using System;
using System.Windows;
using Moq;
using Serilog;
using Xunit;
using XP.Hardware.RaySource.Services;
using XplorePlane.Models;
using XplorePlane.Services.AppState;

namespace XplorePlane.Tests.Services
{
    /// <summary>
    /// AppStateService 单元测试。
    /// 验证默认状态值、Dispose 后行为、null 参数校验、CalibrationMatrix 缺失时的错误处理。
    /// </summary>
    public class AppStateServiceTests : IDisposable
    {
        private readonly AppStateService _service;
        private readonly Mock<IRaySourceService> _mockRaySource;
        private readonly Mock<ILogger> _mockLogger;

        public AppStateServiceTests()
        {
            // Ensure WPF Application exists for Dispatcher
            if (Application.Current == null)
            {
                new Application();
            }

            _mockRaySource = new Mock<IRaySourceService>();
            _mockLogger = new Mock<ILogger>();
            _service = new AppStateService(_mockRaySource.Object, _mockLogger.Object);
        }

        public void Dispose()
        {
            _service.Dispose();
        }

        // ── 默认状态值验证 ──

        [Fact]
        public void DefaultState_MotionState_IsDefault()
        {
            Assert.Same(MotionState.Default, _service.MotionState);
        }

        [Fact]
        public void DefaultState_RaySourceState_IsDefault()
        {
            Assert.Same(RaySourceState.Default, _service.RaySourceState);
        }

        [Fact]
        public void DefaultState_SystemState_IsDefault()
        {
            Assert.Same(SystemState.Default, _service.SystemState);
        }

        [Fact]
        public void DefaultState_CalibrationMatrix_IsNull()
        {
            Assert.Null(_service.CalibrationMatrix);
        }

        // ── null 参数抛出 ArgumentNullException ──

        [Fact]
        public void UpdateMotionState_NullArgument_ThrowsArgumentNullException()
        {
            Assert.Throws<ArgumentNullException>(() => _service.UpdateMotionState(null!));
        }

        [Fact]
        public void UpdateRaySourceState_NullArgument_ThrowsArgumentNullException()
        {
            Assert.Throws<ArgumentNullException>(() => _service.UpdateRaySourceState(null!));
        }

        [Fact]
        public void UpdateDetectorState_NullArgument_ThrowsArgumentNullException()
        {
            Assert.Throws<ArgumentNullException>(() => _service.UpdateDetectorState(null!));
        }

        [Fact]
        public void UpdateSystemState_NullArgument_ThrowsArgumentNullException()
        {
            Assert.Throws<ArgumentNullException>(() => _service.UpdateSystemState(null!));
        }

        // ── Dispose 后 Update 被忽略 ──

        [Fact]
        public void Dispose_ThenUpdate_IsIgnored()
        {
            var originalState = _service.MotionState;
            _service.Dispose();

            // Should not throw, and state should remain unchanged
            var newState = new MotionState(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
            _service.UpdateMotionState(newState);

            Assert.Same(originalState, _service.MotionState);
        }

        // ── CalibrationMatrix 为 null 时 RequestLinkedView 设置错误状态 ──

        [Fact]
        public void RequestLinkedView_NoCalibrationMatrix_SetsErrorState()
        {
            // CalibrationMatrix is null by default
            Assert.Null(_service.CalibrationMatrix);

            _service.RequestLinkedView(100.0, 200.0);

            Assert.True(_service.SystemState.HasError);
            Assert.NotEmpty(_service.SystemState.ErrorMessage);
        }
    }
}