#if UNITY_EDITOR
using System;
using System.IO;
using System.Linq;
using System.Text;
using UnityEditor;
using UnityEngine;
using Object = UnityEngine.Object;

public static class VerifyAnimalWalk
{
    const string Root = "Assets/Bundles/Characters/Animal/RockBall";
    public static Vector3[] WorldVertices(GameObject go)
    {
        return go.GetComponentsInChildren<SkinnedMeshRenderer>().SelectMany(s =>
        {
            var mesh = s.sharedMesh;
            var poses = mesh.bindposes;
            var matrices = s.bones.Select((b,i) => b.localToWorldMatrix * poses[i]).ToArray();
            var weights = mesh.boneWeights;
            return mesh.vertices.Select((v,i) =>
            {
                var w = weights[i];
                return matrices[w.boneIndex0].MultiplyPoint3x4(v) * w.weight0
                    + matrices[w.boneIndex1].MultiplyPoint3x4(v) * w.weight1
                    + matrices[w.boneIndex2].MultiplyPoint3x4(v) * w.weight2
                    + matrices[w.boneIndex3].MultiplyPoint3x4(v) * w.weight3;
            }).ToArray();
        }).ToArray();
    }
    public static Bounds GeometryBounds(GameObject go)
    {
        var points = WorldVertices(go);
        var result = new Bounds(points[0], Vector3.zero);
        foreach (var p in points) result.Encapsulate(p);
        return result;
    }
    public static string Inspect() => Check(false);
    public static string Run() => Check(true);
    public static string Live()
    {
        if(!EditorApplication.isPlaying) throw new Exception("Live check requires Play Mode");
        var unit=GameObject.Find("WalkVerified");
        if(unit==null) throw new Exception("Open RockBallWalkReview first");
        var animator=unit.GetComponentInChildren<Animator>();
        var state=animator.GetCurrentAnimatorStateInfo(0);
        var bounds=GeometryBounds(unit);
        if(!state.IsName("Walk") || animator.applyRootMotion || bounds.min.y < -.01f || bounds.min.y > .01f)
            throw new Exception($"Unexpected live gait: {state.shortNameHash} bottom={bounds.min.y}");
        return $"PASS Play Mode Walk time={state.normalizedTime:F3} bottom={bounds.min.y:F5} height={bounds.size.y:F5}";
    }
    static string Check(bool strict)
    {
        var sb = new StringBuilder();
        var go = Object.Instantiate(AssetDatabase.LoadAssetAtPath<GameObject>(Root + "/RockBall_Rigged.prefab"));
        try
        {
            var anim = go.GetComponentInChildren<Animator>();
            anim.enabled = false;
            var model = anim.gameObject;
            var bones = model.GetComponentsInChildren<Transform>().Where(t => t.name.StartsWith("bone_")).ToArray();
            var bind = GeometryBounds(go);
            sb.AppendLine($"BIND height={bind.size.y:F5} minY={bind.min.y:F5} size={bind.size}");
            var restPositions = WorldVertices(go);
            var staticGo = Object.Instantiate(AssetDatabase.LoadAssetAtPath<GameObject>(Root + "/RockBall.prefab"));
            float shapeError;
            try
            {
                var points = staticGo.GetComponentsInChildren<MeshFilter>().SelectMany(f => f.sharedMesh.vertices.Select(v => f.transform.TransformPoint(v))).ToArray();
                shapeError = restPositions.Max(v => points.Min(p => Vector3.Distance(v,p)));
            }
            finally { Object.DestroyImmediate(staticGo); }
            sb.AppendLine($"BIND vs approved static maxVertexError={shapeError:F6}m bones={bones.Length}");
            var clip = AssetDatabase.LoadAssetAtPath<AnimationClip>(Root + "/Clips/Walk.anim");
            var root = bones.First(t => t.name == "bone_0");
            float minY = float.MaxValue, maxBottom = float.MinValue, tilt = 0, minHeight = float.MaxValue;
            float motion = 0, seam = 0;
            Vector3[] start = null;
            var rotations = new Quaternion[bones.Length];
            var rightFoot = bones.First(t => t.name == "bone_9");
            var leftFoot = bones.First(t => t.name == "bone_11");
            float minFootPhase = float.MaxValue, maxFootPhase = float.MinValue;
            var rightSamples = new Vector3[61];
            var leftSamples = new Vector3[61];
            for (int f = 0; f <= 60; f++)
            {
                clip.SampleAnimation(model, clip.length * f / 60f);
                var bounds = GeometryBounds(go);
                minY = Mathf.Min(minY, bounds.min.y);
                maxBottom = Mathf.Max(maxBottom, bounds.min.y);
                minHeight = Mathf.Min(minHeight, bounds.size.y);
                tilt = Mathf.Max(tilt, Vector3.Angle(root.up, Vector3.up));
                rightSamples[f] = rightFoot.position-root.position;
                leftSamples[f] = leftFoot.position-root.position;
                float phase = rightSamples[f].z-leftSamples[f].z;
                minFootPhase = Mathf.Min(minFootPhase,phase);
                maxFootPhase = Mathf.Max(maxFootPhase,phase);
                if (f == 0)
                {
                    start = WorldVertices(go);
                    for (int b = 0; b < bones.Length; b++) rotations[b] = bones[b].localRotation;
                }
                for (int b = 0; b < bones.Length; b++) motion = Mathf.Max(motion, Quaternion.Angle(rotations[b], bones[b].localRotation));
                if (f == 60)
                {
                    var end = WorldVertices(go);
                    seam = end.Select((v,i) => Vector3.Distance(v,start[i])).Max();
                }
                if (f % 15 == 0) sb.AppendLine($"Walk {f}/60 minY={bounds.min.y:F5} height={bounds.size.y:F5} rootTilt={Vector3.Angle(root.up,Vector3.up):F2}");
            }
            sb.AppendLine($"RESULT len={clip.length:F4} loop={AnimationUtility.GetAnimationClipSettings(clip).loopTime} minY={minY:F5} maxBottom={maxBottom:F5} minHeight={minHeight:F5} maxRootTilt={tilt:F2} maxJointMotion={motion:F2} seamVertexMax={seam:F6}");
            float rightStride = rightSamples.Max(p=>p.z)-rightSamples.Min(p=>p.z);
            float leftStride = leftSamples.Max(p=>p.z)-leftSamples.Min(p=>p.z);
            sb.AppendLine($"FEET rightStride={rightStride:F5}m leftStride={leftStride:F5}m relativePhaseRange={maxFootPhase-minFootPhase:F5}m");
            // Verify the real controller through several loops as well as clip sampling.
            anim.enabled = true;
            anim.Rebind();
            anim.SetInteger("Motion",1);
            anim.Play("Walk",0,0);
            anim.Update(0);
            for (int i = 0; i < 180; i++) anim.Update(1f/30f);
            var state = anim.GetCurrentAnimatorStateInfo(0);
            sb.AppendLine($"ANIMATOR stateWalk={state.IsName("Walk")} normalizedTime={state.normalizedTime:F2}");
            if (strict && (shapeError > .002f || Mathf.Abs(bind.size.y-.55f) > .002f || Mathf.Abs(bind.min.y) > .002f
                || minY < -.01f || maxBottom > .025f || minHeight < .46f || tilt > 15f || motion < 5f || seam > .002f
                || rightStride < .005f || leftStride < .005f || maxFootPhase-minFootPhase < .01f || !state.IsName("Walk")))
                throw new Exception(sb.ToString());
            var report = Path.GetFullPath(Path.Combine(Application.dataPath,"../../Tools/output/rockball_walk_audit/verification.txt"));
            Directory.CreateDirectory(Path.GetDirectoryName(report));
            File.WriteAllText(report,sb.ToString());
            return (strict ? "PASS\n" : "INSPECT\n") + sb;
        }
        finally { Object.DestroyImmediate(go); }
    }
}
#endif