package prometheus

import (
	"testing"
	"time"

	"github.com/grafana/grafana/pkg/components/simplejson"
	"github.com/grafana/grafana/pkg/models"
	"github.com/grafana/grafana/pkg/plugins"
	p "github.com/prometheus/common/model"
	"github.com/stretchr/testify/require"
)

func TestPrometheus(t *testing.T) {
	dsInfo := &models.DataSource{
		JsonData: simplejson.New(),
	}
	plug, err := NewExecutor(dsInfo)
	executor := plug.(*PrometheusExecutor)
	require.NoError(t, err)

	t.Run("converting metric name", func(t *testing.T) {
		metric := map[p.LabelName]p.LabelValue{
			p.LabelName("app"):    p.LabelValue("backend"),
			p.LabelName("device"): p.LabelValue("mobile"),
		}

		query := &PrometheusQuery{
			LegendFormat: "legend {{app}} {{ device }} {{broken}}",
		}

		require.Equal(t, "legend backend mobile ", formatLegend(metric, query))
	})

	t.Run("build full series name", func(t *testing.T) {
		metric := map[p.LabelName]p.LabelValue{
			p.LabelName(p.MetricNameLabel): p.LabelValue("http_request_total"),
			p.LabelName("app"):             p.LabelValue("backend"),
			p.LabelName("device"):          p.LabelValue("mobile"),
		}

		query := &PrometheusQuery{
			LegendFormat: "",
		}

		require.Equal(t, `http_request_total{app="backend", device="mobile"}`, formatLegend(metric, query))
	})

	t.Run("parsing query model with step", func(t *testing.T) {
		json := `{
				"expr": "go_goroutines",
				"format": "time_series",
				"refId": "A"
			}`
		jsonModel, _ := simplejson.NewJson([]byte(json))
		queryModels := []plugins.DataSubQuery{
			{Model: jsonModel},
		}

		timeRange := plugins.NewDataTimeRange("12h", "now")
		queryContext := plugins.DataQuery{
			Queries:   queryModels,
			TimeRange: &timeRange,
		}

		models, err := executor.parseQuery(dsInfo, queryContext)
		require.NoError(t, err)
		require.Equal(t, time.Second*30, models[0].Step)
	})

	t.Run("parsing query model without step parameter", func(t *testing.T) {
		json := `{
				"expr": "go_goroutines",
				"format": "time_series",
				"intervalFactor": 1,
				"refId": "A"
			}`
		jsonModel, _ := simplejson.NewJson([]byte(json))
		queryModels := []plugins.DataSubQuery{
			{Model: jsonModel},
		}

		timeRange := plugins.NewDataTimeRange("48h", "now")
		queryContext := plugins.DataQuery{
			Queries:   queryModels,
			TimeRange: &timeRange,
		}
		models, err := executor.parseQuery(dsInfo, queryContext)
		require.NoError(t, err)
		require.Equal(t, time.Minute*2, models[0].Step)

		timeRange = plugins.NewDataTimeRange("1h", "now")
		queryContext.TimeRange = &timeRange
		models, err = executor.parseQuery(dsInfo, queryContext)
		require.NoError(t, err)
		require.Equal(t, time.Second*15, models[0].Step)
	})

	t.Run("parsing query model with high intervalFactor", func(t *testing.T) {
		json := `{
					"expr": "go_goroutines",
					"format": "time_series",
					"intervalFactor": 10,
					"refId": "A"
				}`
		jsonModel, _ := simplejson.NewJson([]byte(json))
		queryModels := []plugins.DataSubQuery{
			{Model: jsonModel},
		}

		timeRange := plugins.NewDataTimeRange("48h", "now")
		queryContext := plugins.DataQuery{
			TimeRange: &timeRange,
			Queries:   queryModels,
		}

		models, err := executor.parseQuery(dsInfo, queryContext)
		require.NoError(t, err)
		require.Equal(t, time.Minute*20, models[0].Step)
	})

	t.Run("parsing query model with low intervalFactor", func(t *testing.T) {
		json := `{
					"expr": "go_goroutines",
					"format": "time_series",
					"intervalFactor": 1,
					"refId": "A"
				}`
		jsonModel, _ := simplejson.NewJson([]byte(json))
		queryModels := []plugins.DataSubQuery{
			{Model: jsonModel},
		}

		timeRange := plugins.NewDataTimeRange("48h", "now")
		queryContext := plugins.DataQuery{
			TimeRange: &timeRange,
			Queries:   queryModels,
		}

		models, err := executor.parseQuery(dsInfo, queryContext)
		require.NoError(t, err)
		require.Equal(t, time.Minute*2, models[0].Step)
	})
}

func TestParseResponse(t *testing.T) {
	t.Run("value is not of type matrix", func(t *testing.T) {
		queryRes := plugins.DataQueryResult{}
		value := p.Vector{}
		res, err := parseResponse(value, nil)

		require.Equal(t, queryRes, res)
		require.Error(t, err)
	})

	t.Run("response should be parsed normally", func(t *testing.T) {
		values := []p.SamplePair{
			{Value: 1, Timestamp: 1000},
			{Value: 2, Timestamp: 2000},
			{Value: 3, Timestamp: 3000},
			{Value: 4, Timestamp: 4000},
			{Value: 5, Timestamp: 5000},
		}
		value := p.Matrix{
			&p.SampleStream{
				Metric: p.Metric{"app": "Application", "tag2": "tag2"},
				Values: values,
			},
		}
		query := &PrometheusQuery{
			LegendFormat: "legend {{app}}",
		}
		res, err := parseResponse(value, query)
		require.NoError(t, err)

		decoded, _ := res.Dataframes.Decoded()
		require.Len(t, decoded, 1)
		require.Equal(t, decoded[0].Name, "legend Application")
		require.Len(t, decoded[0].Fields, 2)
		require.Len(t, decoded[0].Fields[0].Labels, 0)
		require.Equal(t, decoded[0].Fields[0].Name, "time")
		require.Len(t, decoded[0].Fields[1].Labels, 2)
		require.Equal(t, decoded[0].Fields[1].Labels.String(), "app=Application, tag2=tag2")
		require.Equal(t, decoded[0].Fields[1].Name, "value")
		require.Equal(t, decoded[0].Fields[1].Config.DisplayNameFromDS, "legend Application")

		// Ensure the timestamps are UTC zoned
		testValue := decoded[0].Fields[0].At(0)
		require.Equal(t, "UTC", testValue.(time.Time).Location().String())
	})
}