import { Router, Response } from 'express';
import { PrismaClient, TicketCategory, TicketPriority, TicketStatus } from '@prisma/client';
import PDFDocument from 'pdfkit';
import { AuthedRequest, requireAuth, requireRole } from '../middleware/auth';

const prisma = new PrismaClient();

/**
 * Router für Schadensmeldungen/Tickets.
 *
 * Zugriffsregel (Kern der Berechtigungslogik): ein Mieter darf nur Tickets sehen,
 * die er selbst erstellt hat, die einen Gemeinschaftsbereich betreffen (roomId
 * = null, z. B. Küche/Bad/Allgemein) oder die sein eigenes Zimmer betreffen.
 * Tickets zu den privaten Zimmern anderer Mieter sind für ihn unsichtbar.
 * Vermieter/Admin sehen alles.
 */
export const ticketsRouter = Router();

const CATEGORIES = Object.values(TicketCategory);
const PRIORITIES = Object.values(TicketPriority);

async function getOwnRoomId(userId: string): Promise<string | null> {
  const user = await prisma.user.findUnique({ where: { id: userId }, select: { roomId: true } });
  return user?.roomId ?? null;
}

const TICKET_SELECT = {
  id: true,
  title: true,
  description: true,
  category: true,
  priority: true,
  status: true,
  imageUrls: true,
  createdAt: true,
  resolvedAt: true,
  room: { select: { id: true, roomNumber: true } },
  creator: { select: { id: true, fullName: true } },
  assignee: { select: { id: true, fullName: true } },
  craftsman: { select: { id: true, name: true, trade: true, phone: true, email: true } },
};

ticketsRouter.post('/tickets', requireAuth, async (req: AuthedRequest, res: Response) => {
  const { title, description, category, priority, roomId } = req.body || {};

  if (!title || typeof title !== 'string' || !title.trim()) {
    return res.status(400).json({ error: 'Titel ist erforderlich' });
  }
  if (!description || typeof description !== 'string' || !description.trim()) {
    return res.status(400).json({ error: 'Beschreibung ist erforderlich' });
  }
  if (!category || !CATEGORIES.includes(category)) {
    return res.status(400).json({ error: `Ungültige Kategorie. Erlaubt: ${CATEGORIES.join(', ')}` });
  }
  if (priority && !PRIORITIES.includes(priority)) {
    return res.status(400).json({ error: `Ungültige Priorität. Erlaubt: ${PRIORITIES.join(', ')}` });
  }

  const isLandlord = req.user!.role === 'LANDLORD' || req.user!.role === 'ADMIN';
  let targetRoomId: string | null = roomId || null;

  if (!isLandlord) {
    // Mieter dürfen nur für ihr eigenes Zimmer oder allgemein (Gemeinschaftsbereich) melden.
    const ownRoomId = await getOwnRoomId(req.user!.id);
    if (targetRoomId && targetRoomId !== ownRoomId) {
      return res.status(403).json({ error: 'Du kannst nur für dein eigenes Zimmer oder den Gemeinschaftsbereich melden' });
    }
  } else if (targetRoomId) {
    const room = await prisma.room.findUnique({ where: { id: targetRoomId } });
    if (!room) return res.status(400).json({ error: 'Zimmer nicht gefunden' });
  }

  const ticket = await prisma.ticket.create({
    data: {
      creatorId: req.user!.id,
      roomId: targetRoomId,
      title: title.trim(),
      description: description.trim(),
      category,
      priority: priority || TicketPriority.MEDIUM,
      status: TicketStatus.OPEN,
    },
    select: TICKET_SELECT,
  });

  res.status(201).json({ ticket });
});

ticketsRouter.get('/tickets', requireAuth, async (req: AuthedRequest, res: Response) => {
  const isLandlord = req.user!.role === 'LANDLORD' || req.user!.role === 'ADMIN';
  const statusFilter = typeof req.query.status === 'string' ? req.query.status : undefined;

  const where: Record<string, unknown> = {};
  if (statusFilter && (Object.values(TicketStatus) as string[]).includes(statusFilter)) {
    where.status = statusFilter;
  }

  if (!isLandlord) {
    const ownRoomId = await getOwnRoomId(req.user!.id);
    where.OR = [
      { creatorId: req.user!.id },
      { roomId: null },
      ...(ownRoomId ? [{ roomId: ownRoomId }] : []),
    ];
  }

  const tickets = await prisma.ticket.findMany({
    where,
    orderBy: { createdAt: 'desc' },
    select: TICKET_SELECT,
  });

  res.status(200).json({ tickets });
});

ticketsRouter.patch(
  '/tickets/:id',
  requireAuth,
  requireRole('LANDLORD', 'ADMIN'),
  async (req: AuthedRequest, res: Response) => {
    const { status, priority, assigneeId, craftsmanId } = req.body || {};
    const data: Record<string, unknown> = {};

    if (status !== undefined) {
      if (!(Object.values(TicketStatus) as string[]).includes(status)) {
        return res.status(400).json({ error: `Ungültiger Status. Erlaubt: ${Object.values(TicketStatus).join(', ')}` });
      }
      data.status = status;
      data.resolvedAt = status === 'RESOLVED' || status === 'CLOSED' ? new Date() : null;
    }
    if (priority !== undefined) {
      if (!PRIORITIES.includes(priority)) {
        return res.status(400).json({ error: `Ungültige Priorität. Erlaubt: ${PRIORITIES.join(', ')}` });
      }
      data.priority = priority;
    }
    if (assigneeId !== undefined) {
      data.assigneeId = assigneeId || null;
    }
    if (craftsmanId !== undefined) {
      data.craftsmanId = craftsmanId || null;
    }

    if (Object.keys(data).length === 0) {
      return res.status(400).json({ error: 'Keine Änderungen übergeben' });
    }

    try {
      const ticket = await prisma.ticket.update({
        where: { id: req.params.id },
        data,
        select: TICKET_SELECT,
      });
      res.status(200).json({ ticket });
    } catch {
      res.status(404).json({ error: 'Ticket nicht gefunden' });
    }
  },
);

// Mieter dürfen ihre eigene Meldung zurückziehen, solange sie noch nicht bearbeitet wird.
ticketsRouter.delete('/tickets/:id', requireAuth, async (req: AuthedRequest, res: Response) => {
  const ticket = await prisma.ticket.findUnique({ where: { id: req.params.id } });
  if (!ticket) return res.status(404).json({ error: 'Ticket nicht gefunden' });

  const isLandlord = req.user!.role === 'LANDLORD' || req.user!.role === 'ADMIN';
  const isOwnOpenTicket = ticket.creatorId === req.user!.id && ticket.status === 'OPEN';

  if (!isLandlord && !isOwnOpenTicket) {
    return res.status(403).json({ error: 'Keine Berechtigung, dieses Ticket zurückzuziehen' });
  }

  await prisma.ticket.delete({ where: { id: req.params.id } });
  res.status(204).send();
});

const CATEGORY_LABELS: Record<TicketCategory, string> = {
  SANITAER: 'Sanitär',
  ELEKTRIK: 'Elektrik',
  MOEBEL: 'Möbel',
  HEIZUNG: 'Heizung',
  SCHIMMEL: 'Schimmel',
  SCHLUESSEL_SCHLOSS: 'Schlüssel/Schloss',
  SONSTIGES: 'Sonstiges',
};

const PRIORITY_LABELS: Record<TicketPriority, string> = {
  LOW: 'Niedrig',
  MEDIUM: 'Mittel',
  HIGH: 'Hoch',
  EMERGENCY: 'Notfall',
};

const STATUS_LABELS: Record<TicketStatus, string> = {
  OPEN: 'Gemeldet',
  IN_PROGRESS: 'In Bearbeitung',
  RESOLVED: 'Erledigt',
  CLOSED: 'Geschlossen',
};

// 1-Klick-PDF-Export für Handwerker: kompakte Auftragsübersicht zu einem Ticket.
ticketsRouter.get(
  '/tickets/:id/pdf',
  requireAuth,
  requireRole('LANDLORD', 'ADMIN'),
  async (req: AuthedRequest, res: Response) => {
    const ticket = await prisma.ticket.findUnique({
      where: { id: req.params.id },
      select: TICKET_SELECT,
    });
    if (!ticket) return res.status(404).json({ error: 'Ticket nicht gefunden' });

    res.setHeader('Content-Type', 'application/pdf');
    res.setHeader('Content-Disposition', `attachment; filename="ticket-${ticket.id}.pdf"`);

    const doc = new PDFDocument({ margin: 50 });
    doc.pipe(res);

    doc.fontSize(18).text('Auftrag / Schadensmeldung', { underline: true });
    doc.moveDown();

    doc.fontSize(12).text(`Titel: ${ticket.title}`);
    doc.text(`Kategorie: ${CATEGORY_LABELS[ticket.category]}`);
    doc.text(`Dringlichkeit: ${PRIORITY_LABELS[ticket.priority]}`);
    doc.text(`Status: ${STATUS_LABELS[ticket.status]}`);
    doc.text(`Zimmer: ${ticket.room?.roomNumber ?? 'Gemeinschaftsbereich'}`);
    doc.text(`Gemeldet von: ${ticket.creator.fullName}`);
    doc.text(`Gemeldet am: ${ticket.createdAt.toLocaleDateString('de-DE')}`);
    if (ticket.craftsman) {
      doc.text(`Handwerker: ${ticket.craftsman.name} (${ticket.craftsman.trade})`);
    }
    doc.moveDown();

    doc.fontSize(14).text('Beschreibung', { underline: true });
    doc.fontSize(12).text(ticket.description);

    if (ticket.imageUrls && ticket.imageUrls.length > 0) {
      doc.moveDown();
      doc.fontSize(14).text('Fotos', { underline: true });
      doc.fontSize(10).text(ticket.imageUrls.join('\n'));
    }

    doc.end();
  },
);