import Event from '../../../models/event.js'
import { connectDB } from '../../../utils/mongoose.js'
import mongoose from 'mongoose'

export default defineEventHandler(async (event) => {
  try {
    await connectDB()
    const identifier = getRouterParam(event, 'id')
    const body = await readBody(event)
    
    if (!identifier) {
      throw createError({
        statusCode: 400,
        statusMessage: 'Event identifier is required'
      })
    }
    
    // Validate required fields for guest registration
    if (!body.name || !body.email) {
      throw createError({
        statusCode: 400,
        statusMessage: 'Name and email are required'
      })
    }
    
    // Fetch the event
    let eventData
    if (mongoose.Types.ObjectId.isValid(identifier)) {
      eventData = await Event.findById(identifier)
    }
    if (!eventData) {
      eventData = await Event.findOne({ slug: identifier })
    }
    
    if (!eventData) {
      throw createError({
        statusCode: 404,
        statusMessage: 'Event not found'
      })
    }
    
    // Check if event allows public registration (not members-only)
    if (eventData.membersOnly) {
      throw createError({
        statusCode: 403,
        statusMessage: 'This event is for members only. Please become a member to register.'
      })
    }
    
    // If event requires payment, reject guest registration
    if (eventData.pricing.paymentRequired && !eventData.pricing.isFree) {
      throw createError({
        statusCode: 402,
        statusMessage: 'This event requires payment. Please use the payment registration endpoint.'
      })
    }
    
    // Check if event is full
    if (eventData.maxAttendees && eventData.registrations.length >= eventData.maxAttendees) {
      throw createError({
        statusCode: 400,
        statusMessage: 'Event is full'
      })
    }
    
    // Check if already registered
    const alreadyRegistered = eventData.registrations.some(
      reg => reg.email.toLowerCase() === body.email.toLowerCase()
    )
    
    if (alreadyRegistered) {
      throw createError({
        statusCode: 400,
        statusMessage: 'You are already registered for this event'
      })
    }
    
    // Add guest registration
    eventData.registrations.push({
      name: body.name,
      email: body.email.toLowerCase(),
      membershipLevel: 'guest',
      isMember: false,
      paymentStatus: 'not_required',
      amountPaid: 0,
      registeredAt: new Date()
    })
    
    await eventData.save()
    
    // TODO: Send confirmation email for guest registration
    
    return {
      success: true,
      message: 'Successfully registered as guest',
      registrationId: eventData.registrations[eventData.registrations.length - 1]._id,
      note: 'As a guest, you have access to this free public event. Consider becoming a member for access to all events!'
    }
    
  } catch (error) {
    console.error('Error with guest registration:', error)
    
    if (error.statusCode) {
      throw error
    }
    
    throw createError({
      statusCode: 500,
      statusMessage: 'Failed to register as guest'
    })
  }
})