package utils

import (
	"Quincy_admin/config"
	"errors"
	"strconv"
	"time"

	"github.com/golang-jwt/jwt/v5"
)

// Claims JWT 声明结构
type Claims struct {
	UserID      int    `json:"user_id"`
	Username    string `json:"username"`
	SessionCode string `json:"sessioncode"`
	RoleCode    int    `json:"rolecode"`
	jwt.RegisteredClaims
}

// GenerateToken 生成 JWT token
func GenerateToken(userID int, username, sessionCode string, roleCode int) (string, error) {
	cfg := config.LoadConfig()

	secretKey := []byte(cfg.Jwt.Secret)

	expireHours, _ := strconv.Atoi(cfg.Jwt.Expire)
	if expireHours <= 1 {
		expireHours = 1
	}

	expirationTime := time.Now().Add(time.Duration(expireHours) * time.Hour)

	claims := &Claims{
		UserID:      userID,
		Username:    username,
		SessionCode: sessionCode,
		RoleCode:    roleCode,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(expirationTime),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
			Issuer:    "Quincy_admin",
		},
	}

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

	return token.SignedString(secretKey)
}

// ParseToken 解析 JWT token

func ParseToken(tokenString string) (*Claims, error) {
	cfg := config.LoadConfig()

	secretKey := []byte(cfg.Jwt.Secret)

	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, errors.New("unexpected signing method")
		}
		return secretKey, nil
	})

	if err != nil {
		return nil, err
	}

	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
		return claims, nil
	}

	return nil, errors.New("invalid token")
}