using System;
using System.Linq;
using TMPro;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace AIGame.Review
{
    /// <summary>Scene-authored, synchronized skinning comparison. No UI/model construction at runtime.</summary>
    public sealed class CharacterAnimationLab : MonoBehaviour
    {
        [Serializable] public sealed class Actor
        {
            public string label;
            public GameObject rig;
            public Transform hips;
            public Transform rightHand;
            public SkinnedMeshRenderer renderer;
            // Optional full target-pose walk derived from the common source
            // motion. Used where preserving source angles alone crosses feet.
            public AnimationClip walkingClip;
            // Optional bind translation adaptation. The shared source clip's
            // rotation curves and time remain unchanged across characters.
            public float translationScale = 1f;
            public Vector3[] translationOffsets = Array.Empty<Vector3>();
            public Quaternion[] translationDeltaRotations = Array.Empty<Quaternion>();
            public int[] rotationParents = Array.Empty<int>();
            public Quaternion[] bindRotationCorrections = Array.Empty<Quaternion>();
            [NonSerialized] public Quaternion[] sampledWorldRotations;
            [NonSerialized] public Quaternion[] mappedWorldRotations;
        }
        public Actor[] actors;
        public AnimationClip[] clips;
        public Vector3[] travel;
        public Camera reviewCamera;
        public Transform ui;
        public Material texturedMaterial;
        public Material clayMaterial;
        public int motion;
        public bool playing = true;
        public bool inPlace = true;
        public bool textured = true;
        public float speed = 1f;
        public float time;
        public int focus = -1;
        public int detail;
        public float yaw;
        TMP_Text stateText, timeText, pauseText, travelText, materialText, detailText;
        RectTransform progress;
        float progressWidth;
        float zoom = 1f;
        Vector3 lastMouse;
        bool dragging;
        SkinWeights previousWeights;
        bool changedWeights;
        bool previousRunInBackground;
        public float Duration => clips != null && clips.Length > 0 ? clips[motion].length : 1;
        public int FrameCount => Mathf.RoundToInt(Duration * 30) + 1;

        void OnEnable()
        {
            if (!Application.isPlaying) return;
            previousWeights = QualitySettings.skinWeights;
            previousRunInBackground = Application.runInBackground;
            Application.runInBackground = true;
            QualitySettings.skinWeights = SkinWeights.Unlimited;
            changedWeights = true;
        }
        void OnDisable()
        {
            if (changedWeights) { QualitySettings.skinWeights = previousWeights; Application.runInBackground = previousRunInBackground; }
            changedWeights = false;
        }
        void Awake()
        {
            if (!ui) return;
            var buttons = ui.GetComponentsInChildren<Button>(true).ToDictionary(b => b.name);
            void Bind(string n, UnityEngine.Events.UnityAction action) => buttons[n].onClick.AddListener(action);
            Bind("Btn_Walk", () => SetMotion(0));
            Bind("Btn_Breathe", () => SetMotion(1));
            Bind("Btn_Happy", () => SetMotion(2));
            Bind("Btn_Play", () => { playing = !playing; RefreshUI(); });
            Bind("Btn_Previous", () => Step(-1));
            Bind("Btn_Next", () => Step(1));
            Bind("Btn_Restart", () => { time = 0; Sample(); });
            Bind("Btn_Speed025", () => SetSpeed(.25f));
            Bind("Btn_Speed05", () => SetSpeed(.5f));
            Bind("Btn_Speed1", () => SetSpeed(1));
            Bind("Btn_Speed2", () => SetSpeed(2));
            Bind("Btn_Travel", () => { inPlace = !inPlace; Sample(); });
            Bind("Btn_Front", () => SetYaw(0));
            Bind("Btn_Side", () => SetYaw(90));
            Bind("Btn_Back", () => SetYaw(180));
            Bind("Btn_Material", () => { textured = !textured; Sample(); });
            Bind("Btn_All", () => SetFocus(-1));
            Bind("Btn_Focus1", () => SetFocus(0));
            Bind("Btn_Focus2", () => SetFocus(1));
            Bind("Btn_Focus3", () => SetFocus(2));
            if (buttons.TryGetValue("Btn_Focus4", out var focus4)) focus4.onClick.AddListener(() => SetFocus(3));
            Bind("Btn_Detail", () => { detail = (detail + 1) % 3; if (detail > 0 && focus < 0) focus = 1; zoom = 1; Sample(); });
            TMP_Text Text(string n) => ui.GetComponentsInChildren<TMP_Text>(true).First(t => t.name == n);
            stateText = Text("Txt_State"); timeText = Text("Txt_Time");
            pauseText = Text("Txt_Play"); travelText = Text("Txt_Travel");
            materialText = Text("Txt_Material"); detailText = Text("Txt_Detail");
            progress = ui.GetComponentsInChildren<RectTransform>(true).First(t => t.name == "Img_Progress");
            progressWidth = ((RectTransform)progress.parent).rect.width;
            var seek = ui.GetComponentInChildren<AnimationLabSeekBar>(true);
            if (seek) seek.viewer = this;
            Sample();
        }
        void Update()
        {
            if (Input.GetKeyDown(KeyCode.Space)) playing = !playing;
            if (Input.GetKeyDown(KeyCode.Alpha1)) SetMotion(0);
            if (Input.GetKeyDown(KeyCode.Alpha2)) SetMotion(1);
            if (Input.GetKeyDown(KeyCode.Alpha3)) SetMotion(2);
            if (Input.GetKeyDown(KeyCode.LeftArrow)) Step(-1);
            if (Input.GetKeyDown(KeyCode.RightArrow)) Step(1);
            bool overUI = EventSystem.current && EventSystem.current.IsPointerOverGameObject();
            if (Input.GetMouseButtonDown(0) && !overUI) { dragging = true; lastMouse = Input.mousePosition; }
            if (!Input.GetMouseButton(0)) dragging = false;
            if (dragging) { yaw -= (Input.mousePosition.x - lastMouse.x) * .35f; lastMouse = Input.mousePosition; }
            if (!overUI && Mathf.Abs(Input.mouseScrollDelta.y) > .01f)
                zoom = Mathf.Clamp(zoom * Mathf.Pow(.88f, Input.mouseScrollDelta.y), .35f, 2.5f);
            if (playing) time = Mathf.Repeat(time + Time.unscaledDeltaTime * speed, Mathf.Max(.001f, Duration));
            Sample();
        }
        public void SetMotion(int value) { motion = Mathf.Clamp(value, 0, clips.Length - 1); time = 0; Sample(); }
        public void SetSpeed(float value) { speed = value; RefreshUI(); }
        public void SetYaw(float value) { yaw = value; Sample(); }
        public void SetFocus(int value) { focus = value; if (value < 0) detail = 0; zoom = 1; Sample(); }
        public void Seek(float value) { playing = false; time = Mathf.Clamp01(value) * Duration; Sample(); }
        public void Step(int frames) { playing = false; time = Mathf.Clamp(Mathf.Round(time * 30) + frames, 0, FrameCount - 1) / 30f; Sample(); }
        public void Sample()
        {
            if (actors == null || clips == null || clips.Length == 0) return;
            time = Mathf.Clamp(time, 0, Duration);
            float phase = Duration > 0 ? time / Duration : 0;
            foreach (var actor in actors)
            {
                actor.renderer.enabled = focus < 0 || actor == actors[focus];
                bool mappedWalk = motion == 0 && actor.walkingClip;
                (mappedWalk ? actor.walkingClip : clips[motion]).SampleAnimation(actor.rig, time);
                bool adapt = !mappedWalk && actor.translationOffsets != null && actor.translationOffsets.Length == actor.renderer.bones.Length;
                if (adapt)
                {
                    var bones = actor.renderer.bones;
                    for (int i = 0; i < bones.Length; i++)
                    {
                        var delta = bones[i].localPosition * actor.translationScale;
                        if (actor.translationDeltaRotations != null && actor.translationDeltaRotations.Length == bones.Length)
                            delta = actor.translationDeltaRotations[i] * delta;
                        bones[i].localPosition = delta + actor.translationOffsets[i];
                    }
                    if (actor.bindRotationCorrections != null && actor.bindRotationCorrections.Length == bones.Length && actor.rotationParents.Length == bones.Length)
                    {
                        if (actor.sampledWorldRotations == null || actor.sampledWorldRotations.Length != bones.Length)
                        {
                            actor.sampledWorldRotations = new Quaternion[bones.Length];
                            actor.mappedWorldRotations = new Quaternion[bones.Length];
                        }
                        for (int i = 0; i < bones.Length; i++)
                        {
                            int parent = actor.rotationParents[i];
                            actor.sampledWorldRotations[i] = parent < 0 ? bones[i].localRotation : actor.sampledWorldRotations[parent] * bones[i].localRotation;
                            actor.mappedWorldRotations[i] = actor.sampledWorldRotations[i] * actor.bindRotationCorrections[i];
                        }
                        for (int i = 0; i < bones.Length; i++)
                        {
                            int parent = actor.rotationParents[i];
                            bones[i].localRotation = parent < 0 ? actor.mappedWorldRotations[i] : Quaternion.Inverse(actor.mappedWorldRotations[parent]) * actor.mappedWorldRotations[i];
                        }
                    }
                }
                if (inPlace) actor.hips.localPosition -= travel[motion] * phase * (adapt || mappedWalk ? actor.translationScale : 1f);
                actor.rig.transform.localRotation = Quaternion.Euler(0, yaw, 0);
                actor.renderer.sharedMaterial = textured ? texturedMaterial : clayMaterial;
            }
            UpdateCamera(); RefreshUI();
        }
        void UpdateCamera()
        {
            if (!reviewCamera) return;
            float x = focus >= 0 ? actors[focus].rig.transform.parent.position.x : 0;
            float y = detail == 1 ? 1.18f : detail == 2 ? .78f : .82f;
            Vector3 target = new Vector3(x, y, 0);
            if (detail == 2 && focus >= 0 && actors[focus].rightHand) target = actors[focus].rightHand.position;
            reviewCamera.transform.position = target + new Vector3(0, .12f, -6);
            reviewCamera.transform.LookAt(target);
            reviewCamera.orthographicSize = (focus < 0 ? Mathf.Max(1.15f, (actors.Length >= 4 ? 1.8f : 1.65f) / Mathf.Max(.1f, reviewCamera.aspect)) : detail == 1 ? .62f : detail == 2 ? .37f : 1.08f) * zoom;
        }
        void RefreshUI()
        {
            if (!stateText) return;
            string[] motions = { "行走", "呼吸待机", "轻松待机" };
            stateText.text = motions[motion] + "  ·  " + (focus < 0 ? (actors.Length == 4 ? "四版同步对比" : "三版同步对比") : actors[focus].label);
            timeText.text = string.Format("{0:0.00} / {1:0.00} 秒    第 {2} / {3} 帧    {4:0.##}×", time, Duration, Mathf.RoundToInt(time * 30) + 1, FrameCount, speed);
            pauseText.text = playing ? "暂停" : "播放";
            travelText.text = inPlace ? "原地循环" : "保留位移";
            materialText.text = textured ? "切灰模" : "切贴图";
            detailText.text = new[] { "全身", "上身", "手部" }[detail];
            if (progress)
            {
                if (progressWidth <= 0) progressWidth = ((RectTransform)progress.parent).rect.width;
                progress.SetSizeWithCurrentAnchors(RectTransform.Axis.Horizontal, Mathf.Max(2, progressWidth * (time / Mathf.Max(.001f, Duration))));
            }
        }
    }
}