refactor: 按go modules规范重构

backend/internal/config/config.go

@@ -0,0 +1,91 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/gin-contrib/cors"
+	"github.com/joho/godotenv"
+)
+
+type ServerConfig struct {
+	Port string
+}
+
+type Neo4jConfig struct {
+	URI      string
+	Username string
+	Password string
+}
+
+type DataConfig struct {
+	FilePath string
+}
+
+type CORSConfig struct {
+	AllowOrigins     []string
+	AllowMethods     []string
+	AllowHeaders     []string
+	ExposeHeaders    []string
+	AllowCredentials bool
+	MaxAge           time.Duration
+}
+
+type Config struct {
+	Server ServerConfig
+	Neo4j  Neo4jConfig
+	Data   DataConfig
+	CORS   CORSConfig
+}
+
+func Load() (*Config, error) {
+	var err error
+	err = godotenv.Load("../configs/.env")
+	err = godotenv.Load("./configs/.env")
+	if err != nil {
+		return nil, fmt.Errorf("error loading .env file: %w", err)
+	}
+
+	cfg := &Config{
+		Server: ServerConfig{
+			Port: getEnv("PORT", "3001"),
+		},
+		Neo4j: Neo4jConfig{
+			URI:      os.Getenv("NEO4J_URI"),
+			Username: os.Getenv("NEO4J_USERNAME"),
+			Password: os.Getenv("NEO4J_PASSWORD"),
+		},
+		Data: DataConfig{
+			FilePath: getEnv("DATA_FILE", "data.json"),
+		},
+		CORS: CORSConfig{
+			AllowOrigins:     []string{"http://localhost:5173", "http://localhost:3000"},
+			AllowMethods:     []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
+			AllowHeaders:     []string{"Origin", "Content-Type", "Authorization", "Accept"},
+			ExposeHeaders:    []string{"Content-Length", "Content-Type"},
+			AllowCredentials: true,
+			MaxAge:           12 * time.Hour,
+		},
+	}
+
+	return cfg, nil
+}
+
+func (c *CORSConfig) ToGinConfig() cors.Config {
+	return cors.Config{
+		AllowOrigins:     c.AllowOrigins,
+		AllowMethods:     c.AllowMethods,
+		AllowHeaders:     c.AllowHeaders,
+		ExposeHeaders:    c.ExposeHeaders,
+		AllowCredentials: c.AllowCredentials,
+		MaxAge:           c.MaxAge,
+	}
+}
+
+func getEnv(key, defaultValue string) string {
+	if value := os.Getenv(key); value != "" {
+		return value
+	}
+	return defaultValue
+}