// replication-manager - Replication Manager Monitoring and CLI for MariaDB
// Authors: Guillaume Lefranc <[email protected]>
//          Stephane Varoqui  <[email protected]>
// This source code is licensed under the GNU General Public License, version 3.
// Redistribution/Reuse of this code is permitted under the GNU v3 license, as
// an additional term, ALL code must carry the original Author(s) credit in comment form.
// See LICENSE in this directory for the integral text.

package main

import (
	"encoding/binary"
	"os"
)

type stateFile struct {
	Handle    *os.File
	Name      string
	Count     int32
	Timestamp int64
}

func newStateFile(name string) *stateFile {
	sf := new(stateFile)
	sf.Name = name
	return sf
}

func (sf *stateFile) access() error {
	var err error
	sf.Handle, err = os.OpenFile(sf.Name, os.O_RDWR|os.O_CREATE, 0666)
	if err != nil {
		return err
	}
	return nil
}

func (sf *stateFile) write() error {
	err := sf.Handle.Truncate(0)
	sf.Handle.Seek(0, 0)
	if err != nil {
		return err
	}
	err = binary.Write(sf.Handle, binary.LittleEndian, sf.Count)
	if err != nil {
		return err
	}
	err = binary.Write(sf.Handle, binary.LittleEndian, sf.Timestamp)
	if err != nil {
		return err
	}
	return nil
}

func (sf *stateFile) read() error {
	sf.Handle.Seek(0, 0)
	err := binary.Read(sf.Handle, binary.LittleEndian, &sf.Count)
	if err != nil {
		return err
	}
	err = binary.Read(sf.Handle, binary.LittleEndian, &sf.Timestamp)
	if err != nil {
		return err
	}
	return nil
}