package sql

import (
	"errors"
	"fmt"
	"git.dragon-labs.de/alphyron/group_helper/config"
	"git.dragon-labs.de/alphyron/group_helper/logic"
	"git.dragon-labs.de/alphyron/group_helper/models"
	"github.com/jinzhu/gorm"
	_ "github.com/jinzhu/gorm/dialects/mssql"
	_ "github.com/jinzhu/gorm/dialects/mysql"
	_ "github.com/jinzhu/gorm/dialects/postgres"
	_ "github.com/jinzhu/gorm/dialects/sqlite"
)

type groupHelperRepository struct {
	Conn *gorm.DB
}

func newMySQLConnection(host string, database string, user string, password string) (*gorm.DB, error) {
	return gorm.Open("mysql", fmt.Sprintf("%s:%s@(%s)/%s?charset=utf8mb4&parseTime=True&loc=Local", user, password, host, database))
}

func newPostgresConnection(host string, port int, database string, user string, password string) (*gorm.DB, error) {
	return gorm.Open("postgres", fmt.Sprintf("host=%s port=%d user=%s dbname=%s password=%s", host, port, user, database, password))
}

func newSQLiteConnection(path string) (*gorm.DB, error) {
	return gorm.Open("sqlite3", path)
}

func newMsSqlConnection(host string, database string, user string, password string) (*gorm.DB, error) {
	return gorm.Open("mssql", fmt.Sprintf("sqlserver://%s:%s@%s?database=%s", user, password, host, database))
}

// NewUserRepository tamdp, test
func NewGroupHelperRepository(config *config.DatabaseConfig) (logic.GroupHelperRepository, error) {
	var (
		db  *gorm.DB
		err error
	)

	switch config.DatabaseType {
	case "mysql":
		db, err = newMySQLConnection(fmt.Sprintf("%s:%d", config.Host, config.Port), config.Database, config.Username, config.Password)
		break
	case "postgres":
		db, err = newPostgresConnection(config.Host, config.Port, config.Database, config.Username, config.Password)
		break
	case "sqlite3":
		db, err = newSQLiteConnection(config.Host)
		break
	case "mssql":
		db, err = newMsSqlConnection(fmt.Sprintf("%s:%d", config.Host, config.Port), config.Database, config.Username, config.Password)
		break
	}

	if err != nil {
		return nil, err
	}

	if db == nil {
		return nil, errors.New("no valid type given (mysql,postgres,sqlite3,mssql)")
	}

	db.LogMode(config.Debug)
	return &groupHelperRepository{Conn: db}, nil
}

// NewUserRepositoryDBConnection creates a user repository with an existing gorm database connection
func NewUserRepositoryDBConnection(db *gorm.DB) logic.GroupHelperRepository {
	return &groupHelperRepository{Conn: db}
}

func (g groupHelperRepository) CreateGroup(group *models.Group) (*models.Group, error) {
	err := g.Conn.Create(group).Error

	if err != nil {
		return nil, errors.New("problem while creating a group - " + err.Error())
	}

	return group, nil
}

func (g groupHelperRepository) UpdateGroup(group *models.Group) (*models.Group, error) {
	err := g.Conn.Where("id = ?", group.ID).Save(group).Error
	return group, err
}

func (g groupHelperRepository) GetGroupByID(id int64) (*models.Group, error) {
	var group models.Group

	defaultGroup := &models.Group{}
	defaultGroup.FillDefaultValues()
	defaultGroup.GroupID = id

	err := g.Conn.Where("group_id = ?", id).First(&group)

	if err.RecordNotFound() {
		return g.CreateGroup(defaultGroup)
	}
	return &group, err.Error
}

func (g groupHelperRepository) GetGroupDatabaseSize(group *models.Group) (int, error) {
	association := g.Conn.Model(group).Association("Users")

	if err := association.Error; err != nil {
		return -1, errors.New("problem while getting the size of users connected with the group - " + err.Error())
	}

	return association.Count(), nil
}

func (g groupHelperRepository) CreateUser(user *models.User) (*models.User, error) {
	err := g.Conn.Create(user).Error

	if err != nil {
		return nil, errors.New("problem while creating a user - " + err.Error())
	}

	return user, nil
}

func (g groupHelperRepository) GetUserByID(userID int64) (*models.User, error) {
	var user models.User
	db := g.Conn.Where("user_id = ?", userID).First(&user)

	if db.RecordNotFound() {
		return g.CreateUser(&models.User{
			UserID: userID,
		})
	}

	if db.Error != nil {
		return nil, errors.New("problem while getting the user by his user id - " + db.Error.Error())
	}
	return &user, nil
}

func (g groupHelperRepository) UserJoinGroup(user *models.User, group *models.Group) (bool, error) {

	err := g.Conn.Model(user).Association("Groups").Append(group).Error

	if err != nil {
		return false, errors.New("problem while connect the user with the group - " + err.Error())
	}
	return true, nil
}

func (g groupHelperRepository) UserLeaveGroup(user *models.User, group *models.Group) (bool, error) {
	err := g.Conn.Model(user).Association("Groups").Delete(group).Error

	if err != nil {
		return false, errors.New("problem while disconnecting the user from the group - " + err.Error())
	}
	return true, nil
}

func (g groupHelperRepository) IsUserInGroup(user *models.User, group *models.Group) (bool, error) {
	association := g.Conn.Model(user).Association("Groups")

	if err := association.Error; err != nil {
		return false, errors.New("problem while checking if the user is connected with the group - " + err.Error())
	}

	association = association.Find(group)

	if err := association.Error; err != nil {
		return false, errors.New("problem while find the user is connected with the group - " + err.Error())
	}

	return association.Count() > 0, nil
}

func (g groupHelperRepository) ListGroups() ([]*models.Group, error) {
	var groups []*models.Group
	err := g.Conn.Find(&groups).Error

	if err != nil {
		return nil, errors.New("problem while getting all group - " + err.Error())
	}
	return groups, nil
}

func (g groupHelperRepository) ListGroupUsers(group *models.Group) ([]*models.User, error) {
	var users []*models.User
	err := g.Conn.Model(group).Related(&users, "GroupUser").Error

	if err != nil {
		return nil, errors.New("problem while getting all users from group - " + err.Error())
	}
	return users, nil
}

func (g groupHelperRepository) ListUsers() ([]*models.User, error) {
	var users []*models.User
	err := g.Conn.Find(&users).Error

	if err != nil {
		return nil, errors.New("problem while getting all users - " + err.Error())
	}
	return users, nil
}

func (g groupHelperRepository) InitRepository() error {
	return g.Conn.AutoMigrate(models.Group{}, models.User{}).Error
}