using System;
using System.Collections;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.UI;
using TcgEngine.UI;

namespace TcgEngine
{
    /// <summary>
    /// 资源初始化
    /// </summary>
    public class ResourceInitializer : MonoBehaviour
    {
        [Header("UI References")]
        public GameObject downloadPanel;
        public Text statusText;
        public Slider progressBar;
        public Button retryButton;
        public Button skipButton;
        
        [Header("Settings")]
        public bool allowSkip = false;
        public float timeoutSeconds = 30f;
        
        private bool downloadCompleted = false;
        private bool downloadFailed = false;
        
        public event Action OnInitializationComplete;
        public event Action<string> OnInitializationFailed;
        
        private void Start()
        {
            if (downloadPanel != null)
                downloadPanel.SetActive(false);
                
            if (retryButton != null)
            {
                // TODO 重试
                retryButton.gameObject.SetActive(false);
            }
            
            if (skipButton != null)
            {
                // TODO 跳过
                skipButton.gameObject.SetActive(false);
            }
        }
        
        /// <summary>
        /// 开始资源初始化流程
        /// </summary>
        public async Task<bool> InitializeResources()
        {
            try
            {
                UpdateStatus("正在检查资源版本...");
                
                // 获取或创建ResourceDownloader实例
                ResourceDownloader downloader = ResourceDownloader.Get();
                
                // 订阅下载事件
                SubscribeToDownloadEvents(downloader);
                
                // 检查是否需要更新
                bool needsUpdate = await downloader.CheckForUpdates();
                
                if (!needsUpdate)
                {
                    UpdateStatus("资源已是最新版本");
                    CompleteInitialization();
                    return true;
                }
                
                UpdateStatus("发现新版本，正在下载资源...");
                UpdateProgress(0f);
                
                // 开始下载和更新
                bool success = await DownloadWithTimeout(downloader);
                
                if (success)
                {
                    UpdateStatus("资源更新完成！");
                    UpdateProgress(1f);
                    await Task.Delay(1000);
                    CompleteInitialization();
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch (Exception e)
            {
                Debug.LogError($"Resource initialization failed: {e.Message}");
                UpdateStatus($"初始化失败: {e.Message}");
                return false;
            }
            finally
            {
                // 取消订阅事件
                if (ResourceDownloader.Get() != null)
                {
                    UnsubscribeFromDownloadEvents(ResourceDownloader.Get());
                }
            }
        }
        
        /// <summary>
        /// 带超时的下载
        /// </summary>
        private async Task<bool> DownloadWithTimeout(ResourceDownloader downloader)
        {
            var downloadTask = downloader.DownloadAndUpdateResources();
            var timeoutTask = Task.Delay(TimeSpan.FromSeconds(timeoutSeconds));
            
            var completedTask = await Task.WhenAny(downloadTask, timeoutTask);
            
            if (completedTask == timeoutTask)
            {
                UpdateStatus("下载超时");
                OnInitializationFailed?.Invoke("Download timeout");
                return false;
            }
            
            return await downloadTask;
        }
        
        /// <summary>
        /// 订阅下载事件
        /// </summary>
        private void SubscribeToDownloadEvents(ResourceDownloader downloader)
        {
            downloader.OnDownloadProgress += OnDownloadProgress;
            downloader.OnDownloadComplete += OnDownloadComplete;
            downloader.OnDownloadError += OnDownloadError;
            downloader.OnExtractProgress += OnExtractProgress;
            downloader.OnExtractComplete += OnExtractComplete;
        }
        
        /// <summary>
        /// 取消订阅下载事件
        /// </summary>
        private void UnsubscribeFromDownloadEvents(ResourceDownloader downloader)
        {
            downloader.OnDownloadProgress -= OnDownloadProgress;
            downloader.OnDownloadComplete -= OnDownloadComplete;
            downloader.OnDownloadError -= OnDownloadError;
            downloader.OnExtractProgress -= OnExtractProgress;
            downloader.OnExtractComplete -= OnExtractComplete;
        }
        
        private void OnDownloadProgress(float progress)
        {
            UpdateProgress(progress * 0.7f);
            UpdateStatus($"正在下载资源... {(progress * 100):F1}%");
        }
        
        private void OnDownloadComplete(string filePath)
        {
            UpdateProgress(0.7f);
            UpdateStatus("下载完成，正在解压...");
        }
        
        private void OnDownloadError(string error)
        {
            downloadFailed = true;
            UpdateStatus($"下载失败: {error}");
            OnInitializationFailed?.Invoke(error);
        }
        
        private void OnExtractProgress(float progress)
        {
            UpdateProgress(0.7f + progress * 0.3f);
            UpdateStatus($"正在解压资源... {(progress * 100):F1}%");
        }
        
        private void OnExtractComplete()
        {
            downloadCompleted = true;
            UpdateProgress(1f);
            UpdateStatus("资源解压完成！");
        }
        
        /// <summary>
        /// 更新状态文本
        /// </summary>
        private void UpdateStatus(string status)
        {
            if (statusText != null)
            {
                statusText.text = status;
            }
            Debug.Log($"[ResourceInitializer] {status}");
        }
        
        /// <summary>
        /// 更新进度条
        /// </summary>
        private void UpdateProgress(float progress)
        {
            if (progressBar != null)
            {
                progressBar.value = Mathf.Clamp01(progress);
            }
        }
        
        /// <summary>
        /// 完成初始化
        /// </summary>
        private void CompleteInitialization()
        {
            downloadCompleted = true;
            OnInitializationComplete?.Invoke();
        }
    }
}