// Copyright 2015 The Prometheus 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 marathon

import (
	"errors"
	"testing"
	"time"

	"github.com/prometheus/common/model"
	"golang.org/x/net/context"

	"github.com/prometheus/prometheus/config"
)

var marathonValidLabel = map[string]string{"prometheus": "yes"}

func newTestDiscovery(client AppListClient) (chan []*config.TargetGroup, *Discovery) {
	ch := make(chan []*config.TargetGroup)
	md := &Discovery{
		Servers: []string{"http://localhost:8080"},
		Client:  client,
	}
	return ch, md
}

func TestMarathonSDHandleError(t *testing.T) {
	var errTesting = errors.New("testing failure")
	ch, md := newTestDiscovery(func(url string) (*AppList, error) {
		return nil, errTesting
	})
	go func() {
		select {
		case tg := <-ch:
			t.Fatalf("Got group: %s", tg)
		default:
		}
	}()
	err := md.updateServices(context.Background(), ch)
	if err != errTesting {
		t.Fatalf("Expected error: %s", err)
	}
}

func TestMarathonSDEmptyList(t *testing.T) {
	ch, md := newTestDiscovery(func(url string) (*AppList, error) {
		return &AppList{}, nil
	})
	go func() {
		select {
		case tg := <-ch:
			if len(tg) > 0 {
				t.Fatalf("Got group: %v", tg)
			}
		default:
		}
	}()
	err := md.updateServices(context.Background(), ch)
	if err != nil {
		t.Fatalf("Got error: %s", err)
	}
}

func marathonTestAppList(labels map[string]string, runningTasks int) *AppList {
	task := Task{
		ID:    "test-task-1",
		Host:  "mesos-slave1",
		Ports: []uint32{31000},
	}
	docker := DockerContainer{Image: "repo/image:tag"}
	container := Container{Docker: docker}
	app := App{
		ID:           "test-service",
		Tasks:        []Task{task},
		RunningTasks: runningTasks,
		Labels:       labels,
		Container:    container,
	}
	return &AppList{
		Apps: []App{app},
	}
}

func TestMarathonSDSendGroup(t *testing.T) {
	ch, md := newTestDiscovery(func(url string) (*AppList, error) {
		return marathonTestAppList(marathonValidLabel, 1), nil
	})
	go func() {
		select {
		case tgs := <-ch:
			tg := tgs[0]

			if tg.Source != "test-service" {
				t.Fatalf("Wrong target group name: %s", tg.Source)
			}
			if len(tg.Targets) != 1 {
				t.Fatalf("Wrong number of targets: %v", tg.Targets)
			}
			tgt := tg.Targets[0]
			if tgt[model.AddressLabel] != "mesos-slave1:31000" {
				t.Fatalf("Wrong target address: %s", tgt[model.AddressLabel])
			}
		default:
			t.Fatal("Did not get a target group.")
		}
	}()
	err := md.updateServices(context.Background(), ch)
	if err != nil {
		t.Fatalf("Got error: %s", err)
	}
}

func TestMarathonSDRemoveApp(t *testing.T) {
	ch, md := newTestDiscovery(func(url string) (*AppList, error) {
		return marathonTestAppList(marathonValidLabel, 1), nil
	})

	go func() {
		up1 := (<-ch)[0]
		up2 := (<-ch)[0]
		if up2.Source != up1.Source {
			t.Fatalf("Source is different: %s", up2)
			if len(up2.Targets) > 0 {
				t.Fatalf("Got a non-empty target set: %s", up2.Targets)
			}
		}
	}()
	err := md.updateServices(context.Background(), ch)
	if err != nil {
		t.Fatalf("Got error on first update: %s", err)
	}

	md.Client = func(url string) (*AppList, error) {
		return marathonTestAppList(marathonValidLabel, 0), nil
	}
	err = md.updateServices(context.Background(), ch)
	if err != nil {
		t.Fatalf("Got error on second update: %s", err)
	}
}

func TestMarathonSDRunAndStop(t *testing.T) {
	ch, md := newTestDiscovery(func(url string) (*AppList, error) {
		return marathonTestAppList(marathonValidLabel, 1), nil
	})
	md.RefreshInterval = time.Millisecond * 10
	ctx, cancel := context.WithCancel(context.Background())

	go func() {
		select {
		case <-ch:
			cancel()
		case <-time.After(md.RefreshInterval * 3):
			cancel()
			t.Fatalf("Update took too long.")
		}
	}()

	md.Run(ctx, ch)

	select {
	case <-ch:
	default:
		t.Fatalf("Channel not closed.")
	}
}