JPEGify for Clearinet.app

CAE-Jpegify.cs

using Clearinet;
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Windows.Forms;

[assembly: Clearinet.RequiredVersion("0.0.3.0")]
namespace MakeJPEG
{
    public class JPEGify : IAutoTamper
    {
        private bool _autoConvert;
        private long _autoJPEGQuality = 80;
        private readonly ToolStripMenuItem _rulesMenuItem = new ToolStripMenuItem("JPEGify I&mages...");
        private readonly ToolStripMenuItem _contextMenuItem = new ToolStripMenuItem("&JPEGify...");

        public void OnPeekAtRequestHeaders(Exchange exchange) { }
        public void AutoTamperRequestBefore(Exchange exchange) { }
        public void AutoTamperRequestAfter(Exchange exchange) { }

        public void OnPeekAtResponseHeaders(Exchange exchange)
        {
            if (_autoConvert && exchange?.ResponseHeaders != null && exchange.ResponseHeaders.ExistsAndContains("Content-Type", "image/"))
            {
                // TODO: Enable response buffering.
                // Clearinet handles the actual response tampering in AutoTamperResponseBefore.
            }
        }

        public void AutoTamperResponseBefore(Exchange exchange)
        {
            if (!_autoConvert) return;
            ProcessExchange(exchange, _autoJPEGQuality);
        }

        public void AutoTamperResponseAfter(Exchange exchange) { }
        public void OnBeforeReturningGeneratedError(Exchange exchange) { }

        private void ProcessExchange(Exchange exchange, long quality)
        {
            if (exchange == null || !exchange.bHasResponse || exchange.responseCode != 200)
            {
                return;
            }

            if (!exchange.ResponseBody.HasData()
                || exchange.ResponseHeaders == null
                || !exchange.MediaType.OICStartsWith("image/"))
            {
                return;
            }

            if (!exchange.MediaTypeIs("image/jpeg") &&
                !exchange.MediaTypeIs("image/webp") &&
                !exchange.MediaTypeIs("image/png") &&
                !exchange.MediaTypeIs("image/gif") &&
                !exchange.MediaTypeIs("image/jxl") &&
                !exchange.MediaTypeIs("image/bmp") &&
                !exchange.MediaType.OICStartsWith("image/jp"))
            {
                return;
            }

            try
            {
                int oldSize = exchange.ResponseBody?.Length ?? 0;
                MakeJPEGOfQuality(exchange, quality);
                exchange.oFlags["Size-Before-JPEGify"] = oldSize.ToString("N0");

                float percent = oldSize == 0 ? 0F : 100F * (exchange.ResponseBody.Length / (float)oldSize);
                string summary = $"JPEGify to {exchange.ResponseBody.Length:N0} from {oldSize:N0} bytes ({percent:N1}%)";
                CApp.UI.SetStatusText(summary);
            }
            catch (Exception ex)
            {
                CApp.Log.Log(ex.ToString());
            }
        }

        private void MakeJPEGOfQuality(Exchange exchange, long quality)
        {
            if (quality < 1 || quality > 100)
            {
                throw new ArgumentOutOfRangeException(nameof(quality), quality, "Quality must be between 1 and 100");
            }

            if (!exchange.ResponseBody.HasData())
            {
                return;
            }

            byte[] arrBody = exchange.ResponseBody;

            if (exchange.MediaTypeIs("image/webp"))
            {
                arrBody = Clearinet.Utilities.ConvertWebPToPNG(arrBody);
            }
            else if (exchange.MediaTypeIs("image/jxl"))
            {
                arrBody = Clearinet.Utilities.ConvertJXLToJPEG(arrBody);
            }

            using (MemoryStream inputStream = new MemoryStream(arrBody))
            using (Bitmap bitmap = new Bitmap(inputStream))
            using (MemoryStream outputStream = new MemoryStream())
            {
                ImageCodecInfo encoder = GetEncoder(ImageFormat.Jpeg) ?? throw new InvalidOperationException("Unable to find a JPEG encoder.");
                EncoderParameters parameters = new EncoderParameters(1);
                parameters.Param[0] = new EncoderParameter(Encoder.Quality, quality);
                bitmap.Save(outputStream, encoder, parameters);

                exchange.ResponseBody = outputStream.ToArray();
                exchange.ResponseHeaders["Content-Type"] = "image/jpeg";
                exchange.ResponseHeaders["Cache-Control"] = "no-cache";
            }
        }

        private static ImageCodecInfo GetEncoder(ImageFormat format)
        {
            ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();
            foreach (ImageCodecInfo codec in codecs)
            {
                if (codec.FormatID == format.Guid)
                {
                    return codec;
                }
            }
            return null;
        }

        public void OnBeforeUnload()
        {
            _autoConvert = false;

            _rulesMenuItem.GetCurrentParent()?.Items.Remove(_rulesMenuItem);
            _contextMenuItem.GetCurrentParent()?.Items.Remove(_contextMenuItem);

            _rulesMenuItem.Dispose();
            _contextMenuItem.Dispose();
        }

        public void OnLoad()
        {
            CApp.UI.AddExtensionRulesMenuItem(_rulesMenuItem);
            CApp.UI.lvExchanges.AddExtensionMenuItem(_contextMenuItem);

            _rulesMenuItem.Click += (s, e) =>
            {
                bool newValue = !_rulesMenuItem.Checked;
                if (newValue)
                {
                    string qualityText = frmPrompt.GetUserString(
                        "Set JPEG Quality",
                        "Enter a value, 1 to 100",
                        _autoJPEGQuality.ToString(),
                        true,
                        frmPrompt.PromptKind.Numbers);

                    if (!qualityText.HasText())
                    {
                        newValue = false;
                    }
                    else
                    {
                        if (!long.TryParse(qualityText, out long parsedQuality) || parsedQuality < 1 || parsedQuality > 100)
                        {
                            newValue = false;
                        }
                        else
                        {
                            _autoJPEGQuality = parsedQuality;
                        }
                    }
                }

                _rulesMenuItem.Checked = _autoConvert = newValue;
            };

            _contextMenuItem.Click += (s, e) =>
            {
                string qualityText = frmPrompt.GetUserString(
                    "Set JPEG Quality",
                    "Enter a value, 1 to 100",
                    _autoJPEGQuality.ToString(),
                    true,
                    frmPrompt.PromptKind.Numbers);

                if (!qualityText.HasText()) return;

                if (!long.TryParse(qualityText, out long quality) || quality < 1 || quality > 100) return;

                Exchange[] selectedExchanges = CApp.UI.GetSelectedExchanges();
                foreach (Exchange exchange in selectedExchanges)
                {
                    ProcessExchange(exchange, quality);
                }

                CApp.UI.actRefreshUI(false);
                CApp.UI.SetStatusText("JPEGify Complete");
            };
        }
    }
}