using System.Linq;
using System.Reflection;
using BumpCombat.Enemies;
using NUnit.Framework;
using UnityEditor;
using UnityEditor.Animations;
using UnityEngine;

namespace BumpCombat.Tests
{
    public sealed class SummonAnimationContractTests
    {
        [TestCase(false, 1.25f)]
        [TestCase(true, 1.875f)]
        public void SummonCircle_FollowsShadowCenterAcrossFramesAndMovement(bool flip, float scale)
        {
            var sprites = AssetDatabase.LoadAllAssetsAtPath(
                "Assets/_Project/Art/Characters/Necromancer/Necromancer_Summon-shadow-v2.png")
                .OfType<Sprite>().ToArray();
            Assert.That(sprites.Length, Is.EqualTo(10));
            var owner = new GameObject("Summon anchor test");
            StageEnemyEffectVisual effect = null;
            try
            {
                var body = owner.AddComponent<SpriteRenderer>();
                body.sprite = sprites[0];
                body.flipX = flip;
                owner.transform.localScale = new Vector3(scale, scale, 1f);
                effect = StageEnemyEffectVisual.PlaySummon(owner, owner.transform.position, 1.25f);
                var lateUpdate = typeof(StageEnemyEffectVisual).GetMethod("LateUpdate",
                    BindingFlags.NonPublic | BindingFlags.Instance);
                for (int i = 0; i < sprites.Length; i++)
                {
                    body.sprite = sprites[i];
                    owner.transform.position = new Vector3(i * .3f, i * -.2f, 0f);
                    lateUpdate.Invoke(effect, null);
                    // Measured source shadow center, relative to the imported 50px pivot.
                    Vector3 expected = owner.transform.position
                        + new Vector3((flip ? -.5f : .5f) / 32f, -7.5f / 32f) * scale;
                    Assert.That(Vector3.Distance(effect.transform.position, expected), Is.LessThan(.0001f));
                    Assert.That(effect.transform.localScale, Is.EqualTo(Vector3.one));
                }
            }
            finally
            {
                if (effect != null) Object.DestroyImmediate(effect.gameObject);
                Object.DestroyImmediate(owner);
            }
        }

        [TestCase("Skeleton", 5)]
        [TestCase("GreatswordSkeleton", 5)]
        [TestCase("ArmoredSkeleton", 5)]
        [TestCase("SkeletonArcher", 5)]
        [TestCase("Necromancer", 10)]
        [TestCase("Bat", 4)]
        [TestCase("Slime", 4)]
        [TestCase("Necrofire", 6)]
        [TestCase("Werewolf", 4)]
        [TestCase("Werebear", 4)]
        [TestCase("NecroGolem", 6)]
        public void Summon_PreservesEveryAuthoredFrameAndCannotExitEarly(string name, int frames)
        {
            var prefab = AssetDatabase.LoadAssetAtPath<GameObject>(
                $"Assets/_Project/Prefabs/Enemies/{name}.prefab");
            var controller = prefab.GetComponent<Animator>().runtimeAnimatorController as AnimatorController;
            Assert.That(controller, Is.Not.Null);
            var summon = controller.layers[0].stateMachine.states
                .Select(child => child.state).Single(state => state.name == "Summon");
            var clip = summon.motion as AnimationClip;
            Assert.That(clip, Is.Not.Null);
            Assert.That(clip.frameRate, Is.EqualTo(8f));
            Assert.That(clip.length, Is.EqualTo(frames / 8f).Within(.0001f));
            Assert.That(clip.isLooping, Is.False);
            var binding = AnimationUtility.GetObjectReferenceCurveBindings(clip)
                .Single(b => b.type == typeof(SpriteRenderer) && b.propertyName == "m_Sprite");
            var keys = AnimationUtility.GetObjectReferenceCurve(clip, binding);
            Assert.That(keys.Length, Is.EqualTo(frames));
            for (int i = 0; i < keys.Length; i++)
            {
                Assert.That(keys[i].value, Is.Not.Null);
                Assert.That(keys[i].time, Is.EqualTo(i / 8f).Within(.0001f));
                var texturePath = AssetDatabase.GetAssetPath(keys[i].value);
                var importer = AssetImporter.GetAtPath(texturePath) as TextureImporter;
                Assert.That(importer.filterMode, Is.EqualTo(FilterMode.Point));
                Assert.That(importer.spritePixelsPerUnit, Is.EqualTo(32f));
                if (name == "GreatswordSkeleton" || name == "ArmoredSkeleton")
                {
                    var sprite = (Sprite)keys[i].value;
                    var masks = Resources.LoadAll<Sprite>(
                        "Enemies/Protection-v2/" + sprite.texture.name + "-outline");
                    Assert.That(masks.Any(mask => mask.rect == sprite.rect), Is.True,
                        "Protected summons must retain their outline during every rise frame.");
                }
            }
            Assert.That(summon.transitions, Is.Not.Empty);
            foreach (var transition in summon.transitions)
            {
                Assert.That(transition.hasExitTime, Is.True);
                Assert.That(transition.exitTime, Is.EqualTo(1f));
                Assert.That(transition.duration, Is.Zero);
                // Attack exits are deliberately left independent of the summon clock.
                foreach (var child in controller.layers[0].stateMachine.states)
                    if (child.state != summon)
                        Assert.That(child.state.transitions.Contains(transition), Is.False);
            }
        }

        [TestCase("Bat")]
        [TestCase("Slime")]
        [TestCase("Necrofire")]
        [TestCase("Werewolf")]
        [TestCase("Werebear")]
        [TestCase("NecroGolem")]
        public void DerivedRise_ReusesOriginalDeathSpritesInReverse(string name)
        {
            var prefab = AssetDatabase.LoadAssetAtPath<GameObject>(
                $"Assets/_Project/Prefabs/Enemies/{name}.prefab");
            var controller = prefab.GetComponent<Animator>().runtimeAnimatorController as AnimatorController;
            var states = controller.layers[0].stateMachine.states;
            var death = (AnimationClip)states.Single(s => s.state.name == "Death").state.motion;
            var rise = (AnimationClip)states.Single(s => s.state.name == "Summon").state.motion;
            var deathBinding = AnimationUtility.GetObjectReferenceCurveBindings(death).Single();
            var riseBinding = AnimationUtility.GetObjectReferenceCurveBindings(rise).Single();
            var deathFrames = AnimationUtility.GetObjectReferenceCurve(death, deathBinding);
            var riseFrames = AnimationUtility.GetObjectReferenceCurve(rise, riseBinding);
            Assert.That(riseFrames.Select(f => f.value),
                Is.EqualTo(deathFrames.Reverse().Select(f => f.value)));
        }
    }
}