using System;
using System.Reflection;
using NUnit.Framework;
using UnityEngine;
using XGame.VirtualInput;

public sealed class VirtualJoystickTests
{
    private GameObject _root;

    [TearDown]
    public void TearDown()
    {
        if (_root != null)
        {
            UnityEngine.Object.DestroyImmediate(_root);
            _root = null;
        }
    }

    [Test]
    public void ApplyPointerInsideDeadZone_ReportsInactiveAndZero()
    {
        VirtualJoystick joystick = CreateJoystick(out _);

        ApplyPointer(joystick, new Vector2(106f, 100f));

        Assert.That(joystick.IsActive, Is.False);
        Assert.That(joystick.Value, Is.EqualTo(Vector2.zero));
    }

    [Test]
    public void ApplyPointerBeyondRadius_ClampsValueAndKnobTravel()
    {
        VirtualJoystick joystick = CreateJoystick(out RectTransform knob);

        ApplyPointer(joystick, new Vector2(300f, 100f));

        Assert.That(joystick.IsActive, Is.True);
        Assert.That(joystick.Value.x, Is.EqualTo(1f).Within(0.001f));
        Assert.That(joystick.Value.y, Is.EqualTo(0f).Within(0.001f));
        Assert.That(knob.anchoredPosition.x, Is.EqualTo(24f).Within(0.001f));
        Assert.That(knob.anchoredPosition.y, Is.EqualTo(0f).Within(0.001f));
    }

    [Test]
    public void ReleasePointer_ResetsValueAndRaisesEnded()
    {
        VirtualJoystick joystick = CreateJoystick(out RectTransform knob);
        int ended = 0;
        joystick.Ended += () => ended++;

        ApplyPointer(joystick, new Vector2(300f, 100f));
        ReleasePointer(joystick);

        Assert.That(joystick.IsActive, Is.False);
        Assert.That(joystick.Value, Is.EqualTo(Vector2.zero));
        Assert.That(knob.anchoredPosition, Is.EqualTo(Vector2.zero));
        Assert.That(ended, Is.EqualTo(1));
    }

    [Test]
    public void IsScreenPositionInAcquireArea_UsesAcquireRadiusMultiplier()
    {
        VirtualJoystick joystick = CreateJoystick(out _);

        Assert.That(joystick.IsScreenPositionInAcquireArea(new Vector2(179f, 100f)), Is.True);
        Assert.That(joystick.IsScreenPositionInAcquireArea(new Vector2(181f, 100f)), Is.False);
    }

    private VirtualJoystick CreateJoystick(out RectTransform knob)
    {
        _root = new GameObject("UI_VirtualJoystick", typeof(RectTransform));
        RectTransform rootRect = _root.GetComponent<RectTransform>();
        rootRect.sizeDelta = new Vector2(100f, 100f);

        GameObject knobObject = new GameObject("Knob", typeof(RectTransform));
        knobObject.transform.SetParent(_root.transform, false);
        knob = knobObject.GetComponent<RectTransform>();
        knob.sizeDelta = new Vector2(52f, 52f);

        VirtualJoystick joystick = _root.AddComponent<VirtualJoystick>();
        SetPrivateField(joystick, "screenCenterOverride", new Vector2(100f, 100f));
        SetPrivateField(joystick, "screenRadiusOverride", 50f);
        InvokePrivate(joystick, "Awake");
        return joystick;
    }

    private static void ApplyPointer(VirtualJoystick joystick, Vector2 screenPosition)
    {
        InvokePrivate(joystick, "ApplyPointer", screenPosition);
    }

    private static void ReleasePointer(VirtualJoystick joystick)
    {
        InvokePrivate(joystick, "ReleasePointer");
    }

    private static void SetPrivateField(object target, string name, object value)
    {
        FieldInfo field = target.GetType().GetField(name, BindingFlags.Instance | BindingFlags.NonPublic);
        Assert.That(field, Is.Not.Null);
        field.SetValue(target, value);
    }

    private static void InvokePrivate(object target, string name, params object[] args)
    {
        MethodInfo method = target.GetType().GetMethod(name, BindingFlags.Instance | BindingFlags.NonPublic);
        Assert.That(method, Is.Not.Null);
        method.Invoke(target, args);
    }
}