using System;
using System.Runtime.CompilerServices;
using Animancer;
using RebootReality.jelycho.Items;
using Unity.Mathematics;
using UnityEngine;
using UnityEvent = UnityEngine.Events.UnityEvent;

namespace RebootReality.jelycho.Player {
    public struct PlayerLocomotionAnimatorParams {
        public float VelocityForwardNormalized;
        public float VelocityRightNormalized;
        public float TurnVelocity;
        public bool IsGrounded;
    }

    public class PlayerHandsAnimator {
        enum State {
            None,
            Idle,
            QuickAttack,
            Charging,
            ChargedIdle,
            Charged,
            ChargedUse
        }
        
        AnimancerLayer m_AnimancerLayer;
        AnimancerState m_AnimancerState;

        ItemHandsAnimationClipsSet m_ClipsSet;

        State m_State;

        public event Action OnQuickAttackAnimationFinished = delegate { };
        public event Action OnCharged = delegate { };
        
        public PlayerHandsAnimator(AnimancerLayer layer) {
            m_AnimancerLayer = layer;
        }

        public void Tick(float deltaTime) {
            if (m_AnimancerState == null) {
                return;
            }

            switch (m_State) {
            case State.QuickAttack: {
                if (IsCurrentClipFinished()) {
                    // m_AnimancerState.Stop();
                    m_AnimancerState = null;
                    OnQuickAttackAnimationFinished?.Invoke();
                }
                break;
            }

            case State.Charging: {
                if (IsCurrentClipFinished()) {
                    SetChargedIdle();
                    OnCharged?.Invoke();
                }
                break;
            }

            case State.ChargedUse: {
                if (IsCurrentClipFinished()) {
                    SetIdle();
                }
                break;
            }
            }
        }

        public void UpdateClips(ItemHandsAnimationClipsSet clipsSet) {
            m_ClipsSet = clipsSet;

            if (clipsSet == null) {
                m_State = State.None;
                return;
            }

            SetIdle();
        }

        public void PlayQuickAttack(int combo) {
            if (m_ClipsSet == null) {
                return;
            }

            AnimationClip clip = m_ClipsSet.quickAttacks[combo % m_ClipsSet.quickAttacks.Length];
            m_AnimancerState = m_AnimancerLayer.Play(clip, 0.1f);

            m_State = State.QuickAttack;
        }

        public void SetIdle() {
            if (m_ClipsSet == null) {
                return;
            }
            
            m_AnimancerState = m_AnimancerLayer.Play(m_ClipsSet.idle, 0.1f);
            m_State = State.Idle;
        }

        public void SetCharging() {
            if (m_ClipsSet == null) {
                return;
            }

            m_AnimancerState = m_AnimancerLayer.Play(m_ClipsSet.charging, 0.1f);
            m_State = State.Charging;
        }

        public void SetChargedIdle() {
            if (m_ClipsSet == null) {
                return;
            }

            m_AnimancerState = m_AnimancerLayer.Play(m_ClipsSet.chargedIdle, 0.1f);
            m_State = State.ChargedIdle;
        }

        public void PlayChargedUse() {
            if (m_ClipsSet == null) {
                return;
            }

            m_AnimancerState = m_AnimancerLayer.Play(m_ClipsSet.chargedUse, 0.1f);
            m_State = State.ChargedUse;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        bool IsCurrentClipFinished() {
            return m_AnimancerState.NormalizedTime >= 1.0f;
        }
    }

    public class PlayerAnimator : MonoBehaviour {
        [SerializeField] AnimancerComponent m_Animancer;
        [SerializeField] AnimationClip m_IdleClip;
        
        [SerializeField] TransitionAsset m_GroundLocomotion;
        [SerializeField] StringAsset m_GroundLocomotionPropertyX;
        [SerializeField] StringAsset m_GroundLocomotionPropertyY;
        SmoothedVector2Parameter m_SmoothLocomotionDirection;
        
        [SerializeField] TransitionAsset m_GroundTurn;
        [SerializeField] StringAsset m_GroundTurnProperty;
        SmoothedFloatParameter m_SmoothGroundTurn;
        
        [SerializeField] AnimationClip m_InAirClip;
        
        [SerializeField] AnimationClip m_KickClip;
        
        [SerializeField] AvatarMask m_HandsMask;
        [SerializeField] AvatarMask m_LegsMask;
        
        AnimancerLayer m_BaseLayer;
        AnimancerLayer m_LocomotionLegsLayer;
        AnimancerLayer m_HandsLayer;
        AnimancerLayer m_FullBodyLayer;
        PlayerHandsAnimator m_Hands;
        
        bool m_IsPlayingKickAnimation;

        // @TODO: for some reason `SetLocomotionParams` is called before awake
        bool m_IsReady = false;
        
        public UnityEvent onQuickAttackFinished = new UnityEvent();
        public UnityEvent onChargeReady = new UnityEvent();
        
        void Awake() {
            m_BaseLayer = m_Animancer.Layers[0];
            m_BaseLayer.SetDebugName("Base Layer");
            m_BaseLayer.Play(m_IdleClip);

            m_LocomotionLegsLayer = m_Animancer.Layers[1];
            m_LocomotionLegsLayer.SetDebugName("Locomotion Legs");
            m_LocomotionLegsLayer.Mask = m_LegsMask;
            m_SmoothLocomotionDirection = new SmoothedVector2Parameter(m_Animancer,
                                                                       m_GroundLocomotionPropertyX,
                                                                       m_GroundLocomotionPropertyY,
                                                                       0.1f);
            m_LocomotionLegsLayer.Play(m_GroundLocomotion);
            
            m_SmoothGroundTurn = new SmoothedFloatParameter(m_Animancer,
                                                            m_GroundTurnProperty,
                                                            0.1f);

            m_HandsLayer = m_Animancer.Layers[2];
            m_HandsLayer.SetDebugName("Hands");
            m_HandsLayer.Mask = m_HandsMask;
            m_HandsLayer.SetWeight(0.0f);
            
            m_Hands = new PlayerHandsAnimator(m_HandsLayer);
            m_Hands.OnQuickAttackAnimationFinished += () => onQuickAttackFinished.Invoke();
            m_Hands.OnCharged += () => onChargeReady.Invoke();
            
            m_FullBodyLayer = m_Animancer.Layers[3];
            m_FullBodyLayer.SetDebugName("Full body");
            m_FullBodyLayer.SetWeight(0.0f);

            m_IsReady = true;
        }

        void OnDestroy() {
            m_SmoothLocomotionDirection.Dispose();
        }
        
        void Update() {
            float dt = Time.deltaTime;
            m_Hands.Tick(dt);

            if (m_IsPlayingKickAnimation &&
                m_FullBodyLayer.CurrentState.NormalizedTime >= 1.0f) {
                m_FullBodyLayer.SetWeight(0.0f);
                m_IsPlayingKickAnimation = false;
            }
        }

        public void SetLocomotionParams(PlayerLocomotionAnimatorParams locomotionParams) {
            if (!m_IsReady) {
                return;
            }
            
            if (!locomotionParams.IsGrounded) {
                m_LocomotionLegsLayer.Play(m_InAirClip, 0.1f);
                return;
            }
            
            if (math.abs(locomotionParams.TurnVelocity) > 0.1f) {
                m_SmoothGroundTurn.TargetValue = locomotionParams.TurnVelocity;
                m_LocomotionLegsLayer.Play(m_GroundTurn, 0.1f);
            } else {
                var groundBlendDirection = new float2(locomotionParams.VelocityRightNormalized,
                                                      locomotionParams.VelocityForwardNormalized);
                m_SmoothLocomotionDirection.TargetValue = groundBlendDirection;               
                m_LocomotionLegsLayer.Play(m_GroundLocomotion, 0.1f);
            }
        }
        
        public void SetHandsAnimationSet(ItemHandsAnimationClipsSet clipsSet) {
            if (clipsSet == null) {
                m_HandsLayer.SetWeight(0.0f);
                return;
            }
            
            m_HandsLayer.SetWeight(1.0f);
            m_Hands.UpdateClips(clipsSet);
        }

        public void PlayQuickAttack(int combo) {
            m_Hands.PlayQuickAttack(combo);
        }
        
        public void PlayHandsIdle() {
            m_Hands.SetIdle();
        }

        public void PlayCharging() {
            m_Hands.SetCharging();
        }

        public void PlayChargedUse() {
            m_Hands.PlayChargedUse();
        }

        public void PlayKickAnimation() {
            if (m_IsPlayingKickAnimation) {
                return;
            }
            
            m_FullBodyLayer.Play(m_KickClip, 0.1f).Time = 0.0f;
            m_IsPlayingKickAnimation = true;
        }
    }
}