// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements.  See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License.  You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package discovery

import (
	"encoding/json"
	"fmt"
	"github.com/apache/servicecomb-service-center/pkg/util"
	pb "github.com/apache/servicecomb-service-center/server/core/proto"
	"github.com/apache/servicecomb-service-center/server/plugin/pkg/registry"
	"strconv"
)

var (
	Types     []Type
	typeNames []string
)

const (
	TypeError = Type(-1)
)

type Type int

func (st Type) String() string {
	if int(st) < 0 {
		return "TypeError"
	}
	if int(st) < len(typeNames) {
		return typeNames[st]
	}
	return "TYPE" + strconv.Itoa(int(st))
}

func RegisterType(name string) (newId Type, err error) {
	for _, n := range Types {
		if n.String() == name {
			return TypeError, fmt.Errorf("redeclare store type '%s'", n)
		}
	}
	newId = Type(len(Types))
	Types = append(Types, newId)
	typeNames = append(typeNames, name)
	return
}

type KeyValue struct {
	Key            []byte
	Value          interface{}
	Version        int64
	CreateRevision int64
	ModRevision    int64
	ClusterName    string
}

func (kv *KeyValue) String() string {
	b, _ := json.Marshal(kv.Value)
	return fmt.Sprintf("{key: '%s', value: %s, version: %d, cluster: '%s'}",
		util.BytesToStringWithNoCopy(kv.Key), util.BytesToStringWithNoCopy(b), kv.Version, kv.ClusterName)
}

func NewKeyValue() *KeyValue {
	return &KeyValue{ClusterName: registry.Configuration().ClusterName}
}

type Response struct {
	Kvs   []*KeyValue
	Count int64
}

type KvEvent struct {
	Revision int64
	Type     pb.EventType
	KV       *KeyValue
}

type KvEventFunc func(evt KvEvent)

type KvEventHandler interface {
	Type() Type
	OnEvent(evt KvEvent)
}