"use client";

import { authClient } from "@/lib/auth-client";
import { useMutation, useQuery } from "convex/react";
import { api } from "@/convex/_generated/api";
import { useEffect, useRef } from "react";
import { toast } from "@/lib/toast";
import { msg } from "@/lib/toast-messages";

/**
 * Initialisiert die Credit-Balance für neue User.
 * Wird einmal im Layout eingebunden und sorgt dafür,
 * dass jeder eingeloggte User eine Balance + Free-Subscription hat.
 */
export function InitUser() {
  const { data: session } = authClient.useSession();
  const balance = useQuery(
    api.credits.getBalance,
    session?.user ? {} : "skip"
  );
  const initBalance = useMutation(api.credits.initBalance);
  const initStartedRef = useRef(false);

  useEffect(() => {
    if (
      !session?.user ||
      !balance ||
      balance.balance !== 0 ||
      balance.monthlyAllocation !== 0
    ) {
      return;
    }
    if (initStartedRef.current) return;
    initStartedRef.current = true;

    void initBalance()
      .then(() => {
        toast.success(msg.auth.initialSetup.title, msg.auth.initialSetup.desc);
      })
      .catch(() => {
        initStartedRef.current = false;
      });
  }, [session?.user, balance, initBalance]);

  return null;
}