const express = require('express');
const { prisma } = require('../utils/db');
const { authenticate } = require('../middleware/auth');

const router = express.Router();

// GET /api/events - List all events
router.get('/', authenticate, async (req, res, next) => {
  try {
    const userId = req.user.id;

    // Fetch all events with participation info
    const events = await prisma.event.findMany({
      select: {
        id: true,
        slug: true,
        name: true,
        location: true,
        startDate: true,
        endDate: true,
        worldsdcId: true,
        participantsCount: true,
        description: true,
        createdAt: true,
        participants: {
          where: {
            userId: userId,
          },
          select: {
            joinedAt: true,
          },
        },
      },
    });

    // Transform data and add isJoined flag
    const eventsWithJoinedStatus = events.map(event => ({
      id: event.id,
      slug: event.slug,
      name: event.name,
      location: event.location,
      startDate: event.startDate,
      endDate: event.endDate,
      worldsdcId: event.worldsdcId,
      participantsCount: event.participantsCount,
      description: event.description,
      createdAt: event.createdAt,
      isJoined: event.participants.length > 0,
      joinedAt: event.participants[0]?.joinedAt || null,
    }));

    // Sort: joined events first, then by start date
    eventsWithJoinedStatus.sort((a, b) => {
      // First, sort by joined status (joined events first)
      if (a.isJoined && !b.isJoined) return -1;
      if (!a.isJoined && b.isJoined) return 1;

      // Then sort by start date
      return new Date(a.startDate) - new Date(b.startDate);
    });

    res.json({
      success: true,
      count: eventsWithJoinedStatus.length,
      data: eventsWithJoinedStatus,
    });
  } catch (error) {
    next(error);
  }
});

// GET /api/events/:slug - Get event by slug
router.get('/:slug', async (req, res, next) => {
  try {
    const { slug } = req.params;

    const event = await prisma.event.findUnique({
      where: {
        slug: slug,
      },
      include: {
        chatRooms: true,
        _count: {
          select: {
            matches: true,
          },
        },
      },
    });

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

    res.json({
      success: true,
      data: event,
    });
  } catch (error) {
    next(error);
  }
});

// GET /api/events/:slug/messages - Get event chat messages with pagination
router.get('/:slug/messages', authenticate, async (req, res, next) => {
  try {
    const { slug } = req.params;
    const { before, limit = 20 } = req.query;

    // Find event by slug
    const event = await prisma.event.findUnique({
      where: { slug },
      select: { id: true },
    });

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

    // Find event chat room
    const chatRoom = await prisma.chatRoom.findFirst({
      where: {
        eventId: event.id,
        type: 'event',
      },
    });

    if (!chatRoom) {
      return res.status(404).json({
        success: false,
        error: 'Chat room not found',
      });
    }

    // Build query with pagination
    const where = { roomId: chatRoom.id };
    if (before) {
      where.id = { lt: parseInt(before) };
    }

    const messages = await prisma.message.findMany({
      where,
      include: {
        user: {
          select: {
            id: true,
            username: true,
            avatar: true,
          },
        },
      },
      orderBy: { createdAt: 'desc' },
      take: parseInt(limit),
    });

    // Return in chronological order (oldest first)
    res.json({
      success: true,
      data: messages.reverse().map(msg => ({
        id: msg.id,
        roomId: msg.roomId,
        userId: msg.user.id,
        username: msg.user.username,
        avatar: msg.user.avatar,
        content: msg.content,
        type: msg.type,
        createdAt: msg.createdAt,
      })),
      hasMore: messages.length === parseInt(limit),
    });
  } catch (error) {
    next(error);
  }
});

module.exports = router;