using System;
using System.Collections.Generic;
using UnityEngine;
using OctoCore.Navigation.Data;
using OctoRef = OctoCore.OctoCore;

namespace Unheimlich.Navigation.Debuging
{
    /// <summary>
    /// ScriptableObject holding the ordered list of debug scenes.
    /// Drag OctoSceneData assets in the desired order in the inspector.
    /// </summary>
    [CreateAssetMenu(fileName = "DebugNavigation", menuName = "Unheimlich/Debug/Debug Navigation")]
    public class DebugNavigation : ScriptableObject
    {
        [Tooltip("Ordered list of scenes available in debug mode.")]
        [SerializeField] private List<OctoSceneData> _scenes = new List<OctoSceneData>();

        public IReadOnlyList<OctoSceneData> Scenes => _scenes;

        /// <summary>Invoked when a debug scene change is requested.</summary>
        public Action<OctoSceneData> OnDebugSceneRequested;

        private int _currentIndex = -1;
        public int CurrentIndex => _currentIndex;

        /// <summary>
        /// Sync the current index with the active scene.
        /// If the active scene is not in the list, _currentIndex stays at -1
        /// so Next() will correctly start at index 0.
        /// </summary>
        public void SyncWithCurrentScene(OctoSceneData currentScene)
        {
            _currentIndex = currentScene != null ? _scenes.IndexOf(currentScene) : -1;

            if (_currentIndex == -1)
                UnityEngine.Debug.Log("[DebugNavigation] Scene not found in debug list — Next() will start at index 0.");
        }

        /// <summary>Load the previous scene in the list (wraps).</summary>
        public void Previous()
        {
            if (_scenes == null || _scenes.Count == 0) return;

            // If not in list, go to last
            _currentIndex = (_currentIndex <= 0) ? _scenes.Count - 1 : _currentIndex - 1;
            RequestScene(_currentIndex);
        }

        /// <summary>Load the next scene in the list (wraps).</summary>
        public void Next()
        {
            if (_scenes == null || _scenes.Count == 0) return;

            // If not in list (-1), go to 0. Otherwise increment.
            _currentIndex = (_currentIndex >= _scenes.Count - 1) ? 0 : _currentIndex + 1;
            RequestScene(_currentIndex);
        }

        /// <summary>Load a scene by index directly (called by Debug Menu UI buttons).</summary>
        public void LoadByIndex(int index)
        {
            if (index < 0 || index >= _scenes.Count)
            {
                Debug.LogWarning($"[DebugNavigation] Index {index} out of range.");
                return;
            }

            _currentIndex = index;
            RequestScene(_currentIndex);
        }

        private void RequestScene(int index)
        {
            OctoSceneData scene = _scenes[index];

            if (scene == null)
            {
                Debug.LogWarning($"[DebugNavigation] Scene at index {index} is null.");
                return;
            }

            // Don't reload the scene that's already active
            if (OctoRef.Instance != null &&
                OctoRef.Instance.Navigation.CurrentScene == scene)
            {
                Debug.Log($"[DebugNavigation] Scene '{scene.SceneName}' is already loaded, skipping.");
                return;
            }

            OnDebugSceneRequested?.Invoke(scene);

            if (OctoRef.Instance)
                OctoRef.Instance.Navigation.LoadScene(scene);
            else
                Debug.LogError("[DebugNavigation] OctoCore instance not found.");
        }
    }
}