feat: 🎉 postgresql broker first commit of forked prototype from my original code

pkg/broker/config/config.go

@@ -0,0 +1,180 @@
+package config
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/spf13/viper"
+	"git.warky.dev/wdevs/pgsql-broker/pkg/broker/adapter"
+)
+
+// Config holds all broker configuration
+type Config struct {
+	Databases []DatabaseConfig `mapstructure:"databases"`
+	Broker    BrokerConfig     `mapstructure:"broker"`
+	Logging   LoggingConfig    `mapstructure:"logging"`
+}
+
+// DatabaseConfig holds database connection settings
+type DatabaseConfig struct {
+	Name            string        `mapstructure:"name"`
+	Host            string        `mapstructure:"host"`
+	Port            int           `mapstructure:"port"`
+	Database        string        `mapstructure:"database"`
+	User            string        `mapstructure:"user"`
+	Password        string        `mapstructure:"password"`
+	SSLMode         string        `mapstructure:"sslmode"`
+	MaxOpenConns    int           `mapstructure:"max_open_conns"`
+	MaxIdleConns    int           `mapstructure:"max_idle_conns"`
+	ConnMaxLifetime time.Duration `mapstructure:"conn_max_lifetime"`
+	ConnMaxIdleTime time.Duration `mapstructure:"conn_max_idle_time"`
+	QueueCount      int           `mapstructure:"queue_count"`
+}
+
+// BrokerConfig holds broker-specific settings
+type BrokerConfig struct {
+	Name                 string        `mapstructure:"name"`
+	FetchQueryQueSize    int           `mapstructure:"fetch_query_que_size"`
+	QueueTimerSec        int           `mapstructure:"queue_timer_sec"`
+	QueueBufferSize      int           `mapstructure:"queue_buffer_size"`
+	WorkerIdleTimeoutSec int           `mapstructure:"worker_idle_timeout_sec"`
+	NotifyRetrySeconds   time.Duration `mapstructure:"notify_retry_seconds"`
+	EnableDebug          bool          `mapstructure:"enable_debug"`
+}
+
+// LoggingConfig holds logging settings
+type LoggingConfig struct {
+	Level  string `mapstructure:"level"`
+	Format string `mapstructure:"format"` // json or text
+}
+
+// LoadConfig loads configuration from file and environment variables
+func LoadConfig(configPath string) (*Config, error) {
+	v := viper.New()
+
+	// Set defaults
+	setDefaults(v)
+
+	// Config file settings
+	if configPath != "" {
+		v.SetConfigFile(configPath)
+	} else {
+		v.SetConfigName("broker")
+		v.SetConfigType("yaml")
+		v.AddConfigPath(".")
+		v.AddConfigPath("/etc/pgsql-broker/")
+		v.AddConfigPath("$HOME/.pgsql-broker/")
+	}
+
+	// Read from environment variables
+	v.SetEnvPrefix("BROKER")
+	v.AutomaticEnv()
+
+	// Read config file
+	if err := v.ReadInConfig(); err != nil {
+		if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
+			return nil, fmt.Errorf("failed to read config file: %w", err)
+		}
+	}
+
+	var config Config
+	if err := v.Unmarshal(&config); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal config: %w", err)
+	}
+
+	// Validate configuration
+	if err := validateConfig(&config); err != nil {
+		return nil, err
+	}
+
+	// Apply defaults to databases
+	applyDatabaseDefaults(&config)
+
+	return &config, nil
+}
+
+// setDefaults sets default configuration values
+func setDefaults(v *viper.Viper) {
+	// Broker defaults
+	v.SetDefault("broker.name", "pgsql-broker")
+	v.SetDefault("broker.fetch_query_que_size", 100)
+	v.SetDefault("broker.queue_timer_sec", 10)
+	v.SetDefault("broker.queue_buffer_size", 50)
+	v.SetDefault("broker.worker_idle_timeout_sec", 10)
+	v.SetDefault("broker.notify_retry_seconds", 30*time.Second)
+	v.SetDefault("broker.enable_debug", false)
+
+	// Logging defaults
+	v.SetDefault("logging.level", "info")
+	v.SetDefault("logging.format", "json")
+}
+
+// validateConfig validates the configuration
+func validateConfig(config *Config) error {
+	if len(config.Databases) == 0 {
+		return fmt.Errorf("at least one database must be configured")
+	}
+
+	// Validate each database configuration
+	for i, db := range config.Databases {
+		if db.Name == "" {
+			return fmt.Errorf("database[%d]: name is required", i)
+		}
+		if db.Host == "" {
+			return fmt.Errorf("database[%d] (%s): host is required", i, db.Name)
+		}
+		if db.Database == "" {
+			return fmt.Errorf("database[%d] (%s): database name is required", i, db.Name)
+		}
+		if db.User == "" {
+			return fmt.Errorf("database[%d] (%s): user is required", i, db.Name)
+		}
+	}
+
+	return nil
+}
+
+// applyDatabaseDefaults applies default values to database configurations
+func applyDatabaseDefaults(config *Config) {
+	for i := range config.Databases {
+		db := &config.Databases[i]
+
+		if db.Port == 0 {
+			db.Port = 5432
+		}
+		if db.SSLMode == "" {
+			db.SSLMode = "disable"
+		}
+		if db.MaxOpenConns == 0 {
+			db.MaxOpenConns = 25
+		}
+		if db.MaxIdleConns == 0 {
+			db.MaxIdleConns = 5
+		}
+		if db.ConnMaxLifetime == 0 {
+			db.ConnMaxLifetime = 5 * time.Minute
+		}
+		if db.ConnMaxIdleTime == 0 {
+			db.ConnMaxIdleTime = 10 * time.Minute
+		}
+		if db.QueueCount == 0 {
+			db.QueueCount = 4
+		}
+	}
+}
+
+// ToPostgresConfig converts DatabaseConfig to adapter.PostgresConfig
+func (d *DatabaseConfig) ToPostgresConfig() adapter.PostgresConfig {
+	return adapter.PostgresConfig{
+		Host:            d.Host,
+		Port:            d.Port,
+		Database:        d.Database,
+		User:            d.User,
+		Password:        d.Password,
+		SSLMode:         d.SSLMode,
+		MaxOpenConns:    d.MaxOpenConns,
+		MaxIdleConns:    d.MaxIdleConns,
+		ConnMaxLifetime: d.ConnMaxLifetime,
+		ConnMaxIdleTime: d.ConnMaxIdleTime,
+	}
+}