package cloudwatch

import (
	"context"
	"encoding/json"
	"testing"
	"time"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/cloudwatch"
	"github.com/aws/aws-sdk-go/service/cloudwatch/cloudwatchiface"
	"github.com/grafana/grafana-plugin-sdk-go/backend"
	"github.com/grafana/grafana-plugin-sdk-go/backend/datasource"
	"github.com/grafana/grafana-plugin-sdk-go/backend/instancemgmt"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestTimeSeriesQuery(t *testing.T) {
	executor := newExecutor(nil, newTestConfig(), fakeSessionCache{})
	now := time.Now()

	origNewCWClient := NewCWClient
	t.Cleanup(func() {
		NewCWClient = origNewCWClient
	})

	var cwClient FakeCWClient

	NewCWClient = func(sess *session.Session) cloudwatchiface.CloudWatchAPI {
		return cwClient
	}

	t.Run("Custom metrics", func(t *testing.T) {
		cwClient = FakeCWClient{
			CloudWatchAPI: nil,
			GetMetricDataOutput: cloudwatch.GetMetricDataOutput{
				NextToken: nil,
				Messages:  []*cloudwatch.MessageData{},
				MetricDataResults: []*cloudwatch.MetricDataResult{
					{
						StatusCode: aws.String("Complete"), Id: aws.String("a"), Label: aws.String("NetworkOut"), Values: []*float64{aws.Float64(1.0)}, Timestamps: []*time.Time{&now},
					},
					{
						StatusCode: aws.String("Complete"), Id: aws.String("b"), Label: aws.String("NetworkIn"), Values: []*float64{aws.Float64(1.0)}, Timestamps: []*time.Time{&now},
					},
				},
			},
		}

		im := datasource.NewInstanceManager(func(s backend.DataSourceInstanceSettings) (instancemgmt.Instance, error) {
			return datasourceInfo{}, nil
		})

		executor := newExecutor(im, newTestConfig(), fakeSessionCache{})
		resp, err := executor.QueryData(context.Background(), &backend.QueryDataRequest{
			PluginContext: backend.PluginContext{
				DataSourceInstanceSettings: &backend.DataSourceInstanceSettings{},
			},
			Queries: []backend.DataQuery{
				{
					RefID: "A",
					TimeRange: backend.TimeRange{
						From: now.Add(time.Hour * -2),
						To:   now.Add(time.Hour * -1),
					},
					JSON: json.RawMessage(`{
						"type":      "timeSeriesQuery",
						"subtype":   "metrics",
						"namespace": "AWS/EC2",
						"metricName": "NetworkOut",
						"expression": "",
						"dimensions": {
						  "InstanceId": "i-00645d91ed77d87ac"
						},
						"region": "us-east-2",
						"id": "a",
						"alias": "NetworkOut",
						"statistics": [
						  "Maximum"
						],
						"period": "300",
						"hide": false,
						"matchExact": true,
						"refId": "A"
					}`),
				},
				{
					RefID: "B",
					TimeRange: backend.TimeRange{
						From: now.Add(time.Hour * -2),
						To:   now.Add(time.Hour * -1),
					},
					JSON: json.RawMessage(`{
						"type":      "timeSeriesQuery",
						"subtype":   "metrics",
						"namespace": "AWS/EC2",
						"metricName": "NetworkIn",
						"expression": "",
						"dimensions": {
						"InstanceId": "i-00645d91ed77d87ac"
						},
						"region": "us-east-2",
						"id": "b",
						"alias": "NetworkIn",
						"statistics": [
						"Maximum"
						],
						"period": "300",
						"matchExact": true,
						"refId": "B"
					}`),
				},
			},
		})
		require.NoError(t, err)
		assert.Equal(t, "NetworkOut", resp.Responses["A"].Frames[0].Name)
		assert.Equal(t, "NetworkIn", resp.Responses["B"].Frames[0].Name)
	})

	t.Run("End time before start time should result in error", func(t *testing.T) {
		_, err := executor.executeTimeSeriesQuery(context.Background(), &backend.QueryDataRequest{Queries: []backend.DataQuery{{TimeRange: backend.TimeRange{
			From: now.Add(time.Hour * -1),
			To:   now.Add(time.Hour * -2),
		}}}})
		assert.EqualError(t, err, "invalid time range: start time must be before end time")
	})

	t.Run("End time equals start time should result in error", func(t *testing.T) {
		_, err := executor.executeTimeSeriesQuery(context.Background(), &backend.QueryDataRequest{Queries: []backend.DataQuery{{TimeRange: backend.TimeRange{
			From: now.Add(time.Hour * -1),
			To:   now.Add(time.Hour * -1),
		}}}})
		assert.EqualError(t, err, "invalid time range: start time must be before end time")
	})
}