package models

import (
	"database/sql"
	"fmt"
	"github.com/go-xorm/xorm"
	"os"
	// Use sqlite
	_ "github.com/mattn/go-sqlite3"
)

// Engine represents a xorm engine or session.
type Engine interface {
	Table(tableNameOrBean interface{}) *xorm.Session
	Count(...interface{}) (int64, error)
	Decr(column string, arg ...interface{}) *xorm.Session
	Delete(interface{}) (int64, error)
	Exec(string, ...interface{}) (sql.Result, error)
	Find(interface{}, ...interface{}) error
	Get(interface{}) (bool, error)
	Id(interface{}) *xorm.Session
	In(string, ...interface{}) *xorm.Session
	Incr(column string, arg ...interface{}) *xorm.Session
	Insert(...interface{}) (int64, error)
	InsertOne(interface{}) (int64, error)
	Iterate(interface{}, xorm.IterFunc) error
	Join(joinOperator string, tablename interface{}, condition string, args ...interface{}) *xorm.Session
	SQL(interface{}, ...interface{}) *xorm.Session
	Where(interface{}, ...interface{}) *xorm.Session
}

var (
	x      *xorm.Engine
	tables []interface{}
)

func init() {
	tables = append(tables,
		new(Teacher),
		new(Vertretungsplan),
	)
}

func getEngine() (*xorm.Engine, error) {
	if err := os.MkdirAll("data/organizer.db", os.ModePerm); err != nil {
		return nil, err
	}
	connStr := "file:data/organizer.db?cache=shared&mode=rwc"
	return xorm.NewEngine("sqlite3", connStr)
}

// SetEngine sets the xorm.Engine
// code by github.com/go-gitea/gitea
func SetEngine() (err error) {
	x, err = getEngine()
	x.ShowSQL(true)
	return nil
}

// NewEngine initializes a new xorm.Engine
// code by github.com/go-gitea/gitea
func NewEngine(migrateFunc func(*xorm.Engine) error) (err error) {
	if err = SetEngine(); err != nil {
		return err
	}

	if err = x.Ping(); err != nil {
		return err
	}

	if err = migrateFunc(x); err != nil {
		return fmt.Errorf("migrate: %v", err)
	}

	if err = x.StoreEngine("InnoDB").Sync2(tables...); err != nil {
		return fmt.Errorf("sync database struct error: %v", err)
	}

	return nil
}