package adminauth

import (
	"errors"
	"time"

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

type Claims struct {
	UUID          string
	ID            uint
	Username      string
	NickName      string
	AuthorityID   uint `json:"AuthorityId"`
	BufferTime    int64
	MustChangePwd bool `json:"mustChangePwd"`
	jwt.RegisteredClaims
}

func Generate(secret, issuer string, expires time.Duration, userID, authorityID uint, uuid, username, nickname string, mustChange bool) (string, *Claims, error) {
	if secret == "" {
		return "", nil, errors.New("empty JWT signing key")
	}
	now := time.Now()
	claims := &Claims{UUID: uuid, ID: userID, Username: username, NickName: nickname, AuthorityID: authorityID, MustChangePwd: mustChange, RegisteredClaims: jwt.RegisteredClaims{Issuer: issuer, IssuedAt: jwt.NewNumericDate(now), NotBefore: jwt.NewNumericDate(now.Add(-time.Second)), ExpiresAt: jwt.NewNumericDate(now.Add(expires))}}
	token, err := jwt.NewWithClaims(jwt.SigningMethodHS256, claims).SignedString([]byte(secret))
	return token, claims, err
}

func Parse(tokenString, secret string) (*Claims, error) {
	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (any, error) {
		if token.Method != jwt.SigningMethodHS256 {
			return nil, errors.New("unexpected signing method")
		}
		return []byte(secret), nil
	})
	if err != nil || !token.Valid {
		return nil, errors.New("token is invalid")
	}
	claims, ok := token.Claims.(*Claims)
	if !ok {
		return nil, errors.New("token claims are invalid")
	}
	return claims, nil
}