import { Injectable, NotFoundException } from '@nestjs/common';
import { CreateTicketDto } from './dto/create-ticket.dto';
import { PrismaService } from '../prisma/prisma.service';
import { MailService } from '../mail/mail.service';
import * as QRCode from 'qrcode'; // Import qrcode library

@Injectable()
export class TicketsService {
  constructor(
    private prisma: PrismaService,
    private mailService: MailService,
  ) {}

  async create(createTicketDto: CreateTicketDto) {
    const event = await this.prisma.event.findUnique({
      where: { id: createTicketDto.eventId },
    });

    if (!event) {
      throw new NotFoundException(`Event with ID "${createTicketDto.eventId}" not found`);
    }

    const ticket = await this.prisma.ticket.create({
      data: createTicketDto,
      include: { event: true },
    });

    try {
      // Generate QR code buffer with ticket ID only
      const qrCodeBuffer = await QRCode.toBuffer(ticket.id, {
        errorCorrectionLevel: 'H', // High error correction
        type: 'png', // Output as PNG image
        width: 250, // QR code width
        color: {
          dark: '#000000', // Black dots
          light: '#FFFFFF', // White background
        },
      });

      await this.mailService.sendTicket(
        ticket.attendeeEmail,
        ticket.attendeeName,
        ticket.id,
        ticket.event.name,
        qrCodeBuffer, // Pass the QR code buffer
      );
    } catch (error) {
      console.error('Failed to send ticket email:', error);
      // Optionally throw error or just log it.
      // For now, we log it so the ticket creation doesn't fail if email fails (unless strict requirement).
    }

    return ticket;
  }

  findAll(eventId: string) {
    return this.prisma.ticket.findMany({
      where: { eventId },
    });
  }

  findOne(id: string) {
    return this.prisma.ticket.findUnique({
      where: { id },
      include: { event: true },
    });
  }

  async resendEmail(id: string) {
    const ticket = await this.prisma.ticket.findUnique({
      where: { id },
      include: { event: true },
    });

    if (!ticket) {
      throw new Error('Ticket not found');
    }

    try {
      // Generate QR code buffer with ticket ID only
      const qrCodeBuffer = await QRCode.toBuffer(ticket.id, {
        errorCorrectionLevel: 'H',
        type: 'png',
        width: 250,
        color: {
          dark: '#000000',
          light: '#FFFFFF',
        },
      });

      await this.mailService.sendTicket(
        ticket.attendeeEmail,
        ticket.attendeeName,
        ticket.id,
        ticket.event.name,
        qrCodeBuffer,
      );
      return { success: true, message: 'Email resent successfully' };
    } catch (error) {
      console.error('Failed to resend ticket email:', error);
      throw new Error('Failed to send email');
    }
  }

  updateStatus(id: string, status: string) {
    return this.prisma.ticket.update({
      where: { id },
      data: { status },
    });
  }

  remove(id: string) {
    return this.prisma.ticket.delete({
      where: { id },
    });
  }
}