using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;

namespace OctoCore
{
    /// <summary>
    /// Main entry point for the OctoCore framework.
    /// Manages all modules and coordinates their lifecycle.
    /// </summary>
    [DefaultExecutionOrder(-100)]
    public class OctoCore : MonoBehaviour
    {
        /// <summary>
        /// Singleton instance of OctoCore.
        /// </summary>
        public static OctoCore Instance { get; private set; }

        private List<IOctoModule> _modules = new();

        /// <summary>
        /// Global settings for the OctoCore framework.
        /// </summary>
        public OctoSettings Settings;

        [SerializeField] private Platform.OctoPlatform _platform = new();
        [SerializeField] private Save.OctoSave _save = new();
        [SerializeField] private Inputs.OctoInputs _inputs = new();
        [SerializeField] private Localization.OctoLocalization _localization = new();
        [SerializeField] private UI.OctoUI _ui = new();
        [SerializeField] private Navigation.OctoNavigation _navigation = new();
        [SerializeField] private Development.OctoDevelopment _development = new();

        /// <summary>
        /// Platform detection module.
        /// </summary>
        public Platform.OctoPlatform Platform => _platform;

        /// <summary>
        /// Save system module.
        /// </summary>
        public Save.OctoSave Save => _save;

        /// <summary>
        /// Input management module.
        /// </summary>
        public Inputs.OctoInputs Inputs => _inputs;

        /// <summary>
        /// Localization module for text and audio.
        /// </summary>
        public Localization.OctoLocalization Localization => _localization;

        /// <summary>
        /// UI management module.
        /// </summary>
        public UI.OctoUI UI => _ui;

        /// <summary>
        /// Scenes management module.
        /// </summary>
        public Navigation.OctoNavigation Navigation => _navigation;

        /// <summary>
        /// Development and debugging module.
        /// </summary>
        public Development.OctoDevelopment Development => _development;

        void Awake()
        {
            if (Instance == null)
            {
                Instance = this;
                DontDestroyOnLoad(gameObject);
            }
            else
            {
                Destroy(gameObject);
                return;
            }

            RegisterModule(_platform);
            RegisterModule(_save);
            RegisterModule(_inputs);
            RegisterModule(_localization);
            RegisterModule(_ui);
            RegisterModule(_navigation);
            RegisterModule(_development);

            foreach (IOctoModule module in _modules)
            {
                module.Init(Settings);
            }

            QualitySettings.vSyncCount = Settings.Application.VSyncCount;
            Application.targetFrameRate = Settings.Application.TargetFrameRate;
        }

        void RegisterModule(IOctoModule module)
        {
            _modules.Add(module);
        }

        void OnEnable()
        {
            SceneManager.activeSceneChanged += OnSceneChanged;
        }

        void OnDisable()
        {
            SceneManager.activeSceneChanged -= OnSceneChanged;
        }

        void Update()
        {
            foreach (IOctoModule module in _modules)
            {
                module.Tick();
            }
        }

        void OnApplicationQuit()
        {
            foreach (IOctoModule module in _modules)
            {
                module.OnQuit();
            }
        }

        void OnSceneChanged(Scene oldScene, Scene newScene)
        {
            foreach (IOctoModule module in _modules)
            {
                module.OnSceneChanged(oldScene, newScene);
            }
        }
    }
}