export default defineEventHandler(async (event) => {
  try {
    // Get notification ID from route parameters
    const notificationId = getRouterParam(event, 'id')
    
    if (!notificationId) {
      throw createError({
        statusCode: 400,
        statusMessage: 'Notification ID is required'
      })
    }

    // Get current user (assuming auth middleware provides this)
    const user = event.context.user
    if (!user) {
      throw createError({
        statusCode: 401,
        statusMessage: 'Authentication required'
      })
    }

    const { $db } = useNitroApp()
    
    // Start transaction
    await $db.query('BEGIN')
    
    try {
      // First, check if the notification exists and belongs to the user
      const checkResult = await $db.query(
        'SELECT id, title, status FROM notifications WHERE id = $1 AND created_by = $2',
        [notificationId, user.id]
      )
      
      if (checkResult.rows.length === 0) {
        throw createError({
          statusCode: 404,
          statusMessage: 'Notification not found or you do not have permission to delete it'
        })
      }

      const notification = checkResult.rows[0]

      // Check if notification can be deleted (only draft, scheduled, failed, or cancelled notifications)
      const deletableStatuses = ['draft', 'scheduled', 'failed', 'cancelled']
      if (!deletableStatuses.includes(notification.status)) {
        throw createError({
          statusCode: 400,
          statusMessage: `Cannot delete notification with status: ${notification.status}. Only draft, scheduled, failed, or cancelled notifications can be deleted.`
        })
      }

      // Delete the notification (CASCADE will handle related records)
      const deleteResult = await $db.query(
        'DELETE FROM notifications WHERE id = $1 AND created_by = $2 RETURNING id, title',
        [notificationId, user.id]
      )

      if (deleteResult.rows.length === 0) {
        throw createError({
          statusCode: 404,
          statusMessage: 'Failed to delete notification'
        })
      }

      // If notification was scheduled, remove it from queue
      if (notification.status === 'scheduled') {
        await $db.query(
          'DELETE FROM notification_queue WHERE notification_id = $1',
          [notificationId]
        )
      }

      // Commit transaction
      await $db.query('COMMIT')

      return {
        success: true,
        data: {
          id: notificationId,
          title: notification.title,
          message: 'Notification deleted successfully'
        }
      }

    } catch (error) {
      await $db.query('ROLLBACK')
      throw error
    }

  } catch (error) {
    console.error('Error deleting notification:', error)
    
    if (error.statusCode) {
      throw error
    }
    
    throw createError({
      statusCode: 500,
      statusMessage: 'Failed to delete notification'
    })
  }
})