res.json();
        } catch {
            return null;
        }
    }

    private extractFbField(lead: any, fieldName: string): string | null {
        const fields = lead.field_data ?? [];
        const field = fields.find((f: any) => f.name === fieldName);
        return field?.values?.[0] ?? null;
    }

    // ─── Google Ads Lead Form ───

    @Post('google')
    async googleLead(@Body() body: any) {
        this.logger.log(`[GOOGLE] Webhook received: ${JSON.stringify(body).substring(0, 200)}`);

        // Verify webhook key if configured
        if (this.googleWebhookKey && body.google_key) {
            const expected = createHmac('sha256', this.googleWebhookKey)
                .update(body.lead_id ?? '')
                .digest('hex');
            // Google sends the key directly, not as HMAC — just compare
            if (body.google_key !== this.googleWebhookKey) {
                this.logger.warn('[GOOGLE] Invalid webhook key');
                throw new HttpException('Invalid webhook key', 403);
            }
        }

        const isTest = body.is_test === true;
        const leadId = body.lead_id;
        const campaignId = body.campaign_id;
        const formId = body.form_id;

        // Extract user data from column data
        const userData = body.user_column_data ?? [];
        const name = this.extractGoogleField(userData, 'FULL_NAME')
            ?? this.extractGoogleField(userData, 'FIRST_NAME')
            ?? 'Google Ad Lead';
        const phone = this.extractGoogleField(userData, 'PHONE_NUMBER') ?? '';
        const email = this.extractGoogleField(userData, 'EMAIL') ?? '';
        const city = this.extractGoogleField(userData, 'CITY') ?? '';

        this.logger.log(`[GOOGLE] Lead: ${name} | ${phone} | campaign=${campaignId} | test=${isTest}`);

        try {
            const result = await this.widget.createLead({
                name,
                phone: phone.replace(/[^0-9+]/g, ''),
                interest: `Google Ad${isTest ? ' (TEST)' : ''} (campaign: ${campaignId ?? 'unknown'})`,
                message: [email, city].filter(Boolean).join(', ') || undefined,
                captchaToken: 'webhook-bypass',
            });

            this.logger.log(`[GOOGLE] Lead created: ${result.leadId}${isTest ? ' (test)' : ''}`);
            return { status: 'ok', leadId: result.leadId, isTest };
        } catch (err: any) {
            this.logger.error(`[GOOGLE] Lead creation failed: ${err.message}`);
            throw new HttpException('Lead creation failed', 500);
        }
    }

    private extractGoogleField(columnData: any[], fieldName: string): string | null {
        const field = columnData.find((f: any) => f.column_id === fieldName);
        return field?.string_value ?? null;
    }

    // ─── Ozonetel WhatsApp Callback ───
    // Configure in Ozonetel: Chat Callback URL → https://engage-api.srv1477139.hstgr.cloud/api/webhook/whatsapp
    // Payload format will be adapted once Ozonetel confirms their schema

    @Post('whatsapp')
    async whatsappLead(@Body() body: any) {
        this.logger.log(`[WHATSAPP] Webhook received: ${JSON.stringify(body).substring(0, 300)}`);

        const phone = body.from ?? body.caller_id ?? body.phone ?? body.customerNumber ?? '';
        const name = body.name ?? body.customerName ?? '';
        const message = body.message ?? body.text ?? body.body ?? '';

        if (!phone) {
            this.logger.warn('[WHATSAPP] No phone number in payload');
            return { status: 'ignored', reason: 'no phone number' };
        }

        try {
            const result = await this.widget.createLead({
                name: name || 'WhatsApp Lead',
                phone: phone.replace(/[^0-9+]/g, ''),
                interest: 'WhatsApp Enquiry',
                message: message || undefined,
                captchaToken: 'webhook-bypass',
            });
            this.logger.log(`[WHATSAPP] Lead created: ${result.leadId} (${phone})`);
            return { status: 'ok', leadId: result.leadId };
        } catch (err: any) {
            this.logger.error(`[WHATSAPP] Lead creation failed: ${err.message}`);
            return { status: 'error', message: err.message };
        }
    }

    // ─── Ozonetel SMS Callback ───
    // Configure in Ozonetel: SMS Callback URL → https://engage-api.srv1477139.hstgr.cloud/api/webhook/sms

    @Post('sms')
    async smsLead(@Body() body: any) {
        this.logger.log(`[SMS] Webhook received: ${JSON.stringify(body).substring(0, 300)}`);

        const phone = body.from ?? body.caller_id ?? body.phone ?? body.senderNumber ?? '';
        const name = body.name ?? '';
        const message = body.message ?? body.text ?? body.body ?? '';

        if (!phone) {
            this.logger.warn('[SMS] No phone number in payload');
            return { status: 'ignored', reason: 'no phone number' };
        }

        try {
            const result = await this.widget.createLead({
                name: name || 'SMS Lead',
                phone: phone.replace(/[^0-9+]/g, ''),
                interest: 'SMS Enquiry',
                message: message || undefined,
                captchaToken: 'webhook-bypass',
            });
            this.logger.log(`[SMS] Lead created: ${result.leadId} (${phone})`);
            return { status: 'ok', leadId: result.leadId };
        } catch (err: any) {
            this.logger.error(`[SMS] Lead creation failed: ${err.message}`);
            return { status: 'error', message: err.message };
        }
    }
}