// Copyright 2021-2022 EMQ Technologies Co., Ltd.
//
// Licensed 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 checkpoint

import (
	"github.com/lf-edge/ekuiper/pkg/api"
)

type StreamTask interface {
	Broadcast(data interface{}) error
	GetName() string
	GetStreamContext() api.StreamContext
	SetQos(api.Qos)
}

type NonSourceTask interface {
	StreamTask
	GetInputCount() int
	AddInputCount()

	SetBarrierHandler(BarrierHandler)
}

type SinkTask interface {
	NonSourceTask
}

type BufferOrEvent struct {
	Data    interface{}
	Channel string
}

type StreamCheckpointContext interface {
	Snapshot() error
	SaveState(checkpointId int64) error
}

type Message int

const (
	STOP Message = iota
	ACK
	DEC
)

type Signal struct {
	Message Message
	Barrier
}

type Barrier struct {
	CheckpointId int64
	OpId         string
}