package config

import (
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/joho/godotenv"
)

// Config 应用配置（从环境变量读取，启动时加载 .env）
type Config struct {
	Port           string
	Mode           string
	DBDSN          string
	TrustedProxies []string
	CORSOrigins    []string
	Version        string // APP_VERSION，打包/部署前写在 .env，/health 返回

	// 统一 API 域名字段：支付回调、转账回调、apiDomain 等均由 BaseURL 拼接
	BaseURL string // API_BASE_URL，如 https://soulapi.quwanzhi.com（无尾部斜杠）

	// 微信小程序配置
	WechatAppID            string
	WechatAppSecret        string
	WechatMchID            string
	WechatMchKey           string
	WechatNotifyURL        string // 由 BaseURL + /api/miniprogram/pay/notify 派生
	WechatMiniProgramState string // 订阅消息跳转版本：developer/formal，从 .env WECHAT_MINI_PROGRAM_STATE 读取

	// 微信转账配置（API v3）
	WechatAPIv3Key    string
	WechatCertPath    string
	WechatKeyPath     string
	WechatSerialNo    string
	WechatTransferURL string // 由 BaseURL + /api/payment/wechat/transfer/notify 派生

	// 管理端登录（与 next-project 一致：ADMIN_USERNAME / ADMIN_PASSWORD / ADMIN_SESSION_SECRET）
	AdminUsername      string
	AdminPassword      string
	AdminSessionSecret string

	// 订单对账定时任务间隔（分钟），0 表示不启动内置定时任务
	SyncOrdersIntervalMinutes int

	// 存客宝-链接卡若：可选，用于「添加好友」的 apiKey（与 GET scenarios 示例一致时可填 CKB_LEAD_API_KEY）
	CkbLeadAPIKey string
}

// BaseURLJoin 将路径拼接到 BaseURL，path 应以 / 开头
func (c *Config) BaseURLJoin(path string) string {
	base := strings.TrimSuffix(c.BaseURL, "/")
	if base == "" {
		return ""
	}
	p := strings.TrimSpace(path)
	if p != "" && p[0] != '/' {
		p = "/" + p
	}
	return base + p
}

// 默认 CORS 允许的源（零配置：不设环境变量也能用）
var defaultCORSOrigins = []string{
	"http://localhost:5174",
	"http://127.0.0.1:5174",
	"https://soul.quwanzhi.com",
	"http://soul.quwanzhi.com",
	"https://souladmin.quwanzhi.com",
	"http://souladmin.quwanzhi.com",
}

// current 由 main 在 Load 后设置，供 handler/middleware 读取
var current *Config

// SetCurrent 设置全局配置（main 启动时调用一次）
func SetCurrent(cfg *Config) { current = cfg }

// Get 返回当前配置，未设置时返回 nil
func Get() *Config { return current }

// parseCORSOrigins 从环境变量 CORS_ORIGINS 读取（逗号分隔），未设置则用默认值
func parseCORSOrigins() []string {
	s := os.Getenv("CORS_ORIGINS")
	if s == "" {
		return defaultCORSOrigins
	}
	parts := strings.Split(s, ",")
	origins := make([]string, 0, len(parts))
	for _, p := range parts {
		if o := strings.TrimSpace(p); o != "" {
			origins = append(origins, o)
		}
	}
	if len(origins) == 0 {
		return defaultCORSOrigins
	}
	return origins
}

// Load 加载配置，端口等从 .env 读取。
// 环境区分：APP_ENV=development 加载 .env.development，APP_ENV=production 加载 .env.production；
// air 运行时通过 env_files 或 full_bin 设置 APP_ENV，开发用 .env.development，部署用 .env.production。
func Load() (*Config, error) {
	workDir, _ := os.Getwd()
	execDir := ""
	if execPath, err := os.Executable(); err == nil {
		execDir = filepath.Dir(execPath)
	}
	loadEnv := func(name string) {
		for _, dir := range []string{execDir, workDir, "."} {
			if dir == "" {
				continue
			}
			p := filepath.Join(dir, name)
			if _, err := os.Stat(p); err == nil {
				_ = godotenv.Load(p)
				break
			}
		}
	}
	overloadEnv := func(name string) {
		for _, dir := range []string{execDir, workDir, "."} {
			if dir == "" {
				continue
			}
			p := filepath.Join(dir, name)
			if _, err := os.Stat(p); err == nil {
				_ = godotenv.Overload(p)
				break
			}
		}
	}

	// 1. 加载 .env 作为基础
	loadEnv(".env")
	// 2. 按 APP_ENV 覆盖（优先读已设置的 APP_ENV，如 air 的 env_files 已注入）
	appEnv := strings.ToLower(strings.TrimSpace(os.Getenv("APP_ENV")))
	if appEnv == "development" {
		overloadEnv(".env.development")
	} else if appEnv == "production" {
		overloadEnv(".env.production")
	}

	port := os.Getenv("PORT")
	if port == "" {
		port = "8080"
	}
	mode := os.Getenv("GIN_MODE")
	if mode == "" {
		mode = "debug"
	}
	dsn := os.Getenv("DB_DSN")
	if dsn == "" {
		dsn = "user:pass@tcp(127.0.0.1:3306)/soul?charset=utf8mb4&parseTime=True"
	}
	version := os.Getenv("APP_VERSION")
	if version == "" {
		version = "0.0.0"
	}

	// 微信配置
	wechatAppID := os.Getenv("WECHAT_APPID")
	if wechatAppID == "" {
		wechatAppID = "wxb8bbb2b10dec74aa" // 默认小程序AppID
	}
	wechatAppSecret := os.Getenv("WECHAT_APPSECRET")
	if wechatAppSecret == "" {
		wechatAppSecret = "3c1fb1f63e6e052222bbcead9d07fe0c" // 默认小程序AppSecret
	}
	wechatMchID := os.Getenv("WECHAT_MCH_ID")
	if wechatMchID == "" {
		wechatMchID = "1318592501" // 默认商户号
	}
	wechatMchKey := os.Getenv("WECHAT_MCH_KEY")
	if wechatMchKey == "" {
		wechatMchKey = "wx3e31b068be59ddc131b068be59ddc2" // 默认API密钥(v2)
	}
	// 统一域名：API_BASE_URL 派生支付/转账回调，可选 WECHAT_NOTIFY_URL 覆盖
	baseURL := strings.TrimSpace(strings.TrimSuffix(os.Getenv("API_BASE_URL"), "/"))
	if baseURL == "" {
		baseURL = "https://soulapi.quwanzhi.com"
	}
	wechatNotifyURL := os.Getenv("WECHAT_NOTIFY_URL")
	if wechatNotifyURL == "" {
		wechatNotifyURL = baseURL + "/api/miniprogram/pay/notify"
	}
	wechatMiniProgramState := strings.TrimSpace(os.Getenv("WECHAT_MINI_PROGRAM_STATE"))
	if wechatMiniProgramState != "developer" && wechatMiniProgramState != "trial" {
		wechatMiniProgramState = "formal" // 默认正式版，避免生成开发版码导致「开发版已过期」
	}

	// 转账配置
	wechatAPIv3Key := os.Getenv("WECHAT_APIV3_KEY")
	if wechatAPIv3Key == "" {
		wechatAPIv3Key = "wx3e31b068be59ddc131b068be59ddc2" // 默认 API v3 密钥
	}
	wechatCertPath := os.Getenv("WECHAT_CERT_PATH")
	if wechatCertPath == "" {
		wechatCertPath = "certs/apiclient_cert.pem" // 默认证书路径
	}
	wechatKeyPath := os.Getenv("WECHAT_KEY_PATH")
	if wechatKeyPath == "" {
		wechatKeyPath = "certs/apiclient_key.pem" // 默认私钥路径
	}
	wechatSerialNo := os.Getenv("WECHAT_SERIAL_NO")
	if wechatSerialNo == "" {
		wechatSerialNo = "4A1DB62CD5C9BE0B6FC51C30621D6F99686E75C5" // 默认证书序列号
	}
	wechatTransferURL := os.Getenv("WECHAT_TRANSFER_URL")
	if wechatTransferURL == "" {
		wechatTransferURL = baseURL + "/api/payment/wechat/transfer/notify"
	}

	adminUsername := os.Getenv("ADMIN_USERNAME")
	if adminUsername == "" {
		adminUsername = "admin"
	}
	adminPassword := os.Getenv("ADMIN_PASSWORD")
	if adminPassword == "" {
		adminPassword = "admin123"
	}
	adminSessionSecret := os.Getenv("ADMIN_SESSION_SECRET")
	if adminSessionSecret == "" {
		adminSessionSecret = "soul-admin-secret-change-in-prod"
	}
	// 默认 0：不启动全量定时对账，以「支付发起后单笔订单轮询」为主；需兜底时可设 SYNC_ORDERS_INTERVAL_MINUTES=60 等
	syncOrdersInterval := 0
	if s := os.Getenv("SYNC_ORDERS_INTERVAL_MINUTES"); s != "" {
		if n, e := strconv.Atoi(s); e == nil && n >= 0 {
			syncOrdersInterval = n
		}
	}

	return &Config{
		Port:                   port,
		Mode:                   mode,
		DBDSN:                  dsn,
		TrustedProxies:         []string{"127.0.0.1", "::1"},
		CORSOrigins:            parseCORSOrigins(),
		Version:                version,
		BaseURL:                baseURL,
		WechatAppID:            wechatAppID,
		WechatAppSecret:        wechatAppSecret,
		WechatMchID:            wechatMchID,
		WechatMchKey:           wechatMchKey,
		WechatNotifyURL:        wechatNotifyURL,
		WechatMiniProgramState: wechatMiniProgramState,
		WechatAPIv3Key:         wechatAPIv3Key,
		WechatCertPath:         wechatCertPath,
		WechatKeyPath:          wechatKeyPath,
		WechatSerialNo:         wechatSerialNo,
		WechatTransferURL:      wechatTransferURL,
		AdminUsername:               adminUsername,
		AdminPassword:               adminPassword,
		AdminSessionSecret:          adminSessionSecret,
		SyncOrdersIntervalMinutes:   syncOrdersInterval,
		CkbLeadAPIKey:               strings.TrimSpace(os.Getenv("CKB_LEAD_API_KEY")),
	}, nil
}