"use client"

import { useMutation, useQuery } from "@tanstack/react-query"
import { useSession } from "next-auth/react"
import { useEffect } from "react"

import { dt } from "@scandic-hotels/common/dt"
import { createLogger } from "@scandic-hotels/common/logger/createLogger"
import { isValidSession } from "@scandic-hotels/trpc/utils/session"

import type { User } from "next-auth"

import type { SocialSessionResponse } from "@/app/api/web/auth/scandic/session/route"

const logger = createLogger("useSocialSession")

export function useSocialSession() {
  const socialSession = useSocialSessionQuery()
  const refresh = useRefresh()
  useAutoLogin()

  return {
    session: socialSession,
    refresh,
  }
}

function useSocialSessionQuery() {
  const { data: session } = useSession()
  const enabled = isValidSession(session) && isUserLinked(session?.user)

  return useQuery({
    queryKey: ["socialSession"],
    queryFn: getSocialSession,
    enabled: enabled,
    refetchInterval: getTime(1, "m"),
  })
}
const autoLoginLogger = createLogger("useAutoLogin")
function useAutoLogin() {
  const { data: session } = useSession()
  const { isSuccess, data: socialSession } = useSocialSessionQuery()

  const isLinked = isUserLinked(session?.user)

  useEffect(() => {
    if (!isLinked) {
      autoLoginLogger.info("User is not linked")
      return
    }

    if (!isSuccess) {
      autoLoginLogger.info("Social session is not loaded")
      return
    }

    if (isSuccess && socialSession.status !== "no_session") {
      autoLoginLogger.info("Social session is already active")
      return
    }

    const expires = dt(session?.expires)
    if (!expires || !expires.isValid()) {
      autoLoginLogger.info("Session does not have a valid expiry")
      return
    }

    const hasExpired = expires.isSameOrBefore(dt())
    if (hasExpired) {
      autoLoginLogger.info("Session has expired")
      return
    }

    autoLoginLogger.info("Autologin to Curity")
    // TODO: Check if we can do this silently without redirect
    window.location.href =
      "/api/web/auth/scandic/login?redirect_to=" + window.location.href
  }, [isLinked, isSuccess, session?.expires, socialSession?.status])
}

function useRefresh() {
  const socialSession = useSocialSessionQuery()

  const refresh = useMutation({
    mutationKey: ["refresh", "socialSession"],
    mutationFn: refreshSession,
    onSettled: () => {
      socialSession.refetch()
    },
  })

  useEffect(() => {
    // Refresh the token if it has expired
    if (socialSession.data?.status !== "expired") return
    if (refresh.isPending) return
    if (refresh.isError) return

    logger.debug("Social session has expired, refreshing")
    refresh.mutate()
  }, [socialSession, refresh])

  const expiresAt =
    socialSession.data?.status === "valid" ? socialSession.data.expiresAt : null
  useEffect(() => {
    // Set up a timer to refresh the token 1 minute before it expires
    if (!expiresAt) return
    if (refresh.isPending) return
    if (refresh.isError) return

    const expiresAtDt = dt(expiresAt)
    const timeToExpire = expiresAtDt.diff(dt(), "milliseconds")
    const refreshAt = timeToExpire - getTime(1, "m")

    if (refreshAt <= 0) {
      // If it has already expired it's already being handled by the other useEffect
      return
    }

    logger.debug(
      `Refreshing social session at`,
      dt().add(refreshAt, "milliseconds").toISOString()
    )
    const timeout = setTimeout(() => {
      refresh.mutate()
    }, refreshAt)
    return () => clearTimeout(timeout)
  }, [expiresAt, refresh])

  return refresh
}

async function getSocialSession(): Promise<SocialSessionResponse> {
  const response = await fetch("/api/web/auth/scandic/session", {
    method: "GET",
    headers: {
      "Content-Type": "application/json",
    },
    cache: "no-store",
  })

  if (!response.ok) {
    throw new Error("Failed to fetch social session", {
      cause: { status: response.status, statusText: response.statusText },
    })
  }

  const data = (await response.json()) as SocialSessionResponse

  return data
}

async function refreshSession(): Promise<SocialSessionResponse> {
  const response = await fetch("/api/web/auth/scandic/refresh", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
    },
    cache: "no-store",
  })

  if (!response.ok) {
    throw new Error("Failed to fetch social session", {
      cause: { status: response.status, statusText: response.statusText },
    })
  }

  const data = (await response.json()) as SocialSessionResponse

  return data
}

function getTime(value: number, unit: "m" | "s") {
  switch (unit) {
    case "m":
      return value * 60 * 1000
    case "s":
      return value * 1000
  }
}

function isUserLinked(user: User | undefined): boolean {
  if (user && "isLinked" in user) {
    return !!user.isLinked
  }

  return false
}