package config

import (
	"log"
	"strings"

	"github.com/spf13/viper"
)

type Config struct {
	Server   ServerConfig
	Database DatabaseConfig
	JWT      JWTConfig
	License  LicenseConfig
	Storage  StorageConfig
}

type ServerConfig struct {
	Port       string `mapstructure:"port"`
	Mode       string `mapstructure:"mode"`       // debug | release
	CORSOrigin string `mapstructure:"cors_origin"` // 允许的 CORS 来源，生产设为具体域名
}

type DatabaseConfig struct {
	DSN          string `mapstructure:"dsn"`
	MaxIdleConns int    `mapstructure:"max_idle_conns"`
	MaxOpenConns int    `mapstructure:"max_open_conns"`
}

type JWTConfig struct {
	Secret          string `mapstructure:"secret"`
	AccessExpireMin int    `mapstructure:"access_expire_min"` // Access Token 有效分钟数
	RefreshExpireH  int    `mapstructure:"refresh_expire_h"`  // Refresh Token 有效小时数
}

type LicenseConfig struct {
	HMACSecret       string `mapstructure:"hmac_secret"`        // legacy, kept for backward compat
	Ed25519PublicKey  string `mapstructure:"ed25519_public_key"`  // base64 Ed25519 public key for token verification
	Ed25519PrivateKey string `mapstructure:"ed25519_private_key"` // base64 Ed25519 private key for token signing (keep in Bitwarden)
}

type StorageConfig struct {
	UploadDir string `mapstructure:"upload_dir"`
	BaseURL   string `mapstructure:"base_url"`
	PublicURL string `mapstructure:"public_url"` // 商品公开页基础 URL，用于生成二维码
}

var C Config

func Load() {
	viper.SetConfigName("config")
	viper.SetConfigType("yaml")
	viper.AddConfigPath(".")
	viper.AddConfigPath("./config")

	// 环境变量覆盖（生产部署时使用）
	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
	viper.AutomaticEnv()

	// 显式绑定没有默认值的 key，确保 AutomaticEnv 能找到对应 env var
	_ = viper.BindEnv("database.dsn", "DATABASE_DSN")
	_ = viper.BindEnv("jwt.secret", "JWT_SECRET")
	_ = viper.BindEnv("license.hmac_secret", "LICENSE_HMAC_SECRET")
	_ = viper.BindEnv("license.ed25519_public_key", "LICENSE_ED25519_PUBLIC_KEY")
	_ = viper.BindEnv("license.ed25519_private_key", "LICENSE_ED25519_PRIVATE_KEY")
	_ = viper.BindEnv("storage.upload_dir", "STORAGE_UPLOAD_DIR")
	_ = viper.BindEnv("storage.base_url", "STORAGE_BASE_URL")
	_ = viper.BindEnv("storage.public_url", "STORAGE_PUBLIC_URL")

	// 默认值
	viper.SetDefault("server.port", "8080")
	viper.SetDefault("server.mode", "debug")
	viper.SetDefault("server.cors_origin", "*")
	viper.SetDefault("jwt.access_expire_min", 60)
	viper.SetDefault("jwt.refresh_expire_h", 168) // 7天
	viper.SetDefault("database.max_idle_conns", 10)
	viper.SetDefault("database.max_open_conns", 100)
	viper.SetDefault("storage.upload_dir", "./uploads/images")
	viper.SetDefault("storage.base_url", "http://localhost:8080/images")
	viper.SetDefault("storage.public_url", "http://localhost:8081")

	if err := viper.ReadInConfig(); err != nil {
		log.Println("[config] no config file found, using defaults and env vars")
	}

	if err := viper.Unmarshal(&C); err != nil {
		log.Fatalf("[config] failed to unmarshal config: %v", err)
	}
}