using System.Collections.Generic;
using NightclubArcadia.Player;
using StarterAssets;
using UnityEngine;

namespace NightclubArcadia.UI
{
    /// <summary>
    /// Ref-counted freeze of the player's ThirdPersonController. Multiple
    /// independent holders (dialogue, menu) can Acquire/Release; the controller
    /// stays disabled until the last holder releases.
    /// </summary>
    public sealed class PlayerControlLock : MonoBehaviour
    {
        readonly HashSet<object> holders = new HashSet<object>();

        ThirdPersonController playerController;
        StarterAssetsInputs playerInputs;
        Animator playerAnimator;
        PlayerMotionArbiter motionArbiter;

        static readonly int AnimIDSpeed = Animator.StringToHash("Speed");
        static readonly int AnimIDMotionSpeed = Animator.StringToHash("MotionSpeed");

        public bool IsLocked => holders.Count > 0;

        void Awake()
        {
            playerController = GetComponent<ThirdPersonController>();
            playerInputs = GetComponent<StarterAssetsInputs>();
            playerAnimator = GetComponent<Animator>();
            motionArbiter = GetComponent<PlayerMotionArbiter>();
        }

        public void Acquire(object reason)
        {
            if (reason == null)
            {
                throw new System.ArgumentNullException(nameof(reason));
            }

            var wasLocked = IsLocked;
            holders.Add(reason);

            if (!wasLocked && IsLocked)
            {
                ApplyLock(true);
            }
        }

        public void Release(object reason)
        {
            if (reason == null)
            {
                return;
            }

            var wasLocked = IsLocked;
            holders.Remove(reason);

            if (wasLocked && !IsLocked)
            {
                ApplyLock(false);
            }
        }

        void ApplyLock(bool locked)
        {
            if (playerController == null)
            {
                return;
            }

            if (locked)
            {
                // Clear pending input and the locomotion blend before freezing
                // the controller. Disabling it mid-stride otherwise leaves
                // Speed at its last value, and the character keeps running on
                // the spot for the whole conversation.
                if (playerInputs != null)
                {
                    playerInputs.MoveInput(Vector2.zero);
                    playerInputs.LookInput(Vector2.zero);
                    playerInputs.SprintInput(false);
                    playerInputs.JumpInput(false);
                }

                if (playerAnimator != null)
                {
                    playerAnimator.SetFloat(AnimIDSpeed, 0f);
                    playerAnimator.SetFloat(AnimIDMotionSpeed, 0f);
                }

                motionArbiter?.ResetState();
            }

            // cursor state hook — see plan §3.4
            playerController.enabled = !locked;
        }
    }
}