package config

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

	"github.com/joho/godotenv"
)

type Config struct {
	Port        string
	JWTSecret   string
	DatabaseURL string
	Mode        string // debug / release
	// OpenAPIKey 皮肤源头开放接口标识（Header: X-Api-Key，可公开给对接方）
	OpenAPIKey string
	// OpenAPISecret 签名密钥（仅用于 HMAC，不走 Header）
	OpenAPISecret string
	// OpenSignSkew 签名时间戳允许偏差（秒）
	OpenSignSkew int64
	// OpenAPIDebug 开放接口详细调试日志
	OpenAPIDebug bool
	// LogFile 日志文件路径；非空时同时写控制台与文件
	LogFile string
}

// Load 加载配置：先尝试读取 .env，再读系统环境变量（已存在的系统环境变量优先级更高）
func Load() *Config {
	loadDotEnv()
	mode := getEnv("GIN_MODE", "debug")
	// OPEN_API_DEBUG 优先；未设置时 debug 模式默认开启
	debugOpen := getEnvBool("OPEN_API_DEBUG", mode == "debug" || mode == "")
	return &Config{
		Port:          getEnv("PORT", "8080"),
		JWTSecret:     getEnv("JWT_SECRET", "affiliate-dash-dev-secret-change-me"),
		DatabaseURL:   getEnv("DATABASE_URL", "postgres://affiliate:affiliate_dev_password@127.0.0.1:5432/affiliate_dash?sslmode=disable"),
		Mode:          mode,
		OpenAPIKey:    getEnv("OPEN_API_KEY", "sk_source_dev_key_change_me"),
		OpenAPISecret: getEnv("OPEN_API_SECRET", "sk_source_dev_secret_change_me"),
		OpenSignSkew:  int64(getEnvInt("OPEN_SIGN_SKEW", 300)),
		OpenAPIDebug:  debugOpen,
		LogFile:       getEnv("LOG_FILE", "logs/app.log"),
	}
}

func getEnvBool(key string, def bool) bool {
	v := os.Getenv(key)
	if v == "" {
		return def
	}
	switch strings.ToLower(strings.TrimSpace(v)) {
	case "1", "true", "yes", "on":
		return true
	case "0", "false", "no", "off":
		return false
	default:
		return def
	}
}

// loadDotEnv 依次尝试常见路径，不覆盖已有环境变量
func loadDotEnv() {
	var paths []string
	if wd, err := os.Getwd(); err == nil {
		paths = append(paths,
			filepath.Join(wd, ".env"),
			filepath.Join(wd, "..", ".env"),      // 在 backend/ 下启动时读仓库根 .env
			filepath.Join(wd, "backend", ".env"), // 在仓库根启动时
		)
	}
	paths = append(paths, ".env")

	seen := map[string]struct{}{}
	for _, p := range paths {
		abs, err := filepath.Abs(p)
		if err != nil {
			continue
		}
		if _, ok := seen[abs]; ok {
			continue
		}
		seen[abs] = struct{}{}
		_ = godotenv.Load(abs) // 忽略不存在；不覆盖已在环境中的变量
	}
}

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
}