import { useState, useEffect, useCallback } from 'react'
import { notificationService } from '@/lib/notificationService'
import type { Notification } from '@/lib/notificationService'

const MAX_NOTIFICATIONS = 100
const POLL_INTERVAL_MS = 30_000

export function useNotifications(userPubkey: string | null): {
  notifications: Notification[]
  unreadCount: number
  loading: boolean
  markAsRead: (notificationId: string) => void
  markAllAsRead: () => void
  deleteNotification: (notificationId: string) => void
} {
  const [notifications, setNotifications] = useState<Notification[]>([])
  const [loading, setLoading] = useState(true)

  useNotificationsPoller({ userPubkey, setNotifications, setLoading })

  const effectiveNotifications = userPubkey ? notifications : []
  const effectiveLoading = userPubkey ? loading : false
  const unreadCount = effectiveNotifications.filter((n) => !n.read).length
  const actions = useNotificationActions({ userPubkey, setNotifications })

  return {
    notifications: effectiveNotifications,
    unreadCount,
    loading: effectiveLoading,
    markAsRead: actions.markAsRead,
    markAllAsRead: actions.markAllAsRead,
    deleteNotification: actions.deleteNotification,
  }
}

function useNotificationsPoller(params: {
  userPubkey: string | null
  setNotifications: (value: Notification[]) => void
  setLoading: (value: boolean) => void
}): void {
  useEffect(() => {
    if (!params.userPubkey) {
      return
    }
    void loadAndSetNotifications({ setNotifications: params.setNotifications, setLoading: params.setLoading })
    const interval = setInterval(() => {
      void loadAndSetNotifications({ setNotifications: params.setNotifications, setLoading: params.setLoading })
    }, POLL_INTERVAL_MS)
    return () => clearInterval(interval)
  }, [params.userPubkey, params.setNotifications, params.setLoading])
}

function useNotificationActions(params: {
  userPubkey: string | null
  setNotifications: (value: Notification[]) => void
}): {
  markAsRead: (notificationId: string) => void
  markAllAsRead: () => void
  deleteNotification: (notificationId: string) => void
} {
  const markAsRead = useCallback((notificationId: string): void => {
    if (!params.userPubkey) {
      return
    }
    void markAsReadAndRefresh({ notificationId, setNotifications: params.setNotifications })
  }, [params.userPubkey, params.setNotifications])

  const markAllAsRead = useCallback((): void => {
    if (!params.userPubkey) {
      return
    }
    void markAllAsReadAndRefresh({ setNotifications: params.setNotifications })
  }, [params.userPubkey, params.setNotifications])

  const deleteNotification = useCallback((notificationId: string): void => {
    if (!params.userPubkey) {
      return
    }
    void deleteNotificationAndRefresh({ notificationId, setNotifications: params.setNotifications })
  }, [params.userPubkey, params.setNotifications])

  return { markAsRead, markAllAsRead, deleteNotification }
}

async function loadAndSetNotifications(params: {
  setNotifications: (value: Notification[]) => void
  setLoading: (value: boolean) => void
}): Promise<void> {
  try {
    params.setLoading(true)
    params.setNotifications(await notificationService.getAllNotifications(MAX_NOTIFICATIONS))
  } catch (error) {
    console.error('[useNotifications] Error loading notifications:', error)
  } finally {
    params.setLoading(false)
  }
}

async function refreshNotifications(params: { setNotifications: (value: Notification[]) => void }): Promise<void> {
  params.setNotifications(await notificationService.getAllNotifications(MAX_NOTIFICATIONS))
}

async function markAsReadAndRefresh(params: {
  notificationId: string
  setNotifications: (value: Notification[]) => void
}): Promise<void> {
  try {
    await notificationService.markAsRead(params.notificationId)
    await refreshNotifications({ setNotifications: params.setNotifications })
  } catch (error) {
    console.error('[useNotifications] Error marking notification as read:', error)
  }
}

async function markAllAsReadAndRefresh(params: {
  setNotifications: (value: Notification[]) => void
}): Promise<void> {
  try {
    await notificationService.markAllAsRead()
    await refreshNotifications({ setNotifications: params.setNotifications })
  } catch (error) {
    console.error('[useNotifications] Error marking all as read:', error)
  }
}

async function deleteNotificationAndRefresh(params: {
  notificationId: string
  setNotifications: (value: Notification[]) => void
}): Promise<void> {
  try {
    await notificationService.deleteNotification(params.notificationId)
    await refreshNotifications({ setNotifications: params.setNotifications })
  } catch (error) {
    console.error('[useNotifications] Error deleting notification:', error)
  }
}