using System;
using System.IO;
using System.IO.Compression;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using MelonLoader;
using MelonLoader.Utils;
using O5Kit.Core;
using O5Kit.Factory;
using TMPro;
using UnityEngine;
using UnityEngine.UI;

namespace ADOFAIRenderer.UI;

internal class FFmpegDownloadUI : MonoBehaviour
{
    private GameObject _buttonContainerObj = null!;
    private GameObject _progressBarObj = null!;
    private GameObject _progressBarFillObj = null!;
    private RectTransform _fillRect = null!;
    private TextMeshProUGUI _progressText = null!;
    private GameObject _statusTextObj = null!;
    private TextMeshProUGUI _statusText = null!;

    private O5Window? _window;
    private bool _isDownloading;
    private string DownloadUrl => Application.platform switch
    {
        RuntimePlatform.WindowsPlayer => "https://github.com/BtbN/FFmpeg-Builds/releases/download/autobuild-2026-05-31-13-22/ffmpeg-N-124714-g49a77d37be-win64-gpl-shared.zip", 
        _ => "https://github.com/BtbN/FFmpeg-Builds/releases/download/autobuild-2026-05-31-13-22/ffmpeg-N-124714-g49a77d37be-linux64-gpl-shared.tar.xz"
    };
        
    private System.Threading.CancellationTokenSource? _cts;
    private readonly System.Collections.Concurrent.ConcurrentQueue<Action> _mainThreadQueue = new();

    public static bool CheckFFmpegExists()
    {
        var userLibs = MelonEnvironment.UserLibsDirectory;
        if (!Directory.Exists(userLibs)) return false;

        string[] searchPatterns = Application.platform switch
        {
            RuntimePlatform.WindowsPlayer => new[]
            {
                "avcodec-*.dll", "avformat-*.dll", "avutil-*.dll", "swscale-*.dll", "swresample-*.dll"
            },
            RuntimePlatform.OSXPlayer => new[]
            {
                "libavcodec.*.dylib", "libavformat.*.dylib", "libavutil.*.dylib", "libswscale.*.dylib", "libswresample.*.dylib"
            },
            _ => new[]
            {
                "libavcodec.so*", "libavformat.so*", "libavutil.so*", "libswscale.so*", "libswresample.so*"
            }
        };

        foreach (var pattern in searchPatterns)
        {
            if (Directory.GetFiles(userLibs, pattern).Length == 0)
            {
                return false;
            }
        }

        return true;
    }

    public static void ShowDownloadUI()
    {
            
        if (CheckFFmpegExists()) return;
            
        var obj = new GameObject("FFmpegDownloadUI");
        DontDestroyOnLoad(obj);
        obj.AddComponent<FFmpegDownloadUI>();
    }

    public static FFmpegDownloadUI? Instance { get; private set; }

    private void Awake()
    {
        Instance = this;
        if (CheckFFmpegExists())
        {
            Destroy(gameObject);
        }
    }

    private void Start()
    {
        // Set UI layer (5)
        gameObject.layer = 5;
            
        // Canvas setup
        var canvas = gameObject.AddComponent<Canvas>();
        canvas.renderMode = RenderMode.ScreenSpaceOverlay;
        canvas.sortingOrder = 32767; // Topmost
            
        // Responsive Canvas Scaler setup
        var scaler = gameObject.AddComponent<CanvasScaler>();
        scaler.uiScaleMode = CanvasScaler.ScaleMode.ScaleWithScreenSize;
        scaler.referenceResolution = new Vector2(1920, 1080);
        scaler.screenMatchMode = CanvasScaler.ScreenMatchMode.MatchWidthOrHeight;
        scaler.matchWidthOrHeight = 0.5f;
            
        gameObject.AddComponent<GraphicRaycaster>();

        var ctx = RendererUIManager.Context;

        // 1. Create full screen backdrop
        var bgPanelObj = new GameObject("Backdrop");
        bgPanelObj.transform.SetParent(transform, false);
        bgPanelObj.layer = 5;
            
        var bgImage = bgPanelObj.AddComponent<Image>();
        bgImage.color = new Color(0f, 0f, 0f, 0.65f);
        bgImage.raycastTarget = true;
            
        var bgRect = bgPanelObj.GetComponent<RectTransform>();
        bgRect.anchorMin = Vector2.zero;
        bgRect.anchorMax = Vector2.one;
        bgRect.offsetMin = Vector2.zero;
        bgRect.offsetMax = Vector2.zero;
            
        // 2. Create actual native O5Window
        _window = O5Window.Create(ctx, bgPanelObj.transform, new O5WindowOptions
        {
            Id = "RendererMod_FFmpegDownloadDialog",
            Title = "FFmpeg Library Installation Required",
            Size = new Vector2(580, 270),
            Draggable = true,
            Resizable = false,
            ShowCloseButton = false,
            ShowOutline = true,
            Padding = new RectOffset(16, 16, 16, 16)
        });

        var content = _window.Content;

        var vLayout = content.gameObject.AddComponent<VerticalLayoutGroup>();
        vLayout.spacing = 14f;
        vLayout.padding = new RectOffset(16, 16, 10, 10);
        vLayout.childControlWidth = true;
        vLayout.childControlHeight = true;
        vLayout.childForceExpandWidth = true;
        vLayout.childForceExpandHeight = false;

        // 3. Description text
        var descText = O5Factory.ControlText(ctx, content, 18f, noPad: true);
        var descStrBuilder = new StringBuilder();
        descStrBuilder.AppendLine("FFmpeg shared libraries are required to render video.");
        if (Application.platform == RuntimePlatform.OSXPlayer)
        {
            descStrBuilder.AppendLine("For macOS, reliable public builds are unavailable, so FFmpeg 8.1 must be built manually.");
            descStrBuilder.AppendLine("Click the button below to open the official FFmpeg website.");
        }
        else
        {
            descStrBuilder.AppendLine("Click the button below to automatically download and install from the internet.");
            descStrBuilder.AppendLine("<color=#aaaaaa><size=13>(Download size: ~70MB, extracted to UserLibs folder)</size></color>");
        }
        descText.text = descStrBuilder.ToString();
        descText.alignment = TextAlignmentOptions.Center;
        descText.textWrappingMode = TextWrappingModes.Normal;
        descText.lineSpacing = 5;
        descText.color = new Color(0.85f, 0.85f, 0.85f, 1f);

        var descLE = descText.gameObject.AddComponent<LayoutElement>();
        descLE.flexibleWidth = 1f;
        descLE.flexibleHeight = 1f;

        // 4. Button container
        _buttonContainerObj = new GameObject("ButtonContainer");
        _buttonContainerObj.transform.SetParent(content, false);
        _buttonContainerObj.layer = 5;

        var btnContainerLE = _buttonContainerObj.AddComponent<LayoutElement>();
        btnContainerLE.preferredHeight = 40f;
        btnContainerLE.flexibleWidth = 1f;

        var btnLayout = _buttonContainerObj.AddComponent<HorizontalLayoutGroup>();
        btnLayout.spacing = 10f;
        btnLayout.childAlignment = TextAnchor.MiddleCenter;
        btnLayout.childControlWidth = true;
        btnLayout.childControlHeight = true;
        btnLayout.childForceExpandWidth = true;
        btnLayout.childForceExpandHeight = true;

        Action onDownloadClick = Application.platform != RuntimePlatform.OSXPlayer 
            ? StartDownloadProcess 
            : () => { Application.OpenURL("https://ffmpeg.org"); Destroy(gameObject); };

        var downloadBtn = O5Factory.Button(
            ctx: ctx,
            parent: _buttonContainerObj.transform,
            onClick: onDownloadClick,
            text: Application.platform != RuntimePlatform.OSXPlayer ? "Download & Install" : "Open Website",
            id: "btn_ffmpeg_download",
            height: 40f
        );
        downloadBtn.NormalColor = ctx.Theme.ObjectActiveBright;
        downloadBtn.UpdateVisual();

        var downloadBtnLE = downloadBtn.Rect.gameObject.AddComponent<LayoutElement>();
        downloadBtnLE.flexibleWidth = 1f;
        downloadBtnLE.preferredHeight = 40f;

        var cancelBtn = O5Factory.Button(
            ctx: ctx,
            parent: _buttonContainerObj.transform,
            onClick: CancelProcess,
            text: "Cancel",
            id: "btn_ffmpeg_cancel",
            height: 40f
        );
        var cancelBtnLE = cancelBtn.Rect.gameObject.AddComponent<LayoutElement>();
        cancelBtnLE.flexibleWidth = 1f;
        cancelBtnLE.preferredHeight = 40f;

        // 5. Progress bar container
        _progressBarObj = new GameObject("ProgressBarContainer");
        _progressBarObj.transform.SetParent(content, false);
        _progressBarObj.layer = 5;
        _progressBarObj.SetActive(false);

        var pbLE = _progressBarObj.AddComponent<LayoutElement>();
        pbLE.preferredHeight = 24f;
        pbLE.flexibleWidth = 1f;

        var barBgImg = _progressBarObj.AddComponent<Image>();
        barBgImg.sprite = ctx.Sprites.RoundedControl;
        barBgImg.type = Image.Type.Sliced;
        barBgImg.color = ctx.Theme.ObjectBG;

        var barOutlineObj = new GameObject("BarOutline");
        barOutlineObj.transform.SetParent(_progressBarObj.transform, false);
        barOutlineObj.layer = 5;

        var barOutlineImg = barOutlineObj.AddComponent<Image>();
        barOutlineImg.sprite = ctx.Sprites.RoundedOutline;
        barOutlineImg.type = Image.Type.Sliced;
        barOutlineImg.color = ctx.Theme.ControlOutlineIdle;
        barOutlineImg.raycastTarget = false;

        var barOutlineRect = barOutlineObj.GetComponent<RectTransform>();
        barOutlineRect.anchorMin = Vector2.zero;
        barOutlineRect.anchorMax = Vector2.one;
        barOutlineRect.offsetMin = Vector2.zero;
        barOutlineRect.offsetMax = Vector2.zero;

        // Progress bar fill image
        _progressBarFillObj = new GameObject("ProgressBarFill");
        _progressBarFillObj.transform.SetParent(_progressBarObj.transform, false);
        _progressBarFillObj.layer = 5;

        var fillImg = _progressBarFillObj.AddComponent<Image>();
        fillImg.sprite = ctx.Sprites.RoundedControl;
        fillImg.type = Image.Type.Sliced;
        fillImg.color = ctx.Theme.ObjectActiveBright;

        _fillRect = _progressBarFillObj.GetComponent<RectTransform>();
        _fillRect.anchorMin = new Vector2(0, 0);
        _fillRect.anchorMax = new Vector2(0, 1);
        _fillRect.pivot = new Vector2(0, 0.5f);
        _fillRect.anchoredPosition = Vector2.zero;
        _fillRect.sizeDelta = Vector2.zero;

        // Progress text
        var progressTextObj = new GameObject("ProgressBarText");
        progressTextObj.transform.SetParent(_progressBarObj.transform, false);
        progressTextObj.layer = 5;

        _progressText = progressTextObj.AddComponent<TextMeshProUGUI>();
        _progressText.fontSize = 13;
        _progressText.font = ctx.Fonts.Regular;
        _progressText.color = Color.white;
        _progressText.alignment = TextAlignmentOptions.Center;
        _progressText.raycastTarget = false;

        var progressTextRect = progressTextObj.GetComponent<RectTransform>();
        progressTextRect.anchorMin = Vector2.zero;
        progressTextRect.anchorMax = Vector2.one;
        progressTextRect.offsetMin = Vector2.zero;
        progressTextRect.offsetMax = Vector2.zero;

        // 6. Status text
        _statusTextObj = new GameObject("StatusText");
        _statusTextObj.transform.SetParent(content, false);
        _statusTextObj.layer = 5;
        _statusTextObj.SetActive(false);

        var statusLE = _statusTextObj.AddComponent<LayoutElement>();
        statusLE.preferredHeight = 22f;
        statusLE.flexibleWidth = 1f;

        _statusText = _statusTextObj.AddComponent<TextMeshProUGUI>();
        _statusText.fontSize = 14;
        _statusText.font = ctx.Fonts.Regular;
        _statusText.color = new Color(0.8f, 0.8f, 0.8f, 1f);
        _statusText.alignment = TextAlignmentOptions.Center;
        _statusText.raycastTarget = false;

        var statusRect = _statusTextObj.GetComponent<RectTransform>();
        statusRect.anchorMin = Vector2.zero;
        statusRect.anchorMax = Vector2.one;
        statusRect.offsetMin = Vector2.zero;
        statusRect.offsetMax = Vector2.zero;
    }

    private void Update()
    {
        // Execute queued actions on main thread
        while (_mainThreadQueue.TryDequeue(out var action))
        {
            action?.Invoke();
        }
    }

    private void ExecuteOnMainThread(Action action)
    {
        _mainThreadQueue.Enqueue(action);
    }

    private void StartDownloadProcess()
    {
        if (_isDownloading) return;
        _isDownloading = true;

        // Hide buttons and show progress bar & status text
        _buttonContainerObj.SetActive(false);
        _progressBarObj.SetActive(true);
        _statusTextObj.SetActive(true);

        _cts = new System.Threading.CancellationTokenSource();

        // Start download in background thread
        Task.Run(async () =>
        {
            string tempZipPath = "";
            try
            {
                UpdateStatus("Starting download...", new Color(0.8f, 0.8f, 0.8f));
                UpdateProgress(0f, "0%");

                var userLibsDir = MelonEnvironment.UserLibsDirectory;
                if (!Directory.Exists(userLibsDir))
                {
                    Directory.CreateDirectory(userLibsDir);
                }

                string extension = Application.platform switch
                {
                    RuntimePlatform.WindowsPlayer => ".zip",
                    RuntimePlatform.OSXPlayer => ".zip",
                    _ => ".tar.xz"
                };
                tempZipPath = Path.Combine(userLibsDir, "ffmpeg_temp" + extension);
                    
                var progressReporter = new Progress<float>(percent =>
                {
                    UpdateProgress(percent, $"{percent * 100f:F1}%");
                    UpdateStatus($"Downloading... ({(percent * 100f):F1}%)", new Color(0f, 0.8f, 1f));
                });

                await DownloadFileAsync(DownloadUrl, tempZipPath, progressReporter, _cts.Token);

                // Extract after download complete
                UpdateStatus("Extracting and copying library files...", new Color(0.9f, 0.9f, 0.2f));
                UpdateProgress(0.99f, "Extracting...");

                await ExtractDllsAsync(tempZipPath, userLibsDir);

                // Update completion status
                UpdateStatus("FFmpeg installation complete!", new Color(0.2f, 0.9f, 0.2f));
                UpdateProgress(1f, "100%");

                await Task.Delay(1000);

                // Destroy UI on main thread
                ExecuteOnMainThread(() =>
                {
                    Destroy(gameObject);
                });
            }
            catch (OperationCanceledException)
            {
                // Clean up temporary file on cancellation
                if (!string.IsNullOrEmpty(tempZipPath) && File.Exists(tempZipPath))
                {
                    try { File.Delete(tempZipPath); }
                    catch
                    {
                        // ignored
                    }
                }
                UpdateStatus("Download was cancelled.", new Color(0.9f, 0.5f, 0.2f));
            }
            catch (Exception ex)
            {
                Melon<RenderMod>.Logger.Error($"Error during FFmpeg download/installation: {ex}");
                UpdateStatus($"Installation failed: {ex.Message}", new Color(1f, 0.3f, 0.3f));
                    
                // Reset buttons on failure
                ExecuteOnMainThread(() =>
                {
                    _isDownloading = false;
                    _buttonContainerObj.SetActive(true);
                    var downloadBtnText = _buttonContainerObj.transform.Find("DownloadButton/DownloadText")?.GetComponent<TextMeshProUGUI>();
                    if (downloadBtnText)
                    {
                        downloadBtnText.text = "Retry";
                    }
                });
            }
        });
    }

    private void CancelProcess()
    {
        if (_isDownloading)
        {
            _cts?.Cancel();
        }
        Destroy(gameObject);
    }

    private void UpdateStatus(string message, Color color)
    {
        ExecuteOnMainThread(() =>
        {
            if (_statusText)
            {
                _statusText.text = message;
                _statusText.color = color;
            }
        });
    }

    private void UpdateProgress(float percent, string text)
    {
        ExecuteOnMainThread(() =>
        {
            if (_fillRect)
            {
                _fillRect.anchorMax = new Vector2(percent, 1f);
            }
            if (_progressText)
            {
                _progressText.text = text;
            }
        });
    }

    private async Task DownloadFileAsync(string url, string destinationPath, IProgress<float> progress, System.Threading.CancellationToken cancellationToken)
    {
        using var client = new HttpClient();
        // Add User-Agent header to prevent blocking
        client.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) ADOFAIRenderer/1.0");
            
        using var response = await client.GetAsync(url, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
        response.EnsureSuccessStatusCode();
            
        var totalBytes = response.Content.Headers.ContentLength ?? -1L;
        await using var contentStream = await response.Content.ReadAsStreamAsync();
        await using var fileStream = new FileStream(destinationPath, FileMode.Create, FileAccess.Write, FileShare.None, 8192, true);
            
        var buffer = new byte[8192];
        var totalRead = 0L;
        int read;
            
        while ((read = await contentStream.ReadAsync(buffer, 0, buffer.Length, cancellationToken)) > 0)
        {
            cancellationToken.ThrowIfCancellationRequested();
            await fileStream.WriteAsync(buffer, 0, read, cancellationToken);
            totalRead += read;

            if (totalBytes == -1) continue;
            var progressPercent = (float)totalRead / totalBytes;
            progress.Report(progressPercent);
        }
    }

    private async Task ExtractDllsAsync(string zipPath, string outputDirectory)
    {
        try
        {
            if (Application.platform == RuntimePlatform.OSXPlayer || Application.platform == RuntimePlatform.WindowsPlayer)
            {
                await Task.Run(() =>
                {
                    var targetExtension = Application.platform == RuntimePlatform.OSXPlayer ? ".dylib" : ".dll";
                    using var archive = ZipFile.OpenRead(zipPath);
                    foreach (var entry in archive.Entries)
                    {
                        if (entry.FullName.EndsWith(targetExtension, StringComparison.OrdinalIgnoreCase))
                        {
                            var targetPath = Path.Combine(outputDirectory, entry.Name);
                                
                            var dir = Path.GetDirectoryName(targetPath);
                            if (dir != null && !Directory.Exists(dir))
                            {
                                Directory.CreateDirectory(dir);
                            }
                                
                            entry.ExtractToFile(targetPath, overwrite: true);
                        }
                    }
                });
            }
            else
            {
                // Linux (or other platforms) - extract tar.xz
                await Task.Run(() =>
                {
                    var tempExtractDir = Path.Combine(outputDirectory, "ffmpeg_temp_extracted");
                    if (Directory.Exists(tempExtractDir))
                    {
                        Directory.Delete(tempExtractDir, true);
                    }
                    Directory.CreateDirectory(tempExtractDir);

                    var archiveUnixPath = zipPath.Replace('\\', '/');
                    var tempExtractUnixDir = tempExtractDir.Replace('\\', '/');

                    var startInfo = new System.Diagnostics.ProcessStartInfo
                    {
                        FileName = "tar",
                        Arguments = $"-xf \"{archiveUnixPath}\" -C \"{tempExtractUnixDir}\"",
                        RedirectStandardOutput = true,
                        RedirectStandardError = true,
                        UseShellExecute = false,
                        CreateNoWindow = true
                    };

                    using (var process = System.Diagnostics.Process.Start(startInfo))
                    {
                        process!.WaitForExit();
                        if (process.ExitCode != 0)
                        {
                            var error = process.StandardError.ReadToEnd();
                            throw new Exception($"tar extraction failed (ExitCode: {process.ExitCode}): {error}");
                        }
                    }

                    // Find .so files and copy to outputDirectory
                    var soFiles = Directory.GetFiles(tempExtractDir, "*.so*", SearchOption.AllDirectories);
                    foreach (var soFile in soFiles)
                    {
                        var fileName = Path.GetFileName(soFile);
                        var targetPath = Path.Combine(outputDirectory, fileName);
                        File.Copy(soFile, targetPath, true);
                    }

                    // Clean up temporary directory
                    try
                    {
                        Directory.Delete(tempExtractDir, true);
                    }
                    catch
                    {
                        // ignored
                    }
                });
            }
        }
        finally
        {
            if (File.Exists(zipPath))
            {
                try
                {
                    File.Delete(zipPath);
                }
                catch (Exception ex)
                {
                    Melon<RenderMod>.Logger.Warning($"Failed to delete temporary zip file: {ex.Message}");
                }
            }
        }
    }

    private void OnDestroy()
    {
        _window?.Dispose();
        _window = null;
        _cts?.Dispose();
        if (Instance == this)
        {
            Instance = null;
        }
    }
}