/*
   Copyright © 2022 Sameer Rahmani <lxsameer@gnu.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 core

import (
	"io"

	"github.com/cockroachdb/pebble"
	log "github.com/sirupsen/logrus"
)

type DB struct {
	connection *pebble.DB
}

var FILE int8 = 0
var ITEM int8 = 1
var TYPE int8 = 2
var TAG int8 = 4

func tagFor(value []byte, objType int8) []byte {
	// Just to make the stupid go-critic to shutup
	tmp := value
	tmp = append(tmp, byte(objType))
	return tmp
}

func CreateDB(path string) (*DB, error) {
	log.Debugf("Opening up the state db at '%s'", path)
	db, err := pebble.Open(path, nil)
	if err != nil {
		return nil, err
	}

	return &DB{
		connection: db,
	}, nil
}

func (db *DB) Set(k []byte, v []byte, item int8) error {
	taggedKey := tagFor(k, item)
	return db.connection.Set(taggedKey, v, pebble.Sync)
}

func (db *DB) SetItem(k []byte, v []byte) error {
	return db.Set(k, v, ITEM)
}

func (db *DB) SetType(k []byte, v []byte) error {
	return db.Set(k, v, TYPE)
}

func (db *DB) SetTAG(k []byte, v []byte) error {
	return db.Set(k, v, TAG)
}

func (db *DB) SetFile(k []byte, v []byte) error {
	return db.Set(k, v, FILE)
}

func (db *DB) GetString(k string) ([]byte, error) {
	v, closer, err := db.connection.Get([]byte(k))

	if err != nil {
		return nil, err
	}
	defer closer.Close()
	return v, nil
}

func (db *DB) Get(k []byte, defaultValue *[]byte) ([]byte, io.Closer, error) {
	v, closer, err := db.connection.Get(k)
	if err == pebble.ErrNotFound {
		var defaultV []byte

		if defaultValue != nil {
			defaultV = *defaultValue
		}

		return defaultV, closer, nil
	}

	return v, closer, err
}

func (db *DB) GetItem(k []byte, defaultValue *[]byte) ([]byte, io.Closer, error) {
	return db.Get(k, defaultValue)
}

func (db *DB) GetStringOrDefault(k string, default_ interface{}) (interface{}, error) {
	v, closer, err := db.connection.Get([]byte(k))

	if err == pebble.ErrNotFound {
		return default_, nil
	}

	if err != nil {
		return nil, err
	}
	defer closer.Close()
	return v, nil
}

func (db *DB) Close() error {
	return db.connection.Close()
}