feat: implement export and import commands

- Add export command with JSON file output and size summary
- Add import command with replace/merge strategies and dry-run preview
- Add integration test for export/import round-trip via storage layer
- Update project state documentation

cmd/hostkeeper/export.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+
+	"git.tukangketik.id/swanadiva/hostkeeper/pkg/config"
+	"git.tukangketik.id/swanadiva/hostkeeper/pkg/storage"
+)
+
+var (
+	exportFormat     string
+	exportIncludeKeys bool
+)
+
+// exportCmd represents the export command
+var exportCmd = &cobra.Command{
+	Use:   "export [filename]",
+	Short: "Export hosts and credentials to file",
+	Long: `Export all saved hosts, SSH keys, snippets to a file for backup or transfer.
+
+Examples:
+  # Export to default file
+  hostkeeper export my-backup
+
+  # Export with .json extension
+  hostkeeper export my-backup.json`,
+	Args: cobra.ExactArgs(1),
+	RunE: runExport,
+}
+
+func init() {
+	exportCmd.Flags().StringVar(&exportFormat, "format", "json", "Export format (json)")
+	exportCmd.Flags().BoolVar(&exportIncludeKeys, "include-keys", true, "Include SSH keys in export")
+
+	rootCmd.AddCommand(exportCmd)
+}
+
+func runExport(cmd *cobra.Command, args []string) error {
+	filename := args[0]
+
+	if filepath.Ext(filename) != ".json" {
+		filename = filename + ".json"
+	}
+
+	cfg := appCfg
+	if cfg == nil {
+		var err error
+		cfg, err = config.New()
+		if err != nil {
+			return fmt.Errorf("failed to initialize config: %w", err)
+		}
+	}
+
+	store, err := storage.NewJSONStorage(cfg.GetDataDir())
+	if err != nil {
+		return fmt.Errorf("failed to initialize storage: %w", err)
+	}
+
+	ctx := context.Background()
+
+	data, err := store.ExportData(ctx)
+	if err != nil {
+		return fmt.Errorf("failed to export data: %w", err)
+	}
+
+	jsonBytes, err := json.MarshalIndent(data, "", "  ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal export data: %w", err)
+	}
+
+	if err := os.WriteFile(filename, jsonBytes, 0600); err != nil {
+		return fmt.Errorf("failed to write export file: %w", err)
+	}
+
+	fmt.Printf("Export successful!\n")
+	fmt.Printf("  File: %s\n", filename)
+	fmt.Printf("  Hosts: %d\n", len(data.Hosts))
+	fmt.Printf("  Keys: %d\n", len(data.KeyPairs))
+	fmt.Printf("  Snippets: %d\n", len(data.Snippets))
+	fmt.Printf("  Size: %.2f KB\n", float64(len(jsonBytes))/1024)
+
+	return nil
+}

cmd/hostkeeper/import.go

@@ -0,0 +1,128 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"git.tukangketik.id/swanadiva/hostkeeper/pkg/config"
+	"git.tukangketik.id/swanadiva/hostkeeper/pkg/storage"
+)
+
+var (
+	importMergeStrategy string
+	importDryRun        bool
+)
+
+// importCmd represents the import command
+var importCmd = &cobra.Command{
+	Use:   "import <filename>",
+	Short: "Import hosts and credentials from file",
+	Long: `Import hosts, SSH keys, snippets from a previously exported file.
+
+Merge strategies:
+  replace  Replace all existing data with imported data
+  merge    Keep existing data, add only new items
+
+Examples:
+  # Import with merge (default)
+  hostkeeper import my-backup.json
+
+  # Import replacing all existing data
+  hostkeeper import my-backup.json --strategy replace
+
+  # Preview without importing
+  hostkeeper import my-backup.json --dry-run`,
+	Args: cobra.ExactArgs(1),
+	RunE: runImport,
+}
+
+func init() {
+	importCmd.Flags().StringVar(&importMergeStrategy, "strategy", "merge", "Merge strategy: replace or merge")
+	importCmd.Flags().BoolVar(&importDryRun, "dry-run", false, "Show what would be imported without actually importing")
+
+	rootCmd.AddCommand(importCmd)
+}
+
+func runImport(cmd *cobra.Command, args []string) error {
+	filename := args[0]
+
+	if _, err := os.Stat(filename); os.IsNotExist(err) {
+		return fmt.Errorf("file not found: %s", filename)
+	}
+
+	jsonBytes, err := os.ReadFile(filename)
+	if err != nil {
+		return fmt.Errorf("failed to read import file: %w", err)
+	}
+
+	var data storage.ExportData
+	if err := json.Unmarshal(jsonBytes, &data); err != nil {
+		return fmt.Errorf("failed to parse import file: %w", err)
+	}
+
+	cfg := appCfg
+	if cfg == nil {
+		var err error
+		cfg, err = config.New()
+		if err != nil {
+			return fmt.Errorf("failed to initialize config: %w", err)
+		}
+	}
+
+	store, err := storage.NewJSONStorage(cfg.GetDataDir())
+	if err != nil {
+		return fmt.Errorf("failed to initialize storage: %w", err)
+	}
+
+	ctx := context.Background()
+
+	if importDryRun {
+		return previewImport(&data, filename)
+	}
+
+	// Map strategy string to MergeStrategy type
+	var strategy storage.MergeStrategy
+	switch importMergeStrategy {
+	case "replace":
+		strategy = storage.MergeStrategyReplace
+	case "merge":
+		strategy = storage.MergeStrategyMerge
+	default:
+		return fmt.Errorf("invalid strategy: %s (use 'replace' or 'merge')", importMergeStrategy)
+	}
+
+	if err := store.ImportData(ctx, &data, strategy); err != nil {
+		return fmt.Errorf("failed to import data: %w", err)
+	}
+
+	hosts, _ := store.ListHosts(ctx)
+	keys, _ := store.ListKeyPairs(ctx)
+	snippets, _ := store.ListSnippets(ctx)
+
+	fmt.Printf("Import successful!\n")
+	fmt.Printf("  Strategy: %s\n", importMergeStrategy)
+	fmt.Printf("  Total Hosts: %d\n", len(hosts))
+	fmt.Printf("  Total Keys: %d\n", len(keys))
+	fmt.Printf("  Total Snippets: %d\n", len(snippets))
+
+	return nil
+}
+
+func previewImport(data *storage.ExportData, filename string) error {
+	fmt.Println("Import Preview (Dry Run)")
+	fmt.Println("------------------------")
+	fmt.Printf("File: %s\n", filename)
+	fmt.Printf("Hosts: %d\n", len(data.Hosts))
+	fmt.Printf("Keys: %d\n", len(data.KeyPairs))
+	fmt.Printf("Snippets: %d\n", len(data.Snippets))
+	fmt.Printf("Strategy: %s\n\n", importMergeStrategy)
+
+	fmt.Println("To perform the import, run:")
+	fmt.Printf("  hostkeeper import %s --strategy %s\n", filename, importMergeStrategy)
+
+	return nil
+}