Implement SQLite database persistence for instance management

cmd/server/migrate_json.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"llamactl/pkg/config"
+	"llamactl/pkg/database"
+	"llamactl/pkg/instance"
+	"log"
+	"os"
+	"path/filepath"
+)
+
+// migrateFromJSON migrates instances from JSON files to SQLite database
+// This is a one-time migration that runs on first startup with existing JSON files.
+//
+// TODO: This migration code can be removed in a future version (post-1.0)
+// once most users have migrated from JSON to SQLite.
+func migrateFromJSON(cfg *config.AppConfig, db database.Database) error {
+	instancesDir := cfg.Instances.InstancesDir
+	if instancesDir == "" {
+		return nil // No instances directory configured
+	}
+
+	// Check if instances directory exists
+	if _, err := os.Stat(instancesDir); os.IsNotExist(err) {
+		return nil // No instances directory, nothing to migrate
+	}
+
+	// Check if database is empty (no instances)
+	existing, err := db.LoadAll()
+	if err != nil {
+		return fmt.Errorf("failed to check existing instances: %w", err)
+	}
+
+	if len(existing) > 0 {
+		return nil // Database already has instances, skip migration
+	}
+
+	// Find all JSON files
+	files, err := filepath.Glob(filepath.Join(instancesDir, "*.json"))
+	if err != nil {
+		return fmt.Errorf("failed to list instance files: %w", err)
+	}
+
+	if len(files) == 0 {
+		return nil // No JSON files to migrate
+	}
+
+	log.Printf("Migrating %d instances from JSON to SQLite...", len(files))
+
+	// Migrate each JSON file
+	var migrated int
+	for _, file := range files {
+		if err := migrateJSONFile(file, db); err != nil {
+			log.Printf("Failed to migrate %s: %v", file, err)
+			continue
+		}
+		migrated++
+	}
+
+	log.Printf("Successfully migrated %d/%d instances to SQLite", migrated, len(files))
+
+	// Archive old JSON files
+	if migrated > 0 {
+		archiveDir := filepath.Join(instancesDir, "json_archive")
+		if err := os.MkdirAll(archiveDir, 0755); err == nil {
+			for _, file := range files {
+				newPath := filepath.Join(archiveDir, filepath.Base(file))
+				if err := os.Rename(file, newPath); err != nil {
+					log.Printf("Failed to archive %s: %v", file, err)
+				}
+			}
+			log.Printf("Archived old JSON files to %s", archiveDir)
+		}
+	}
+
+	return nil
+}
+
+// migrateJSONFile migrates a single JSON file to the database
+func migrateJSONFile(filename string, db database.Database) error {
+	data, err := os.ReadFile(filename)
+	if err != nil {
+		return fmt.Errorf("failed to read file: %w", err)
+	}
+
+	var inst instance.Instance
+	if err := json.Unmarshal(data, &inst); err != nil {
+		return fmt.Errorf("failed to unmarshal instance: %w", err)
+	}
+
+	if err := db.Save(&inst); err != nil {
+		return fmt.Errorf("failed to save instance to database: %w", err)
+	}
+
+	log.Printf("Migrated instance %s from JSON to SQLite", inst.Name)
+	return nil
+}