Publish comparison bundles safely

internal/app/output.go

@@ -6,6 +6,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/comparison"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
 )
 
@@ -51,6 +52,35 @@ func resolveOutputDirWithConfigured(workingDir, override, configuredDir string)
 	return resolveOutputDir(workingDir, directory)
 }
 
+func resolveComparisonOutputDirectory(workingDir, override, configuredDir, reportOutputName string) (string, error) {
+	workingDir, err := validateWorkingDir(workingDir)
+	if err != nil {
+		return "", err
+	}
+	if override != "" {
+		return resolveComparisonDirectoryPath(workingDir, override)
+	}
+	outputDir, err := resolveOutputDir(workingDir, configuredDir)
+	if err != nil {
+		return "", err
+	}
+	name, err := comparison.DefaultDirectoryName(reportOutputName)
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(outputDir, name), nil
+}
+
+func resolveComparisonDirectoryPath(workingDir, directory string) (string, error) {
+	if strings.TrimSpace(directory) == "" {
+		return "", fmt.Errorf("comparison output directory is required")
+	}
+	if !filepath.IsAbs(directory) {
+		directory = filepath.Join(workingDir, directory)
+	}
+	return filepath.Clean(directory), nil
+}
+
 func resolveOutputDir(workingDir, override string) (string, error) {
 	workingDir, err := validateWorkingDir(workingDir)
 	if err != nil {