package gorm

import (
	"github.com/jinzhu/gorm"
	"src.dualinventive.com/go/lib/dilog"
	"src.dualinventive.com/go/users-service/internal/domain"
	"src.dualinventive.com/go/users-service/internal/storage"
)

//UserRepository reflects a gorm based UserRepository
type UserRepository struct {
	DB     *gorm.DB
	logger dilog.Logger
}

//NewUserRepository returns a new gorm based storage.UserRepository
func NewUserRepository(logger dilog.Logger, dbconn *gorm.DB) (storage.UserRepository, error) {
	repo := &UserRepository{
		DB:     dbconn,
		logger: logger,
	}
	return repo, nil
}

//GetUserByID returns a user by the given userID or nil if not found.
func (r *UserRepository) GetUserByID(userID uint64) (*domain.User, error) {
	var user domain.User
	err := r.DB.
		Preload("Roles").
		Preload("Roles.Rights").
		Preload("Company").
		Where(&domain.User{ID: uint(userID)}).
		First(&user).Error
	if err == gorm.ErrRecordNotFound {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}

	return &user, nil
}

//ListUsers returns users based on filter, paginated and sorted or nil if not found.
func (r *UserRepository) ListUsers(
	filter domain.UsersFilter, page uint64, perPage uint64, sort domain.SortCol,
) ([]domain.User, uint64, error) {
	var users []domain.User
	var count uint64

	sortMapping := map[domain.SortCol]SortColQuery{
		domain.SortColIDAsc:    SortColQueryIDAsc,
		domain.SortColIDDesc:   SortColQueryIDDesc,
		domain.SortColNameAsc:  SortColQueryNameAsc,
		domain.SortColNameDesc: SortColQueryNameDesc,
	}

	order, ok := sortMapping[sort]
	if !ok {
		order = SortColQueryIDAsc
	}

	whereClause := make(map[string]interface{})
	if len(filter) != 0 {
		for k, v := range filter {
			columnname := k.String()
			whereClause[columnname] = v
		}
	}

	err := r.DB.
		Preload("Roles").
		Preload("Roles.Rights").
		Preload("Company").
		Where(whereClause).
		Order(order.String()).
		Offset((page - 1) * perPage).
		Limit(perPage).
		Find(&users).
		Offset(0). // Count doesn't work with offset (https://github.com/jinzhu/gorm/issues/1752)
		Count(&count).
		Error
	if err == gorm.ErrRecordNotFound {
		return nil, 0, nil
	}
	if err != nil {
		return nil, 0, err
	}

	return users, count, nil
}

// SortColQuery represents the sorting column
type SortColQuery string

// SortColQuery constants
const (
	SortColQueryIDAsc    SortColQuery = "user_id asc"
	SortColQueryIDDesc   SortColQuery = "user_id desc"
	SortColQueryNameAsc  SortColQuery = "user_name asc"
	SortColQueryNameDesc SortColQuery = "user_name desc"
)

// String for MsgType
func (scq SortColQuery) String() string {
	return string(scq)
}