using System.Collections.Concurrent;
using System.Threading.Channels;
using Domain.Interfaces;

namespace Domain;

public class RenderManager : IRenderManager
{
    private readonly Channel<IFrameRender> _taskChannel;
    private readonly ConcurrentDictionary<Guid, Render> _renders = [];
    
    public RenderManager(int channelCapacity = 5)
    {
        var options = new BoundedChannelOptions(channelCapacity)
        {
            FullMode = BoundedChannelFullMode.Wait // Ожидание при переполнении канала
        };
        _taskChannel = Channel.CreateBounded<IFrameRender>(options);
    }
    
    public Task<Guid> StartRender(Project project)
    {
        var render = new Render(project);
        if (_renders.TryAdd(render.Id, render))
        {
            _ =render.Run(_taskChannel);
        }
        _ = ProcessQueue();
        return Task.FromResult(render.Id);
    }

    private async Task ProcessQueue(CancellationToken cancellationToken = default)
    {
        while (await _taskChannel.Reader.WaitToReadAsync(cancellationToken))
        {
            while (_taskChannel.Reader.TryRead(out var task))
            {
                try
                {
                    await task.Execute(cancellationToken);
                }
                catch (OperationCanceledException)
                {
                    // Console.WriteLine($"Task {task.RenderId} was cancelled.");
                }
            }
        }
    }
    
    public async Task StopRender(Guid renderId)
    {
        if (_renders.TryRemove(renderId, out var render))
        {
            await render.Stop();
            UpdateProjectHistoryToHistory(render.ProjectId, render.Id);
        }
    }
    
    private async Task ClearTasksForRender(Guid renderId)
    {
        var remainingTasks = new List<IFrameRender>();
        while (await _taskChannel.Reader.WaitToReadAsync())
        {
            if (_taskChannel.Reader.TryRead(out var task))
            {
                // if (task.RenderId != renderId)
                // {
                //     remainingTasks.Add(task);
                // }
            }
        }

        foreach (var task in remainingTasks)
        {
            await _taskChannel.Writer.WriteAsync(task);
        }
    }

    private void UpdateProjectHistoryToHistory(Guid projectId, Guid renderId)
    {
        Console.WriteLine($"UpdateProjectHistoryToHistory: {projectId}, {renderId}");
    }
    
    public IEnumerable<Guid> GetActiveRenders()
    {
        return new List<Guid>();
    }

}