package storage

import (
	"fmt"
	"regexp"

	"github.com/jinzhu/gorm"
	// Import only the mysql driver for the connection. Functions are not needed.
	_ "github.com/jinzhu/gorm/dialects/mysql"
)

// DatabaseRepository contains functions to interact with a MySQL database
type DatabaseRepository struct {
	db *gorm.DB
}

// NewDatabaseRepository returns a repository that interacts with a MySQL database
func NewDatabaseRepository(host, user, password, name string) (*DatabaseRepository, error) {
	var err error
	constring := fmt.Sprintf("%s:%s@(%s)/%s?charset=utf8&parseTime=True&loc=Local",
		user,
		password,
		host,
		name)
	dbHandle, err := gorm.Open("mysql", constring)
	if err != nil {
		return nil, fmt.Errorf("failed to connect database: %v", err)
	}

	r := &DatabaseRepository{
		db: dbHandle,
	}
	return r, nil
}

// GetDeviceByIMEI returns a device by it's IMEI
func (c *DatabaseRepository) GetDeviceByIMEI(imei string) (*Device, error) {
	v := &Device{}
	if err := c.db.First(v, "imei = ?", imei).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, ErrNotFound
		}
		return nil, err
	}
	return v, nil
}

// GetDeviceByDeviceUID returns a device by it's device UID
func (c *DatabaseRepository) GetDeviceByDeviceUID(deviceUID string) (*Device, error) {
	var devRegex = regexp.MustCompile(`^010+([0-9]+)$`)
	res := devRegex.FindStringSubmatch(deviceUID)
	if len(res) < 2 {
		return nil, ErrNotFound
	}
	v := &Device{}
	if err := c.db.First(v, "id = ?", res[1]).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, ErrNotFound
		}
		return nil, err
	}
	return v, nil
}