package cluster

import (
	"fmt"
	"io"
	"sync"

	"github.com/hashicorp/raft"
	"gitlink.org.cn/cloudream/common/utils/io2"
)

type FSM struct {
	data string
	lock sync.Mutex
}

func NewFSM() *FSM {
	return &FSM{data: ""}
}

func (f *FSM) Apply(l *raft.Log) interface{} {
	fmt.Printf("log: %v\n", string(l.Data))

	f.lock.Lock()
	defer f.lock.Unlock()

	f.data = f.data + "\n" + string(l.Data)
	return nil
}

func (f *FSM) Snapshot() (raft.FSMSnapshot, error) {
	f.lock.Lock()
	defer f.lock.Unlock()

	return &Snapshot{data: f.data}, nil
}

func (f *FSM) Restore(rc io.ReadCloser) error {
	data, err := io.ReadAll(rc)
	if err != nil {
		return err
	}

	f.lock.Lock()
	defer f.lock.Unlock()

	f.data = string(data)
	return nil
}

var _ raft.FSM = (*FSM)(nil)

type Snapshot struct {
	data string
}

func (s *Snapshot) Persist(sink raft.SnapshotSink) error {
	err := io2.WriteAll(sink, []byte(s.data))
	if err != nil {
		return sink.Cancel()
	}

	return sink.Close()
}

func (s *Snapshot) Release() {
}