feat(backend): some member routes, half-broken avatar uploading

backend/db/avatars.go

@@ -0,0 +1,166 @@
+package db
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"io"
+	"os/exec"
+	"strings"
+
+	"emperror.dev/errors"
+	"github.com/minio/minio-go/v7"
+	"github.com/rs/xid"
+)
+
+var (
+	webpArgs = []string{"-quality", "50", "webp:-"}
+	jpgArgs  = []string{"-quality", "50", "jpg:-"}
+)
+
+const ErrInvalidDataURI = errors.Sentinel("invalid data URI")
+const ErrInvalidContentType = errors.Sentinel("invalid avatar content type")
+
+// ConvertAvatar parses an avatar from a data URI, converts it to WebP and JPEG, and returns the results.
+func (db *DB) ConvertAvatar(data string) (
+	webp io.Reader,
+	jpg io.Reader,
+	err error,
+) {
+	data = strings.TrimSpace(data)
+	if !strings.Contains(data, ",") || !strings.Contains(data, ":") || !strings.Contains(data, ";") {
+		return nil, nil, ErrInvalidDataURI
+	}
+	split := strings.Split(data, ",")
+	rest, b64 := split[0], split[1]
+
+	rest = strings.Split(rest, ":")[1]
+	contentType := strings.Split(rest, ";")[0]
+
+	var contentArg []string
+	switch contentType {
+	case "image/png":
+		contentArg = []string{"png:-"}
+	case "image/jpeg":
+		contentArg = []string{"jpg:-"}
+	case "image/gif":
+		contentArg = []string{"gif:-"}
+	case "image/webp":
+		contentArg = []string{"webp:-"}
+	default:
+		return nil, nil, ErrInvalidContentType
+	}
+
+	rawData, err := base64.StdEncoding.DecodeString(b64)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "invalid base64 data")
+	}
+
+	// create webp convert command and get its pipes
+	webpConvert := exec.Command("convert", append(contentArg, webpArgs...)...)
+	stdIn, err := webpConvert.StdinPipe()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "getting webp stdin")
+	}
+	stdOut, err := webpConvert.StdoutPipe()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "getting webp stdout")
+	}
+
+	// start webp command
+	err = webpConvert.Start()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "starting webp command")
+	}
+
+	// write data
+	_, err = stdIn.Write(rawData)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "writing webp data")
+	}
+	err = stdIn.Close()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "closing webp stdin")
+	}
+
+	// read webp output
+	webpBuffer := new(bytes.Buffer)
+	_, err = io.Copy(webpBuffer, stdOut)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "reading webp data")
+	}
+	webp = webpBuffer
+
+	// finish webp command
+	err = webpConvert.Wait()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "running webp command")
+	}
+
+	// create jpg convert command and get its pipes
+	jpgConvert := exec.Command("convert", append(contentArg, jpgArgs...)...)
+	stdIn, err = jpgConvert.StdinPipe()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "getting jpg stdin")
+	}
+	stdOut, err = jpgConvert.StdoutPipe()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "getting jpg stdout")
+	}
+
+	// start jpg command
+	err = jpgConvert.Start()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "starting jpg command")
+	}
+
+	// write data
+	_, err = stdIn.Write(rawData)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "writing jpg data")
+	}
+	err = stdIn.Close()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "closing jpg stdin")
+	}
+
+	// read jpg output
+	jpgBuffer := new(bytes.Buffer)
+	_, err = io.Copy(jpgBuffer, stdOut)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "reading jpg data")
+	}
+	jpg = jpgBuffer
+
+	// finish jpg command
+	err = jpgConvert.Wait()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "running jpg command")
+	}
+
+	return webp, jpg, nil
+}
+
+func (db *DB) WriteUserAvatar(ctx context.Context,
+	userID xid.ID, webp io.Reader, jpeg io.Reader,
+) (
+	webpLocation string,
+	jpegLocation string,
+	err error,
+) {
+	webpInfo, err := db.minio.PutObject(ctx, db.minioBucket, "/users/"+userID.String()+".webp", webp, -1, minio.PutObjectOptions{
+		ContentType: "image/webp",
+	})
+	if err != nil {
+		return "", "", errors.Wrap(err, "uploading webp avatar")
+	}
+
+	jpegInfo, err := db.minio.PutObject(ctx, db.minioBucket, "/users/"+userID.String()+".jpg", jpeg, -1, minio.PutObjectOptions{
+		ContentType: "image/jpeg",
+	})
+	if err != nil {
+		return "", "", errors.Wrap(err, "uploading jpeg avatar")
+	}
+
+	return webpInfo.Location, jpegInfo.Location, nil
+}