viewer open image files

internal/viewer/input.go

@@ -9,6 +9,22 @@ import (
 	"strings"
 )
 
+var imageExtensions = map[string]bool{
+	".png":  true,
+	".jpg":  true,
+	".jpeg": true,
+	".gif":  true,
+	".bmp":  true,
+	".tiff": true,
+	".tif":  true,
+	".webp": true,
+	".svg":  true,
+}
+
+func isImageFile(path string) bool {
+	return imageExtensions[strings.ToLower(filepath.Ext(path))]
+}
+
 // viewer input parsing: decides whether to run the markdown viewer and resolves a
 // single positional argument into candidate sources. accepted inputs: "-" for
 // stdin, file paths, http(s) urls, and github/gitlab repo or file links.
@@ -22,6 +38,7 @@ const (
 	InputURL    InputKind = "url"
 	InputGitHub InputKind = "github"
 	InputGitLab InputKind = "gitlab"
+	InputImage  InputKind = "image"
 )
 
 // InputSpec carries the resolved input plus candidate URLs/paths to try.
@@ -142,8 +159,13 @@ func buildInputSpec(raw string) (InputSpec, error) {
 		return InputSpec{}, fmt.Errorf("resolve file path: %w", err)
 	}
 
+	kind := InputFile
+	if isImageFile(raw) {
+		kind = InputImage
+	}
+
 	return InputSpec{
-		Kind:        InputFile,
+		Kind:        kind,
 		Raw:         raw,
 		Candidates:  []string{absPath},
 		SearchRoots: []string{filepath.Dir(absPath)},

internal/viewer/input_test.go

@@ -140,6 +140,44 @@ func TestParseViewerInputInitReserved(t *testing.T) {
 	}
 }
 
+func TestIsImageFile(t *testing.T) {
+	for _, name := range []string{"photo.png", "photo.jpg", "photo.jpeg", "photo.gif", "photo.bmp", "photo.tiff", "photo.tif", "photo.webp", "photo.svg"} {
+		if !isImageFile(name) {
+			t.Errorf("expected %q to be detected as image", name)
+		}
+	}
+	for _, name := range []string{"PHOTO.PNG", "Photo.Jpg", "image.SVG"} {
+		if !isImageFile(name) {
+			t.Errorf("expected %q (mixed case) to be detected as image", name)
+		}
+	}
+	for _, name := range []string{"readme.md", "main.go", "data.json", "file.txt", "noext"} {
+		if isImageFile(name) {
+			t.Errorf("expected %q to NOT be detected as image", name)
+		}
+	}
+}
+
+func TestParseViewerInputImageFile(t *testing.T) {
+	spec, ok, err := ParseViewerInput([]string{"photo.png"}, map[string]struct{}{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if !ok {
+		t.Fatalf("expected viewer mode")
+	}
+	if spec.Kind != InputImage {
+		t.Fatalf("expected image input, got %s", spec.Kind)
+	}
+	abs, err := filepath.Abs("photo.png")
+	if err != nil {
+		t.Fatalf("abs path error: %v", err)
+	}
+	if len(spec.Candidates) != 1 || spec.Candidates[0] != abs {
+		t.Fatalf("unexpected candidates: %v", spec.Candidates)
+	}
+}
+
 func TestParseViewerInputUnknownFlag(t *testing.T) {
 	_, ok, err := ParseViewerInput([]string{"--verson"}, map[string]struct{}{})
 	if !errors.Is(err, ErrUnknownFlag) {

internal/viewer/markdown_viewer.go

@@ -127,6 +127,12 @@ func loadInitialContent(input InputSpec, provider *loaders.FileHTTP) (string, st
 		return "", "", fmt.Errorf("no input candidates provided")
 	}
 
+	// image files: wrap in synthetic markdown so the image pipeline renders them
+	if input.Kind == InputImage || (input.Kind == InputURL && isImageFile(input.Raw)) {
+		src := input.Candidates[0]
+		return fmt.Sprintf("![%s](%s)\n", filepath.Base(src), src), src, nil
+	}
+
 	var lastErr error
 	for _, candidate := range input.Candidates {
 		content, err := provider.FetchContent(nav.NavElement{URL: candidate})

main.go

@@ -138,7 +138,7 @@ func printUsage() {
 Usage:
   tiki                  Launch TUI in initialized repo
   tiki init             Initialize project in current git repo
-  tiki file.md/URL      View markdown file
+  tiki file.md/URL      View markdown file or image
   echo "Title" | tiki   Create task from piped input
   tiki sysinfo          Display system information
   tiki --version        Show version