using System;
using UnityEngine;
using Ashwild.Inventory;

namespace Ashwild.Player
{
    [DisallowMultipleComponent]
    public class PlayerToolHolder : MonoBehaviour
    {
        // ============================================================
        // Tunables
        // ============================================================

        [Header("References")]
        [SerializeField] private Transform toolHolder;

        [Header("Weapon bob")]
        [SerializeField] private bool enableWeaponBob = true;
        [SerializeField] private float bobFrequency = 8f;
        [SerializeField] private float bobAmplitudeY = 0.04f;
        [SerializeField] private float bobAmplitudeX = 0.03f;
        [SerializeField] private float bobSmooth = 8f;
        [SerializeField] private float sprintBobMultiplier = 1.4f;
        [SerializeField] private float crouchBobMultiplier = 0.5f;

        [Header("Weapon sway")]
        [SerializeField] private bool enableWeaponSway = true;
        [SerializeField] private float swayAmount = 0.02f;
        [SerializeField] private float swaySmooth = 6f;
        [SerializeField] private float swayMaxAmount = 0.06f;

        [Header("Idle tilt")]
        [SerializeField] private bool enableIdleTilt = true;
        [SerializeField] private float idleTiltFrequency = 0.4f;
        [SerializeField] private float idleTiltAmplitudeZ = 1.5f;
        [SerializeField] private float idleTiltAmplitudeX = 0.8f;
        [SerializeField] private float idleTiltSmooth = 4f;

        [Header("Equip / Unequip")]
        [SerializeField] private float equipDropOffset = -0.5f;
        [SerializeField] private float equipTiltAngle = -15f;
        [SerializeField] private float equipDuration = 0.25f;
        [SerializeField] private float unequipDuration = 0.12f;

        // ============================================================
        // Wiring
        // ============================================================

        // ============================================================
        // Runtime
        // ============================================================

        private Vector2 lookInput;
        private float currentSpeed;
        private bool isSprinting;
        private bool isCrouching;
        private bool isGrounded = true;

        private Vector3 toolHolderBasePos;
        private Quaternion toolHolderBaseRot;
        private Vector3 currentSway;
        private float bobTimer;
        private float idleTimer;
        private float currentBobIntensity;

        private float equipAnimProgress = 1f;
        private float equipAnimTimer;
        private bool isUnequipping;
        private float unequipAnimProgress = 1f;
        private float unequipAnimTimer;
        private Action onUnequipComplete;

        // ============================================================
        // Public API (consumed by HotbarController)
        // ============================================================

        public void PlayEquipAnimation()
        {
            equipAnimProgress = 0f;
            equipAnimTimer = 0f;
        }

        public void PlayUnequipAnimation(Action onComplete)
        {
            isUnequipping = true;
            unequipAnimProgress = 0f;
            unequipAnimTimer = 0f;
            onUnequipComplete = onComplete;
        }

        // ============================================================
        // Lifecycle
        // ============================================================

        private void Awake()
        {
            if (toolHolder != null)
            {
                toolHolderBasePos = toolHolder.localPosition;
                toolHolderBaseRot = toolHolder.localRotation;
            }
        }

        private void OnEnable()
        {
            PlayerEvents.LookInput += OnLookInput;
            PlayerEvents.VelocityChanged += OnVelocityChanged;
            PlayerEvents.SprintChanged += OnSprintChanged;
            PlayerEvents.CrouchChanged += OnCrouchChanged;
            PlayerEvents.GroundedChanged += OnGroundedChanged;
        }

        private void OnDisable()
        {
            PlayerEvents.LookInput -= OnLookInput;
            PlayerEvents.VelocityChanged -= OnVelocityChanged;
            PlayerEvents.SprintChanged -= OnSprintChanged;
            PlayerEvents.CrouchChanged -= OnCrouchChanged;
            PlayerEvents.GroundedChanged -= OnGroundedChanged;
        }

        // ============================================================
        // Event handlers
        // ============================================================

        private void OnLookInput(Vector2 v) => lookInput = v;
        private void OnVelocityChanged(Vector3 v) => currentSpeed = v.magnitude;
        private void OnSprintChanged(bool b) => isSprinting = b;
        private void OnCrouchChanged(bool b) => isCrouching = b;
        private void OnGroundedChanged(bool grounded, float _) => isGrounded = grounded;

        // ============================================================
        // Main loop
        // ============================================================

        private void LateUpdate()
        {
            if (toolHolder == null) return;

            bool dead = PlayerEvents.IsDead;
            if (dead)
            {
                currentBobIntensity = 0f;
                currentSway = Vector3.zero;
                toolHolder.localPosition = Vector3.Lerp(toolHolder.localPosition, toolHolderBasePos, Time.deltaTime * bobSmooth);
                toolHolder.localRotation = Quaternion.Slerp(toolHolder.localRotation, toolHolderBaseRot, Time.deltaTime * idleTiltSmooth);
                return;
            }

            UpdateBobTimers();
            UpdateSway();
            UpdateEquipAnimations();
            ApplyToolHolderPose();
        }

        private void UpdateBobTimers()
        {
            float dt = Time.deltaTime;
            float target = (isGrounded && currentSpeed > 0.1f) ? 1f : 0f;
            currentBobIntensity = Mathf.Lerp(currentBobIntensity, target, dt * 4f);

            if (isGrounded && currentSpeed > 0.1f)
                bobTimer += dt * bobFrequency * (currentSpeed / 5f);

            if (currentBobIntensity < 0.05f) idleTimer += dt;
            else idleTimer = 0f;
        }

        private void UpdateSway()
        {
            if (enableWeaponSway)
            {
                Vector3 target = new Vector3(-lookInput.x * swayAmount, -lookInput.y * swayAmount, 0f);
                target.x = Mathf.Clamp(target.x, -swayMaxAmount, swayMaxAmount);
                target.y = Mathf.Clamp(target.y, -swayMaxAmount, swayMaxAmount);
                currentSway = Vector3.Lerp(currentSway, target, Time.deltaTime * swaySmooth);
            }
            else
            {
                currentSway = Vector3.Lerp(currentSway, Vector3.zero, Time.deltaTime * swaySmooth);
            }
        }

        private void UpdateEquipAnimations()
        {
            if (isUnequipping)
            {
                unequipAnimTimer += Time.deltaTime;
                float t = Mathf.Clamp01(unequipAnimTimer / unequipDuration);
                unequipAnimProgress = t * t;
                if (t >= 1f)
                {
                    isUnequipping = false;
                    PlayerEvents.RaiseUnequipAnimComplete();
                    onUnequipComplete?.Invoke();
                    onUnequipComplete = null;
                }
            }

            if (equipAnimTimer < equipDuration)
            {
                equipAnimTimer += Time.deltaTime;
                float t = Mathf.Clamp01(equipAnimTimer / equipDuration);
                const float c1 = 1.70158f;
                const float c3 = c1 + 1f;
                equipAnimProgress = 1f + c3 * Mathf.Pow(t - 1f, 3f) + c1 * Mathf.Pow(t - 1f, 2f);
                if (t >= 1f) PlayerEvents.RaiseEquipAnimComplete();
            }
            else
            {
                equipAnimProgress = 1f;
            }
        }

        private void ApplyToolHolderPose()
        {
            Vector3 targetPos = toolHolderBasePos;
            float mult = isCrouching ? crouchBobMultiplier : (isSprinting ? sprintBobMultiplier : 1f);

            if (enableWeaponBob)
            {
                targetPos.y += Mathf.Sin(bobTimer) * bobAmplitudeY * mult * currentBobIntensity;
                targetPos.x += Mathf.Cos(bobTimer * 0.5f) * bobAmplitudeX * mult * currentBobIntensity;
            }
            targetPos += currentSway;

            bool isAnimating = isUnequipping || equipAnimProgress < 1f;
            float animFactor = isUnequipping ? unequipAnimProgress : (1f - equipAnimProgress);

            if (isAnimating)
            {
                targetPos.y += animFactor * equipDropOffset;
                toolHolder.localPosition = targetPos;
            }
            else
            {
                toolHolder.localPosition = Vector3.Lerp(toolHolder.localPosition, targetPos, Time.deltaTime * bobSmooth);
            }

            if (enableIdleTilt || isAnimating)
            {
                float idleWeight = 1f - currentBobIntensity;
                float phase = idleTimer * idleTiltFrequency * Mathf.PI * 2f;
                float tiltZ = Mathf.Sin(phase) * idleTiltAmplitudeZ * idleWeight;
                float tiltX = Mathf.Cos(phase * 0.6f) * idleTiltAmplitudeX * idleWeight;
                if (isAnimating) tiltZ += animFactor * equipTiltAngle;

                Quaternion targetTilt = toolHolderBaseRot * Quaternion.Euler(tiltX, 0f, tiltZ);
                if (isAnimating) toolHolder.localRotation = targetTilt;
                else toolHolder.localRotation = Quaternion.Slerp(toolHolder.localRotation, targetTilt, Time.deltaTime * idleTiltSmooth);
            }
        }
    }
}