import { useCallback, useState } from "react";
import { authLogin, authMe, authRegister, authLogout } from "@/lib/client/auth";
import type { User } from "@/lib/shared/types";
import type { ApiResult } from "@/lib/client/fetch-json";

type LoginInput = {
    email: string;
    password: string;
    remember: boolean;
};

type RegisterInput = {
    email: string;
    password: string;
    displayName?: string;
};

export default function useAuth() {
    const [error, setError] = useState("");
    const [loading, setLoading] = useState(false);

    function isError<T>(result: ApiResult<T>): result is { error: { code: string; message: string } } {
        return "error" in result;
    }

    const checkSession = useCallback(async () => {
        const res = await authMe();
        if (isError(res)) return null;
        return res.data.user as User;
    }, []);

    const login = useCallback(async (input: LoginInput) => {
        setError("");
        setLoading(true);
        try {
            const result = await authLogin(input);
            if (isError(result)) {
                setError(result.error.message || "");
                return { ok: false, error: result.error.message || "" };
            }
            return { ok: true } as { ok: true };
        } finally {
            setLoading(false);
        }
    }, []);

    const register = useCallback(async (input: RegisterInput) => {
        setError("");
        setLoading(true);
        try {
            const result = await authRegister(input);
            if (isError(result)) {
                setError(result.error.message || "");
                return { ok: false, error: result.error.message || "" };
            }
            return { ok: true } as { ok: true };
        } finally {
            setLoading(false);
        }
    }, []);

    const logout = useCallback(async () => {
        const result = await authLogout();
        if (isError(result)) {
            setError(result.error.message || "");
            return { ok: false, error: result.error.message || "" };
        }
        return { ok: true } as { ok: true };
    }, []);

    return { checkSession, login, register, logout, error, loading };
}