using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.JSInterop;

namespace Blazored.SessionStorage;

public interface ISessionStorageService
{
    /// <summary>
    /// Clears all data from session storage.
    /// </summary>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask ClearAsync(CancellationToken cancellationToken = default);

    /// <summary>
    /// Retrieve the specified data from session storage and deseralise it to the specfied type.
    /// </summary>
    /// <param name="key">A <see cref="string"/> value specifying the name of the session storage slot to use</param>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask<T> GetItemAsync<T>(string key, CancellationToken cancellationToken = default);

    /// <summary>
    /// Retrieve the specified data from session storage as a <see cref="string"/>.
    /// </summary>
    /// <param name="key">A <see cref="string"/> value specifying the name of the storage slot to use</param>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask<string> GetItemAsStringAsync(string key, CancellationToken cancellationToken = default);

    /// <summary>
    /// Return the name of the key at the specified <paramref name="index"/>.
    /// </summary>
    /// <param name="index"></param>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask<string> KeyAsync(int index, CancellationToken cancellationToken = default);
    
    /// <summary>
    /// Returns a collection of strings representing the names of the keys in the Session storage.
    /// </summary>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask<IEnumerable<string>> KeysAsync(CancellationToken cancellationToken = default);

    /// <summary>
    /// Checks if the <paramref name="key"/> exists in session storage, but does not check its value.
    /// </summary>
    /// <param name="key">A <see cref="string"/> value specifying the name of the storage slot to use</param>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask<bool> ContainKeyAsync(string key, CancellationToken cancellationToken = default);

    /// <summary>
    /// The number of items stored in session storage.
    /// </summary>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask<int> LengthAsync(CancellationToken cancellationToken = default);

    /// <summary>
    /// Remove the data with the specified <paramref name="key"/>.
    /// </summary>
    /// <param name="key">A <see cref="string"/> value specifying the name of the storage slot to use</param>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask RemoveItemAsync(string key, CancellationToken cancellationToken = default);
    
    /// <summary>
    /// Removes a collection of <paramref name="keys"/>.
    /// </summary>
    /// <param name="keys">A IEnumerable collection of strings specifying the name of the storage slot to remove</param>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask RemoveItemsAsync(IEnumerable<string> keys, CancellationToken cancellationToken = default);

    /// <summary>
    /// Sets or updates the <paramref name="data"/> in session storage with the specified <paramref name="key"/>.
    /// </summary>
    /// <param name="key">A <see cref="string"/> value specifying the name of the storage slot to use</param>
    /// <param name="data">The data to be saved</param>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask SetItemAsync<T>(string key, T data, CancellationToken cancellationToken = default);

    /// <summary>
    /// Sets or updates the <paramref name="data"/> in session storage with the specified <paramref name="key"/>. Does not serialize the value before storing.
    /// </summary>
    /// <param name="key">A <see cref="string"/> value specifying the name of the storage slot to use</param>
    /// <param name="data">The string to be saved</param>
    /// <param name="cancellationToken">A cancellation token to signal the cancellation of the operation. Specifying this parameter will override any default cancellations such as due to timeouts (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.</param>
    /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
    ValueTask SetItemAsStringAsync(string key, string data, CancellationToken cancellationToken = default);

    event EventHandler<ChangingEventArgs> Changing;
    event EventHandler<ChangedEventArgs> Changed;
}