// app/api/events/register/route.ts
// API endpoint for event registration

import { NextResponse } from 'next/server';
import { query, queryOne } from '@/lib/db';

export async function POST(request: Request) {
  try {
    const body = await request.json();
    const { eventId, steamId, carModel, carSkin, teamName } = body;

    console.log('Received registration data:', body);

    // Validate required fields
    if (!eventId || !steamId || !carModel) {
      return NextResponse.json(
        { success: false, error: 'Missing required fields' },
        { status: 400 }
      );
    }

    // Validate steamId format to prevent SQL injection
    const steamId = inputSteamId.trim(); // just in case

    if (!/^[0-9]{15,20}$/.test(steamId)) {
      return NextResponse.json(
        { success: false, error: "Invalid Steam ID format" },
        { status: 400 }
      );
    } 

    const driverGuid = steamId;
    console.log('Parsed driver GUID:', driverGuid);
    if (isNaN(driverGuid)) {
      return NextResponse.json(
        { success: false, error: 'Invalid Steam ID format' },
        { status: 400 }
      );
    }

    // Check if user exists in database
    const userCheck = await queryOne(
      'SELECT driver_guid FROM users WHERE driver_guid = $1;',
      [driverGuid]
    );

    if (!userCheck) {
      return NextResponse.json(
        { success: false, error: 'Steam ID not found in database. Please join a server first.' },
        { status: 404 }
      );
    }

    // Check if event exists and is open
    const eventCheck: any = await queryOne(
      `SELECT event_id, event_status, max_participants,
              (SELECT COUNT(*) FROM event_registrations 
               WHERE event_id = $1 AND status = 'REGISTERED') as current_registrations
       FROM events WHERE event_id = $1`,
      [eventId]
    );

    if (!eventCheck) {
      return NextResponse.json(
        { success: false, error: 'Event not found' },
        { status: 404 }
      );
    }

    if (eventCheck.event_status !== 'OPEN') {
      return NextResponse.json(
        { success: false, error: 'Event registration is closed' },
        { status: 400 }
      );
    }

    if (eventCheck.current_registrations >= eventCheck.max_participants) {
      return NextResponse.json(
        { success: false, error: 'Event is full' },
        { status: 400 }
      );
    }

    // Check if already registered
    const existingReg = await queryOne(
      'SELECT registration_id FROM event_registrations WHERE event_id = $1 AND driver_guid = $2',
      [eventId, driverGuid]
    );

    if (existingReg) {
      return NextResponse.json(
        { success: false, error: 'You are already registered for this event' },
        { status: 400 }
      );
    }

    // Insert registration
    await query(
      `INSERT INTO event_registrations 
       (event_id, driver_guid, car_model, car_skin, team_name, status)
       VALUES ($1, $2, $3, $4, $5, 'REGISTERED')`,
      [eventId, driverGuid, carModel, carSkin || null, teamName || null]
    );

    return NextResponse.json({
      success: true,
      message: 'Registration successful',
    });

  } catch (error) {
    console.error('Registration error:', error);
    return NextResponse.json(
      { success: false, error: 'Registration failed. Please try again.' },
      { status: 500 }
    );
  }
}