using System.Collections;
using System.Collections.Generic;
using System.Text;
using UnityEngine;

public class BackgroundSave : MonoBehaviour
{
    static public BackgroundSave Instance { get; private set; }

    private string _localUDT = "";
    private string _serverUDT = "";
#if UNITY_EDITOR
    [SerializeField]
#endif
    private float _defaultSaveInterval = 5.0f * 60.0f;
    private float _saveInterval;
    private float _timer;
    private float _delayAmount = 5.0f;
    private bool _isEnabled;

#if UNITY_EDITOR
    [SerializeField] private bool TEST_force_enabled = false;
    [SerializeField] private bool TEST_force_save = false;
#endif
    private void Awake()
    {
        if (Instance != null && Instance != this)
        {
            Debug.Log($"Cannot have multiple instances of class {nameof(BackgroundSave)}.");
            Destroy(gameObject);
            return;
        }

        Instance = this;
    }

    private void Update()
    {
#if UNITY_EDITOR && false
        _isEnabled = TEST_force_enabled;
#endif
        if (!_isEnabled)
        {
            return;
        }

#if UNITY_EDITOR
        if (!TEST_force_save && _timer < _saveInterval)
#else
        if (_timer < _saveInterval)
#endif
        {
            _timer += Time.deltaTime;
            return;
        }

        bool isReadyToSave = SceneModeManager.CompareSceneMode(SceneModes.Navigate);
        if (isReadyToSave)
        {
            Debug.Log("Background Save : Getting local save");
            byte[] bytes = SaveXML.BuildXmlBytes();
            _localUDT = Encoding.UTF8.GetString(bytes);

            bool isModified = _localUDT != _serverUDT;
            if (!isModified)
            {
                Debug.Log("Background Save : No changes detected");

                ResetTimer();
                return;
            }

            if (_localUDT != _serverUDT)
            {
                Debug.Log("Background Save : Saving to server");
                StartCoroutine(LoadHistory.Instance.RequestAutoSaveToServer(_localUDT));
            }
            else
            {
                Debug.Log("Background Save : No changes made (matching local and server saves)");
            }

            ResetTimer();
        }
        else
        {
#if UNITY_EDITOR
            if (TEST_force_save) { return; }
#endif

            Debug.Log("Background Save : Waiting To Save...");
            _timer -= _delayAmount;
        }
    }

    public void InitTimer()
    {
        if (!_isEnabled)
        {
            Debug.Log("Background Save : Init");

            _saveInterval = _defaultSaveInterval;
            _timer = 0.0f;
            _isEnabled = true;
        }
    }

    public void StopTimer()
    {
        Debug.Log("Background Save : Timer Stopped");

        _timer = 0.0f;
        _isEnabled = false;
    }

    public void ResetTimer()
    {
        Debug.Log("Background Save : Timer Reset");

        _timer = 0.0f;
#if UNITY_EDITOR
        TEST_force_save = false;
#endif
    }

    public void SetLastestServerUDT(string udt)
    {
        _serverUDT = udt;
    }

    public string GetLastestServerUDT()
    {
        return _serverUDT;
    }

    public void ValidateRefId()
    {
        if (!_P.AutoSave_RefId || string.IsNullOrEmpty(_G.ref_id))
        {
            _P.AutoSave_RefId = false;
            Destroy(gameObject);
        }
    }
}