using System.Collections;
using System.Reflection;
using BumpCombat.Defense.Comparison;
using NUnit.Framework;
using UnityEngine;
using UnityEngine.TestTools;
using Object = UnityEngine.Object;

namespace BumpCombat.Tests
{
    public sealed class Defense25DStatusVisualPlayModeTests
    {
        private GameObject enemyObject;
        private GameObject actorObject;
        private GameObject spriteObject;
        private GameObject worldObject;

        [UnityTearDown]
        public IEnumerator TearDown()
        {
            if (worldObject != null) Object.Destroy(worldObject);
            else
            {
                if (enemyObject != null) Object.Destroy(enemyObject);
                if (actorObject != null) Object.Destroy(actorObject);
                if (spriteObject != null) Object.Destroy(spriteObject);
            }
            yield return null;
        }

        [UnityTest]
        public IEnumerator ActiveStatusesRenderExistingFramesAndClearWhenTheirTimersExpire()
        {
            const string ignitePath = "Artifacts/ThreeColor-v1/StatusEffects/Ignite-Warlock-v1";
            Sprite[] importedFrames = Resources.LoadAll<Sprite>(ignitePath);
            Texture2D igniteTexture = importedFrames.Length > 0
                ? importedFrames[0].texture : Resources.Load<Texture2D>(ignitePath);
            Assert.That(igniteTexture, Is.Not.Null);

            worldObject = new GameObject("Status visual world");
            Defense25DComparison owner = worldObject.AddComponent<Defense25DComparison>();
            SetBackingField(owner, "IsRunning", true);
            SetBackingField(owner, "Paused", true);

            spriteObject = new GameObject("Status visual source");
            SpriteRenderer sourceRenderer = spriteObject.AddComponent<SpriteRenderer>();
            actorObject = new GameObject("Status visual actor");
            actorObject.transform.SetParent(worldObject.transform, false);
            spriteObject.transform.SetParent(actorObject.transform, false);
            spriteObject.transform.rotation = Quaternion.Euler(30f, 0f, 0f);
            sourceRenderer.sortingOrder = 12;
            sourceRenderer.flipX = true;
            sourceRenderer.color = new Color(1f, 1f, 1f, .4f);

            Defense25DActor actor = actorObject.AddComponent<Defense25DActor>();
            SetBackingField(actor, "CurrentHealth", 10f);
            Defense25DSprite actorVisual = actorObject.AddComponent<Defense25DSprite>();
            SetPrivateField(actorVisual, "sprite", sourceRenderer);
            actorVisual.enabled = false;
            SetBackingField(actor, "Visual", actorVisual);

            enemyObject = new GameObject("Status visual enemy");
            enemyObject.transform.SetParent(worldObject.transform, false);
            Defense25DEnemy enemy = enemyObject.AddComponent<Defense25DEnemy>();
            SetBackingField(enemy, "Actor", actor);
            SetPrivateField(enemy, "world", owner);
            SetPrivateField(enemy, "igniteRemaining", .5f);
            SetPrivateField(enemy, "shockRemaining", .5f);
            SetPrivateField(enemy, "stunUntil", .5f);
            SetPrivateField(enemy, "stunVisualRevision", 1);
            Defense25DStatusVisual statusVisual = enemyObject.AddComponent<Defense25DStatusVisual>();
            statusVisual.Bind(enemy);

            statusVisual.SendMessage("LateUpdate");

            Transform igniteVisual = spriteObject.transform.Find("Ignite Status Visual");
            Transform shockVisual = spriteObject.transform.Find("Shock Status Visual");
            Assert.That(igniteVisual, Is.Not.Null);
            Assert.That(shockVisual, Is.Not.Null);
            Assert.That(enemy.IsIgnited, Is.True);
            Assert.That(enemy.IsShocked, Is.True);
            Assert.That(GetPrivateField(GetPrivateField(statusVisual, "ignite"), "FrameElapsed"),
                Is.EqualTo(0f));
            Assert.That(GetPrivateField(GetPrivateField(statusVisual, "shock"), "FrameElapsed"),
                Is.EqualTo(0f));
            Assert.That(GetPrivateField(statusVisual, "stunElapsed"), Is.EqualTo(0f));
            Transform stunMarker = actorObject.transform.Find("Stun Runes");
            Assert.That(stunMarker, Is.Not.Null);
            SpriteRenderer stunRenderer = stunMarker.GetComponent<SpriteRenderer>();
            Assert.That(stunRenderer.sharedMaterial, Is.SameAs(sourceRenderer.sharedMaterial));
            Assert.That(stunRenderer.color.a, Is.EqualTo(sourceRenderer.color.a).Within(.001f));
            Assert.That(stunMarker.localPosition.z, Is.GreaterThan(0f));

            SpriteRenderer igniteRenderer = igniteVisual.GetComponent<SpriteRenderer>();
            Assert.That(igniteRenderer.sprite, Is.Not.Null);
            Assert.That(igniteRenderer.sprite.texture, Is.SameAs(igniteTexture));
            Assert.That(igniteRenderer.sortingOrder, Is.EqualTo(sourceRenderer.sortingOrder + 1));
            Assert.That(igniteRenderer.flipX, Is.EqualTo(sourceRenderer.flipX));
            Assert.That(igniteRenderer.color.a, Is.EqualTo(sourceRenderer.color.a).Within(.001f));
            Assert.That(igniteVisual.localPosition.y,
                Is.EqualTo(Defense25DStatusVisual.StatusVisualAnchorOffsetY).Within(.001f));

            SetPrivateField(enemy, "igniteRemaining", 0f);
            SetPrivateField(enemy, "shockRemaining", 0f);
            statusVisual.SendMessage("LateUpdate");
            Assert.That(enemy.IsIgnited, Is.False);
            Assert.That(enemy.IsShocked, Is.False);
            Assert.That(GetPrivateField(GetPrivateField(statusVisual, "ignite"), "Root"), Is.Null);
            Assert.That(GetPrivateField(GetPrivateField(statusVisual, "shock"), "Root"), Is.Null);

            SetPrivateField(enemy, "igniteRemaining", .5f);
            SetBackingField(owner, "Paused", false);
            statusVisual.SendMessage("LateUpdate");
            Assert.That(GetPrivateField(GetPrivateField(statusVisual, "ignite"), "Root"), Is.Not.Null);
            SetBackingField(owner, "IsRunning", false);
            statusVisual.SendMessage("LateUpdate");
            Assert.That(GetPrivateField(GetPrivateField(statusVisual, "ignite"), "Root"), Is.Null);

            SetBackingField(owner, "IsRunning", true);
            statusVisual.SendMessage("LateUpdate");
            Assert.That(GetPrivateField(GetPrivateField(statusVisual, "ignite"), "Root"), Is.Not.Null);
            owner.enabled = false;
            statusVisual.SendMessage("LateUpdate");
            Assert.That(GetPrivateField(GetPrivateField(statusVisual, "ignite"), "Root"), Is.Null);
            yield return null;
        }

        private static void SetBackingField(object target, string propertyName, object value) =>
            SetPrivateField(target, $"<{propertyName}>k__BackingField", value);

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

        private static object GetPrivateField(object target, string fieldName)
        {
            FieldInfo field = target.GetType().GetField(
                fieldName, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public);
            Assert.That(field, Is.Not.Null, $"Missing test field {fieldName}");
            return field.GetValue(target);
        }
    }
}