package etcd

import (
	"context"
	"errors"
	"strings"

	"git.giftfish.de/ston1th/vipman/pkg/cluster"
	//"go.etcd.io/etcd/clientv3"
	"github.com/coreos/etcd/clientv3"
	"github.com/go-logr/logr"
)

var ErrKeyNotFound = errors.New("key not found")

type Cluster struct {
	logr.Logger
	cli *clientv3.Client
	ctx context.Context

	stepdown  chan struct{}
	stop      chan struct{}
	done      chan struct{}
	callbacks cluster.Callbacks

	kvPrefix      string
	id            string
	keyID         string
	session       bool
	cancelSession func()
}

func NewCluster(log logr.Logger) cluster.Cluster {
	return &Cluster{
		Logger:   log,
		ctx:      context.Background(),
		stepdown: make(chan struct{}, 1),
		stop:     make(chan struct{}, 1),
		done:     make(chan struct{}, 1),
	}
}

func (c *Cluster) Get(k string) (v []byte, err error) {
	r, err := c.cli.Get(c.ctx, c.kvPrefix+"/"+k)
	if err != nil {
		return
	}
	if len(r.Kvs) == 0 {
		err = ErrKeyNotFound
		return
	}
	v = r.Kvs[0].Value
	return
}

func (c *Cluster) GetPrefix(k string) (m map[string][]byte, err error) {
	r, err := c.cli.Get(c.ctx, c.kvPrefix+"/"+k, clientv3.WithPrefix())
	if err != nil {
		return
	}
	if len(r.Kvs) == 0 {
		err = ErrKeyNotFound
		return
	}
	m = make(map[string][]byte)
	for _, kv := range r.Kvs {
		k := strings.TrimPrefix(c.kvPrefix+"/", string(kv.Key))
		m[k] = kv.Value
	}
	return
}

func (c *Cluster) Set(k string, v []byte) (err error) {
	_, err = c.cli.Put(c.ctx, c.kvPrefix+"/"+k, string(v))
	return
}

func (c *Cluster) Delete(k string) (err error) {
	_, err = c.cli.Delete(c.ctx, c.kvPrefix+"/"+k)
	return
}

func (c *Cluster) SetCallbacks(callbacks cluster.Callbacks) error {
	c.callbacks = callbacks
	return c.checkConfig()
}

func (c *Cluster) ID() string {
	return c.id
}

func (c *Cluster) checkConfig() error {
	if c.callbacks.Leader == nil {
		return errors.New("Leader callback is nil")
	}
	if c.callbacks.Follower == nil {
		return errors.New("Follower callback is nil")
	}
	return nil
}