using BotPages.Core.Abstractions;
using System.Collections.Concurrent;

namespace BotPages.Core.Storage;

/// <summary>
/// Памятное хранилище состояния.
/// </summary>
public sealed class InMemoryStateStorage : IStateStorage
{
    private readonly ConcurrentDictionary<CompositeSessionKey, ConcurrentDictionary<string, object?>> _store = new();

    /// <inheritdoc />
    public Task<T?> GetAsync<T>(CompositeSessionKey session, string key, CancellationToken ct)
        => Task.FromResult(_store.TryGetValue(session, out var dict) ?
            dict.TryGetValue(key, out var obj) ? (T?)obj : default
            : default);

    /// <inheritdoc />
    public Task SetAsync<T>(CompositeSessionKey session, string key, T state, CancellationToken ct)
    {
        if (!_store.ContainsKey(session))
        {
            _store[session] = new();
        }
        _store[session][key] = state!;
        return Task.CompletedTask;
    }

    /// <inheritdoc />
    public Task<bool> RemoveAsync(CompositeSessionKey session, string key, CancellationToken ct)
        => Task.FromResult(_store.TryGetValue(session, out var dict) ? dict.TryRemove(key, out _) : true);

    /// <inheritdoc />
    public Task<bool> ClearAsync(CompositeSessionKey session, CancellationToken ct)
        => Task.FromResult(_store.TryRemove(session, out _));
}