#pragma warning disable xUnit1031 // FsCheck property tests require synchronous execution via GetAwaiter().GetResult()

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using FsCheck;
using FsCheck.Fluent;
using FsCheck.Xunit;
using Moq;
using Prism.Events;
using XP.Common.Logging.Interfaces;
using XplorePlane.Events;
using XplorePlane.Models;
using XplorePlane.Services;
using XplorePlane.Services.AppState;
using XplorePlane.Services.Cnc;
using XplorePlane.Services.InspectionResults;
using XplorePlane.Services.MainViewport;
using Xunit;

namespace XplorePlane.Tests.Services
{
    /// <summary>
    /// Property 8: 取消令牌中止后续位置执行
    /// **Validates: Requirements 3.5**
    ///
    /// For any CNC program being executed, when a CancellationToken is triggered,
    /// no SavePositionNode with Index greater than the currently executing node SHALL be processed.
    /// </summary>
    public class CancellationPropertyTests
    {
        /// <summary>
        /// Creates a CncExecutionService with all dependencies mocked.
        /// The SaveImageAsync mock triggers cancellation after K positions have been processed.
        /// </summary>
        private static (CncExecutionService Service, Mock<IImagePersistenceService> ImagePersistence, List<string> ExecutedNodeNames)
            CreateServiceWithCancellation(CancellationTokenSource cts, int cancelAfterK)
        {
            var mockStore = new Mock<IInspectionResultStore>();
            var mockLogger = new Mock<ILoggerService>();
            var mockMainViewportService = new Mock<IMainViewportService>();
            var mockAppStateService = new Mock<IAppStateService>();
            var mockPipelineExecutionService = new Mock<IPipelineExecutionService>();
            var mockImageProcessingService = new Mock<IImageProcessingService>();
            var mockEventAggregator = new Mock<IEventAggregator>();
            var mockImagePersistenceService = new Mock<IImagePersistenceService>();

            // Logger setup
            mockLogger.Setup(l => l.ForModule<CncExecutionService>()).Returns(mockLogger.Object);

            // EventAggregator setup - prevent NRE on constructor subscription
            mockEventAggregator
                .Setup(ea => ea.GetEvent<DetectorDisconnectedEvent>())
                .Returns(new DetectorDisconnectedEvent());

            // InspectionResultStore setup
            mockStore.Setup(s => s.BeginRunAsync(
                    It.IsAny<InspectionRunRecord>(),
                    It.IsAny<InspectionAssetWriteRequest>()))
                .Returns(Task.CompletedTask);

            mockStore.Setup(s => s.AppendNodeResultAsync(
                    It.IsAny<InspectionNodeResult>(),
                    It.IsAny<IEnumerable<InspectionMetricResult>>(),
                    It.IsAny<PipelineExecutionSnapshot>(),
                    It.IsAny<IEnumerable<InspectionAssetWriteRequest>>()))
                .Returns(Task.CompletedTask);

            mockStore.Setup(s => s.CompleteRunAsync(
                    It.IsAny<Guid>(),
                    It.IsAny<bool?>(),
                    It.IsAny<DateTime?>()))
                .Returns(Task.CompletedTask);

            // Provide a valid BitmapSource from the viewport so image acquisition succeeds
            var dummyBitmap = BitmapSource.Create(
                1, 1, 96, 96, PixelFormats.Gray8, null, new byte[] { 128 }, 1);
            dummyBitmap.Freeze();
            mockMainViewportService
                .Setup(m => m.LatestManualImage)
                .Returns(dummyBitmap);

            // Track which nodes have their images saved (i.e., which positions were executed)
            var executedNodeNames = new List<string>();
            int saveCallCount = 0;

            // ImagePersistenceService - cancel after K positions have been saved
            mockImagePersistenceService
                .Setup(s => s.SaveImageAsync(
                    It.IsAny<byte[]>(),
                    It.IsAny<string>(),
                    It.IsAny<string>(),
                    It.IsAny<CancellationToken>()))
                .Returns<byte[], string, string, CancellationToken>((_, nodeName, __, ___) =>
                {
                    executedNodeNames.Add(nodeName);
                    int currentCount = Interlocked.Increment(ref saveCallCount);
                    // Cancel after K positions have been processed
                    if (currentCount >= cancelAfterK)
                    {
                        cts.Cancel();
                    }
                    return Task.FromResult(new ImageSaveResult(true, $"C:\\test\\{nodeName}.bmp", 1024));
                });

            mockImagePersistenceService
                .Setup(s => s.WriteSummaryAsync(
                    It.IsAny<BatchCaptureResult>(),
                    It.IsAny<string>(),
                    It.IsAny<CancellationToken>()))
                .ReturnsAsync(true);

            var service = new CncExecutionService(
                mockStore.Object,
                mockLogger.Object,
                mockMainViewportService.Object,
                mockAppStateService.Object,
                mockPipelineExecutionService.Object,
                mockImageProcessingService.Object,
                mockEventAggregator.Object,
                mockImagePersistenceService.Object);

            return (service, mockImagePersistenceService, executedNodeNames);
        }

        /// <summary>
        /// FsCheck generator for a cancellation test scenario:
        /// - N SavePositionNodes (N between 2 and 10)
        /// - A cancellation point K (1 &lt;= K &lt; N), meaning cancel after K positions are processed
        /// </summary>
        private static Arbitrary<(List<SavePositionNode> Nodes, int CancelAfterK)> CancellationScenarioArb()
        {
            var gen =
                from count in Gen.Choose(2, 10)
                from cancelAfterK in Gen.Choose(1, count - 1)
                from indices in Gen.Shuffle(Enumerable.Range(0, count).ToArray())
                    .Select(arr => arr.ToList())
                select (
                    Nodes: indices.Select(idx =>
                        new SavePositionNode(
                            Guid.NewGuid(),
                            idx,
                            $"Position_{idx}",
                            MotionState.Default,
                            SaveImage: true,
                            ManualImagePath: ""))
                        .ToList(),
                    CancelAfterK: cancelAfterK
                );

            return gen.ToArbitrary();
        }

        // Feature: cnc-multi-position-image-capture, Property 8: 取消令牌中止后续位置执行
        // **Validates: Requirements 3.5**
        [Property(MaxTest = 100)]
        public Property Cancellation_StopsSubsequentPositionExecution()
        {
            return Prop.ForAll(
                CancellationScenarioArb(),
                scenario =>
                {
                    var (nodes, cancelAfterK) = scenario;

                    using var cts = new CancellationTokenSource();
                    var (service, _, executedNodeNames) = CreateServiceWithCancellation(cts, cancelAfterK);

                    // Build a CncProgram containing the SavePositionNodes
                    // (in their original random order - the service sorts by Index)
                    var program = new CncProgram(
                        Guid.NewGuid(),
                        "TestProgram",
                        DateTime.UtcNow,
                        DateTime.UtcNow,
                        nodes.Cast<CncNode>().ToList().AsReadOnly());

                    // Track progress reports to verify which positions were executed
                    var executedPositionIndices = new List<int>();
                    var progress = new SynchronousProgress<CncNodeExecutionProgress>(p =>
                    {
                        if (p.State == NodeExecutionState.Running && p.PositionIndex.HasValue)
                        {
                            executedPositionIndices.Add(p.PositionIndex.Value);
                        }
                    });

                    service.ExecuteAsync(program, progress, cts.Token)
                           .GetAwaiter().GetResult();

                    // The expected sorted order of nodes by Index
                    var sortedNodes = nodes.OrderBy(n => n.Index).ToList();

                    // Verify: No more than cancelAfterK positions should have been executed.
                    // The cancellation is triggered after K SaveImageAsync calls complete,
                    // so at most K positions should have their images saved.
                    // The (K+1)th position might start (Running reported) but its SaveImageAsync
                    // should not be called because cancellation is checked at loop start.
                    bool noExcessiveSaves = executedNodeNames.Count <= cancelAfterK;

                    // Verify: Positions after the cancellation point should NOT be executed.
                    // The service checks cancellation at the start of each loop iteration,
                    // so after K positions complete and cancellation is triggered,
                    // subsequent positions should not receive Running state.
                    bool noSubsequentExecution = executedPositionIndices.Count <= cancelAfterK;

                    // Verify: The executed positions should be the first K positions in sorted order
                    bool correctPositionsExecuted = true;
                    for (int i = 0; i < executedNodeNames.Count && i < cancelAfterK; i++)
                    {
                        if (executedNodeNames[i] != sortedNodes[i].Name)
                        {
                            correctPositionsExecuted = false;
                            break;
                        }
                    }

                    return noExcessiveSaves && noSubsequentExecution && correctPositionsExecuted;
                });
        }
    }
}