using BuildFlow.Domain.Interfaces;

namespace BuildFlow.Rag.Tests.Stub;

/// <summary>
/// Stub IChatMessageCache:内存字典模拟 Redis cache,验证双写一致性。
/// </summary>
public sealed class StubChatMessageCache : IChatMessageCache
{
    private readonly Dictionary<Guid, List<CachedChatMessage>> _store = new();

    public Task<List<CachedChatMessage>?> GetMessagesAsync(Guid conversationId, CancellationToken ct = default)
    {
        _store.TryGetValue(conversationId, out var list);
        return Task.FromResult(list);
    }

    public Task SetMessagesAsync(Guid conversationId, List<CachedChatMessage> messages, CancellationToken ct = default)
    {
        _store[conversationId] = messages.ToList();
        return Task.CompletedTask;
    }

    public Task AppendMessageAsync(Guid conversationId, CachedChatMessage message, CancellationToken ct = default)
    {
        if (!_store.TryGetValue(conversationId, out var list))
        {
            list = [];
            _store[conversationId] = list;
        }
        list.Add(message);
        return Task.CompletedTask;
    }

    public Task RemoveAsync(Guid conversationId, CancellationToken ct = default)
    {
        _store.Remove(conversationId);
        return Task.CompletedTask;
    }

    /// <summary>测试辅助:获取某会话缓存消息数。</summary>
    public int Count(Guid conversationId)
        => _store.TryGetValue(conversationId, out var list) ? list.Count : 0;
}