Initial commit: Database Backup Tool v1.1.0

- PostgreSQL and MySQL support
- Interactive TUI with fixed menu navigation
- Line-by-line progress display
- CPU-aware parallel processing
- Cross-platform build support
- Configuration settings menu
- Silent mode for TUI operations

cmd/backup.go

@@ -0,0 +1,129 @@
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+// backupCmd represents the backup command
+var backupCmd = &cobra.Command{
+	Use:   "backup",
+	Short: "Create database backups",
+	Long: `Create database backups with support for various modes:
+
+Backup Modes:
+  cluster    - Full cluster backup (all databases + globals) [PostgreSQL only]
+  single     - Single database backup
+  sample     - Sample database backup (reduced dataset)
+
+Examples:
+  # Full cluster backup (PostgreSQL)
+  dbbackup backup cluster --db-type postgres
+
+  # Single database backup
+  dbbackup backup single mydb --db-type postgres
+  dbbackup backup single mydb --db-type mysql
+
+  # Sample database backup
+  dbbackup backup sample mydb --sample-ratio 10 --db-type postgres`,
+}
+
+var clusterCmd = &cobra.Command{
+	Use:   "cluster",
+	Short: "Create full cluster backup (PostgreSQL only)",
+	Long:  `Create a complete backup of the entire PostgreSQL cluster including all databases and global objects (roles, tablespaces, etc.)`,
+	Args:  cobra.NoArgs,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		return runClusterBackup(cmd.Context())
+	},
+}
+
+var singleCmd = &cobra.Command{
+	Use:   "single [database]",
+	Short: "Create single database backup",
+	Long:  `Create a backup of a single database with all its data and schema`,
+	Args:  cobra.MaximumNArgs(1),
+	RunE: func(cmd *cobra.Command, args []string) error {
+		dbName := ""
+		if len(args) > 0 {
+			dbName = args[0]
+		} else if cfg.SingleDBName != "" {
+			dbName = cfg.SingleDBName
+		} else {
+			return fmt.Errorf("database name required (provide as argument or set SINGLE_DB_NAME)")
+		}
+		
+		return runSingleBackup(cmd.Context(), dbName)
+	},
+}
+
+var sampleCmd = &cobra.Command{
+	Use:   "sample [database]",
+	Short: "Create sample database backup",
+	Long: `Create a sample database backup with reduced dataset for testing/development.
+
+Sampling Strategies:
+  --sample-ratio N     - Take every Nth record (e.g., 10 = every 10th record)
+  --sample-percent N   - Take N% of records (e.g., 20 = 20% of data)  
+  --sample-count N     - Take first N records from each table
+
+Warning: Sample backups may break referential integrity due to sampling!`,
+	Args: cobra.MaximumNArgs(1),
+	RunE: func(cmd *cobra.Command, args []string) error {
+		dbName := ""
+		if len(args) > 0 {
+			dbName = args[0]
+		} else if cfg.SingleDBName != "" {
+			dbName = cfg.SingleDBName
+		} else {
+			return fmt.Errorf("database name required (provide as argument or set SAMPLE_DB_NAME)")
+		}
+		
+		return runSampleBackup(cmd.Context(), dbName)
+	},
+}
+
+func init() {
+	// Add backup subcommands
+	backupCmd.AddCommand(clusterCmd)
+	backupCmd.AddCommand(singleCmd)
+	backupCmd.AddCommand(sampleCmd)
+	
+	// Sample backup flags - use local variables to avoid cfg access during init
+	var sampleStrategy string
+	var sampleValue int
+	var sampleRatio int
+	var samplePercent int
+	var sampleCount int
+	
+	sampleCmd.Flags().StringVar(&sampleStrategy, "sample-strategy", "ratio", "Sampling strategy (ratio|percent|count)")
+	sampleCmd.Flags().IntVar(&sampleValue, "sample-value", 10, "Sampling value")
+	sampleCmd.Flags().IntVar(&sampleRatio, "sample-ratio", 0, "Take every Nth record")
+	sampleCmd.Flags().IntVar(&samplePercent, "sample-percent", 0, "Take N% of records")
+	sampleCmd.Flags().IntVar(&sampleCount, "sample-count", 0, "Take first N records")
+	
+	// Set up pre-run hook to handle convenience flags and update cfg
+	sampleCmd.PreRunE = func(cmd *cobra.Command, args []string) error {
+		// Update cfg with flag values
+		if cmd.Flags().Changed("sample-ratio") && sampleRatio > 0 {
+			cfg.SampleStrategy = "ratio"
+			cfg.SampleValue = sampleRatio
+		} else if cmd.Flags().Changed("sample-percent") && samplePercent > 0 {
+			cfg.SampleStrategy = "percent"
+			cfg.SampleValue = samplePercent
+		} else if cmd.Flags().Changed("sample-count") && sampleCount > 0 {
+			cfg.SampleStrategy = "count"
+			cfg.SampleValue = sampleCount
+		} else if cmd.Flags().Changed("sample-strategy") {
+			cfg.SampleStrategy = sampleStrategy
+		}
+		if cmd.Flags().Changed("sample-value") {
+			cfg.SampleValue = sampleValue
+		}
+		return nil
+	}
+	
+	// Mark the strategy flags as mutually exclusive
+	sampleCmd.MarkFlagsMutuallyExclusive("sample-ratio", "sample-percent", "sample-count")
+}