---

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using ImageMagick;
using FFMpegCore;
using Spire.Doc;
using Spire.Presentation;
using SkiaSharp;

namespace UniversalConverter
{
    public partial class Form1 : Form
    {
        private string[] _selectedFiles;
        private readonly Dictionary<string, List<string>> _categories = new Dictionary<string, List<string>>
        {
            ["Image"] = new List<string> { "jpg", "png", "webp", "avif", "bmp", "pdf", "docx", "pptx" },
            ["Audio"] = new List<string> { "mp3", "wav", "flac", "aac" },
            ["Video"] = new List<string> { "mp4", "mkv", "mov", "avi" }
        };

        public Form1()
        {
            InitializeComponent();
            cmbTargetFormat.Items.AddRange(new object[] { "jpg", "png", "pdf", "mp3", "mp4" });
            cmbTargetFormat.SelectedIndex = 0;
        }

        private void btnSelect_Click(object sender, EventArgs e)
        {
            using (OpenFileDialog ofd = new OpenFileDialog { Multiselect = true })
            {
                if (ofd.ShowDialog() == DialogResult.OK)
                {
                    _selectedFiles = ofd.FileNames;
                    lstFiles.Items.Clear();
                    lstFiles.Items.AddRange(_selectedFiles.Select(Path.GetFileName).ToArray());
                }
            }
        }

        private async void btnStart_Click(object sender, EventArgs e)
        {
            if (_selectedFiles == null || _selectedFiles.Length == 0) return;

            string savePath = "";
            using (FolderBrowserDialog fbd = new FolderBrowserDialog())
            {
                if (fbd.ShowDialog() == DialogResult.OK) savePath = fbd.SelectedPath;
                else return;
            }

            btnStart.Enabled = false;
            string targetExt = "." + cmbTargetFormat.SelectedItem.ToString();
            progressBar.Maximum = _selectedFiles.Length;
            progressBar.Value = 0;

            foreach (var file in _selectedFiles)
            {
                try
                {
                    string inputExt = Path.GetExtension(file).ToLower();
                    lblStatus.Text = $"Обработка: {Path.GetFileName(file)}";

                    if ((inputExt == ".docx" || inputExt == ".pptx" || inputExt == ".pdf") && (targetExt == ".jpg" || targetExt == ".png"))
                    {
                        await Task.Run(() => ConvertDocToImages(file, savePath, targetExt));
                    }
                    else
                    {
                        await ProcessGeneralFile(file, savePath, targetExt, inputExt);
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show($"Ошибка в {Path.GetFileName(file)}: {ex.Message}");
                }
                progressBar.Value++;
            }

            lblStatus.Text = "Готово!";
            btnStart.Enabled = true;
        }

        private void ConvertDocToImages(string inputFile, string outFolder, string format)
        {
            string ext = Path.GetExtension(inputFile).ToLower();
            string baseName = Path.GetFileNameWithoutExtension(inputFile);

            if (ext == ".docx")
            {
                Document doc = new Document();
                doc.LoadFromFile(inputFile);
                for (int i = 0; i < doc.PageCount; i++)
                {
                    object result = doc.SaveToImages(i, Spire.Doc.Documents.ImageType.Bitmap);
                    SaveUniversal(result, Path.Combine(outFolder, $"{baseName}_p{i + 1}{format}"));
                }
            }
            else if (ext == ".pptx")
            {
                Presentation ppt = new Presentation();
                ppt.LoadFromFile(inputFile);
                for (int i = 0; i < ppt.Slides.Count; i++)
                {
                    object result = ppt.Slides[i].SaveAsImage();
                    SaveUniversal(result, Path.Combine(outFolder, $"{baseName}_s{i + 1}{format}"));
                }
            }
            else if (ext == ".pdf")
            {
                using (var images = new MagickImageCollection())
                {
                    images.Read(inputFile);
                    for (int i = 0; i < images.Count; i++)
                    {
                        images[i].Write(Path.Combine(outFolder, $"{baseName}_p{i + 1}{format}"));
                    }
                }
            }
        }

        // УНИВЕРСАЛЬНЫЙ МЕТОД СОХРАНЕНИЯ
        private void SaveUniversal(object source, string fullPath)
        {
            // 1. Если это уже поток (Stream)
            if (source is Stream stream)
            {
                using (stream)
                using (var image = new MagickImage(stream))
                {
                    image.Write(fullPath);
                }
            }
            // 2. Если это картинка SkiaSharp (SKImage)
            else if (source is SKImage skiaImg)
            {
                using (skiaImg)
                using (var data = skiaImg.Encode(SKEncodedImageFormat.Png, 100))
                using (var ms = new MemoryStream())
                {
                    data.SaveTo(ms);
                    ms.Position = 0;
                    using (var image = new MagickImage(ms))
                    {
                        image.Write(fullPath);
                    }
                }
            }
        }

        private async Task ProcessGeneralFile(string file, string savePath, string targetExt, string inputExt)
        {
            string outPath = Path.Combine(savePath, Path.GetFileNameWithoutExtension(file) + "_conv" + targetExt);
            
            if (_categories["Image"].Contains(inputExt.Replace(".", "")) && inputExt != ".pdf" && inputExt != ".docx" && inputExt != ".pptx")
            {
                await Task.Run(() => {
                    using (var img = new MagickImage(file)) img.Write(outPath);
                });
            }
            else
            {
                await FFMpegArguments.FromFileInput(file).OutputToFile(outPath).ProcessAsynchronously();
            }
        }
    }
}