using StarterAssets;
using UnityEngine;
using Yarn.Unity;

namespace NightclubArcadia.Dialogue
{
    /// <summary>
    /// Owns the hand-off between dialogue and the 3D environment: locks the
    /// player's controls for as long as a conversation is running, and registers
    /// the <<enter_environment>> Yarn command that hands control back.
    ///
    /// The lock is driven by the DialogueRunner's own lifecycle events rather
    /// than by each interactable, so every entry point — auto-started nodes,
    /// NPCStandIn, DialogueInteractable — gets the same behaviour without
    /// having to remember to do it.
    /// </summary>
    public class DialogueTransitionController : MonoBehaviour
    {
        [SerializeField] private DialogueRunner dialogueRunner;
        [SerializeField] private GameObject dialogueUI;
        [SerializeField] private GameObject playerArmature;

        private ThirdPersonController playerController;
        private StarterAssetsInputs playerInputs;
        private Animator playerAnimator;

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

        void Awake()
        {
            if (playerArmature != null)
            {
                playerController = playerArmature.GetComponent<ThirdPersonController>();
                playerInputs = playerArmature.GetComponent<StarterAssetsInputs>();
                playerAnimator = playerArmature.GetComponent<Animator>();
            }

            // Subscribed in Awake rather than Start: the runner auto-starts its
            // first node from its own Start(), and script execution order
            // between the two is not guaranteed.
            dialogueRunner.onDialogueStart?.AddListener(OnDialogueStart);
            dialogueRunner.onDialogueComplete?.AddListener(OnDialogueComplete);
        }

        void Start()
        {
            // Dialogue is in progress as soon as this controller is active
            // (including auto-started nodes), so the player stays locked out
            // until <<enter_environment>>. The armature itself stays
            // active/visible — only its controls are disabled.
            SetPlayerControlEnabled(false);

            dialogueRunner.AddCommandHandler("enter_environment", EnterEnvironment);
        }

        void OnDestroy()
        {
            dialogueRunner.onDialogueStart?.RemoveListener(OnDialogueStart);
            dialogueRunner.onDialogueComplete?.RemoveListener(OnDialogueComplete);
        }

        void OnDialogueStart()
        {
            DialogueUIVisibility.Show(dialogueUI);
            SetPlayerControlEnabled(false);
        }

        // Safety net: a node that ends without <<enter_environment>> must still
        // give the player their controls back.
        void OnDialogueComplete() => EnterEnvironment();

        void EnterEnvironment()
        {
            // Hide, don't deactivate: deactivating the Canvas breaks TMP's
            // cached Canvas reference and makes the next conversation throw.
            // See DialogueUIVisibility.
            DialogueUIVisibility.Hide(dialogueUI);
            SetPlayerControlEnabled(true);
        }

        void SetPlayerControlEnabled(bool value)
        {
            if (playerController == null)
            {
                return;
            }

            if (!value)
            {
                // 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);
                }
            }

            playerController.enabled = value;
        }
    }
}