// Copyright 2015 CoreOS, 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 rafthttp

import (
	"errors"
	"io/ioutil"
	"net/http"
	"sync"
	"testing"

	"github.com/coreos/etcd/etcdserver/stats"
	"github.com/coreos/etcd/pkg/testutil"
	"github.com/coreos/etcd/pkg/types"
	"github.com/coreos/etcd/raft/raftpb"
)

// TestSenderSend tests that send func could post data using roundtripper
// and increase success count in stats.
func TestSenderSend(t *testing.T) {
	tr := &roundTripperRecorder{}
	fs := &stats.FollowerStats{}
	p := NewPeer(tr, "http://10.0.0.1", types.ID(1), types.ID(1), &nopProcessor{}, fs, nil)

	if err := p.Send(raftpb.Message{Type: raftpb.MsgApp}); err != nil {
		t.Fatalf("unexpect send error: %v", err)
	}
	p.Stop()

	if tr.Request() == nil {
		t.Errorf("sender fails to post the data")
	}
	fs.Lock()
	defer fs.Unlock()
	if fs.Counts.Success != 1 {
		t.Errorf("success = %d, want 1", fs.Counts.Success)
	}
}

func TestSenderExceedMaximalServing(t *testing.T) {
	tr := newRoundTripperBlocker()
	fs := &stats.FollowerStats{}
	p := NewPeer(tr, "http://10.0.0.1", types.ID(1), types.ID(1), &nopProcessor{}, fs, nil)

	// keep the sender busy and make the buffer full
	// nothing can go out as we block the sender
	for i := 0; i < connPerSender+senderBufSize; i++ {
		if err := p.Send(raftpb.Message{}); err != nil {
			t.Errorf("send err = %v, want nil", err)
		}
		// force the sender to grab data
		testutil.ForceGosched()
	}

	// try to send a data when we are sure the buffer is full
	if err := p.Send(raftpb.Message{}); err == nil {
		t.Errorf("unexpect send success")
	}

	// unblock the senders and force them to send out the data
	tr.unblock()
	testutil.ForceGosched()

	// It could send new data after previous ones succeed
	if err := p.Send(raftpb.Message{}); err != nil {
		t.Errorf("send err = %v, want nil", err)
	}
	p.Stop()
}

// TestSenderSendFailed tests that when send func meets the post error,
// it increases fail count in stats.
func TestSenderSendFailed(t *testing.T) {
	fs := &stats.FollowerStats{}
	p := NewPeer(newRespRoundTripper(0, errors.New("blah")), "http://10.0.0.1", types.ID(1), types.ID(1), &nopProcessor{}, fs, nil)

	if err := p.Send(raftpb.Message{Type: raftpb.MsgApp}); err != nil {
		t.Fatalf("unexpect Send error: %v", err)
	}
	p.Stop()

	fs.Lock()
	defer fs.Unlock()
	if fs.Counts.Fail != 1 {
		t.Errorf("fail = %d, want 1", fs.Counts.Fail)
	}
}

func TestSenderPost(t *testing.T) {
	tr := &roundTripperRecorder{}
	p := NewPeer(tr, "http://10.0.0.1", types.ID(1), types.ID(1), &nopProcessor{}, nil, nil)
	if err := p.post([]byte("some data")); err != nil {
		t.Fatalf("unexpect post error: %v", err)
	}
	p.Stop()

	if g := tr.Request().Method; g != "POST" {
		t.Errorf("method = %s, want %s", g, "POST")
	}
	if g := tr.Request().URL.String(); g != "http://10.0.0.1" {
		t.Errorf("url = %s, want %s", g, "http://10.0.0.1")
	}
	if g := tr.Request().Header.Get("Content-Type"); g != "application/protobuf" {
		t.Errorf("content type = %s, want %s", g, "application/protobuf")
	}
	if g := tr.Request().Header.Get("X-Etcd-Cluster-ID"); g != "1" {
		t.Errorf("cluster id = %s, want %s", g, "1")
	}
	b, err := ioutil.ReadAll(tr.Request().Body)
	if err != nil {
		t.Fatalf("unexpected ReadAll error: %v", err)
	}
	if string(b) != "some data" {
		t.Errorf("body = %s, want %s", b, "some data")
	}
}

func TestSenderPostBad(t *testing.T) {
	tests := []struct {
		u    string
		code int
		err  error
	}{
		// bad url
		{":bad url", http.StatusNoContent, nil},
		// RoundTrip returns error
		{"http://10.0.0.1", 0, errors.New("blah")},
		// unexpected response status code
		{"http://10.0.0.1", http.StatusOK, nil},
		{"http://10.0.0.1", http.StatusCreated, nil},
	}
	for i, tt := range tests {
		p := NewPeer(newRespRoundTripper(tt.code, tt.err), tt.u, types.ID(1), types.ID(1), &nopProcessor{}, nil, make(chan error))
		err := p.post([]byte("some data"))
		p.Stop()

		if err == nil {
			t.Errorf("#%d: err = nil, want not nil", i)
		}
	}
}

func TestPeerPostErrorc(t *testing.T) {
	tests := []struct {
		u    string
		code int
		err  error
	}{
		{"http://10.0.0.1", http.StatusForbidden, nil},
		{"http://10.0.0.1", http.StatusPreconditionFailed, nil},
	}
	for i, tt := range tests {
		errorc := make(chan error, 1)
		p := NewPeer(newRespRoundTripper(tt.code, tt.err), tt.u, types.ID(1), types.ID(1), &nopProcessor{}, nil, errorc)
		p.post([]byte("some data"))
		p.Stop()
		select {
		case <-errorc:
		default:
			t.Fatalf("#%d: cannot receive from errorc", i)
		}
	}
}

type roundTripperBlocker struct {
	c chan struct{}
}

func newRoundTripperBlocker() *roundTripperBlocker {
	return &roundTripperBlocker{c: make(chan struct{})}
}
func (t *roundTripperBlocker) RoundTrip(req *http.Request) (*http.Response, error) {
	<-t.c
	return &http.Response{StatusCode: http.StatusNoContent, Body: &nopReadCloser{}}, nil
}
func (t *roundTripperBlocker) unblock() {
	close(t.c)
}

type respRoundTripper struct {
	code int
	err  error
}

func newRespRoundTripper(code int, err error) *respRoundTripper {
	return &respRoundTripper{code: code, err: err}
}
func (t *respRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
	return &http.Response{StatusCode: t.code, Body: &nopReadCloser{}}, t.err
}

type roundTripperRecorder struct {
	req *http.Request
	sync.Mutex
}

func (t *roundTripperRecorder) RoundTrip(req *http.Request) (*http.Response, error) {
	t.Lock()
	defer t.Unlock()
	t.req = req
	return &http.Response{StatusCode: http.StatusNoContent, Body: &nopReadCloser{}}, nil
}
func (t *roundTripperRecorder) Request() *http.Request {
	t.Lock()
	defer t.Unlock()
	return t.req
}

type nopReadCloser struct{}

func (n *nopReadCloser) Read(p []byte) (int, error) { return 0, nil }
func (n *nopReadCloser) Close() error               { return nil }