using System.Diagnostics;
using System.Runtime.InteropServices;
using Duempelkas.App.Services;

namespace Duempelkas.Infrastructure.Services;

public class FileSaveService : IFileSaveService
{
    public async Task<string?> SaveFileAsync(byte[] content, string suggestedFileName)
    {
        var filePath = await ShowSaveDialogAsync(suggestedFileName);
        if (filePath == null) return null;

        await File.WriteAllBytesAsync(filePath, content);
        return filePath;
    }

    public Task OpenFileAsync(string filePath)
    {
        if (string.IsNullOrWhiteSpace(filePath) || !File.Exists(filePath))
        {
            return Task.CompletedTask;
        }

        return Task.Run(() =>
        {
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            {
                Process.Start(new ProcessStartInfo
                {
                    FileName = filePath,
                    UseShellExecute = true
                });

                return;
            }

            if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
            {
                Process.Start("open", filePath);
                return;
            }

            Process.Start("xdg-open", filePath);
        });
    }

    private static Task<string?> ShowSaveDialogAsync(string suggestedFileName)
    {
        return Task.Run(() =>
        {
            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            {
                // Fallback: save to Documents folder
                var documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
                return Path.Combine(documentsPath, suggestedFileName);
            }

            var extension = Path.GetExtension(suggestedFileName);
            var filterName = extension == ".pdf" ? "PDF-Dateien" : "Dateien";
            var filter = $"{filterName} (*{extension})|*{extension}|Alle Dateien (*.*)|*.*";

            var script = $@"
Add-Type -AssemblyName System.Windows.Forms
$dialog = New-Object System.Windows.Forms.SaveFileDialog
$dialog.Filter = '{filter}'
$dialog.FileName = '{suggestedFileName.Replace("'", "''")}'
$dialog.Title = 'Datei speichern'
if ($dialog.ShowDialog() -eq 'OK') {{ $dialog.FileName }} else {{ '' }}
";

            var psi = new ProcessStartInfo
            {
                FileName = "powershell",
                Arguments = $"-NoProfile -Command \"{script.Replace("\"", "\\\"\"")}\"",
                RedirectStandardOutput = true,
                UseShellExecute = false,
                CreateNoWindow = true
            };

            using var process = Process.Start(psi);
            if (process == null) return null;

            var result = process.StandardOutput.ReadToEnd().Trim();
            process.WaitForExit();

            return string.IsNullOrWhiteSpace(result) ? null : result;
        });
    }
}