package raft

import (
	"errors"
	"sync"

	"git.giftfish.de/ston1th/raftbbolt/msgpack"
	"github.com/hashicorp/raft"
)

var ErrNotLeader = errors.New("not leader")

type kv map[string][]byte

type KV struct {
	mu sync.Mutex
	m  kv
	r  *raft.Raft
}

func (kv *KV) Get(k string) []byte {
	kv.mu.Lock()
	defer kv.mu.Unlock()
	return kv.m[k]
}

func (kv *KV) Set(k string, v []byte) error {
	if kv.r.State() != raft.Leader {
		return ErrNotLeader
	}

	c := &raftCmd{SET, k, v}
	b, err := msgpack.Marshal(c)
	if err != nil {
		return err
	}

	f := kv.r.Apply(b, raftTimeout)
	return f.Error()
}

// Delete deletes the given key.
func (kv *KV) Delete(k string) error {
	if kv.r.State() != raft.Leader {
		return ErrNotLeader
	}

	c := &raftCmd{Op: DELETE, K: k}
	b, err := msgpack.Marshal(c)
	if err != nil {
		return err
	}

	f := kv.r.Apply(b, raftTimeout)
	return f.Error()
}