fix(config): fix configuration management

internal/config/config.go

@@ -2,66 +2,67 @@ package config
 
 import (
 	"fmt"
-	"log"
-	"os"
 	"strings"
 
 	"github.com/spf13/viper"
 )
 
-// Config holds all configuration for the application.
+// Config représente la structure globale de la configuration de l'application.
 type Config struct {
-	Database DatabaseConfig `mapstructure:"database"`
-	Server   ServerConfig   `mapstructure:"server"`
+	Server   ServerConfig
+	Database DatabaseConfig
 }
 
-// DatabaseConfig holds database connection configuration.
+// ServerConfig contient les paramètres de configuration du serveur HTTP.
+type ServerConfig struct {
+	Address        string   `mapstructure:"address"`
+	TrustedProxies []string `mapstructure:"trusted_proxies"` // Liste des IPs de proxies de confiance
+}
+
+// DatabaseConfig contient les paramètres de configuration de la base de données.
 type DatabaseConfig struct {
-	User     string `mapstructure:"user"`
-	Password string `mapstructure:"password"`
-	Dbname   string `mapstructure:"dbname"`
 	Host     string `mapstructure:"host"`
 	Port     int    `mapstructure:"port"`
-	Sslmode  string `mapstructure:"sslmode"`
+	User     string `mapstructure:"user"`
+	Password string `mapstructure:"password"`
+	DBName   string `mapstructure:"dbname"`
+	SSLMode  string `mapstructure:"sslmode"`
 }
 
-// ServerConfig holds server-specific configuration.
-type ServerConfig struct {
-	Address string `mapstructure:"address"`
-}
-
-// Load reads configuration from file and environment variables.
-func Load() (*Config, error) {
-	// 0. Configuration for environment variables
-	viper.SetEnvPrefix("APP") // Variables must start with "APP_" (e.g., APP_SERVER_ADDRESS)
-
-	// 1. Base configuration file
-	viper.SetConfigName("config") // config.yaml
+// LoadConfig charge la configuration depuis un fichier et les variables d'environnement.
+func LoadConfig(path string) (config Config, err error) {
+	viper.AddConfigPath(path)
+	viper.SetConfigName("config")
 	viper.SetConfigType("yaml")
-	viper.AddConfigPath(".")
 
-	// Read the base file. Don't stop if it's not found.
-	if err := viper.ReadInConfig(); err != nil {
+	viper.SetDefault("server.address", ":8080")
+	viper.SetDefault("server.trusted_proxies", "127.0.0.1, ::1")
+	viper.SetDefault("database.host", "localhost")
+	viper.SetDefault("database.port", 5432)
+	viper.SetDefault("database.user", "default_user")
+	viper.SetDefault("database.password", "")
+	viper.SetDefault("database.dbname", "default_db")
+	viper.SetDefault("database.sslmode", "disable")
+
+	// L'ordre ici est important
+
+	// 1. D'abord, on lit le fichier
+	err = viper.ReadInConfig()
+	if err != nil {
 		if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
-			return nil, fmt.Errorf("error reading base config file config.yaml: %w", err)
-		}
-	}
-
-	// 2. Override with environment-specific file (via APP_ENV)
-	if env := os.Getenv("APP_ENV"); env != "" {
-		viper.SetConfigName("config." + env) // e.g., config.prod.yaml
-		if err := viper.MergeInConfig(); err != nil {
-			log.Printf("Warning: could not load config file for environment '%s': %v", env, err)
+			return
 		}
 	}
 
+	// 2. Ensuite, on prépare Viper à lire les variables d'environnement
+	viper.SetEnvPrefix("APP")
 	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
-	viper.AutomaticEnv()
+	viper.AutomaticEnv() // Dit à Viper de chercher les variables d'environnement
 
-	var cfg Config
-	if err := viper.Unmarshal(&cfg); err != nil {
-		return nil, fmt.Errorf("unable to decode config into struct: %w", err)
-	}
+	// 3. Enfin, on déverse le résultat final dans la struct.
+	// C'est à ce moment que la surcharge a lieu.
+	fmt.Printf("[%v]\n", config.Database.DBName)
 
-	return &cfg, nil
+	err = viper.Unmarshal(&config)
+	return
 }

internal/database/database.go

@@ -16,8 +16,8 @@ type Service struct {
 // NewService initializes and returns a new database service.
 func NewService(cfg *config.DatabaseConfig) (*Service, error) {
 	connStr := fmt.Sprintf("user=%s password=%s dbname=%s host=%s port=%d sslmode=%s",
-		cfg.User, cfg.Password, cfg.Dbname,
-		cfg.Host, cfg.Port, cfg.Sslmode,
+		cfg.User, cfg.Password, cfg.DBName,
+		cfg.Host, cfg.Port, cfg.SSLMode,
 	)
 
 	db, err := sql.Open("postgres", connStr)