package stackdriver

import (
	"context"
	"errors"
	"fmt"
	"log"
	"net"
	"os"
	"strings"
	"testing"
	"time"

	monitoring "cloud.google.com/go/monitoring/apiv3"
	"github.com/golang/protobuf/proto"
	emptypb "github.com/golang/protobuf/ptypes/empty"
	googlepb "github.com/golang/protobuf/ptypes/timestamp"
	"github.com/influxdata/telegraf"
	"github.com/influxdata/telegraf/testutil"
	"github.com/stretchr/testify/require"
	"google.golang.org/api/option"
	monitoringpb "google.golang.org/genproto/googleapis/monitoring/v3"
	"google.golang.org/grpc"
	"google.golang.org/grpc/metadata"
)

// clientOpt is the option tests should use to connect to the test server.
// It is initialized by TestMain.
var clientOpt option.ClientOption

var mockMetric mockMetricServer

type mockMetricServer struct {
	// Embed for forward compatibility.
	// Tests will keep working if more methods are added
	// in the future.
	monitoringpb.MetricServiceServer

	reqs []proto.Message

	// If set, all calls return this error.
	err error

	// responses to return if err == nil
	resps []proto.Message
}

func (s *mockMetricServer) CreateTimeSeries(ctx context.Context, req *monitoringpb.CreateTimeSeriesRequest) (*emptypb.Empty, error) {
	md, _ := metadata.FromIncomingContext(ctx)
	if xg := md["x-goog-api-client"]; len(xg) == 0 || !strings.Contains(xg[0], "gl-go/") {
		return nil, fmt.Errorf("x-goog-api-client = %v, expected gl-go key", xg)
	}
	s.reqs = append(s.reqs, req)
	if s.err != nil {
		return nil, s.err
	}
	return s.resps[0].(*emptypb.Empty), nil
}

func TestMain(m *testing.M) {
	serv := grpc.NewServer()
	monitoringpb.RegisterMetricServiceServer(serv, &mockMetric)

	lis, err := net.Listen("tcp", "localhost:0")
	if err != nil {
		log.Fatal(err)
	}
	go serv.Serve(lis)

	conn, err := grpc.Dial(lis.Addr().String(), grpc.WithInsecure())
	if err != nil {
		log.Fatal(err)
	}
	clientOpt = option.WithGRPCConn(conn)

	os.Exit(m.Run())
}

func TestWrite(t *testing.T) {
	expectedResponse := &emptypb.Empty{}
	mockMetric.err = nil
	mockMetric.reqs = nil
	mockMetric.resps = append(mockMetric.resps[:0], expectedResponse)

	c, err := monitoring.NewMetricClient(context.Background(), clientOpt)
	if err != nil {
		t.Fatal(err)
	}

	s := &Stackdriver{
		Project:   fmt.Sprintf("projects/%s", "[PROJECT]"),
		Namespace: "test",
		client:    c,
	}

	err = s.Connect()
	require.NoError(t, err)
	err = s.Write(testutil.MockMetrics())
	require.NoError(t, err)

	request := mockMetric.reqs[0].(*monitoringpb.CreateTimeSeriesRequest)
	require.Equal(t, request.TimeSeries[0].Resource.Type, "global")
	require.Equal(t, request.TimeSeries[0].Resource.Labels["project_id"], "projects/[PROJECT]")
}

func TestWriteResourceTypeAndLabels(t *testing.T) {
	expectedResponse := &emptypb.Empty{}
	mockMetric.err = nil
	mockMetric.reqs = nil
	mockMetric.resps = append(mockMetric.resps[:0], expectedResponse)

	c, err := monitoring.NewMetricClient(context.Background(), clientOpt)
	if err != nil {
		t.Fatal(err)
	}

	s := &Stackdriver{
		Project:      fmt.Sprintf("projects/%s", "[PROJECT]"),
		Namespace:    "test",
		ResourceType: "foo",
		ResourceLabels: map[string]string{
			"mylabel": "myvalue",
		},
		client: c,
	}

	err = s.Connect()
	require.NoError(t, err)
	err = s.Write(testutil.MockMetrics())
	require.NoError(t, err)

	request := mockMetric.reqs[0].(*monitoringpb.CreateTimeSeriesRequest)
	require.Equal(t, request.TimeSeries[0].Resource.Type, "foo")
	require.Equal(t, request.TimeSeries[0].Resource.Labels["project_id"], "projects/[PROJECT]")
	require.Equal(t, request.TimeSeries[0].Resource.Labels["mylabel"], "myvalue")
}

func TestWriteAscendingTime(t *testing.T) {
	expectedResponse := &emptypb.Empty{}
	mockMetric.err = nil
	mockMetric.reqs = nil
	mockMetric.resps = append(mockMetric.resps[:0], expectedResponse)

	c, err := monitoring.NewMetricClient(context.Background(), clientOpt)
	if err != nil {
		t.Fatal(err)
	}

	s := &Stackdriver{
		Project:   fmt.Sprintf("projects/%s", "[PROJECT]"),
		Namespace: "test",
		client:    c,
	}

	// Metrics in descending order of timestamp
	metrics := []telegraf.Metric{
		testutil.MustMetric("cpu",
			map[string]string{},
			map[string]interface{}{
				"value": 42,
			},
			time.Unix(2, 0),
		),
		testutil.MustMetric("cpu",
			map[string]string{},
			map[string]interface{}{
				"value": 43,
			},
			time.Unix(1, 0),
		),
	}

	err = s.Connect()
	require.NoError(t, err)
	err = s.Write(metrics)
	require.NoError(t, err)

	require.Len(t, mockMetric.reqs, 2)
	request := mockMetric.reqs[0].(*monitoringpb.CreateTimeSeriesRequest)
	require.Len(t, request.TimeSeries, 1)
	ts := request.TimeSeries[0]
	require.Len(t, ts.Points, 1)
	require.Equal(t, ts.Points[0].Interval, &monitoringpb.TimeInterval{
		EndTime: &googlepb.Timestamp{
			Seconds: 1,
		},
	})
	require.Equal(t, ts.Points[0].Value, &monitoringpb.TypedValue{
		Value: &monitoringpb.TypedValue_Int64Value{
			Int64Value: int64(43),
		},
	})

	request = mockMetric.reqs[1].(*monitoringpb.CreateTimeSeriesRequest)
	require.Len(t, request.TimeSeries, 1)
	ts = request.TimeSeries[0]
	require.Len(t, ts.Points, 1)
	require.Equal(t, ts.Points[0].Interval, &monitoringpb.TimeInterval{
		EndTime: &googlepb.Timestamp{
			Seconds: 2,
		},
	})
	require.Equal(t, ts.Points[0].Value, &monitoringpb.TypedValue{
		Value: &monitoringpb.TypedValue_Int64Value{
			Int64Value: int64(42),
		},
	})
}

func TestWriteBatchable(t *testing.T) {
	expectedResponse := &emptypb.Empty{}
	mockMetric.err = nil
	mockMetric.reqs = nil
	mockMetric.resps = append(mockMetric.resps[:0], expectedResponse)

	c, err := monitoring.NewMetricClient(context.Background(), clientOpt)
	if err != nil {
		t.Fatal(err)
	}

	s := &Stackdriver{
		Project:   fmt.Sprintf("projects/%s", "[PROJECT]"),
		Namespace: "test",
		client:    c,
	}

	// Metrics in descending order of timestamp
	metrics := []telegraf.Metric{
		testutil.MustMetric("cpu",
			map[string]string{
				"foo": "bar",
			},
			map[string]interface{}{
				"value": 42,
			},
			time.Unix(2, 0),
		),
		testutil.MustMetric("cpu",
			map[string]string{
				"foo": "foo",
			},
			map[string]interface{}{
				"value": 43,
			},
			time.Unix(3, 0),
		),
		testutil.MustMetric("cpu",
			map[string]string{
				"foo": "bar",
			},
			map[string]interface{}{
				"value": 43,
			},
			time.Unix(1, 0),
		),
	}

	err = s.Connect()
	require.NoError(t, err)
	err = s.Write(metrics)
	require.NoError(t, err)

	require.Len(t, mockMetric.reqs, 2)
	request := mockMetric.reqs[0].(*monitoringpb.CreateTimeSeriesRequest)
	require.Len(t, request.TimeSeries, 2)
	ts := request.TimeSeries[0]
	require.Len(t, ts.Points, 1)
	require.Equal(t, ts.Points[0].Interval, &monitoringpb.TimeInterval{
		EndTime: &googlepb.Timestamp{
			Seconds: 3,
		},
	})
	require.Equal(t, ts.Points[0].Value, &monitoringpb.TypedValue{
		Value: &monitoringpb.TypedValue_Int64Value{
			Int64Value: int64(43),
		},
	})

	ts = request.TimeSeries[1]
	require.Len(t, ts.Points, 1)
	require.Equal(t, ts.Points[0].Interval, &monitoringpb.TimeInterval{
		EndTime: &googlepb.Timestamp{
			Seconds: 1,
		},
	})
	require.Equal(t, ts.Points[0].Value, &monitoringpb.TypedValue{
		Value: &monitoringpb.TypedValue_Int64Value{
			Int64Value: int64(43),
		},
	})
}

func TestWriteIgnoredErrors(t *testing.T) {
	tests := []struct {
		name        string
		err         error
		expectedErr bool
	}{
		{
			name: "points too old",
			err:  errors.New(errStringPointsTooOld),
		},
		{
			name: "points out of order",
			err:  errors.New(errStringPointsOutOfOrder),
		},
		{
			name: "points too frequent",
			err:  errors.New(errStringPointsTooFrequent),
		},
		{
			name:        "other errors reported",
			err:         errors.New("test"),
			expectedErr: true,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			mockMetric.err = tt.err
			mockMetric.reqs = nil

			c, err := monitoring.NewMetricClient(context.Background(), clientOpt)
			if err != nil {
				t.Fatal(err)
			}

			s := &Stackdriver{
				Project:   fmt.Sprintf("projects/%s", "[PROJECT]"),
				Namespace: "test",
				client:    c,
			}

			err = s.Connect()
			require.NoError(t, err)
			err = s.Write(testutil.MockMetrics())
			if tt.expectedErr {
				require.Error(t, err)
			} else {
				require.NoError(t, err)
			}
		})
	}
}

func TestGetStackdriverLabels(t *testing.T) {
	tags := []*telegraf.Tag{
		{Key: "project", Value: "bar"},
		{Key: "discuss", Value: "revolutionary"},
		{Key: "marble", Value: "discount"},
		{Key: "applied", Value: "falsify"},
		{Key: "test", Value: "foo"},
		{Key: "porter", Value: "discount"},
		{Key: "play", Value: "tiger"},
		{Key: "fireplace", Value: "display"},
		{Key: "host", Value: "this"},
		{Key: "name", Value: "bat"},
		{Key: "device", Value: "local"},
		{Key: "reserve", Value: "publication"},
		{Key: "xpfqacltlmpguimhtjlou2qlmf9uqqwk3teajwlwqkoxtsppbnjksaxvzc1aa973pho9m96gfnl5op8ku7sv93rexyx42qe3zty12ityv", Value: "keyquota"},
		{Key: "valuequota", Value: "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"},
	}

	labels := getStackdriverLabels(tags)
	require.Equal(t, QuotaLabelsPerMetricDescriptor, len(labels))
}