feat: add service-advisor for package boundary analysis

cmd/nightshift/commands/serviceadvisor.go

@@ -0,0 +1,151 @@
+package commands
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/spf13/cobra"
+
+	"github.com/marcus/nightshift/internal/analysis"
+	"github.com/marcus/nightshift/internal/config"
+	"github.com/marcus/nightshift/internal/db"
+	"github.com/marcus/nightshift/internal/logging"
+)
+
+var serviceAdvisorCmd = &cobra.Command{
+	Use:   "service-advisor [path]",
+	Short: "Analyze Go package structure for service boundary opportunities",
+	Long: `Analyze Go package structure to identify service boundary opportunities.
+
+Examines packages by coupling (afferent/efferent import ratios), cohesion
+(internal vs cross-package references), size (LOC/file count), and change
+coupling (git co-change frequency) to produce a ranked list of packages
+with extract/merge/keep recommendations.
+
+Metrics:
+  - Coupling: Import dependency connections (afferent + efferent)
+  - Cohesion: Internal references vs exported API surface
+  - Size: Lines of code relative to project total
+  - Churn: Co-change frequency from git history
+  - Extract-Worthiness: Composite score for service extraction potential`,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		path, err := cmd.Flags().GetString("path")
+		if err != nil {
+			return err
+		}
+
+		if path == "" && len(args) > 0 {
+			path = args[0]
+		}
+		if path == "" {
+			path, err = os.Getwd()
+			if err != nil {
+				return fmt.Errorf("getting current directory: %w", err)
+			}
+		}
+
+		jsonOutput, _ := cmd.Flags().GetBool("json")
+		saveReport, _ := cmd.Flags().GetBool("save")
+		dbPath, _ := cmd.Flags().GetString("db")
+		minLOC, _ := cmd.Flags().GetInt("min-loc")
+
+		return runServiceAdvisor(path, jsonOutput, saveReport, dbPath, minLOC)
+	},
+}
+
+func init() {
+	serviceAdvisorCmd.Flags().StringP("path", "p", "", "Repository or directory path")
+	serviceAdvisorCmd.Flags().Bool("json", false, "Output as JSON")
+	serviceAdvisorCmd.Flags().Bool("save", false, "Save results to database")
+	serviceAdvisorCmd.Flags().String("db", "", "Database path (uses config if not set)")
+	serviceAdvisorCmd.Flags().Int("min-loc", 10, "Minimum LOC threshold for package analysis")
+	rootCmd.AddCommand(serviceAdvisorCmd)
+}
+
+func runServiceAdvisor(path string, jsonOutput, saveReport bool, dbPath string, minLOC int) error {
+	logger := logging.Component("service-advisor")
+
+	absPath, err := filepath.Abs(path)
+	if err != nil {
+		return fmt.Errorf("resolving path: %w", err)
+	}
+
+	if !analysis.RepositoryExists(absPath) {
+		return fmt.Errorf("not a git repository: %s", absPath)
+	}
+
+	// Analyze packages
+	analyzer := analysis.NewServiceAnalyzer(absPath)
+	pkgs, err := analyzer.Analyze(minLOC)
+	if err != nil {
+		return fmt.Errorf("analyzing packages: %w", err)
+	}
+
+	if len(pkgs) == 0 {
+		logger.Warnf("no Go packages found in %s (above %d LOC threshold)", absPath, minLOC)
+		return nil
+	}
+
+	// Calculate metrics
+	analyses := analysis.CalculateServiceMetrics(pkgs)
+
+	// Generate report
+	gen := analysis.NewServiceReportGenerator()
+	component := filepath.Base(absPath)
+	report := gen.Generate(component, analyses)
+
+	// Output
+	if jsonOutput {
+		enc := json.NewEncoder(os.Stdout)
+		enc.SetIndent("", "  ")
+		return enc.Encode(report)
+	}
+
+	markdown := gen.RenderMarkdown(report)
+	fmt.Println(markdown)
+
+	// Save if requested
+	if saveReport {
+		if dbPath == "" {
+			cfg, err := config.Load()
+			if err != nil {
+				logger.Warnf("could not load config for db path: %v", err)
+			} else {
+				dbPath = cfg.ExpandedDBPath()
+			}
+		}
+
+		if dbPath != "" {
+			database, err := db.Open(dbPath)
+			if err != nil {
+				logger.Errorf("opening database: %v", err)
+			} else {
+				defer func() { _ = database.Close() }()
+
+				metrics := make([]analysis.ServiceMetrics, len(analyses))
+				for i, a := range analyses {
+					metrics[i] = a.Metrics
+				}
+
+				result := &analysis.ServiceAdvisorResult{
+					Component:       component,
+					Timestamp:       time.Now(),
+					Packages:        analyses,
+					Metrics:         metrics,
+					Recommendations: report.Recommendations,
+				}
+
+				if err := result.Store(database.SQL()); err != nil {
+					logger.Errorf("storing result: %v", err)
+				} else {
+					logger.Infof("results saved (ID: %d)", result.ID)
+				}
+			}
+		}
+	}
+
+	return nil
+}