// Copyright (c) 2016-2019 Uber Technologies, Inc.
//
// 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 conn

import (
	"net"
	"time"

	"github.com/andres-erbsen/clock"
	"github.com/uber-go/tally"
	"go.uber.org/zap"

	"github.com/uber/kraken/core"
	"github.com/uber/kraken/lib/torrent/networkevent"
	"github.com/uber/kraken/lib/torrent/storage"
	"github.com/uber/kraken/utils/closers"
	"github.com/uber/kraken/utils/testutil"
)

type noopEvents struct{}

func (e noopEvents) ConnClosed(*Conn) {}

// noopDeadline wraps a Conn which does not support deadlines (e.g. net.Pipe)
// and makes it accept deadlines.
type noopDeadline struct {
	net.Conn
}

func (n noopDeadline) SetDeadline(t time.Time) error      { return nil }
func (n noopDeadline) SetReadDeadline(t time.Time) error  { return nil }
func (n noopDeadline) SetWriteDeadline(t time.Time) error { return nil }

// PipeFixture returns Conns for both sides of a live connection for testing.
func PipeFixture(
	config Config, info *storage.TorrentInfo) (local *Conn, remote *Conn, cleanupFunc func()) {

	var cleanup testutil.Cleanup
	defer cleanup.Recover()

	nc1, nc2 := net.Pipe()
	cleanup.Add(func() { closers.Close(nc1) })
	cleanup.Add(func() { closers.Close(nc2) })

	var err error

	local, err = HandshakerFixture(config).newConn(
		noopDeadline{nc1}, core.PeerIDFixture(), false, info, false)
	if err != nil {
		panic(err)
	}
	local.Start()

	remote, err = HandshakerFixture(config).newConn(
		noopDeadline{nc2}, core.PeerIDFixture(), false, info, true)
	if err != nil {
		panic(err)
	}
	remote.Start()

	return local, remote, cleanup.Run
}

// Fixture returns a single local Conn for testing.
func Fixture() (*Conn, func()) {
	info := storage.TorrentInfoFixture(1, 1)
	local, _, cleanup := PipeFixture(Config{}, info)
	return local, cleanup
}

// HandshakerFixture returns a Handshaker for testing.
func HandshakerFixture(config Config) *Handshaker {
	h, err := NewHandshaker(
		config,
		tally.NewTestScope("", nil),
		clock.New(),
		networkevent.NewTestProducer(),
		core.PeerIDFixture(),
		noopEvents{},
		zap.NewNop().Sugar())
	if err != nil {
		panic(err)
	}
	return h
}

// ConfigFixture returns a Config for testing.
func ConfigFixture() Config {
	return Config{}.applyDefaults()
}