using System.Threading.Tasks;
using UnityEngine;
using BaseGames.Core.Events;

namespace BaseGames.Core.Save
{
    public class EmergencySaveService : MonoBehaviour
    {
        public const int EmergencySlot = 99;

        [SerializeField] private float              _intervalSeconds = 120f;
        [SerializeField] private SaveManager        _saveManager;
        [SerializeField] private BoolEventChannelSO _onGameplayActive;

        private bool  _gameplayActive;
        private float _timer;
        private readonly CompositeDisposable _subscriptions = new();

        private void OnEnable()
        {
            _onGameplayActive?.Subscribe(OnGameplayActiveChanged).AddTo(_subscriptions);
        }

        private void OnDisable() => _subscriptions.Clear();

        private void OnGameplayActiveChanged(bool value) => _gameplayActive = value;

        private void Update()
        {
            if (!_gameplayActive || _saveManager == null) return;
            _timer += Time.deltaTime;
            if (_timer >= _intervalSeconds)
            {
                _timer = 0f;
                _ = _saveManager.SaveAsync(EmergencySlot);
            }
        }

        public bool HasEmergencySave()
            => _saveManager != null && _saveManager.SlotExists(EmergencySlot);

        public async Task PromoteToSlot(int targetSlot)
        {
            if (_saveManager == null) return;
            var storage = new LocalFileStorage();
            if (!storage.Exists(EmergencySlot)) return;
            string json = await storage.ReadAsync(EmergencySlot);
            if (json == null) return;
            await storage.WriteAsync(targetSlot, json);
            await storage.DeleteAsync(EmergencySlot);
        }
    }
}