using Hi.Disp;
using Hi.Geom;
using Hi.Native;
using System.Collections.Concurrent;

namespace Hi.Webapi.Services
{
    /// <summary>
    /// 管理 DispEngine 實例和渲染操作的服務
    /// </summary>
    public class RenderingService : IDisposable
    {
        private readonly ConcurrentDictionary<string, DispEngine> _engines = new();
        private readonly ILogger<RenderingService> _logger;

        public RenderingService(ILogger<RenderingService> logger)
        {
            _logger = logger;
        }

        /// <summary>
        /// 創建或獲取一個 DispEngine 實例
        /// </summary>
        public DispEngine GetOrCreateEngine(string sessionId)
        {
            return _engines.GetOrAdd(sessionId, id =>
            {
                _logger.LogInformation($"創建新的 DispEngine，SessionId: {id}");
                var engine = new DispEngine();
                engine.BackgroundColor = new Vec3d(0.1, 0.1, 0.5);
                engine.BackgroundOpacity = 0.1;
                return engine;
            });
        }

        /// <summary>
        /// 移除指定的 DispEngine
        /// </summary>
        public bool RemoveEngine(string sessionId)
        {
            if (_engines.TryRemove(sessionId, out var engine))
            {
                _logger.LogInformation($"移除 DispEngine，SessionId: {sessionId}");
                
                try
                {
                    // 停止渲染
                    engine.IsVisible = false;
                    
                    // 釋放資源
                    engine.Dispose();
                }
                catch (Exception ex)
                {
                    _logger.LogError(ex, $"清理 DispEngine 時發生錯誤，SessionId: {sessionId}");
                }
                
                return true;
            }
            return false;
        }

        /// <summary>
        /// 獲取當前活動的引擎數量
        /// </summary>
        public int GetActiveEngineCount() => _engines.Count;

        public void Dispose()
        {
            foreach (var kvp in _engines)
            {
                try
                {
                    kvp.Value.IsVisible = false;
                    kvp.Value.Dispose();
                }
                catch (Exception ex)
                {
                    _logger.LogError(ex, $"Dispose 時清理引擎錯誤，SessionId: {kvp.Key}");
                }
            }
            _engines.Clear();
        }
    }
}