// Copyright 2018 The etcd Authors
//
// 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 tester

import (
	"fmt"
	"time"

	"github.com/coreos/etcd/tools/functional-tester/rpcpb"
)

const (
	// TODO
	slowNetworkLatency = 500 // 500 millisecond

	// delay duration to trigger leader election (default election timeout 1s)
	triggerElectionDur = 5 * time.Second

	// Wait more when it recovers from slow network, because network layer
	// needs extra time to propagate traffic control (tc command) change.
	// Otherwise, we get different hash values from the previous revision.
	// For more detail, please see https://github.com/coreos/etcd/issues/5121.
	waitRecover = 5 * time.Second
)

func injectDelayPeerPortTxRx(clus *Cluster, idx int) error {
	return clus.sendOperation(idx, rpcpb.Operation_DelayPeerPortTxRx)
}

func recoverDelayPeerPortTxRx(clus *Cluster, idx int) error {
	err := clus.sendOperation(idx, rpcpb.Operation_UndelayPeerPortTxRx)
	time.Sleep(waitRecover)
	return err
}

func newFailureDelayPeerPortTxRxOneMember() Failure {
	desc := fmt.Sprintf("delay one member's network by adding %d ms latency", slowNetworkLatency)
	f := &failureOne{
		description:   description(desc),
		injectMember:  injectDelayPeerPortTxRx,
		recoverMember: recoverDelayPeerPortTxRx,
	}
	return &failureDelay{
		Failure:       f,
		delayDuration: triggerElectionDur,
	}
}

func newFailureDelayPeerPortTxRxLeader() Failure {
	desc := fmt.Sprintf("delay leader's network by adding %d ms latency", slowNetworkLatency)
	ff := failureByFunc{
		description:   description(desc),
		injectMember:  injectDelayPeerPortTxRx,
		recoverMember: recoverDelayPeerPortTxRx,
	}
	f := &failureLeader{ff, 0}
	return &failureDelay{
		Failure:       f,
		delayDuration: triggerElectionDur,
	}
}

func newFailureDelayPeerPortTxRxAll() Failure {
	f := &failureAll{
		description:   "delay all members' network",
		injectMember:  injectDelayPeerPortTxRx,
		recoverMember: recoverDelayPeerPortTxRx,
	}
	return &failureDelay{
		Failure:       f,
		delayDuration: triggerElectionDur,
	}
}