namespace OpenArchival.Blazor.FileViewer;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


public static class FileViewerFactory
{
    private static Dictionary<string, Type> _extensionMapping = [];

    static FileViewerFactory() {
        // Image types taken from https://developer.mozilla.org/en-US/docs/Web/Media/Guides/Formats/Image_types
        RegisterViewerComponent<ImageViewer>([".apng", ".png", ".avif", ".gif", ".jpg", ".jpeg", ".jfif", ".pjpeg", ".pjp", ".svg", ".webp"]);
    }

    public static void RegisterViewerComponent<ComponentType>(IEnumerable<string> extensions) where ComponentType : IFileViewer
    {
        foreach (var extension in extensions)
        {
            _extensionMapping.Add(extension, typeof(ComponentType));
        }
    }

    public static Type GetViewerComponent(string filename)
    {
        if (_extensionMapping.TryGetValue(Path.GetExtension(filename).ToLowerInvariant(), out var componentType)) 
        {
            return componentType;
        } 
        else
        {
            return typeof(UnsupportedFileViewer);
        }
    }
}