added bundle generation

pipeline/05_bundle_gen/convert.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"fmt"
+	"image"
+	"image/png"
+	_ "image/gif"
+	_ "image/jpeg"
+
+	_ "github.com/biessek/golang-ico"
+	_ "golang.org/x/image/webp"
+)
+
+// convertIconToBase64PNG downloads an icon from S3, converts it to PNG, and returns base64-encoded data.
+func convertIconToBase64PNG(ctx context.Context, s3Key string, iconsBucket string) (encoded string, width, height int, err error) {
+	data, err := s3Download(ctx, iconsBucket, s3Key)
+	if err != nil {
+		return "", 0, 0, fmt.Errorf("s3 download: %w", err)
+	}
+
+	// Check for SVG (can't decode to raster without external deps)
+	if isSVG(data) {
+		return "", 0, 0, fmt.Errorf("svg not supported")
+	}
+
+	// image.Decode handles PNG, GIF, JPEG, WebP, BMP, and ICO (via registered decoders)
+	img, _, err := image.Decode(bytes.NewReader(data))
+	if err != nil {
+		return "", 0, 0, fmt.Errorf("decode: %w", err)
+	}
+
+	// Downscale icons >128px to 32x32 to keep bundle sizes reasonable
+	bounds := img.Bounds()
+	w, h := bounds.Dx(), bounds.Dy()
+	if w > 128 || h > 128 {
+		img = resizeNearestNeighbor(img, 32, 32)
+		w, h = 32, 32
+	}
+
+	// Re-encode as PNG
+	var pngBuf bytes.Buffer
+	if err := png.Encode(&pngBuf, img); err != nil {
+		return "", 0, 0, fmt.Errorf("png encode: %w", err)
+	}
+
+	encoded = base64.StdEncoding.EncodeToString(pngBuf.Bytes())
+	return encoded, w, h, nil
+}
+
+// resizeNearestNeighbor does a simple nearest-neighbor resize.
+func resizeNearestNeighbor(src image.Image, dstW, dstH int) image.Image {
+	srcBounds := src.Bounds()
+	srcW := srcBounds.Dx()
+	srcH := srcBounds.Dy()
+	dst := image.NewRGBA(image.Rect(0, 0, dstW, dstH))
+	for y := 0; y < dstH; y++ {
+		srcY := srcBounds.Min.Y + y*srcH/dstH
+		for x := 0; x < dstW; x++ {
+			srcX := srcBounds.Min.X + x*srcW/dstW
+			dst.Set(x, y, src.At(srcX, srcY))
+		}
+	}
+	return dst
+}
+
+func isSVG(data []byte) bool {
+	if len(data) < 5 {
+		return false
+	}
+	header := data[:min(256, len(data))]
+	return bytes.Contains(header, []byte("<svg")) || bytes.Contains(header, []byte("<?xml"))
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}