using System;
using Xunit;
using XplorePlane.Models;

namespace XplorePlane.Tests.Models
{
    public class StateModelsTests
    {
        // ── Default Value Tests ───────────────────────────────────────

        [Fact]
        public void MotionState_Default_AllZeros()
        {
            var state = MotionState.Default;

            Assert.Equal(0, state.XM);
            Assert.Equal(0, state.YM);
            Assert.Equal(0, state.ZT);
            Assert.Equal(0, state.ZD);
            Assert.Equal(0, state.TiltD);
            Assert.Equal(0, state.Dist);
            Assert.Equal(0, state.XMSpeed);
            Assert.Equal(0, state.YMSpeed);
            Assert.Equal(0, state.ZTSpeed);
            Assert.Equal(0, state.ZDSpeed);
            Assert.Equal(0, state.TiltDSpeed);
            Assert.Equal(0, state.DistSpeed);
        }

        [Fact]
        public void RaySourceState_Default_IsOffAndZeros()
        {
            var state = RaySourceState.Default;

            Assert.False(state.IsOn);
            Assert.Equal(0, state.Voltage);
            Assert.Equal(0, state.Power);
        }

        [Fact]
        public void DetectorState_Default_DisconnectedAndZeros()
        {
            var state = DetectorState.Default;

            Assert.False(state.IsConnected);
            Assert.False(state.IsAcquiring);
            Assert.Equal(0, state.FrameRate);
            Assert.Equal(string.Empty, state.Resolution);
        }

        [Fact]
        public void SystemState_Default_IdleNoError()
        {
            var state = SystemState.Default;

            Assert.Equal(OperationMode.Idle, state.OperationMode);
            Assert.False(state.HasError);
            Assert.Equal(string.Empty, state.ErrorMessage);
        }

        [Fact]
        public void CameraState_Default_DisconnectedAndZeros()
        {
            var state = CameraState.Default;

            Assert.False(state.IsConnected);
            Assert.False(state.IsStreaming);
            Assert.Null(state.CurrentFrame);
            Assert.Equal(0, state.Width);
            Assert.Equal(0, state.Height);
            Assert.Equal(0, state.FrameRate);
        }

        [Fact]
        public void LinkedViewState_Default_ZeroPositionNotExecuting()
        {
            var state = LinkedViewState.Default;

            Assert.Equal(0, state.TargetPosition.X);
            Assert.Equal(0, state.TargetPosition.Y);
            Assert.Equal(0, state.TargetPosition.Z);
            Assert.False(state.IsExecuting);
            Assert.Equal(DateTime.MinValue, state.LastRequestTime);
        }

        [Fact]
        public void RecipeExecutionState_Default_IdleAndZeros()
        {
            var state = RecipeExecutionState.Default;

            Assert.Equal(0, state.CurrentStepIndex);
            Assert.Equal(0, state.TotalSteps);
            Assert.Equal(RecipeExecutionStatus.Idle, state.Status);
            Assert.Equal(string.Empty, state.CurrentRecipeName);
        }

        // ── Immutability Test ─────────────────────────────────────────

        [Fact]
        public void MotionState_WithExpression_ProducesNewInstance()
        {
            var original = MotionState.Default;

            var modified = original with { XM = 100 };

            // New instance is different from original
            Assert.NotSame(original, modified);
            Assert.Equal(100, modified.XM);

            // Original is unchanged
            Assert.Equal(0, original.XM);
        }

        // ── CalibrationMatrix Transform Tests ─────────────────────────

        [Fact]
        public void CalibrationMatrix_Transform_CorrectCalculation()
        {
            // Known matrix: scaling X by 2, Y by 3, with offsets
            var matrix = new CalibrationMatrix(
                M11: 2, M12: 0, M13: 10,
                M21: 0, M22: 3, M23: 20,
                M31: 0, M32: 0, M33: 0
            );

            var (x, y, z) = matrix.Transform(pixelX: 5, pixelY: 8);

            // x = 2*5 + 0*8 + 10 = 20
            Assert.Equal(20, x);
            // y = 0*5 + 3*8 + 20 = 44
            Assert.Equal(44, y);
            // z = 0*5 + 0*8 + 0 = 0
            Assert.Equal(0, z);
        }

        [Fact]
        public void CalibrationMatrix_Transform_IdentityMatrix()
        {
            // Identity-like matrix: should return (pixelX, pixelY, 0) approximately
            var identity = new CalibrationMatrix(
                M11: 1, M12: 0, M13: 0,
                M21: 0, M22: 1, M23: 0,
                M31: 0, M32: 0, M33: 0
            );

            var (x, y, z) = identity.Transform(pixelX: 42.5, pixelY: 99.1);

            Assert.Equal(42.5, x, precision: 10);
            Assert.Equal(99.1, y, precision: 10);
            Assert.Equal(0, z, precision: 10);
        }
    }
}