import type { FastifyInstance } from 'fastify';
import { Prisma } from '@prisma/client';
import { prisma } from '../../db.js';
import { env } from '../../env.js';

// Точка не подписывает webhook-ы; защита — секрет в URL (rotatable через .env),
// raw-store перед обработкой, dedupe по комбинации (source, eventType, externalId).

type TochkaWebhookPayload = {
  webhookType?: string;
  paymentId?: string;
  amount?: number;
  payerInn?: string;
  payerName?: string;
  purpose?: string;
  paidAt?: string;
  Data?: TochkaWebhookPayload;
};

function flatten(p: TochkaWebhookPayload): TochkaWebhookPayload {
  return { ...p, ...(p.Data ?? {}) };
}

function extractDocNumber(purpose: string | undefined): string | null {
  if (!purpose) return null;
  // популярные форматы: «Оплата по счёту № 123 от ...», «по счёту №ДГ-2026/001», «инвойс 123»
  const m = purpose.match(/(?:сч[её]т|инвойс|invoice|№)[^\dA-ZА-Я]*([A-ZА-Я0-9][A-ZА-Я0-9\-_/]{0,49})/i);
  return m && m[1] ? m[1].replace(/[.,;:]+$/, '') : null;
}

const PAYMENT_KIND_MAP: Record<string, 'incoming' | 'incoming_sbp' | 'incoming_sbp_b2b' | 'outgoing'> = {
  incomingPayment: 'incoming',
  incomingSbpPayment: 'incoming_sbp',
  incomingSbpB2BPayment: 'incoming_sbp_b2b',
  outgoingPayment: 'outgoing',
};

export async function tochkaWebhookRoutes(app: FastifyInstance) {
  app.post('/webhooks/tochka/:secret', async (req, reply) => {
    const { secret } = req.params as { secret: string };
    if (!env.TOCHKA_WEBHOOK_SECRET || secret !== env.TOCHKA_WEBHOOK_SECRET) {
      reply.code(404).send({ error: 'not_found' });
      return;
    }

    const body = (req.body ?? {}) as TochkaWebhookPayload;
    const flat = flatten(body);
    const eventType = flat.webhookType ?? 'unknown';
    const externalId = flat.paymentId ?? null;

    const dedupeKey = `tochka:${eventType}:${externalId ?? JSON.stringify(flat).slice(0, 100)}`;

    let event;
    try {
      event = await prisma.webhookEvent.create({
        data: {
          source: 'tochka',
          eventType,
          dedupeKey,
          raw: body as Prisma.InputJsonValue,
        },
      });
    } catch (e) {
      if ((e as { code?: string }).code === 'P2002') {
        app.log.info({ dedupeKey }, 'webhook dedupe hit');
        return { ok: true, deduped: true };
      }
      throw e;
    }

    try {
      const kind = PAYMENT_KIND_MAP[eventType];
      if (!kind || !externalId) {
        await prisma.webhookEvent.update({
          where: { id: event.id },
          data: { processedAt: new Date(), error: 'unsupported_event_type' },
        });
        return { ok: true, ignored: true };
      }

      let docId: string | null = null;
      const docNumber = extractDocNumber(flat.purpose);
      if (docNumber) {
        const doc = await prisma.document.findFirst({
          where: { number: docNumber, docType: 'invoice' },
          select: { id: true, organizationId: true },
        });
        if (doc) docId = doc.id;
      }

      const fallbackOrg = await prisma.organization.findFirst({ where: { archivedAt: null }, select: { id: true } });
      const orgId = docId
        ? (await prisma.document.findUnique({ where: { id: docId }, select: { organizationId: true } }))!.organizationId
        : fallbackOrg!.id;

      const amount = typeof flat.amount === 'number' ? Math.round(flat.amount * 100) : 0;
      try {
        await prisma.payment.create({
          data: {
            organizationId: orgId,
            documentId: docId,
            tochkaPaymentId: externalId,
            kind,
            amountCents: BigInt(amount),
            payerInn: flat.payerInn ?? null,
            payerName: flat.payerName ?? null,
            purpose: flat.purpose ?? null,
            paidAt: flat.paidAt ? new Date(flat.paidAt) : null,
            raw: body as Prisma.InputJsonValue,
          },
        });
      } catch (e) {
        if ((e as { code?: string }).code !== 'P2002') throw e;
      }

      if (docId) {
        const doc = await prisma.document.findUnique({
          where: { id: docId },
          include: { payments: true },
        });
        if (doc) {
          const incoming = doc.payments
            .filter((p) => p.kind === 'incoming' || p.kind === 'incoming_sbp' || p.kind === 'incoming_sbp_b2b')
            .reduce((s, p) => s + p.amountCents, 0n);
          const newStatus =
            incoming >= doc.totalCents ? 'paid' : incoming > 0n ? 'partially_paid' : doc.status;
          if (newStatus !== doc.status) {
            await prisma.document.update({ where: { id: docId }, data: { status: newStatus } });
          }

          // Если документ привязан к Order через project → обновить Order.status
          if (doc.projectId) {
            const order = await prisma.order.findFirst({
              where: { projectId: doc.projectId },
              select: { id: true },
            });
            if (order && newStatus === 'paid') {
              await prisma.order.update({ where: { id: order.id }, data: { status: 'paid' } });
            }
          }
        }
      }

      await prisma.webhookEvent.update({
        where: { id: event.id },
        data: { processedAt: new Date() },
      });
      return { ok: true, matchedDocument: docId };
    } catch (e) {
      const msg = (e as Error).message ?? 'unknown';
      app.log.error({ err: e, dedupeKey }, 'webhook processing failed');
      await prisma.webhookEvent.update({
        where: { id: event.id },
        data: { error: msg.slice(0, 500) },
      });
      return { ok: false, error: 'processing_failed' };
    }
  });
}