package auth

import (
	"errors"
	"time"

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

var jwtSecret = []byte("task-track-jwt-secret-key")

type Claims struct {
	UserID         uint   `json:"user_id"`
	Username       string `json:"username"`
	OrganizationID uint   `json:"organization_id"`
	jwt.RegisteredClaims
}

// GenerateToken 生成JWT token
func GenerateToken(userID uint, username string, organizationID uint) (string, error) {
	claims := Claims{
		UserID:         userID,
		Username:       username,
		OrganizationID: organizationID,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(24 * time.Hour)),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
			NotBefore: jwt.NewNumericDate(time.Now()),
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString(jwtSecret)
}

// ValidateToken 验证JWT token
func ValidateToken(tokenString string) (*Claims, error) {
	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
		return jwtSecret, 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")
}

// RefreshToken 刷新JWT token
func RefreshToken(tokenString string) (string, error) {
	claims, err := ValidateToken(tokenString)
	if err != nil {
		return "", err
	}

	// 生成新的token
	return GenerateToken(claims.UserID, claims.Username, claims.OrganizationID)
}