package service

import (
	"context"
	"time"

	"github.com/gogf/gf/v2/errors/gerror"
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/util/gconv"
	"github.com/golang-jwt/jwt/v5"
)

type sAuth struct{}

var Auth = sAuth{}

// Claims JWT声明
type Claims struct {
	UserId   uint64 `json:"user_id"`
	Username string `json:"username"`
	jwt.RegisteredClaims
}

// GenerateToken 生成JWT Token
func (s *sAuth) GenerateToken(ctx context.Context, userId uint64) (string, error) {
	// 获取JWT配置
	jwtConfig := g.Cfg().MustGet(ctx, "jwt")
	signingKey := jwtConfig.Map()["signingKey"].(string)
	expire := gconv.Int64(jwtConfig.Map()["expire"])
	
	// 创建声明
	claims := Claims{
		UserId:   userId,
		Username: "", // 将在后续获取
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(time.Duration(expire) * time.Second)),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
			NotBefore: jwt.NewNumericDate(time.Now()),
			Issuer:    "cms-api",
			Subject:   gconv.String(userId),
		},
	}
	
	// 创建token
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	
	// 签名token
	tokenString, err := token.SignedString([]byte(signingKey))
	if err != nil {
		return "", gerror.New("生成Token失败")
	}
	
	return tokenString, nil
}

// ParseToken 解析JWT Token
func (s *sAuth) ParseToken(ctx context.Context, tokenString string) (*Claims, error) {
	// 获取JWT配置
	jwtConfig := g.Cfg().MustGet(ctx, "jwt")
	signingKey := jwtConfig.Map()["signingKey"].(string)
	
	// 解析token
	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
		return []byte(signingKey), nil
	})
	
	if err != nil {
		return nil, gerror.New("Token解析失败")
	}
	
	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
		return claims, nil
	}
	
	return nil, gerror.New("Token无效")
}

// ValidateToken 验证Token
func (s *sAuth) ValidateToken(ctx context.Context, tokenString string) (uint64, error) {
	claims, err := s.ParseToken(ctx, tokenString)
	if err != nil {
		return 0, err
	}
	
	// 检查管理员是否存在且状态正常
	admin, err := Admin().GetById(ctx, int(claims.UserId))
	if err != nil {
		return 0, gerror.New("管理员不存在")
	}
	
	if admin == nil || admin.Status != 1 {
		return 0, gerror.New("管理员已被禁用")
	}
	
	return claims.UserId, nil
}

// RefreshToken 刷新Token
func (s *sAuth) RefreshToken(ctx context.Context, tokenString string) (string, error) {
	claims, err := s.ParseToken(ctx, tokenString)
	if err != nil {
		return "", err
	}
	
	// 生成新的Token
	return s.GenerateToken(ctx, claims.UserId)
}

// GetTokenExpire 获取Token过期时间
func (s *sAuth) GetTokenExpire(ctx context.Context) int {
	jwtConfig := g.Cfg().MustGet(ctx, "jwt")
	return gconv.Int(jwtConfig.Map()["expire"])
}