import { Response } from 'express';
import { AuthRequest } from '../middleware/auth';
import { eventService } from '../services/eventService';
import prisma from '../config/database';
import { clerkClient } from '@clerk/clerk-sdk-node';

// Helper to find or create user from Clerk ID
async function findOrCreateUser(clerkId: string): Promise<string> {
  // Check if user exists
  let user = await prisma.user.findUnique({
    where: { clerkId },
    select: { id: true },
  });

  if (user) {
    return user.id;
  }

  // User doesn't exist, fetch from Clerk and create
  try {
    const clerkUser = await clerkClient.users.getUser(clerkId);
    
    user = await prisma.user.create({
      data: {
        clerkId,
        email: clerkUser.emailAddresses[0]?.emailAddress || `${clerkId}@temp.com`,
        username: clerkUser.username || `user_${clerkId.substring(0, 8)}`,
        firstName: clerkUser.firstName,
        lastName: clerkUser.lastName,
        avatarUrl: clerkUser.imageUrl,
      },
      select: { id: true },
    });

    return user.id;
  } catch (error) {
    console.error('Error creating user from Clerk:', error);
    throw new Error('Failed to create user');
  }
}

export const eventController = {
  // Get all events with optional filters
  async getEvents(req: AuthRequest, res: Response) {
    try {
      const { status, startDate, endDate, latitude, longitude, radius } = req.query;

      const filters: any = {};
      if (status) filters.status = status as string;
      if (startDate) filters.startDate = new Date(startDate as string);
      if (endDate) filters.endDate = new Date(endDate as string);
      if (latitude && longitude) {
        filters.latitude = parseFloat(latitude as string);
        filters.longitude = parseFloat(longitude as string);
        if (radius) filters.radius = parseFloat(radius as string);
      }

      const events = await eventService.getEvents(filters);
      res.json(events);
    } catch (error: any) {
      console.error('Error fetching events:', error);
      res.status(500).json({
        code: 'FETCH_EVENTS_ERROR',
        message: 'Failed to fetch events',
        details: error.message,
        timestamp: new Date().toISOString(),
      });
    }
  },

  // Get single event by ID
  async getEvent(req: AuthRequest, res: Response) {
    try {
      const { id } = req.params;
      const event = await eventService.getEventById(id);

      if (!event) {
        return res.status(404).json({
          code: 'EVENT_NOT_FOUND',
          message: 'Event not found',
          timestamp: new Date().toISOString(),
        });
      }

      res.json(event);
    } catch (error: any) {
      console.error('Error fetching event:', error);
      res.status(500).json({
        code: 'FETCH_EVENT_ERROR',
        message: 'Failed to fetch event',
        details: error.message,
        timestamp: new Date().toISOString(),
      });
    }
  },

  // Create new event
  async createEvent(req: AuthRequest, res: Response) {
    try {
      const clerkId = req.userId;
      if (!clerkId) {
        return res.status(401).json({
          code: 'UNAUTHORIZED',
          message: 'User not authenticated',
          timestamp: new Date().toISOString(),
        });
      }

      // Find or create user in database
      const userId = await findOrCreateUser(clerkId);

      const { title, description, latitude, longitude, locationName, scheduledDate, duration } = req.body;

      // Validation
      if (!title || !description || !latitude || !longitude || !locationName || !scheduledDate || !duration) {
        return res.status(400).json({
          code: 'VALIDATION_ERROR',
          message: 'Missing required fields',
          timestamp: new Date().toISOString(),
        });
      }

      const eventData = {
        organizerId: userId,
        title,
        description,
        latitude: parseFloat(latitude),
        longitude: parseFloat(longitude),
        locationName,
        scheduledDate: new Date(scheduledDate),
        duration: parseInt(duration),
      };

      const event = await eventService.createEvent(eventData);
      res.status(201).json(event);
    } catch (error: any) {
      console.error('Error creating event:', error);
      res.status(500).json({
        code: 'CREATE_EVENT_ERROR',
        message: 'Failed to create event',
        details: error.message,
        timestamp: new Date().toISOString(),
      });
    }
  },

  // Update event
  async updateEvent(req: AuthRequest, res: Response) {
    try {
      const clerkId = req.userId;
      if (!clerkId) {
        return res.status(401).json({
          code: 'UNAUTHORIZED',
          message: 'User not authenticated',
          timestamp: new Date().toISOString(),
        });
      }

      const userId = await findOrCreateUser(clerkId);

      const { id } = req.params;
      const event = await eventService.getEventById(id);

      if (!event) {
        return res.status(404).json({
          code: 'EVENT_NOT_FOUND',
          message: 'Event not found',
          timestamp: new Date().toISOString(),
        });
      }

      // Check if user is the organizer
      if (event.organizerId !== userId) {
        return res.status(403).json({
          code: 'FORBIDDEN',
          message: 'Only the event organizer can update this event',
          timestamp: new Date().toISOString(),
        });
      }

      const updatedEvent = await eventService.updateEvent(id, req.body);
      res.json(updatedEvent);
    } catch (error: any) {
      console.error('Error updating event:', error);
      res.status(500).json({
        code: 'UPDATE_EVENT_ERROR',
        message: 'Failed to update event',
        details: error.message,
        timestamp: new Date().toISOString(),
      });
    }
  },

  // Delete event
  async deleteEvent(req: AuthRequest, res: Response) {
    try {
      const clerkId = req.userId;
      if (!clerkId) {
        return res.status(401).json({
          code: 'UNAUTHORIZED',
          message: 'User not authenticated',
          timestamp: new Date().toISOString(),
        });
      }

      const userId = await findOrCreateUser(clerkId);

      const { id } = req.params;
      const event = await eventService.getEventById(id);

      if (!event) {
        return res.status(404).json({
          code: 'EVENT_NOT_FOUND',
          message: 'Event not found',
          timestamp: new Date().toISOString(),
        });
      }

      // Check if user is the organizer
      if (event.organizerId !== userId) {
        return res.status(403).json({
          code: 'FORBIDDEN',
          message: 'Only the event organizer can delete this event',
          timestamp: new Date().toISOString(),
        });
      }

      await eventService.deleteEvent(id);
      res.status(204).send();
    } catch (error: any) {
      console.error('Error deleting event:', error);
      res.status(500).json({
        code: 'DELETE_EVENT_ERROR',
        message: 'Failed to delete event',
        details: error.message,
        timestamp: new Date().toISOString(),
      });
    }
  },

  // Register for event
  async registerForEvent(req: AuthRequest, res: Response) {
    try {
      const clerkId = req.userId;
      if (!clerkId) {
        return res.status(401).json({
          code: 'UNAUTHORIZED',
          message: 'User not authenticated',
          timestamp: new Date().toISOString(),
        });
      }

      const userId = await findOrCreateUser(clerkId);

      const { id } = req.params;
      const registration = await eventService.registerForEvent(id, userId);
      res.status(201).json(registration);
    } catch (error: any) {
      console.error('Error registering for event:', error);
      
      if (error.message.includes('already registered')) {
        return res.status(409).json({
          code: 'ALREADY_REGISTERED',
          message: error.message,
          timestamp: new Date().toISOString(),
        });
      }

      res.status(500).json({
        code: 'REGISTER_EVENT_ERROR',
        message: 'Failed to register for event',
        details: error.message,
        timestamp: new Date().toISOString(),
      });
    }
  },

  // Unregister from event
  async unregisterFromEvent(req: AuthRequest, res: Response) {
    try {
      const clerkId = req.userId;
      if (!clerkId) {
        return res.status(401).json({
          code: 'UNAUTHORIZED',
          message: 'User not authenticated',
          timestamp: new Date().toISOString(),
        });
      }

      const userId = await findOrCreateUser(clerkId);

      const { id } = req.params;
      await eventService.unregisterFromEvent(id, userId);
      res.status(204).send();
    } catch (error: any) {
      console.error('Error unregistering from event:', error);
      res.status(500).json({
        code: 'UNREGISTER_EVENT_ERROR',
        message: 'Failed to unregister from event',
        details: error.message,
        timestamp: new Date().toISOString(),
      });
    }
  },

  // Get event registrations
  async getEventRegistrations(req: AuthRequest, res: Response) {
    try {
      const { id } = req.params;
      const registrations = await eventService.getEventRegistrations(id);
      res.json(registrations);
    } catch (error: any) {
      console.error('Error fetching event registrations:', error);
      res.status(500).json({
        code: 'FETCH_REGISTRATIONS_ERROR',
        message: 'Failed to fetch event registrations',
        details: error.message,
        timestamp: new Date().toISOString(),
      });
    }
  },

  // Check registration status
  async getRegistrationStatus(req: AuthRequest, res: Response) {
    try {
      const clerkId = req.userId;
      if (!clerkId) {
        return res.json({ registered: false });
      }

      const userId = await findOrCreateUser(clerkId);

      const { id } = req.params;
      const isRegistered = await eventService.isUserRegistered(id, userId);
      res.json({ registered: isRegistered });
    } catch (error: any) {
      console.error('Error checking registration status:', error);
      res.status(500).json({
        code: 'CHECK_REGISTRATION_ERROR',
        message: 'Failed to check registration status',
        details: error.message,
        timestamp: new Date().toISOString(),
      });
    }
  },
};