package app

import (
	"fmt"
	"os"
	"path/filepath"
	"time"
)

type Config struct {
	AppEnv              string
	HTTPAddr            string
	DatabaseURL         string
	JWTIssuer           string
	JWTAccessSecret     string
	JWTAccessTTL        time.Duration
	RefreshTTL          time.Duration
	SMSCodeTTL          time.Duration
	SMSCodeCooldown     time.Duration
	SMSProvider         string
	DevSMSCode          string
	WechatMiniAppID     string
	WechatMiniSecret    string
	WechatMiniDevPrefix string
	LocalEventDir       string
	AssetBaseURL        string
	AssetPublicBaseURL  string
	AssetBucketRoot     string
	OSSUtilPath         string
	OSSUtilConfigFile   string
}

func LoadConfigFromEnv() (Config, error) {
	cfg := Config{
		AppEnv:              getEnv("APP_ENV", "development"),
		HTTPAddr:            getEnv("HTTP_ADDR", ":8080"),
		DatabaseURL:         os.Getenv("DATABASE_URL"),
		JWTIssuer:           getEnv("JWT_ISSUER", "cmr-backend"),
		JWTAccessSecret:     getEnv("JWT_ACCESS_SECRET", "change-me-in-production"),
		JWTAccessTTL:        getDurationEnv("JWT_ACCESS_TTL", 2*time.Hour),
		RefreshTTL:          getDurationEnv("AUTH_REFRESH_TTL", 30*24*time.Hour),
		SMSCodeTTL:          getDurationEnv("AUTH_SMS_CODE_TTL", 10*time.Minute),
		SMSCodeCooldown:     getDurationEnv("AUTH_SMS_COOLDOWN", 60*time.Second),
		SMSProvider:         getEnv("AUTH_SMS_PROVIDER", "console"),
		DevSMSCode:          os.Getenv("AUTH_DEV_SMS_CODE"),
		WechatMiniAppID:     getEnv("WECHAT_MINI_APP_ID", ""),
		WechatMiniSecret:    getEnv("WECHAT_MINI_APP_SECRET", ""),
		WechatMiniDevPrefix: getEnv("WECHAT_MINI_DEV_PREFIX", "dev-"),
		LocalEventDir:       getEnv("LOCAL_EVENT_DIR", filepath.Clean("..\\event")),
		AssetBaseURL:        getEnv("ASSET_BASE_URL", "https://oss-mbh5.colormaprun.com/gotomars"),
		AssetPublicBaseURL:  getEnv("ASSET_PUBLIC_BASE_URL", "https://oss-mbh5.colormaprun.com"),
		AssetBucketRoot:     getEnv("ASSET_BUCKET_ROOT", "oss://color-map-html"),
		OSSUtilPath:         getEnv("OSSUTIL_PATH", filepath.Clean("..\\tools\\ossutil.exe")),
		OSSUtilConfigFile:   getEnv("OSSUTIL_CONFIG_FILE", filepath.Join(mustUserHomeDir(), ".ossutilconfig")),
	}

	if cfg.DatabaseURL == "" {
		return Config{}, fmt.Errorf("DATABASE_URL is required")
	}
	if cfg.JWTAccessSecret == "" {
		return Config{}, fmt.Errorf("JWT_ACCESS_SECRET is required")
	}

	return cfg, nil
}

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

func getDurationEnv(key string, fallback time.Duration) time.Duration {
	if value := os.Getenv(key); value != "" {
		if parsed, err := time.ParseDuration(value); err == nil {
			return parsed
		}
	}
	return fallback
}

func mustUserHomeDir() string {
	home, err := os.UserHomeDir()
	if err != nil {
		return "."
	}
	return home
}