const MINUTE = 60 * 1000;
const MAX_RELOAD_COUNT = 1;
const MIN_COOL_DOWN_INTERVAL = 5 * MINUTE;

export interface ReloadCounter {
    count: number;
    expiresAt: number;
}

export interface ReloadHandlerOptions {
    id: string;
    coolDownInterval?: number;
    handler?: () => void;
    storage?: 'local' | 'session';
}

export class ReloadHandler {
    #reloadCounter?: Partial<ReloadCounter>;
    readonly #options: ReloadHandlerOptions;

    constructor(options: ReloadHandlerOptions) {
        this.#options = options;
        this.#reloadCounter = this.getCounter();
    }

    reload() {
        if (this.incrementCounter() <= MAX_RELOAD_COUNT) {
            if (this.#options.handler) {
                this.#options.handler();
            } else {
                window.location.reload();
            }
        }
    }

    reset() {
        this.storage.removeItem(this.counterKey);
        this.#reloadCounter = undefined;
    }

    private incrementCounter() {
        const { count = 0, expiresAt = 0 } = this.#reloadCounter ?? {};

        const counter =
            expiresAt < Date.now()
                ? { count: 1, expiresAt: Date.now() + this.coolDownInterval }
                : { count: count + 1, expiresAt };

        this.setCounter(counter);
        return counter.count;
    }

    private getCounter(): Partial<ReloadCounter> | undefined {
        try {
            const counter = JSON.parse(this.storage.getItem(this.counterKey) ?? '{}');
            if (counter && typeof counter === 'object') {
                return counter;
            }
        } catch {
            // ignore JSON.parse error
        }
    }

    private setCounter(counter: ReloadCounter) {
        this.storage.setItem(this.counterKey, JSON.stringify(counter));
        this.#reloadCounter = counter;
    }

    private get counterKey() {
        return `reload-counter-${this.#options.id}`;
    }

    private get coolDownInterval() {
        return Math.max(
            MIN_COOL_DOWN_INTERVAL,
            this.#options.coolDownInterval ?? MIN_COOL_DOWN_INTERVAL
        );
    }

    private get storage() {
        return this.#options.storage === 'local' ? localStorage : sessionStorage;
    }
}