using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;
using Hawkeye.VisionBuilder.Workflow;
using Hawkeye.VisionBuilder.Workflow.Datatypes;
using VisionBuilder.UI.Common.Commands;
using VisionBuilder.UI.Common.RecipeProcessing;
using VisionBuilder.UI.Common.ViewModel.Classes;

namespace VisionBuilder.UI.Recipes.HawkeyeRecipe
{
    public class HawkeyeRecognitionControl: IRecognitionControl
    {
        private readonly IImageSource _imageSource;
        private readonly HawkeyeRecognitionSettings _recognitionConfiguration;
        private readonly ILoadingService _loadingService;

        private CancellationTokenSource _cts;
        private Task _loopTask;

        public HawkeyeRecognitionControl(IImageSource imageSource, HawkeyeRecognitionSettings recognitionConfiguration, ILoadingService loadingService)
        {
            _imageSource = imageSource;
            _recognitionConfiguration = recognitionConfiguration;
            _loadingService = loadingService;
        }

        public List<RecipeData> GetRecipesData()
        {
            _loadingService.StartLoading($"Loading recipes for {_recognitionConfiguration.CameraName}...");
            try
            {
                var files = WorkflowRecipeHelper.ListRecipeFiles(_recognitionConfiguration.RecipeNameFilter);
                List<RecipeData> recipes = new List<RecipeData>();
                foreach (var file in files)
                {
                    var workFlow = WorkflowList.LoadJSONFromFile(file);

                    var recipe = new RecipeData
                    {
                        RecipeName = Path.GetFileNameWithoutExtension(file),
                        Image = workFlow.RecipeImage
                    };
                    recipes.Add(recipe);
                }

                return recipes;
            }
            finally
            {
                _loadingService.StopLoading($"Loading recipes for {_recognitionConfiguration.CameraName}...");
            }
        }

        RecipeData _currentRecipe;

        public void SetRecipe(RecipeData recipe)
        {
            // error if running
            if (IsRunning)
            {
                throw new InvalidOperationException("Cannot change recipe while recognition is running.");
            }
            _currentRecipe = recipe;
        }

        public bool IsRunning { get; set; }
        public bool IsPaused { get; set; }

        private DateTime _startTime;
        private WorkflowList _workflow;

        public void Start()
        {
            
            if (_currentRecipe == null)
            {
                throw new InvalidOperationException("No recipe set.");
            }
            if (IsRunning)
            {
                throw new InvalidOperationException("Recognition is already running.");
            }
            _loadingService.StartLoading($"Starting recipe {_currentRecipe.RecipeName} on {_recognitionConfiguration.CameraName}...");
            _workflow = WorkflowList.LoadJSONFromFile("..\\Data\\Recipes\\" + _currentRecipe.RecipeName + ".jhrcp");
            _startTime = DateTime.Now;
            IsRunning = true;
            _cts = new CancellationTokenSource();
            _loopTask = Task.Run(() => Loop(_cts.Token), _cts.Token);

            SessionStarted?.Invoke(new SessionStartedEvent
            {
                RecipeName = _currentRecipe.RecipeName,
                SessionStarted = _startTime,
                
            });
            _loadingService.StopLoading($"Starting recipe {_currentRecipe.RecipeName} on {_recognitionConfiguration.CameraName}...");

        }

        public void Stop()
        {
            if (!IsRunning)
                return  ;
            _loadingService.StartLoading($"Stopping {_recognitionConfiguration.CameraName}");
            _cts?.Cancel();
            try
            {
                _loopTask?.Wait();
            }
            catch (AggregateException ex) when (ex.InnerExceptions.All(e => e is TaskCanceledException))
            {
                // Ignore cancellation exceptions
            }
            finally
            {
                IsRunning = false;
                _cts?.Dispose();
                _cts = null;
                _loopTask = null;
            }

            SessionEnded?.Invoke(new SessionEndedEvent
            {
                SessionEnded = DateTime.Now
            });
            _loadingService.StopLoading($"Stopping {_recognitionConfiguration.CameraName}");

        }

        public void Pause()
        {
            IsPaused= true;
        }

        public void Resume()
        {
            IsPaused = false;
        }

        private async Task Loop(CancellationToken token)
        {
            // Start the recognition process using the Hawkeye library
            
            while (!token.IsCancellationRequested)
            {
                if (IsPaused)
                {
                    await Task.Delay(100, token);
                    continue;
                }
                
                var sw = Stopwatch.StartNew();
                _workflow.Context.CancellationToken= token;
                _workflow.ImageSource= _imageSource;
                try
                {
                    _workflow.Execute();
                }
                catch (Exception e) when(token.IsCancellationRequested)
                {
                    sw.Stop();
                    return;
                }
                
                sw.Stop();
                
                if (sw.ElapsedMilliseconds < _recognitionConfiguration.MinimumProcessingTime)
                {
                    Thread.Sleep(_recognitionConfiguration.MinimumProcessingTime - (int)sw.ElapsedMilliseconds);
                }
                string[] errorNames = _workflow.Operations.Where(x => !x.Result).Select(x => x.Label).ToArray();

                var annotated = _workflow.Context.ActiveImage.ImageData.Clone();
                var canvas = new OpenCVCanvas(annotated);
                _workflow.Context.GraphicsElements.ForEach(x => x.Draw(canvas));
                var processingResult = new ImageProcessedEvent()
                {
                    SessionStart = _startTime,
                    RecipeName = _currentRecipe.RecipeName,
                    AnalysisTime = sw.Elapsed,
                    ErrorNames = errorNames.ToList(),
                    HasError = errorNames.Length > 0,
                    ImageSource = _recognitionConfiguration.CameraName,
                    ImageOriginal = _workflow.Context.LastCameraImage.ImageData,
                    ImageAnalysis = annotated
                };

                ImageProcessed(processingResult);


            }
        }

        public event Action<ImageProcessedEvent> ImageProcessed = delegate{};
        public event Action<SessionStartedEvent>? SessionStarted = delegate { };
        public event Action<SessionEndedEvent>? SessionEnded = delegate { };
    }
}