/*
   Copyright 2014 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{}
	s := NewSender(tr, "http://10.0.0.1", types.ID(1), &nopProcessor{}, fs, nil)

	if err := s.Send(raftpb.Message{}); err != nil {
		t.Fatalf("unexpect send error: %v", err)
	}
	s.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{}
	s := NewSender(tr, "http://10.0.0.1", 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 := s.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 := s.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 := s.Send(raftpb.Message{}); err != nil {
		t.Errorf("send err = %v, want nil", err)
	}
	s.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{}
	s := NewSender(newRespRoundTripper(0, errors.New("blah")), "http://10.0.0.1", types.ID(1), &nopProcessor{}, fs, nil)

	if err := s.Send(raftpb.Message{}); err != nil {
		t.Fatalf("unexpect Send error: %v", err)
	}
	s.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{}
	s := NewSender(tr, "http://10.0.0.1", types.ID(1), &nopProcessor{}, nil, nil)
	if err := s.post([]byte("some data")); err != nil {
		t.Fatalf("unexpect post error: %v", err)
	}
	s.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 {
		shouldstop := make(chan struct{})
		s := NewSender(newRespRoundTripper(tt.code, tt.err), tt.u, types.ID(1), &nopProcessor{}, nil, shouldstop)
		err := s.post([]byte("some data"))
		s.Stop()

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

func TestSenderPostShouldStop(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 {
		shouldstop := make(chan struct{}, 1)
		s := NewSender(newRespRoundTripper(tt.code, tt.err), tt.u, types.ID(1), &nopProcessor{}, nil, shouldstop)
		s.post([]byte("some data"))
		s.Stop()
		select {
		case <-shouldstop:
		default:
			t.Fatalf("#%d: cannot receive shouldstop notification", 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 }