Centralize atomic artifact writes

internal/promptinput/package.go

@@ -2,14 +2,12 @@
 package promptinput
 
 import (
-	"encoding/json"
 	"fmt"
-	"os"
-	"path/filepath"
 	"time"
 
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/briefing"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/changes"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/fileutil"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/forecast"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
@@ -117,29 +115,8 @@ func Save(path string, pkg Package) error {
 	if err := Validate(pkg); err != nil {
 		return err
 	}
-	data, err := json.MarshalIndent(pkg, "", "  ")
-	if err != nil {
-		return fmt.Errorf("marshal data package: %w", err)
-	}
-	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
-		return fmt.Errorf("create data package directory %q: %w", filepath.Dir(path), err)
-	}
-	tmp, err := os.CreateTemp(filepath.Dir(path), "."+filepath.Base(path)+".*.tmp")
-	if err != nil {
-		return fmt.Errorf("create temporary data package file: %w", err)
-	}
-	tmpName := tmp.Name()
-	defer os.Remove(tmpName)
-
-	if _, err := tmp.Write(data); err != nil {
-		tmp.Close()
-		return fmt.Errorf("write temporary data package file: %w", err)
-	}
-	if err := tmp.Close(); err != nil {
-		return fmt.Errorf("close temporary data package file: %w", err)
-	}
-	if err := os.Rename(tmpName, path); err != nil {
-		return fmt.Errorf("save data package %q: %w", path, err)
+	if err := fileutil.WriteJSONAtomic(path, pkg); err != nil {
+		return fmt.Errorf("save data package: %w", err)
 	}
 	return nil
 }