gorm4.go

package gorm4

import (
	"time"

	"github.com/jinzhu/gorm"
)

func getGormDB() *gorm.DB {
	db, _ := gorm.Open("mysql",
		"user:password@/dbname?charset=utf8&parseTime=True&loc=Local")
	return db
}

//go:generate goqueryset -in gorm4.go

// User struct represents user model.
// gen:qs
type User struct {
	gorm.Model
	Rating      int
	RatingMarks int
}

func getTodayBegin() time.Time {
	year, month, day := time.Now().Date()
	return time.Date(year, month, day, 0, 0, 0, 0, time.Now().Location())
}

// WithMaxRating is our defined on UserQuerySet method, that selects
// users with max rating.
// UserQuerySet is an autogenerated struct with a lot of typesafe methods.
// We can define any methods on it because it's in the same package
func (qs UserQuerySet) WithMaxRating(minMarks int) UserQuerySet {
	return qs.RatingMarksGte(minMarks).OrderDescByRating()
}

// RegisteredToday returns only users registered today
func (qs UserQuerySet) RegisteredToday() UserQuerySet {
	// autogenerated typesafe method CreatedAtGte(time.Time)
	return qs.CreatedAtGte(getTodayBegin())
}

// now we can parametrize it
const minRatingMarks = 10

// GetUsersWithMaxRating returns limit users with max rating
func GetUsersWithMaxRating(limit int) ([]User, error) {
	var users []User
	err := NewUserQuerySet(getGormDB()).
		WithMaxRating(minRatingMarks). // reuse our method
		Limit(limit).                  // autogenerated typesafe method Limit(int)
		All(&users)                    // autogenerated typesafe method All(*[]User)
	if err != nil {
		return nil, err
	}
	return users, nil
}

// GetUsersRegisteredToday returns limit users registered today
func GetUsersRegisteredToday(limit int) ([]User, error) {
	var users []User
	err := NewUserQuerySet(getGormDB()).
		RegisteredToday(). // reuse our method
		Limit(limit).      // autogenerated typesafe method Limit(int)
		All(&users)        // autogenerated typesafe method All(*[]User)
	if err != nil {
		return nil, err
	}
	return users, nil
}

// GetUsersRegisteredTodayWithMaxRating returns limit users
// registered today and with max rating
func GetUsersRegisteredTodayWithMaxRating(limit int) ([]User, error) {
	var users []User
	err := NewUserQuerySet(getGormDB()).
		RegisteredToday().             // reuse our method
		WithMaxRating(minRatingMarks). // reuse our method
		Limit(limit).
		All(&users) // autogenerated typesafe method All(*[]User)
	if err != nil {
		return nil, err
	}
	return users, nil
}