package config

import (
	"os"
	"strconv"
)

// Config 全局配置，优先从环境变量读取，提供默认值以便开箱即用。
type Config struct {
	Port         string
	JWTSecret    string
	JWTExpireHrs int
	UploadDir    string

	// MySQL
	DBHost     string
	DBPort     string
	DBUser     string
	DBPassword string
	DBName     string
	DBCharset  string

	// 平台管理员账号（首次启动自动创建）
	AdminUsername string
	AdminPassword string
	// 班级审核补齐期限（天），逾期自动删除
	AuditGraceDays int

	// 极验行为验证（参数后期补，为空则跳过极验校验）
	GeeTestID  string
	GeeTestKey string

	// 短信验证码（参数后期补，为空则短信接口返回配置缺失）
	SMSProvider    string // aliyun / tencent
	SMSAccessKey   string
	SMSSecretKey   string
	SMSSignName    string
	SMSTemplateCode string

	// 微信扫码登录（参数后期补，为空则微信接口返回配置缺失）
	WechatAppID       string
	WechatAppSecret   string
	WechatRedirectURI string

	// Redis（缓存/验证码/限流，连接失败自动降级内存）
	RedisHost     string
	RedisPort     string
	RedisPassword string
	RedisDB       int
}

var C *Config

func Load() *Config {
	C = &Config{
		Port:           getEnv("PORT", "8010"),
		JWTSecret:      getEnv("JWT_SECRET", "photowall-dev-secret-change-in-prod"),
		JWTExpireHrs:   getEnvInt("JWT_EXPIRE_HOURS", 3),
		UploadDir:      getEnv("UPLOAD_DIR", "uploads"),
		DBHost:         getEnv("DB_HOST", "10.31.100.3"),
		DBPort:         getEnv("DB_PORT", "3306"),
		DBUser:         getEnv("DB_USER", "photowall"),
		DBPassword:     getEnv("DB_PASSWORD", "Dfn47yeKpyJfwz8n"),
		DBName:         getEnv("DB_NAME", "photowall"),
		DBCharset:      getEnv("DB_CHARSET", "utf8mb4"),
		AdminUsername:  getEnv("ADMIN_USERNAME", "hero920103"),
		AdminPassword:  getEnv("ADMIN_PASSWORD", "920103"),
		AuditGraceDays: getEnvInt("AUDIT_GRACE_DAYS", 30),
		// 极验（后期补参数）
		GeeTestID:  getEnv("GEETEST_ID", ""),
		GeeTestKey: getEnv("GEETEST_KEY", ""),
		// 短信（后期补参数）
		SMSProvider:     getEnv("SMS_PROVIDER", "aliyun"),
		SMSAccessKey:    getEnv("SMS_ACCESS_KEY", ""),
		SMSSecretKey:    getEnv("SMS_SECRET_KEY", ""),
		SMSSignName:     getEnv("SMS_SIGN_NAME", ""),
		SMSTemplateCode: getEnv("SMS_TEMPLATE_CODE", ""),
		// 微信扫码登录（后期补参数）
		WechatAppID:       getEnv("WECHAT_APP_ID", ""),
		WechatAppSecret:   getEnv("WECHAT_APP_SECRET", ""),
		WechatRedirectURI: getEnv("WECHAT_REDIRECT_URI", ""),
		// Redis
		RedisHost:     getEnv("REDIS_HOST", "localhost"),
		RedisPort:     getEnv("REDIS_PORT", "6379"),
		RedisPassword: getEnv("REDIS_PASSWORD", ""),
		RedisDB:       getEnvInt("REDIS_DB", 0),
	}
	return C
}

// DSN 生成 MySQL 连接串
func (c *Config) DSN() string {
	return c.DBUser + ":" + c.DBPassword + "@tcp(" + c.DBHost + ":" + c.DBPort + ")/" +
		c.DBName + "?charset=" + c.DBCharset + "&parseTime=True&loc=Local"
}

func getEnv(key, def string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return def
}

func getEnvInt(key string, def int) int {
	if v := os.Getenv(key); v != "" {
		if n, err := strconv.Atoi(v); err == nil {
			return n
		}
	}
	return def
}