using UnityEngine;
using UnityEngine.InputSystem;
using Yarn.Unity;
using NightclubArcadia.Core;

namespace NightclubArcadia.Dialogue
{
    /// <summary>
    /// Trigger-zone interactable: player walks in range, presses E, and this
    /// starts the given Yarn node. The reverse of DialogueTransitionController's
    /// <<enter_environment>> — this is the "step into dialogue" half of the loop.
    /// </summary>
    public class DialogueInteractable : MonoBehaviour
    {
        [SerializeField] private DialogueRunner dialogueRunner;
        [SerializeField] private GameObject dialogueUI;
        [SerializeField] private string yarnNodeName = "Bartender_Chat";

        private bool playerInRange;
        private InputAction interactAction;

        void Awake()
        {
            // Best-effort and silent; the real lookup happens at the point of use, since
            // Systems may not have loaded when this level object awakes. See Runner.
            dialogueRunner = SceneServices.TryResolve(dialogueRunner);

            interactAction = new InputAction("Interact");
            interactAction.AddBinding("<Keyboard>/e");
            interactAction.AddBinding("<Gamepad>/buttonNorth");
            interactAction.performed += _ =>
            {
                if (playerInRange)
                {
                    StartConversation();
                }
            };
        }

        /// <summary>
        /// The dialogue runner, resolved on demand rather than in Awake, so that load
        /// order between this level scene and Systems does not matter. Cached once found.
        /// </summary>
        DialogueRunner Runner =>
            dialogueRunner != null
                ? dialogueRunner
                : dialogueRunner = SceneServices.TryResolve<DialogueRunner>(null);

        void OnEnable() => interactAction?.Enable();
        void OnDisable() => interactAction?.Disable();

        void OnTriggerEnter(Collider other)
        {
            if (other.CompareTag("Player"))
            {
                playerInRange = true;
            }
        }

        void OnTriggerExit(Collider other)
        {
            if (other.CompareTag("Player"))
            {
                playerInRange = false;
            }
        }

        async void StartConversation()
        {
            var runner = Runner;
            if (runner == null)
            {
                Debug.LogError(
                    $"[DialogueInteractable] {name}: no DialogueRunner in any loaded scene. " +
                    "It lives in Systems.unity — open Bootstrap, or Tools → Nightclub Arcadia → " +
                    "Open Game Scenes.", this);
                return;
            }

            // Player controls are locked by DialogueTransitionController off the
            // runner's onDialogueStart event — nothing to do for that here.
            if (DialogueUIVisibility.Show(dialogueUI))
            {
                // Only reached if the UI was found deactivated; give TMP a
                // frame to re-cache its Canvas in OnEnable before any text is
                // generated.
                await Awaitable.NextFrameAsync();
            }

            await runner.StartDialogue(yarnNodeName);
        }
    }
}