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

internal/database/interface.go

@@ -0,0 +1,133 @@
+package database
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	"dbbackup/internal/config"
+	"dbbackup/internal/logger"
+	
+	_ "github.com/lib/pq"           // PostgreSQL driver
+	_ "github.com/go-sql-driver/mysql" // MySQL driver
+)
+
+// Database represents a database connection and operations
+type Database interface {
+	// Connection management
+	Connect(ctx context.Context) error
+	Close() error
+	Ping(ctx context.Context) error
+	
+	// Database discovery
+	ListDatabases(ctx context.Context) ([]string, error)
+	ListTables(ctx context.Context, database string) ([]string, error)
+	
+	// Database operations
+	CreateDatabase(ctx context.Context, name string) error
+	DropDatabase(ctx context.Context, name string) error
+	DatabaseExists(ctx context.Context, name string) (bool, error)
+	
+	// Information
+	GetVersion(ctx context.Context) (string, error)
+	GetDatabaseSize(ctx context.Context, database string) (int64, error)
+	GetTableRowCount(ctx context.Context, database, table string) (int64, error)
+	
+	// Backup/Restore command building
+	BuildBackupCommand(database, outputFile string, options BackupOptions) []string
+	BuildRestoreCommand(database, inputFile string, options RestoreOptions) []string
+	BuildSampleQuery(database, table string, strategy SampleStrategy) string
+	
+	// Validation
+	ValidateBackupTools() error
+}
+
+// BackupOptions holds options for backup operations
+type BackupOptions struct {
+	Compression     int
+	Parallel        int
+	Format          string  // "custom", "plain", "directory"
+	Blobs          bool
+	SchemaOnly     bool
+	DataOnly       bool
+	NoOwner        bool
+	NoPrivileges   bool
+	Clean          bool
+	IfExists       bool
+	Role           string
+}
+
+// RestoreOptions holds options for restore operations
+type RestoreOptions struct {
+	Parallel     int
+	Clean        bool
+	IfExists     bool
+	NoOwner      bool
+	NoPrivileges bool
+	SingleTransaction bool
+}
+
+// SampleStrategy defines how to sample data
+type SampleStrategy struct {
+	Type  string // "ratio", "percent", "count"
+	Value int
+}
+
+// DatabaseInfo holds database metadata
+type DatabaseInfo struct {
+	Name         string
+	Size         int64
+	Owner        string
+	Encoding     string
+	Collation    string
+	Tables       []TableInfo
+}
+
+// TableInfo holds table metadata
+type TableInfo struct {
+	Schema   string
+	Name     string
+	RowCount int64
+	Size     int64
+}
+
+// New creates a new database instance based on configuration
+func New(cfg *config.Config, log logger.Logger) (Database, error) {
+	if cfg.IsPostgreSQL() {
+		return NewPostgreSQL(cfg, log), nil
+	} else if cfg.IsMySQL() {
+		return NewMySQL(cfg, log), nil
+	}
+	return nil, fmt.Errorf("unsupported database type: %s", cfg.DatabaseType)
+}
+
+// Common database implementation
+type baseDatabase struct {
+	cfg  *config.Config
+	log  logger.Logger
+	db   *sql.DB
+	dsn  string
+}
+
+func (b *baseDatabase) Close() error {
+	if b.db != nil {
+		return b.db.Close()
+	}
+	return nil
+}
+
+func (b *baseDatabase) Ping(ctx context.Context) error {
+	if b.db == nil {
+		return fmt.Errorf("database not connected")
+	}
+	return b.db.PingContext(ctx)
+}
+
+// buildTimeout creates a context with timeout for database operations
+func buildTimeout(ctx context.Context, timeout time.Duration) (context.Context, context.CancelFunc) {
+	if timeout <= 0 {
+		timeout = 30 * time.Second
+	}
+	return context.WithTimeout(ctx, timeout)
+}