Refactor image processing for more flexibility. Add support for resizing images if they exceed the discord 8Mb limit.

image/watermark.go

@@ -0,0 +1,64 @@
+package image
+
+import (
+	"fmt"
+	i "image"
+	"image/jpeg"
+	"image/png"
+	"os"
+
+	daulog "github.com/tardisx/discord-auto-upload/log"
+
+	"github.com/fogleman/gg"
+	"golang.org/x/image/font/inconsolata"
+)
+
+// applyWatermark applies the watermark to the image
+func (s *Store) applyWatermark() error {
+
+	in, err := os.Open(s.uploadSourceFilename())
+
+	defer in.Close()
+
+	im, _, err := i.Decode(in)
+	if err != nil {
+		daulog.Errorf("Cannot decode image: %v - skipping watermarking", err)
+		return fmt.Errorf("cannot decode image: %w", err)
+	}
+	bounds := im.Bounds()
+	// var S float64 = float64(bounds.Max.X)
+
+	dc := gg.NewContext(bounds.Max.X, bounds.Max.Y)
+	dc.Clear()
+	dc.SetRGB(0, 0, 0)
+
+	dc.SetFontFace(inconsolata.Regular8x16)
+
+	dc.DrawImage(im, 0, 0)
+
+	dc.DrawRoundedRectangle(0, float64(bounds.Max.Y-18.0), 320, float64(bounds.Max.Y), 0)
+	dc.SetRGB(0, 0, 0)
+	dc.Fill()
+
+	dc.SetRGB(1, 1, 1)
+
+	dc.DrawString("github.com/tardisx/discord-auto-upload", 5.0, float64(bounds.Max.Y)-5.0)
+
+	waterMarkedFile, err := os.CreateTemp("", "dau_watermark_file_*")
+
+	if err != nil {
+		return err
+	}
+	defer waterMarkedFile.Close()
+
+	if s.OriginalFormat == "png" {
+		png.Encode(waterMarkedFile, dc.Image())
+	} else if s.OriginalFormat == "jpeg" {
+		jpeg.Encode(waterMarkedFile, dc.Image(), nil)
+	} else {
+		panic("Cannot handle " + s.OriginalFormat)
+	}
+
+	s.WatermarkedFilename = waterMarkedFile.Name()
+	return nil
+}