optional author and avatar params

internal/preview/preview.go

@@ -23,12 +23,15 @@ const (
 	maxTitleLength    = 90
 	defaultBgColor    = "#FFFFFF"
 	avatarBorderColor = "#FFFFFF"
+	logoKey           = "logo"
+	avaKey            = "avatar"
+	bgKey             = "bg"
 )
 
 var hexRe = regexp.MustCompile("^#(?:[0-9a-fA-F]{3}){1,2}$")
 
 type getter interface {
-	GetAll(context.Context, []string) ([][]byte, error)
+	GetAll(context.Context, map[string]string) (map[string][]byte, error)
 }
 
 // Options defines a set of options required to draw a p.ctx.
@@ -87,13 +90,17 @@ func (p *Preview) Draw(ctx context.Context, opts Options) (image.Image, error) {
 	p.opts = &opts
 	p.ctx = gg.NewContext(opts.CanvasW, opts.CanvasH)
 	bgColor := defaultBgColor
-	urlsOrPaths := []string{opts.AvaURL, opts.LogoURL}
 	isBgHEX := hexRe.Match([]byte(p.opts.Bg))
+	urlsOrPaths := map[string]string{logoKey: p.opts.LogoURL}
+
+	if opts.AvaURL != "" {
+		urlsOrPaths[avaKey] = p.opts.AvaURL
+	}
 
 	if isBgHEX {
 		bgColor = p.opts.Bg
 	} else if p.opts.Bg != "" {
-		urlsOrPaths = append(urlsOrPaths, p.opts.Bg)
+		urlsOrPaths[bgKey] = p.opts.Bg
 	}
 
 	imgBufs, err := p.remote.GetAll(ctx, urlsOrPaths)
@@ -107,7 +114,7 @@ func (p *Preview) Draw(ctx context.Context, opts Options) (image.Image, error) {
 			return nil, err
 		}
 	} else {
-		if err := p.drawBackground(imgBufs[2], bgColor); err != nil {
+		if err := p.drawBackground(imgBufs[bgKey], bgColor); err != nil {
 			return nil, err
 		}
 	}
@@ -116,8 +123,10 @@ func (p *Preview) Draw(ctx context.Context, opts Options) (image.Image, error) {
 		return nil, err
 	}
 
-	if err := p.drawAvatar(imgBufs[0]); err != nil {
-		return nil, err
+	if _, exists := imgBufs[avaKey]; exists {
+		if err := p.drawAvatar(imgBufs[avaKey]); err != nil {
+			return nil, err
+		}
 	}
 
 	if err := p.drawAuthor(); err != nil {
@@ -128,7 +137,7 @@ func (p *Preview) Draw(ctx context.Context, opts Options) (image.Image, error) {
 		return nil, err
 	}
 
-	if err := p.drawLogo(imgBufs[1]); err != nil {
+	if err := p.drawLogo(imgBufs[logoKey]); err != nil {
 		return nil, err
 	}
 
@@ -199,6 +208,10 @@ func (p *Preview) drawAvatar(avaBuf []byte) error {
 }
 
 func (p *Preview) drawAuthor() error {
+	if p.opts.Author == "" {
+		return nil
+	}
+
 	font, err := loadFont(p.opts.AuthorSize)
 
 	if err != nil {

internal/remote/remote.go

@@ -76,26 +76,26 @@ func (r *Remote) Get(ctx context.Context, urlOrPath string) (buf []byte, err err
 }
 
 // GetAll fetches remote resources concurrently using Get
-func (r *Remote) GetAll(ctx context.Context, urlsOrPaths []string) ([][]byte, error) {
-	bufs := make([][]byte, len(urlsOrPaths))
+func (r *Remote) GetAll(ctx context.Context, urlsOrPaths map[string]string) (map[string][]byte, error) {
+	bufs := make(map[string][]byte, len(urlsOrPaths))
 	errCh := make(chan error)
 	doneCh := make(chan bool)
 	var wg sync.WaitGroup
 
 	wg.Add(len(urlsOrPaths))
 
-	for i, urlOrPath := range urlsOrPaths {
-		go func(i int, urlOrPath string) {
+	for key, urlOrPath := range urlsOrPaths {
+		go func(key string, urlOrPath string) {
 			buf, err := r.Get(ctx, urlOrPath)
 
 			if err != nil {
 				errCh <- err
 			}
 
-			bufs[i] = buf
+			bufs[key] = buf
 
 			wg.Done()
-		}(i, urlOrPath)
+		}(key, urlOrPath)
 	}
 
 	go func() {

internal/server/handlers.go

@@ -50,13 +50,12 @@ func getPreview(d drawer) http.HandlerFunc {
 
 		authorParam := r.URL.Query().Get("author")
 
-		if authorParam == "" {
-			handleBadRequest(w, errors.New("Missing required author parameter"))
-			return
+		if authorParam != "" {
+			opts.Author = authorParam
+		} else {
+			opts.AvaD = 0
 		}
 
-		opts.Author = authorParam
-
 		bgParam := r.URL.Query().Get("bg")
 
 		if bgParam != "" {
@@ -65,13 +64,12 @@ func getPreview(d drawer) http.HandlerFunc {
 
 		avaParam := r.URL.Query().Get("ava")
 
-		if avaParam == "" {
-			handleBadRequest(w, errors.New("Missing required ava parameter"))
-			return
+		if avaParam != "" {
+			opts.AvaURL = avaParam
+		} else {
+			opts.AuthorSize = 0
 		}
 
-		opts.AvaURL = avaParam
-
 		logoParam := r.URL.Query().Get("logo")
 
 		if logoParam == "" {

internal/server/handlers_test.go

@@ -39,6 +39,10 @@ func TestGetPreviewHandler_Success(t *testing.T) {
 		name:     "basic",
 		req:      "/preview?title=The%20quick%20brown%20fox%20jumps%20over%20the%20lazy%20dog&author=%40Tester&ava=avatar.png&logo=logo.png",
 		expected: "./testdata/expected/basic.jpeg",
+	}, {
+		name:     "no author",
+		req:      "/preview?title=The%20quick%20brown%20fox%20jumps%20over%20the%20lazy%20dog&logo=logo.png",
+		expected: "./testdata/expected/no-author.jpeg",
 	}, {
 		name:     "opacity",
 		req:      "/preview?title=The%20quick%20brown%20fox%20jumps%20over%20the%20lazy%20dog&author=%40Tester&ava=avatar.png&logo=logo.png&op=0.5",
@@ -92,14 +96,6 @@ func TestGetPreviewHandler_Bad(t *testing.T) {
 		name:     "title",
 		req:      "/preview?author=%40Tester&ava=avatar.png&logo=logo.png",
 		expected: "Missing required title parameter",
-	}, {
-		name:     "author",
-		req:      "/preview?title=The%20quick%20brown%20fox%20jumps%20over%20the%20lazy%20dog&ava=avatar.png&logo=logo.png",
-		expected: "Missing required author parameter",
-	}, {
-		name:     "ava",
-		req:      "/preview?title=The%20quick%20brown%20fox%20jumps%20over%20the%20lazy%20dog&author=%40Tester&logo=logo.png",
-		expected: "Missing required ava parameter",
 	}, {
 		name:     "logo",
 		req:      "/preview?title=The%20quick%20brown%20fox%20jumps%20over%20the%20lazy%20dog&author=%40Tester&ava=avatar.png",

requests.http

@@ -15,3 +15,8 @@ GET http://localhost:8201/preview?title=The%20quick%20brown%20fox%20jumps%20over
 
 # only local and already resized images, color background
 GET http://localhost:8201/preview?title=The%20quick%20brown%20fox%20jumps%20over%20the%20lazy%20dog.%20Sphinx%20of%20black%20quartz%2C%20judge%20my%20vow&author=%40DmitryNikitenko&bg=%23FFA&ava=avatar.png&logo=logo.png&op=0.5
+
+###
+
+# hidden author section
+GET http://localhost:8201/preview?title=The%20quick%20brown%20fox%20jumps%20over%20the%20lazy%20dog&logo=logo.png