// Copyright © 2019 Ettore Di Giacinto <mudler@gentoo.org>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, see <http://www.gnu.org/licenses/>.

package pkg

import (
	"errors"
	"os"
	"strconv"

	storm "github.com/asdine/storm"
	"github.com/asdine/storm/q"
)

//var BoltInstance PackageDatabase

type BoltDatabase struct {
	Path string
}

func NewBoltDatabase(path string) PackageDatabase {
	// if BoltInstance == nil {
	// 	BoltInstance = &BoltDatabase{Path: path}
	// }
	//return BoltInstance, nil
	return &BoltDatabase{Path: path}
}

func (db *BoltDatabase) Get(s string) (string, error) {
	return "", errors.New("Not implemented")
}

func (db *BoltDatabase) Set(k, v string) error {
	return errors.New("Not implemented")

}

func (db *BoltDatabase) Create(v []byte) (string, error) {
	return "", errors.New("Not implemented")
}

func (db *BoltDatabase) Retrieve(ID string) ([]byte, error) {
	return []byte{}, errors.New("Not implemented")
}

func (db *BoltDatabase) FindPackage(tofind Package) (Package, error) {
	p := &DefaultPackage{}
	bolt, err := storm.Open(db.Path)
	if err != nil {
		return nil, err
	}
	defer bolt.Close()

	err = bolt.Select(q.Eq("Name", tofind.GetName()), q.Eq("Category", tofind.GetCategory()), q.Eq("Version", tofind.GetVersion())).Limit(1).First(p)
	if err != nil {
		return nil, err
	}
	return p, nil
}

func (db *BoltDatabase) UpdatePackage(p Package) error {

	bolt, err := storm.Open(db.Path)
	if err != nil {
		return err
	}
	defer bolt.Close()

	dp, ok := p.(*DefaultPackage)
	if !ok {
		return errors.New("Bolt DB support only DefaultPackage type for now")
	}
	err = bolt.Update(dp)
	if err != nil {
		return err
	}

	return err
}

func (db *BoltDatabase) GetPackage(ID string) (Package, error) {
	p := &DefaultPackage{}
	bolt, err := storm.Open(db.Path)
	if err != nil {
		return nil, err
	}
	defer bolt.Close()
	iid, err := strconv.Atoi(ID)
	if err != nil {
		return nil, err
	}
	err = bolt.One("ID", iid, p)
	return p, err
}

func (db *BoltDatabase) GetPackages() []string {
	ids := []string{}
	bolt, err := storm.Open(db.Path)
	if err != nil {
		return []string{}
	}
	defer bolt.Close()
	// Fetching records one by one (useful when the bucket contains a lot of records)
	query := bolt.Select()

	query.Each(new(DefaultPackage), func(record interface{}) error {
		u := record.(*DefaultPackage)
		ids = append(ids, strconv.Itoa(u.ID))
		return nil
	})
	return ids
}

// Encode encodes the package to string.
// It returns an ID which can be used to retrieve the package later on.
func (db *BoltDatabase) CreatePackage(p Package) (string, error) {
	bolt, err := storm.Open(db.Path)
	if err != nil {
		return "", err
	}
	defer bolt.Close()

	dp, ok := p.(*DefaultPackage)
	if !ok {
		return "", errors.New("Bolt DB support only DefaultPackage type for now")
	}
	err = bolt.Save(dp)
	if err != nil {
		return "", err
	}

	return strconv.Itoa(dp.ID), err
}

func (db *BoltDatabase) Clean() error {
	return os.RemoveAll(db.Path)
}