import type { Preference, TokenStore, Nullable, UserStore, User, PreferenceStore } from "../types";
import { writable, derived } from "svelte/store";


function createTokenStore(): TokenStore {
    const storedToken = localStorage.getItem("token");
    const { subscribe, set } = writable<string | null>(storedToken);

    function authenticate(newToken: string): void {
        try {
            localStorage.setItem("token", newToken);
            set(newToken);
        } catch (e) {
            console.error("error", e);
        }
    }

    function unauthenticate(): void {
        localStorage.removeItem("token");
        set(null);
    }

    return {
        subscribe,
        authenticate,
        unauthenticate
    };
}

function onTokenChange($token: Nullable<string>): boolean {
    return $token ? true : false;
}

function createUserStore(): UserStore {
    const user = localStorage.getItem("user");
    const userObj: Nullable<User> = user ? JSON.parse(user) : null;
    const { subscribe, set } = writable<User | null>(userObj);

    const setUser = (user: User) => {
        localStorage.setItem("user", JSON.stringify(user));
        set(user);
    };

    const reset = () => {
        localStorage.removeItem("user");
        set(null);
    };

    return {
        subscribe,
        setUser,
        reset
    };
}


function createPreferenceStore(): PreferenceStore {
    const preferences = localStorage.getItem("preferences");
    const preferenceObj: Preference = preferences ? JSON.parse(preferences) : {
        id: 0,
        color: "#FF0000",
        size_id: 0,
        user_id: 0
    };

    const { subscribe, set, update } = writable<Nullable<Preference>>(preferenceObj);

    const setPreference = (preference: Preference) => {
        localStorage.setItem("preference", JSON.stringify(preference));
        set(preference);
    };

    const reset = () => {
        localStorage.removeItem("preference");
        set(null);
    };

    return {
        set,
        subscribe,
        reset,
        update,
        setPreference,
    };
}

export const token = createTokenStore();
export const authenticated = derived(token, onTokenChange);
export const user = createUserStore();
export const preferences = createPreferenceStore();