package utils

import (
	"fmt"
	"time"

	"github.com/beego/beego/v2/server/web"
	"github.com/golang-jwt/jwt/v5"
)

// LocalTokenClaims 本地JWT token的claims结构
type LocalTokenClaims struct {
	UserID    uint   `json:"user_id"`
	Username  string `json:"username"`
	Role      string `json:"role"`
	TokenType string `json:"token_type"` // "local" 标识为本地token
	jwt.RegisteredClaims
}

// GenerateLocalToken 生成本地JWT token
func GenerateLocalToken(userID uint, username string, role string) (string, error) {
	// 从配置读取JWT密钥
	jwtSecret, err := web.AppConfig.String("jwt_secret")
	if err != nil || jwtSecret == "" {
		jwtSecret = "default-secret-key-please-change-in-production" // 默认密钥
	}

	// 设置token有效期为24小时
	expirationTime := time.Now().Add(24 * time.Hour)

	// 创建claims
	claims := &LocalTokenClaims{
		UserID:    userID,
		Username:  username,
		Role:      role,
		TokenType: "local",
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(expirationTime),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
			Issuer:    "shudao-local-auth",
		},
	}

	// 创建token
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)

	// 签名token
	tokenString, err := token.SignedString([]byte(jwtSecret))
	if err != nil {
		return "", fmt.Errorf("生成token失败: %v", err)
	}

	return tokenString, nil
}

// VerifyLocalToken 验证本地JWT token并返回claims
func VerifyLocalToken(tokenString string) (*LocalTokenClaims, error) {
	// 从配置读取JWT密钥
	jwtSecret, err := web.AppConfig.String("jwt_secret")
	if err != nil || jwtSecret == "" {
		jwtSecret = "default-secret-key-please-change-in-production"
	}

	// 解析token
	token, err := jwt.ParseWithClaims(tokenString, &LocalTokenClaims{}, func(token *jwt.Token) (interface{}, error) {
		// 验证签名方法
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
		}
		return []byte(jwtSecret), nil
	})

	if err != nil {
		return nil, fmt.Errorf("解析token失败: %v", err)
	}

	// 验证token有效性
	if claims, ok := token.Claims.(*LocalTokenClaims); ok && token.Valid {
		// 检查是否为本地token
		if claims.TokenType != "local" {
			return nil, fmt.Errorf("不是本地token")
		}
		return claims, nil
	}

	return nil, fmt.Errorf("token无效")
}

// ConvertLocalClaimsToTokenUserInfo 将本地token claims转换为TokenUserInfo
func ConvertLocalClaimsToTokenUserInfo(claims *LocalTokenClaims) *TokenUserInfo {
	return &TokenUserInfo{
		AccountID:     fmt.Sprintf("local_%d", claims.UserID),
		ID:            int64(claims.UserID),
		Name:          claims.Username,
		UserCode:      claims.Username,
		ContactNumber: "",
		TokenType:     "local",
		Exp:           claims.ExpiresAt.Unix(),
		Iat:           claims.IssuedAt.Unix(),
	}
}