package service

import (
	"exam_registration/internal/dao"
	"exam_registration/internal/model"
	"errors"
	"github.com/golang-jwt/jwt/v5"
	"github.com/spf13/viper"
	"golang.org/x/crypto/bcrypt"
	"time"
)

type UserService struct{}

type LoginRequest struct {
	Username string `json:"username" binding:"required"`
	Password string `json:"password" binding:"required"`
}

type RegisterRequest struct {
	Username string `json:"username" binding:"required"`
	Password string `json:"password" binding:"required"`
	Email    string `json:"email"`
	Phone    string `json:"phone"`
	RealName string `json:"real_name"`
	IDCard   string `json:"id_card"`
}

func (s *UserService) Login(req *LoginRequest) (string, error) {
	var user model.User
	if err := dao.DB.Where("username = ?", req.Username).First(&user).Error; err != nil {
		return "", errors.New("用户名或密码错误")
	}

	if err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(req.Password)); err != nil {
		return "", errors.New("用户名或密码错误")
	}

	if user.Status != 1 {
		return "", errors.New("账号已被禁用")
	}

	// 生成 JWT token
	claims := jwt.MapClaims{
		"user_id":   user.ID,
		"username":  user.Username,
		"role":      user.Role,
		"exp":       time.Now().Add(time.Duration(viper.GetInt("jwt.expire")) * time.Second).Unix(),
		"issued_at": time.Now().Unix(),
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(viper.GetString("jwt.secret")))
}

func (s *UserService) Register(req *RegisterRequest) error {
	var existingUser model.User
	if err := dao.DB.Where("username = ?", req.Username).First(&existingUser).Error; err == nil {
		return errors.New("用户名已存在")
	}

	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(req.Password), bcrypt.DefaultCost)
	if err != nil {
		return errors.New("密码加密失败")
	}

	user := model.User{
		Username: req.Username,
		Password: string(hashedPassword),
		Email:    req.Email,
		Phone:    req.Phone,
		RealName: req.RealName,
		IDCard:   req.IDCard,
		Role:     "user",
		Status:   1,
	}

	return dao.DB.Create(&user).Error
}

func (s *UserService) GetUserByID(userID uint64) (*model.User, error) {
	var user model.User
	if err := dao.DB.First(&user, userID).Error; err != nil {
		return nil, errors.New("用户不存在")
	}
	return &user, nil
}

func (s *UserService) UpdateUser(userID uint64, updates map[string]interface{}) error {
	return dao.DB.Model(&model.User{}).Where("id = ?", userID).Updates(updates).Error
}