"use client"

import { useEffect, useState } from "react"
import { useSession } from "@/lib/auth-client"
import type { Profile } from "@/types"

interface UserState {
  user: { id: string; email: string; name?: string | null } | null
  profile: Profile | null
  loading: boolean
}

export function useUser(): UserState {
  const { data: session, isPending } = useSession()

  // The fetched profile is stored together with the user id it belongs to, so
  // "loaded" is DERIVED rather than tracked in a second state variable. That
  // removes the synchronous setState in the effect body (which caused cascading
  // renders) and, as a bonus, stops a previous user's profile from flashing
  // while a new one loads.
  const [fetched, setFetched] = useState<{ userId: string; profile: Profile | null } | null>(null)

  const userId = session?.user?.id

  useEffect(() => {
    if (!userId) return
    let active = true

    fetch("/api/profile")
      .then((r) => (r.ok ? r.json() : { profile: null }))
      .then((data) => {
        if (active) setFetched({ userId, profile: data.profile ?? null })
      })
      .catch(() => {
        if (active) setFetched({ userId, profile: null })
      })

    return () => {
      active = false
    }
  }, [userId])

  const isCurrent = !!userId && fetched?.userId === userId

  return {
    user: session?.user
      ? { id: session.user.id, email: session.user.email, name: session.user.name }
      : null,
    profile: isCurrent ? (fetched?.profile ?? null) : null,
    // Signed out: nothing to load. Signed in: loading until this user's profile
    // has actually come back.
    loading: isPending || (!!userId && !isCurrent),
  }
}