using ABI_RC.Core.Player;
using ABI_RC.Systems.IK.SubSystems;
using ABI_RC.Systems.Movement;
using RootMotion.FinalIK;
using System.Collections.Generic;
using UnityEngine;

namespace ml_amt
{
    [DisallowMultipleComponent]
    class MotionTweaker : MonoBehaviour
    {
        struct IKState
        {
            public float m_weight;
            public float m_locomotionWeight;
            public bool m_plantFeet;
            public bool m_bendNormalLeft;
            public bool m_bendNormalRight;
        }

        static readonly Vector4 ms_pointVector = new Vector4(0f, 0f, 0f, 1f);
        static readonly int ms_emoteHash = Animator.StringToHash("Emote");

        IKState m_ikState;
        VRIK m_vrIk = null;
        int m_locomotionLayer = 0;
        float m_avatarScale = 1f;
        Vector3 m_locomotionOffset = Vector3.zero; // Original locomotion offset

        bool m_avatarReady = false;
        bool m_grounded = false;
        bool m_moving = false;

        bool m_locomotionOverride = false;
        bool m_emoteActive = false;

        Vector3 m_massCenter = Vector3.zero;

        Transform m_ikLimits = null;

        readonly List<AvatarParameter> m_parameters = null;

        internal MotionTweaker()
        {
            m_parameters = new List<AvatarParameter>();
        }

        // Unity events
        void Start()
        {
            OnCrouchLimitChanged(Settings.CrouchLimit);
            OnProneLimitChanged(Settings.ProneLimit);

            Settings.OnCrouchLimitChanged.AddListener(this.OnCrouchLimitChanged);
            Settings.OnProneLimitChanged.AddListener(this.OnProneLimitChanged);
            Settings.OnMassCenterChanged.AddListener(this.OnMassCenterChanged);

            GameEvents.OnAvatarSetup.AddListener(this.OnAvatarSetup);
            GameEvents.OnAvatarClear.AddListener(this.OnAvatarClear);
            GameEvents.OnAvatarReuse.AddListener(this.OnAvatarReuse);
            GameEvents.OnPlayspaceScale.AddListener(this.OnPlayspaceScale);
        }

        void OnDestroy()
        {
            m_vrIk = null;
            m_ikLimits = null;
            m_parameters.Clear();

            Settings.OnCrouchLimitChanged.RemoveListener(this.OnCrouchLimitChanged);
            Settings.OnProneLimitChanged.RemoveListener(this.OnProneLimitChanged);
            Settings.OnMassCenterChanged.RemoveListener(this.OnMassCenterChanged);

            GameEvents.OnAvatarSetup.RemoveListener(this.OnAvatarSetup);
            GameEvents.OnAvatarClear.RemoveListener(this.OnAvatarClear);
            GameEvents.OnAvatarReuse.RemoveListener(this.OnAvatarReuse);
            GameEvents.OnPlayspaceScale.RemoveListener(this.OnPlayspaceScale);
        }

        void Update()
        {
            if(m_avatarReady)
            {
                m_grounded = BetterBetterCharacterController.Instance.IsGrounded();
                m_moving = BetterBetterCharacterController.Instance.IsMoving();

                UpdateIKLimits();

                m_emoteActive = false;
                if(Settings.DetectEmotes && (m_locomotionLayer >= 0))
                {
                    AnimatorStateInfo l_animState = PlayerSetup.Instance._animator.GetCurrentAnimatorStateInfo(m_locomotionLayer);
                    m_emoteActive = (l_animState.tagHash == ms_emoteHash);
                }

                foreach(AvatarParameter l_param in m_parameters)
                    l_param.Update(this);
            }
        }

        // Game events
        void OnAvatarClear()
        {
            m_vrIk = null;
            m_locomotionLayer = -1;
            m_grounded = false;
            m_avatarReady = false;
            m_avatarScale = 1f;
            m_locomotionOffset = Vector3.zero;
            m_emoteActive = false;
            m_moving = false;
            m_locomotionOverride = false;
            m_massCenter = Vector3.zero;
            m_ikLimits = null;
            m_parameters.Clear();

            BetterBetterCharacterController.Instance.avatarCrouchLimit = Mathf.Clamp01(Settings.CrouchLimit);
            BetterBetterCharacterController.Instance.avatarProneLimit = Mathf.Clamp01(Settings.ProneLimit);
        }

        void OnAvatarSetup()
        {
            Utils.SetAvatarTPose();

            m_vrIk = PlayerSetup.Instance._avatar.GetComponent<VRIK>();
            m_locomotionLayer = PlayerSetup.Instance._animator.GetLayerIndex("Locomotion/Emotes");
            m_avatarScale = Mathf.Abs(PlayerSetup.Instance._avatar.transform.localScale.y);

            // Parse animator parameters
            m_parameters.Add(new AvatarParameter(AvatarParameter.ParameterType.Moving, PlayerSetup.Instance.animatorManager));
            m_parameters.RemoveAll(p => !p.IsValid());

            // Avatar custom IK limits
            m_ikLimits = PlayerSetup.Instance._avatar.transform.Find("[IKLimits]");
            UpdateIKLimits();

            // Apply VRIK tweaks
            if(m_vrIk != null)
            {
                m_locomotionOffset = m_vrIk.solver.locomotion.offset;
                m_massCenter = m_locomotionOffset;

                if(m_vrIk.solver.HasToes())
                {
                    Transform l_foot = PlayerSetup.Instance._animator.GetBoneTransform(HumanBodyBones.LeftFoot);
                    if(l_foot == null)
                        l_foot = PlayerSetup.Instance._animator.GetBoneTransform(HumanBodyBones.RightFoot);

                    Transform l_toe = PlayerSetup.Instance._animator.GetBoneTransform(HumanBodyBones.LeftToes);
                    if(l_toe == null)
                        l_toe = PlayerSetup.Instance._animator.GetBoneTransform(HumanBodyBones.RightToes);

                    if((l_foot != null) && (l_toe != null))
                    {
                        Vector3 l_footPos = (PlayerSetup.Instance._avatar.transform.GetMatrix().inverse * l_foot.GetMatrix()) * ms_pointVector;
                        Vector3 l_toePos = (PlayerSetup.Instance._avatar.transform.GetMatrix().inverse * l_toe.GetMatrix()) * ms_pointVector;
                        m_massCenter = new Vector3(0f, 0f, l_toePos.z - l_footPos.z);
                    }
                }

                m_vrIk.solver.locomotion.offset = (Settings.MassCenter ? m_massCenter : m_locomotionOffset);

                m_vrIk.onPreSolverUpdate.AddListener(this.OnIKPreSolverUpdate);
                m_vrIk.onPostSolverUpdate.AddListener(this.OnIKPostSolverUpdate);
            }

            m_avatarReady = true;
        }

        void OnPlayspaceScale()
        {
            if((m_vrIk != null) && Settings.MassCenter)
                m_vrIk.solver.locomotion.offset = m_massCenter * GetRelativeScale();
        }

        void OnAvatarReuse()
        {
            // Old VRIK is destroyed by game
            Utils.SetAvatarTPose();

            m_vrIk = PlayerSetup.Instance._animator.GetComponent<VRIK>();
            if(m_vrIk != null)
            {
                m_vrIk.solver.locomotion.offset = (Settings.MassCenter ? m_massCenter : m_locomotionOffset);

                m_vrIk.onPreSolverUpdate.AddListener(this.OnIKPreSolverUpdate);
                m_vrIk.onPostSolverUpdate.AddListener(this.OnIKPostSolverUpdate);
            }
        }

        // IK events
        void OnIKPreSolverUpdate()
        {
            bool l_locomotionOverride = false;

            m_ikState.m_weight = m_vrIk.solver.IKPositionWeight;
            m_ikState.m_locomotionWeight = m_vrIk.solver.locomotion.weight;
            m_ikState.m_plantFeet = m_vrIk.solver.plantFeet;
            m_ikState.m_bendNormalLeft = m_vrIk.solver.leftLeg.useAnimatedBendNormal;
            m_ikState.m_bendNormalRight = m_vrIk.solver.rightLeg.useAnimatedBendNormal;

            if(Settings.DetectEmotes && m_emoteActive)
                m_vrIk.solver.IKPositionWeight = 0f;

            if(!BodySystem.isCalibratedAsFullBody)
            {
                if(BetterBetterCharacterController.Instance.AvatarUpright <= BetterBetterCharacterController.Instance.avatarCrouchLimit)
                {
                    m_vrIk.solver.leftLeg.useAnimatedBendNormal = true;
                    m_vrIk.solver.rightLeg.useAnimatedBendNormal = true;
                    l_locomotionOverride = true;
                }
                if(Settings.IKOverrideFly && BetterBetterCharacterController.Instance.IsFlying())
                {
                    m_vrIk.solver.locomotion.weight = 0f;
                    m_vrIk.solver.leftLeg.useAnimatedBendNormal = true;
                    m_vrIk.solver.rightLeg.useAnimatedBendNormal = true;
                    l_locomotionOverride = true;
                }
                if(Settings.IKOverrideJump && !m_grounded && !BetterBetterCharacterController.Instance.IsFlying())
                {
                    m_vrIk.solver.locomotion.weight = 0f;
                    m_vrIk.solver.leftLeg.useAnimatedBendNormal = true;
                    m_vrIk.solver.rightLeg.useAnimatedBendNormal = true;
                    l_locomotionOverride = true;
                }
            }

            if(m_locomotionOverride && !l_locomotionOverride)
                m_vrIk.solver.Reset();
            m_locomotionOverride = l_locomotionOverride;
        }

        void OnIKPostSolverUpdate()
        {
            m_vrIk.solver.IKPositionWeight = m_ikState.m_weight;
            m_vrIk.solver.locomotion.weight = m_ikState.m_locomotionWeight;
            m_vrIk.solver.plantFeet = m_ikState.m_plantFeet;
            m_vrIk.solver.leftLeg.useAnimatedBendNormal = m_ikState.m_bendNormalLeft;
            m_vrIk.solver.rightLeg.useAnimatedBendNormal = m_ikState.m_bendNormalRight;
        }

        // Settings
        void OnCrouchLimitChanged(float p_value)
        {
            if(m_ikLimits == null)
                BetterBetterCharacterController.Instance.avatarCrouchLimit = Mathf.Clamp01(p_value);
        }
        void OnProneLimitChanged(float p_value)
        {
            if(m_ikLimits == null)
                BetterBetterCharacterController.Instance.avatarProneLimit = Mathf.Clamp01(p_value);
        }
        void OnMassCenterChanged(bool p_state)
        {
            if(m_vrIk != null)
                m_vrIk.solver.locomotion.offset = (Settings.MassCenter ? (m_massCenter * GetRelativeScale()) : m_locomotionOffset);
        }

        // Arbitrary
        float GetRelativeScale()
        {
            return ((m_avatarScale > 0f) ? (PlayerSetup.Instance._avatar.transform.localScale.y / m_avatarScale) : 0f);
        }

        void UpdateIKLimits()
        {
            if(m_ikLimits != null)
            {
                Vector3 l_values = m_ikLimits.localPosition;
                BetterBetterCharacterController.Instance.avatarCrouchLimit = Mathf.Clamp01(l_values.x);
                BetterBetterCharacterController.Instance.avatarProneLimit = Mathf.Clamp01(l_values.y);
            }
        }

        // Parameters access
        public bool IsMoving() => m_moving;
    }
}