inabox/InABox.Avalonia.Platform.Android/PdfRenderer.Android.cs

using InABox.Core;
using PDFtoImage;
using SkiaSharp;

namespace InABox.Avalonia.Platform.Android;

public class Android_PdfRenderer : IPdfRenderer
{
    public Logger? Logger { get; set; }
    
    public byte[]? PdfToImage(byte[]? pdf, int page, int dpi)
    {
        if (pdf is null || pdf.Length == 0)
            return null;
        var result = Conversion.ToImage(pdf, page, options: new RenderOptions(Dpi: dpi));
        using var ms = new MemoryStream();
        result.Encode(ms, SKEncodedImageFormat.Jpeg, 65);
        return ms.ToArray();
    }

    public Task<byte[]?> PdfToImageAsync(byte[]? pdf, int page, int dpi)
        => Task.Run(() => PdfToImage(pdf, page, dpi));

    public byte[][]? PdfToImages(byte[]? pdf, int dpi)
    {
        if (pdf is null || pdf.Length == 0)
            return null;
        var result = Conversion.ToImages(pdf, options: new RenderOptions(Dpi: dpi));
        return result.Select(x =>
        {
            using var ms = new MemoryStream();
            x.Encode(ms, SKEncodedImageFormat.Jpeg, 65);
            return ms.ToArray();
        }).ToArray();
    }

    public Task<byte[][]?> PdfToImagesAsync(byte[]? pdf, int dpi)
        => Task.Run(() => PdfToImages(pdf, dpi));

    public int? PdfPageCount(byte[]? pdf)
    {
        if (pdf is null || pdf.Length == 0)
            return null;
        return Conversion.GetPageCount(pdf);
    }

    public Task<int?> PdfPageCountAsync(byte[]? pdf)
        => Task.Run(() => PdfPageCount(pdf));

    public byte[]? ImageToPdf(byte[]? image) => null;

    public Task<byte[]?> ImageToPdfAsync(byte[]? image)
        => Task.Run(() => ImageToPdf(image));
}