/**
 * The key-value store a save is written to.
 *
 * Kept behind an interface so the save logic itself has no engine dependency
 * and can be tested headlessly. `CocosStorage` is the real implementation;
 * `MemoryStorage` is the one tests use.
 */
export interface IStorage {
    getItem(key: string): string | null;
    setItem(key: string, value: string): void;
    removeItem(key: string): void;
}

/** An in-process store. Used by tests, and as a fallback when storage is unavailable. */
export class MemoryStorage implements IStorage {
    private readonly _data = new Map<string, string>();

    getItem(key: string): string | null {
        const value = this._data.get(key);
        return value === undefined ? null : value;
    }

    setItem(key: string, value: string): void {
        this._data.set(key, value);
    }

    removeItem(key: string): void {
        this._data.delete(key);
    }

    /** Test helper: everything currently stored. */
    get entries(): ReadonlyMap<string, string> {
        return this._data;
    }
}