| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package dbdriver |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "database/sql" |
| 8 | "fmt" |
| 9 | "slices" |
| 10 | "sync" |
| 11 | ) |
| 12 | |
| 13 | // Driver represents a database driver with its capabilities |
| 14 | type Driver struct { |
| 15 | Name string |
| 16 | Description string |
| 17 | Available bool |
| 18 | RequiresCGO bool |
| 19 | RequiresLibs []string // Required system libraries |
| 20 | DSNFormat string // Example DSN format |
| 21 | } |
| 22 | |
| 23 | // Registry manages available database drivers |
| 24 | type Registry struct { |
| 25 | mu sync.RWMutex |
| 26 | drivers map[string]*Driver |
| 27 | } |
| 28 | |
| 29 | var defaultRegistry = &Registry{ |
| 30 | drivers: make(map[string]*Driver), |
| 31 | } |
| 32 | |
| 33 | // DBConnection wraps database connection with driver info |
| 34 | type DBConnection struct { |
| 35 | *sql.DB |
| 36 | Driver string |
| 37 | DSN string // Sanitized DSN for logging |
| 38 | DriverInfo *Driver |
| 39 | } |
| 40 | |
| 41 | // Register adds a driver to the registry |
| 42 | func Register(name string, driver *Driver) { |
| 43 | defaultRegistry.mu.Lock() |
| 44 | defer defaultRegistry.mu.Unlock() |
| 45 | defaultRegistry.drivers[name] = driver |
| 46 | } |
| 47 | |
| 48 | // GetAvailableDrivers returns list of available drivers |
| 49 | func GetAvailableDrivers() []string { |
| 50 | defaultRegistry.mu.RLock() |
| 51 | defer defaultRegistry.mu.RUnlock() |
| 52 | |
| 53 | var available []string |
| 54 | for name, driver := range defaultRegistry.drivers { |
| 55 | if driver.Available { |
| 56 | available = append(available, name) |
| 57 | } |
| 58 | } |
| 59 | return available |
| 60 | } |
| 61 | |
| 62 | // IsDriverAvailable checks if a specific driver is available |
| 63 | func IsDriverAvailable(name string) bool { |
| 64 | defaultRegistry.mu.RLock() |
| 65 | defer defaultRegistry.mu.RUnlock() |
| 66 | |
| 67 | if driver, exists := defaultRegistry.drivers[name]; exists { |
| 68 | return driver.Available |
| 69 | } |
| 70 | return false |
| 71 | } |
| 72 | |
| 73 | // GetDriverInfo returns information about a specific driver |
| 74 | func GetDriverInfo(name string) *Driver { |
| 75 | defaultRegistry.mu.RLock() |
| 76 | defer defaultRegistry.mu.RUnlock() |
| 77 | |
| 78 | if driver, exists := defaultRegistry.drivers[name]; exists { |
| 79 | return driver |
| 80 | } |
| 81 | return nil |
| 82 | } |
| 83 | |
| 84 | // Connect creates a database connection using the best available driver |
| 85 | func Connect(ctx context.Context, config *ConnectionConfig) (*DBConnection, error) { |
| 86 | // Determine which driver to use |
| 87 | driverName, dsn, err := determineDriver(config) |
| 88 | if err != nil { |
| 89 | return nil, err |
| 90 | } |
| 91 | |
| 92 | // Get driver info |
| 93 | driverInfo := GetDriverInfo(driverName) |
| 94 | if driverInfo == nil || !driverInfo.Available { |
| 95 | return nil, fmt.Errorf("driver %s not available", driverName) |
| 96 | } |
| 97 | |
| 98 | // Open database connection |
| 99 | db, err := sql.Open(driverName, dsn) |
| 100 | if err != nil { |
| 101 | return nil, fmt.Errorf("failed to open database with %s: %w", driverName, err) |
| 102 | } |
| 103 | |
| 104 | // Configure connection pool |
| 105 | if config.MaxOpenConns > 0 { |
| 106 | db.SetMaxOpenConns(config.MaxOpenConns) |
| 107 | } |
| 108 | if config.MaxIdleConns > 0 { |
| 109 | db.SetMaxIdleConns(config.MaxIdleConns) |
| 110 | } |
| 111 | if config.ConnMaxLifetime > 0 { |
| 112 | db.SetConnMaxLifetime(config.ConnMaxLifetime) |
| 113 | } |
| 114 | |
| 115 | // Test connection |
| 116 | pingCtx, cancel := context.WithTimeout(ctx, config.Timeout) |
| 117 | defer cancel() |
| 118 | |
| 119 | if err := db.PingContext(pingCtx); err != nil { |
| 120 | db.Close() |
| 121 | return nil, fmt.Errorf("failed to ping database with %s: %w", driverName, err) |
| 122 | } |
| 123 | |
| 124 | return &DBConnection{ |
| 125 | DB: db, |
| 126 | Driver: driverName, |
| 127 | DSN: SanitizeDSN(dsn), |
| 128 | DriverInfo: driverInfo, |
| 129 | }, nil |
| 130 | } |
| 131 | |
| 132 | // determineDriver selects the best driver based on configuration and availability |
| 133 | func determineDriver(config *ConnectionConfig) (driver, dsn string, err error) { |
| 134 | available := GetAvailableDrivers() |
| 135 | if len(available) == 0 { |
| 136 | return "", "", fmt.Errorf("no database drivers available. Install IBM DB2 client or configure ODBC") |
| 137 | } |
| 138 | |
| 139 | // If DSN provided, try to auto-detect |
| 140 | if config.DSN != "" { |
| 141 | driver, dsn = detectDriverFromDSN(config.DSN) |
| 142 | if driver != "" && IsDriverAvailable(driver) { |
| 143 | return driver, dsn, nil |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | // Build based on connection type |
| 148 | switch config.ConnectionType { |
| 149 | case "db2": |
| 150 | if !IsDriverAvailable("go_ibm_db") { |
| 151 | return "", "", fmt.Errorf("IBM DB2 client driver requested but not available. Available drivers: %v", available) |
| 152 | } |
| 153 | return "go_ibm_db", BuildDB2DSN(config), nil |
| 154 | |
| 155 | case "odbc": |
| 156 | if !IsDriverAvailable("odbc") { |
| 157 | return "", "", fmt.Errorf("ODBC driver requested but not available. Available drivers: %v", available) |
| 158 | } |
| 159 | return "odbc", BuildODBCDSN(config), nil |
| 160 | |
| 161 | case "auto", "": |
| 162 | // Auto-select best available driver |
| 163 | // Prefer ODBC if configured or for AS/400 |
| 164 | if config.PreferODBC || config.SystemType == "AS400" { |
| 165 | if slices.Contains(available, "odbc") { |
| 166 | return "odbc", BuildODBCDSN(config), nil |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | // Try IBM DB2 client |
| 171 | if slices.Contains(available, "go_ibm_db") { |
| 172 | return "go_ibm_db", BuildDB2DSN(config), nil |
| 173 | } |
| 174 | |
| 175 | // Use whatever is available |
| 176 | driver := available[0] |
| 177 | if driver == "odbc" { |
| 178 | return driver, BuildODBCDSN(config), nil |
| 179 | } |
| 180 | return driver, config.DSN, nil |
| 181 | |
| 182 | default: |
| 183 | return "", "", fmt.Errorf("unknown connection type: %s", config.ConnectionType) |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | // detectDriverFromDSN attempts to determine the driver from DSN format |
| 188 | func detectDriverFromDSN(dsn string) (driver, cleanDSN string) { |
| 189 | // Check for DB2 format |
| 190 | if containsDB2Keywords(dsn) { |
| 191 | return "go_ibm_db", dsn |
| 192 | } |
| 193 | |
| 194 | // Check for ODBC format |
| 195 | if containsODBCKeywords(dsn) { |
| 196 | return "odbc", dsn |
| 197 | } |
| 198 | |
| 199 | // Unknown format |
| 200 | return "", dsn |
| 201 | } |