using Moq;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using Xunit;
using XP.Common.Logging.Interfaces;
using XplorePlane.Models;
using XplorePlane.Services.AppState;
using XplorePlane.Services.Debug;
using XplorePlane.ViewModels.Debug;

namespace XplorePlane.Tests.Services
{
    /// <summary>
    /// 调试面板集成测试
    /// Integration tests for the Debug Panel feature
    ///
    /// Tests the full lifecycle of DebugPanelViewModel including:
    /// - Opening and initialising the panel
    /// - Singleton window behaviour (single instance)
    /// - Configuration load and save round-trip
    ///
    /// Validates: Requirements 1.1-1.5, 12.1-12.7
    /// </summary>
    public class DebugPanelIntegrationTests : IDisposable
    {
        private readonly Mock<IAppStateService> _mockAppStateService;
        private readonly Mock<ILoggerService> _mockLoggerService;
        private readonly Mock<ILoggerService> _mockModuleLogger;
        private readonly string _tempConfigDir;
        private readonly string _tempConfigPath;
        private readonly DebugPanelConfigService _realConfigService;

        public DebugPanelIntegrationTests()
        {
            // Application.Current may already exist (created by another test class in the same AppDomain).
            // Attempting to create a second instance throws InvalidOperationException, so we skip it.
            // The Dispatcher is available regardless — WPF initialises it on the first STA thread access.

            _mockAppStateService = new Mock<IAppStateService>();
            _mockLoggerService = new Mock<ILoggerService>();
            _mockModuleLogger = new Mock<ILoggerService>();

            // Wire up all ForModule<T> calls to return the module logger mock
            _mockLoggerService.Setup(l => l.ForModule<DebugPanelViewModel>()).Returns(_mockModuleLogger.Object);
            _mockLoggerService.Setup(l => l.ForModule<StateDisplayViewModel>()).Returns(_mockModuleLogger.Object);
            _mockLoggerService.Setup(l => l.ForModule<EventLogViewModel>()).Returns(_mockModuleLogger.Object);
            _mockLoggerService.Setup(l => l.ForModule<SnapshotManagerViewModel>()).Returns(_mockModuleLogger.Object);
            _mockLoggerService.Setup(l => l.ForModule<PerformanceMonitorViewModel>()).Returns(_mockModuleLogger.Object);
            _mockLoggerService.Setup(l => l.ForModule<DebugPanelConfigService>()).Returns(_mockModuleLogger.Object);

            // Use a temp directory so tests don't pollute %AppData%
            _tempConfigDir = Path.Combine(Path.GetTempPath(), "XplorePlaneIntegrationTests", Guid.NewGuid().ToString("N"));
            Directory.CreateDirectory(_tempConfigDir);
            _tempConfigPath = Path.Combine(_tempConfigDir, "DebugPanel.config");

            _realConfigService = new DebugPanelConfigService(_mockLoggerService.Object);

            // Redirect the config path to the temp directory via reflection
            var configPathField = typeof(DebugPanelConfigService)
                .GetField("_configPath", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
            configPathField?.SetValue(_realConfigService, _tempConfigPath);
        }

        public void Dispose()
        {
            if (Directory.Exists(_tempConfigDir))
            {
                Directory.Delete(_tempConfigDir, recursive: true);
            }
        }

        // ─── Panel opening / initialisation ──────────────────────────────────────

        /// <summary>
        /// 创建 DebugPanelViewModel 后，所有子 ViewModel 应被初始化
        /// After creating DebugPanelViewModel, all child ViewModels should be initialised
        /// Validates: Requirements 1.1, 1.5
        /// </summary>
        [Fact]
        public void CreateDebugPanelViewModel_InitializesAllChildViewModels()
        {
            var vm = CreateViewModel();

            Assert.NotNull(vm.StateDisplay);
            Assert.NotNull(vm.EventLog);
            Assert.NotNull(vm.SnapshotManager);
            Assert.NotNull(vm.PerformanceMonitor);
        }

        /// <summary>
        /// 调用 Initialize 后，各子 ViewModel 应各自订阅状态变更事件（每个事件共 3 次）
        /// After calling Initialize, each child VM subscribes once — 3 total per event
        /// Validates: Requirement 1.5
        /// </summary>
        [Fact]
        public void Initialize_SubscribesAllChildViewModels_ToStateChangeEvents()
        {
            var vm = CreateViewModel();

            vm.Initialize();

            // 3 child VMs (StateDisplay, EventLog, PerformanceMonitor) each subscribe once
            _mockAppStateService.VerifyAdd(
                s => s.MotionStateChanged += It.IsAny<EventHandler<StateChangedEventArgs<MotionState>>>(),
                Times.Exactly(3));
            _mockAppStateService.VerifyAdd(
                s => s.RaySourceStateChanged += It.IsAny<EventHandler<StateChangedEventArgs<RaySourceState>>>(),
                Times.Exactly(3));
        }

        /// <summary>
        /// 重复调用 Initialize 不应重复订阅事件
        /// Calling Initialize twice should not double-subscribe events.
        /// Each child VM (StateDisplay, EventLog, PerformanceMonitor) subscribes once,
        /// so after the first Initialize() there are 3 subscriptions total.
        /// The second Initialize() must be a no-op — the count must not grow.
        /// Validates: Requirement 1.5
        /// </summary>
        [Fact]
        public void Initialize_CalledTwice_DoesNotDoubleSubscribe()
        {
            var vm = CreateViewModel();

            // First call — 3 child VMs each subscribe once → 3 total
            vm.Initialize();
            _mockAppStateService.VerifyAdd(
                s => s.MotionStateChanged += It.IsAny<EventHandler<StateChangedEventArgs<MotionState>>>(),
                Times.Exactly(3),
                "After first Initialize(), each of the 3 child VMs should have subscribed once");

            // Second call — must be a no-op; count stays at 3
            vm.Initialize();
            _mockAppStateService.VerifyAdd(
                s => s.MotionStateChanged += It.IsAny<EventHandler<StateChangedEventArgs<MotionState>>>(),
                Times.Exactly(3),
                "After second Initialize(), subscription count must not increase");
        }

        // ─── Singleton window behaviour ───────────────────────────────────────────

        /// <summary>
        /// 同一 ViewModel 实例不应被初始化两次（单例行为）
        /// The same ViewModel instance should not be initialised twice (singleton behaviour)
        /// Validates: Requirement 1.2
        /// </summary>
        [Fact]
        public void SingletonBehaviour_SameViewModelInstance_InitializedOnce()
        {
            var vm = CreateViewModel();

            vm.Initialize();
            vm.Initialize(); // Second call should be a no-op

            // After first Initialize(): 3 child VMs × 1 subscription = 3 total.
            // After second Initialize(): still 3 — the guard prevents re-subscription.
            _mockAppStateService.VerifyAdd(
                s => s.MotionStateChanged += It.IsAny<EventHandler<StateChangedEventArgs<MotionState>>>(),
                Times.Exactly(3),
                "MotionStateChanged should be subscribed exactly 3 times (once per child VM) even if Initialize is called twice");
        }

        // ─── Dispose / resource cleanup ───────────────────────────────────────────

        /// <summary>
        /// Dispose 后，子 ViewModel 的集合应被清空
        /// After Dispose, child ViewModel collections should be cleared
        /// Validates: Requirement 1.3
        /// </summary>
        [Fact]
        public void Dispose_ClearsChildViewModelCollections()
        {
            var vm = CreateViewModel();
            vm.Initialize();

            vm.Dispose();

            Assert.Empty(vm.EventLog.EventLog);
            Assert.Empty(vm.PerformanceMonitor.Metrics);
            Assert.Empty(vm.PerformanceMonitor.TrendData);
        }

        /// <summary>
        /// Dispose 后再次调用 Dispose 不应抛出异常
        /// Calling Dispose twice should not throw
        /// Validates: Requirement 1.3
        /// </summary>
        [Fact]
        public void Dispose_CalledTwice_DoesNotThrow()
        {
            var vm = CreateViewModel();
            vm.Initialize();

            var ex = Record.Exception(() =>
            {
                vm.Dispose();
                vm.Dispose();
            });

            Assert.Null(ex);
        }

        // ─── Configuration load and save ─────────────────────────────────────────

        /// <summary>
        /// 创建 ViewModel 时应从配置文件加载偏好设置
        /// Creating the ViewModel should load preferences from the config file
        /// Validates: Requirement 12.6
        /// </summary>
        [Fact]
        public void CreateViewModel_LoadsConfigFromFile()
        {
            // Arrange: pre-write a config with custom filter settings
            var savedConfig = new DebugPanelConfig
            {
                Window = new WindowConfig { Width = 1400, Height = 900, State = WindowState.Normal },
                EventFilters = new Dictionary<string, bool>
                {
                    ["MotionState"] = false,
                    ["RaySourceState"] = true,
                    ["DetectorState"] = true,
                    ["SystemState"] = true,
                    ["CameraState"] = true,
                    ["LinkedViewState"] = true,
                    ["RecipeExecutionState"] = true,
                    ["CalibrationMatrix"] = true
                }
            };
            _realConfigService.SaveConfig(savedConfig);

            // Act
            var vm = CreateViewModel();
            vm.Initialize();

            // Assert: the filter for MotionState should be false as saved
            Assert.False(vm.EventLog.FilterOptions["MotionState"],
                "MotionState filter should be false as saved in config");
            Assert.True(vm.EventLog.FilterOptions["RaySourceState"],
                "RaySourceState filter should be true as saved in config");
        }

        /// <summary>
        /// Dispose 时应将当前过滤器设置保存到配置文件
        /// On Dispose, current filter settings should be saved to the config file
        /// Validates: Requirements 12.1-12.3
        /// </summary>
        [Fact]
        public void Dispose_SavesFilterSettingsToConfig()
        {
            var vm = CreateViewModel();
            vm.Initialize();

            // Change a filter setting
            vm.EventLog.FilterOptions["MotionState"] = false;

            // Act: Dispose triggers SaveLayout which calls SaveConfig
            vm.Dispose();

            // Assert: reload config and verify the filter was persisted
            var reloadedConfig = _realConfigService.LoadConfig();
            Assert.NotNull(reloadedConfig.EventFilters);
            Assert.False(reloadedConfig.EventFilters.TryGetValue("MotionState", out var motionFilter) && motionFilter,
                "MotionState filter should have been saved as false");
        }

        /// <summary>
        /// 当配置文件不存在时，ViewModel 应使用默认配置
        /// When no config file exists, ViewModel should use default configuration
        /// Validates: Requirement 12.7
        /// </summary>
        [Fact]
        public void CreateViewModel_WhenNoConfigFile_UsesDefaultConfig()
        {
            // Ensure no config file exists
            if (File.Exists(_tempConfigPath))
            {
                File.Delete(_tempConfigPath);
            }

            var vm = CreateViewModel();
            vm.Initialize();

            // Default config enables all filters
            Assert.True(vm.EventLog.FilterOptions["MotionState"],
                "Default config should enable MotionState filter");
            Assert.True(vm.EventLog.FilterOptions["RaySourceState"],
                "Default config should enable RaySourceState filter");
            Assert.NotNull(vm.CurrentConfig);
            Assert.Equal(1200, vm.CurrentConfig.Window.Width);
            Assert.Equal(800, vm.CurrentConfig.Window.Height);
        }

        /// <summary>
        /// ResetLayoutCommand 应将所有过滤器恢复为启用状态
        /// ResetLayoutCommand should restore all filters to enabled
        /// Validates: Requirement 12.2
        /// </summary>
        [Fact]
        public void ResetLayoutCommand_RestoresAllFiltersToEnabled()
        {
            var vm = CreateViewModel();
            vm.Initialize();

            // Disable some filters
            vm.EventLog.FilterOptions["MotionState"] = false;
            vm.EventLog.FilterOptions["RaySourceState"] = false;

            // Act
            vm.ResetLayoutCommand.Execute();

            // Assert: all filters should be re-enabled
            Assert.All(vm.EventLog.FilterOptions.Values, enabled => Assert.True(enabled));
        }

        /// <summary>
        /// SaveLayoutCommand 应将当前过滤器状态持久化到配置文件
        /// SaveLayoutCommand should persist current filter state to the config file
        /// Validates: Requirements 12.1-12.3
        /// </summary>
        [Fact]
        public void SaveLayoutCommand_PersistsCurrentFilterState()
        {
            var vm = CreateViewModel();
            vm.Initialize();

            // Change a filter
            vm.EventLog.FilterOptions["DetectorState"] = false;

            // Act
            vm.SaveLayoutCommand.Execute();

            // Assert: reload and verify
            var reloadedConfig = _realConfigService.LoadConfig();
            Assert.NotNull(reloadedConfig.EventFilters);
            Assert.True(reloadedConfig.EventFilters.ContainsKey("DetectorState"),
                "DetectorState key should be present in saved config");
            Assert.False(reloadedConfig.EventFilters["DetectorState"],
                "DetectorState filter should have been saved as false");
        }

        // ─── State event propagation ──────────────────────────────────────────────

        /// <summary>
        /// 状态变更事件应传播到 StateDisplay 子 ViewModel（验证事件订阅已建立）
        /// State-change events should be routed to StateDisplayViewModel (verify subscription is wired)
        /// Validates: Requirements 1.5, 2.9
        /// Note: UI updates happen via Dispatcher.BeginInvoke which requires a running message pump.
        /// This test verifies the subscription is established; the StateDisplayViewModelTests cover
        /// the actual update logic with a proper Dispatcher.
        /// </summary>
        [Fact]
        public void StateChangeEvent_PropagatesTo_StateDisplayViewModel()
        {
            var vm = CreateViewModel();
            vm.Initialize();

            // Verify the subscription is wired: raising the event should not throw
            var ex = Record.Exception(() =>
            {
                var oldState = new RaySourceState(false, 100.0, 5.0);
                var newState = new RaySourceState(true, 160.0, 8.0);

                _mockAppStateService.Raise(
                    s => s.RaySourceStateChanged += null,
                    _mockAppStateService.Object,
                    new StateChangedEventArgs<RaySourceState>(oldState, newState));
            });

            Assert.Null(ex);

            // Verify the StateTree is initialised with the expected root nodes
            Assert.Equal(8, vm.StateDisplay.StateTree.Count);
            Assert.Contains(vm.StateDisplay.StateTree, n => n.Name == "RaySourceState");
        }

        /// <summary>
        /// 状态变更事件应传播到 EventLog 子 ViewModel（验证事件订阅已建立）
        /// State-change events should be routed to EventLogViewModel (verify subscription is wired)
        /// Validates: Requirements 1.5, 4.2
        /// Note: EventLog entries are added via Dispatcher.BeginInvoke. This test verifies the
        /// subscription is established and no exception is thrown; the EventLogViewModelTests
        /// cover the actual entry-addition logic with a proper Dispatcher.
        /// </summary>
        [Fact]
        public void StateChangeEvent_PropagatesTo_EventLogViewModel()
        {
            var vm = CreateViewModel();
            vm.Initialize();

            // Verify the subscription is wired: raising the event should not throw
            var ex = Record.Exception(() =>
            {
                var oldState = new RaySourceState(false, 100.0, 5.0);
                var newState = new RaySourceState(true, 160.0, 8.0);

                _mockAppStateService.Raise(
                    s => s.RaySourceStateChanged += null,
                    _mockAppStateService.Object,
                    new StateChangedEventArgs<RaySourceState>(oldState, newState));
            });

            Assert.Null(ex);

            // Verify filter options are initialised (proves EventLogViewModel is wired up)
            Assert.True(vm.EventLog.FilterOptions.ContainsKey("RaySourceState"));
            Assert.True(vm.EventLog.FilterOptions["RaySourceState"]);
        }

        /// <summary>
        /// 状态变更事件应传播到 PerformanceMonitor 子 ViewModel（验证事件订阅已建立）
        /// State-change events should be routed to PerformanceMonitorViewModel (verify subscription is wired)
        /// Validates: Requirements 1.5, 9.1
        /// </summary>
        [Fact]
        public void StateChangeEvent_PropagatesTo_PerformanceMonitorViewModel()
        {
            var vm = CreateViewModel();
            vm.Initialize();

            // Verify the subscription is wired: raising the event should not throw,
            // and the event is recorded synchronously into the ConcurrentQueue.
            var ex = Record.Exception(() =>
            {
                var oldState = new MotionState(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0);
                var newState = new MotionState(1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0);

                _mockAppStateService.Raise(
                    s => s.MotionStateChanged += null,
                    _mockAppStateService.Object,
                    new StateChangedEventArgs<MotionState>(oldState, newState));
            });

            Assert.Null(ex);

            // Verify the MotionState metric exists (proves PerformanceMonitorViewModel is wired up)
            var motionMetric = vm.PerformanceMonitor.Metrics.FirstOrDefault(m => m.StateType == "MotionState");
            Assert.NotNull(motionMetric);
        }

        // ─── Snapshot capture integration ─────────────────────────────────────────

        /// <summary>
        /// 捕获快照后，快照应包含所有 8 种状态对象的当前值
        /// After capturing a snapshot, it should contain current values of all 8 state objects
        /// Validates: Requirements 7.2-7.4
        /// </summary>
        [Fact]
        public void CaptureSnapshot_IncludesAllStateObjects()
        {
            // Arrange: set up mock state values
            var motionState = new MotionState(10, 20, 30, 40, 5, 1000, 1, 2, 3, 4, 0.5, 50, 0, 0, 500, 2, 0, 0);
            var raySourceState = new RaySourceState(true, 160.0, 8.0);
            var detectorState = new DetectorState(true, false, 30.0, "1920x1080");
            var systemState = new SystemState(OperationMode.Idle, false, string.Empty);
            var cameraState = new CameraState(true, false, null, 1920, 1080, 30.0);
            var linkedViewState = new LinkedViewState(new PhysicalPosition(0, 0, 0), false, DateTime.Now);
            var recipeState = new RecipeExecutionState(0, 5, RecipeExecutionStatus.Idle, "TestRecipe");
            var calibMatrix = new CalibrationMatrix(1, 0, 0, 0, 1, 0, 0, 0, 1);

            _mockAppStateService.Setup(s => s.MotionState).Returns(motionState);
            _mockAppStateService.Setup(s => s.RaySourceState).Returns(raySourceState);
            _mockAppStateService.Setup(s => s.DetectorState).Returns(detectorState);
            _mockAppStateService.Setup(s => s.SystemState).Returns(systemState);
            _mockAppStateService.Setup(s => s.CameraState).Returns(cameraState);
            _mockAppStateService.Setup(s => s.LinkedViewState).Returns(linkedViewState);
            _mockAppStateService.Setup(s => s.RecipeExecutionState).Returns(recipeState);
            _mockAppStateService.Setup(s => s.CalibrationMatrix).Returns(calibMatrix);

            var vm = CreateViewModel();
            vm.Initialize();

            // Act
            vm.SnapshotManager.CaptureSnapshot();

            // Assert
            Assert.Single(vm.SnapshotManager.Snapshots);
            var snapshot = vm.SnapshotManager.Snapshots[0].Snapshot;

            Assert.NotNull(snapshot);
            Assert.Equal(motionState, snapshot.MotionState);
            Assert.Equal(raySourceState, snapshot.RaySourceState);
            Assert.Equal(detectorState, snapshot.DetectorState);
            Assert.Equal(systemState, snapshot.SystemState);
            Assert.Equal(cameraState, snapshot.CameraState);
            Assert.Equal(linkedViewState, snapshot.LinkedViewState);
            Assert.Equal(recipeState, snapshot.RecipeExecutionState);
            Assert.Equal(calibMatrix, snapshot.CalibrationMatrix);
        }

        // ─── Helpers ─────────────────────────────────────────────────────────────

        private DebugPanelViewModel CreateViewModel() =>
            new DebugPanelViewModel(
                _mockAppStateService.Object,
                _mockLoggerService.Object,
                _realConfigService);
    }
}