import type { BetterFetchError } from "@better-fetch/fetch"
import { persistentAtom } from "@nanostores/persistent"
import type { Session, User } from "better-auth"
import SuperJSON from "superjson"

import { emptyResult } from "../empty-result"
import { $authClient } from "./auth-client"

type PersistentSessionResult = {
    data: { session: Session; user: User } | null
    isPending: boolean
    isRefetching: boolean
    optimistic?: boolean
    error: BetterFetchError["error"] | null
    refetch: () => Promise<void>
}

export const $persistentSession = persistentAtom<PersistentSessionResult>(
    "session",
    { ...emptyResult, isPending: false },
    {
        encode: SuperJSON.stringify,
        decode: (value) => {
            const parsed = SuperJSON.parse(value) as PersistentSessionResult
            parsed.refetch = refetchSession
            return parsed
        }
    }
)

const refetchSession = async () => {
    const authClient = $authClient.get()

    if (!authClient) {
        console.warn("$authClient not found")
        return
    }

    $persistentSession.set({
        ...$persistentSession.get(),
        isRefetching: true
    })

    const result = await authClient.getSession()

    if (result.error) {
        $persistentSession.set({
            ...$persistentSession.get(),
            isRefetching: false,
            isPending: false,
            error: result.error
        })
    } else {
        $persistentSession.set({
            ...$persistentSession.get(),
            optimistic: false,
            data: result.data,
            isRefetching: false,
            isPending: false,
            error: null
        })
    }
}