package service

import (
	"errors"
	"time"

	"github.com/golang-jwt/jwt/v5"
	"github.com/gouki/lunar-server/internal/config"
	"github.com/gouki/lunar-server/internal/model"
	"gorm.io/gorm"
)

// UserService 用户服务
type UserService struct {
	db *gorm.DB
}

// NewUserService 创建用户服务
func NewUserService() *UserService {
	return &UserService{
		db: config.GetDB(),
	}
}

// GetUserByOpenID 根据OpenID获取用户
func (s *UserService) GetUserByOpenID(openID string) (*model.User, error) {
	var user model.User
	if err := s.db.Where("open_id = ?", openID).First(&user).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil
		}
		return nil, err
	}
	return &user, nil
}

// GetUserByID 根据ID获取用户
func (s *UserService) GetUserByID(id uint) (*model.User, error) {
	var user model.User
	if err := s.db.First(&user, id).Error; err != nil {
		return nil, err
	}
	return &user, nil
}

// CreateUser 创建用户
func (s *UserService) CreateUser(user *model.User) error {
	return s.db.Create(user).Error
}

// UpdateUser 更新用户
func (s *UserService) UpdateUser(user *model.User) error {
	return s.db.Save(user).Error
}

// UpdateUserProfile 更新用户资料
func (s *UserService) UpdateUserProfile(profile *model.UserProfile) error {
	return s.db.Save(profile).Error
}

// GetUserProfile 获取用户资料
func (s *UserService) GetUserProfile(userID uint) (*model.UserProfile, error) {
	var profile model.UserProfile
	if err := s.db.Where("user_id = ?", userID).First(&profile).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil
		}
		return nil, err
	}
	return &profile, nil
}

// GenerateToken 生成JWT Token
func (s *UserService) GenerateToken(userID uint, secret string) (string, error) {
	claims := jwt.MapClaims{
		"user_id": userID,
		"exp":     time.Now().Add(time.Hour * 24 * 7).Unix(), // 7天过期
		"iat":     time.Now().Unix(),
	}

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

// ParseToken 解析JWT Token
func (s *UserService) ParseToken(tokenString, secret string) (uint, error) {
	token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
		return []byte(secret), nil
	})

	if err != nil {
		return 0, err
	}

	if claims, ok := token.Claims.(jwt.MapClaims); ok && token.Valid {
		userID := uint(claims["user_id"].(float64))
		return userID, nil
	}

	return 0, errors.New("invalid token")
}