import { SignalStoreFeatureResult, SignalStoreFeature, EmptyFeatureResult } from '@ngrx/signals';

interface Config<T> {
    /**
     * These keys will not get saved to storage
     */
    excludeKeys: Array<keyof T>;
    /**
     * Serializer for the state, by default it uses `JSON.stringify()`
     * @param state the last state known before it gets saved to storage
     */
    serialize: (state: T) => string;
    /**
     * Deserializer for the state, by default it uses `JSON.parse()`
     * @param state the last state known from the storage location
     */
    deserialize: (state: string) => T;
    /**
     * Save to storage will only occur when this function returns true
     * @param state the last state known before it gets saved to storage
     */
    saveIf: (state: T) => boolean;
    /**
     * Function that gets executed on a storage error (get/set)
     * @param error the error that occurred
     */
    error: (error: any) => void;
}

/**
 * Helper function for SSR (Server Side Rendered) apps to get a storage location.
 *
 * @example
 *  export const CounterStore = signalStore(
 *     withState({
 *       count: 0
 *     }),
 *     withStorage('myKey', getStorage('sessionStorage'))
 *   )
 *
 * Check out github for more information.
 * @see https://github.com/larscom/ngrx-signals-storage
 */
declare function getStorage(storageType: 'localStorage' | 'sessionStorage'): Storage;

/**
 * The `withStorage` function that lets you save the state to localstorage/sessionstorage
 * and rehydrate the state upon page load.
 *
 * @param key the key under which the state should be saved into `Storage`
 * @param storage an implementation of the `Storage` interface, like: `sessionStorage` or `localStorage`
 *
 * @example
 *  // for apps *without* SSR (Server Side Rendering)
 *  export const CounterStore = signalStore(
 *     withState({
 *       count: 0
 *     }),
 *     withStorage('myKey', sessionStorage)
 *   )
 *
 * @example
 *  // for apps *with* SSR (Server Side Rendering)
 *  export const CounterStore = signalStore(
 *     withState({
 *       count: 0
 *     }),
 *     withStorage('myKey', getStorage('sessionStorage'))
 *   )
 *
 * Check out github for more information.
 * @see https://github.com/larscom/ngrx-signals-storage
 */
declare function withStorage<State extends SignalStoreFeatureResult>(key: string, storage: Storage, config?: Partial<Config<State['state']>>): SignalStoreFeature<State, EmptyFeatureResult>;

export { getStorage, withStorage };
export type { Config };