using System;
using System.IO;

using Avalonia;
using Avalonia.Styling;

using AvaloniaEdit;
using AvaloniaEdit.TextMate;

using TextMateSharp.Grammars;

namespace SourceGit.Models
{
    public static class TextMateHelper
    {
        public static TextMate.Installation CreateForEditor(TextEditor editor)
        {
            if (Application.Current?.ActualThemeVariant == ThemeVariant.Dark)
                return editor.InstallTextMate(new RegistryOptions(ThemeName.DarkPlus));

            return editor.InstallTextMate(new RegistryOptions(ThemeName.LightPlus));
        }

        public static void SetThemeByApp(TextMate.Installation installation)
        {
            if (installation == null)
                return;

            if (installation.RegistryOptions is RegistryOptions reg)
            {
                if (Application.Current?.ActualThemeVariant == ThemeVariant.Dark)
                    installation.SetTheme(reg.LoadTheme(ThemeName.DarkPlus));
                else
                    installation.SetTheme(reg.LoadTheme(ThemeName.LightPlus));
            }
        }

        public static void SetGrammarByFileName(TextMate.Installation installation, string filePath)
        {
            if (installation is { RegistryOptions: RegistryOptions reg })
            {
                var ext = Path.GetExtension(filePath);
                if (ext == ".h")
                    ext = ".cpp";
                else if (ext == ".resx" || ext == ".plist")
                    ext = ".xml";

                installation.SetGrammar(reg.GetScopeByExtension(ext));
                GC.Collect();
            }
        }
    }
}