package conditions

import (
	"context"
	"math"
	"testing"
	"time"

	"github.com/google/go-cmp/cmp"
	"github.com/google/go-cmp/cmp/cmpopts"
	"github.com/grafana/grafana-plugin-sdk-go/data"
	"github.com/stretchr/testify/require"

	"github.com/grafana/grafana/pkg/components/null"
	"github.com/grafana/grafana/pkg/components/simplejson"
	"github.com/grafana/grafana/pkg/infra/db/dbtest"
	"github.com/grafana/grafana/pkg/infra/localcache"
	"github.com/grafana/grafana/pkg/services/alerting"
	"github.com/grafana/grafana/pkg/services/datasources"
	fd "github.com/grafana/grafana/pkg/services/datasources/fakes"
	"github.com/grafana/grafana/pkg/services/featuremgmt"
	"github.com/grafana/grafana/pkg/services/validations"
	"github.com/grafana/grafana/pkg/setting"
	"github.com/grafana/grafana/pkg/tsdb/legacydata"
	"github.com/grafana/grafana/pkg/util"
)

func newTimeSeriesPointsFromArgs(values ...float64) legacydata.DataTimeSeriesPoints {
	points := make(legacydata.DataTimeSeriesPoints, 0)

	for i := 0; i < len(values); i += 2 {
		points = append(points, legacydata.DataTimePoint{null.FloatFrom(values[i]), null.FloatFrom(values[i+1])})
	}

	return points
}

func TestQueryCondition(t *testing.T) {
	setup := func() *queryConditionTestContext {
		ctx := &queryConditionTestContext{}
		db := dbtest.NewFakeDB()
		store := alerting.ProvideAlertStore(db, localcache.ProvideService(), &setting.Cfg{}, nil, featuremgmt.WithFeatures())
		ctx.reducer = `{"type":"avg"}`
		ctx.evaluator = `{"type":"gt","params":[100]}`
		ctx.result = &alerting.EvalContext{
			Ctx:              context.Background(),
			Rule:             &alerting.Rule{},
			RequestValidator: &validations.OSSPluginRequestValidator{},
			Store:            store,
			DatasourceService: &fd.FakeDataSourceService{
				DataSources: []*datasources.DataSource{
					{ID: 1, Type: datasources.DS_GRAPHITE},
				},
			},
		}
		return ctx
	}

	t.Run("Can read query condition from json model", func(t *testing.T) {
		ctx := setup()
		_, err := ctx.exec(t)
		require.Nil(t, err)

		require.Equal(t, "5m", ctx.condition.Query.From)
		require.Equal(t, "now", ctx.condition.Query.To)
		require.Equal(t, int64(1), ctx.condition.Query.DatasourceID)

		t.Run("Can read query reducer", func(t *testing.T) {
			reducer := ctx.condition.Reducer
			require.Equal(t, "avg", reducer.Type)
		})

		t.Run("Can read evaluator", func(t *testing.T) {
			evaluator, ok := ctx.condition.Evaluator.(*thresholdEvaluator)
			require.True(t, ok)
			require.Equal(t, "gt", evaluator.Type)
		})
	})

	t.Run("should fire when avg is above 100", func(t *testing.T) {
		ctx := setup()
		points := newTimeSeriesPointsFromArgs(120, 0)
		ctx.series = legacydata.DataTimeSeriesSlice{legacydata.DataTimeSeries{Name: "test1", Points: points}}
		cr, err := ctx.exec(t)

		require.Nil(t, err)
		require.True(t, cr.Firing)
	})

	t.Run("should fire when avg is above 100 on dataframe", func(t *testing.T) {
		ctx := setup()
		ctx.frame = data.NewFrame("",
			data.NewField("time", nil, []time.Time{time.Now(), time.Now()}),
			data.NewField("val", nil, []int64{120, 150}),
		)
		cr, err := ctx.exec(t)

		require.Nil(t, err)
		require.True(t, cr.Firing)
	})

	t.Run("Should not fire when avg is below 100", func(t *testing.T) {
		ctx := setup()
		points := newTimeSeriesPointsFromArgs(90, 0)
		ctx.series = legacydata.DataTimeSeriesSlice{legacydata.DataTimeSeries{Name: "test1", Points: points}}
		cr, err := ctx.exec(t)

		require.Nil(t, err)
		require.False(t, cr.Firing)
	})

	t.Run("Should not fire when avg is below 100 on dataframe", func(t *testing.T) {
		ctx := setup()
		ctx.frame = data.NewFrame("",
			data.NewField("time", nil, []time.Time{time.Now(), time.Now()}),
			data.NewField("val", nil, []int64{12, 47}),
		)
		cr, err := ctx.exec(t)

		require.Nil(t, err)
		require.False(t, cr.Firing)
	})

	t.Run("Should fire if only first series matches", func(t *testing.T) {
		ctx := setup()
		ctx.series = legacydata.DataTimeSeriesSlice{
			legacydata.DataTimeSeries{Name: "test1", Points: newTimeSeriesPointsFromArgs(120, 0)},
			legacydata.DataTimeSeries{Name: "test2", Points: newTimeSeriesPointsFromArgs(0, 0)},
		}
		cr, err := ctx.exec(t)

		require.Nil(t, err)
		require.True(t, cr.Firing)
	})

	t.Run("No series", func(t *testing.T) {
		ctx := setup()
		t.Run("Should set NoDataFound when condition is gt", func(t *testing.T) {
			ctx.series = legacydata.DataTimeSeriesSlice{}
			cr, err := ctx.exec(t)

			require.Nil(t, err)
			require.False(t, cr.Firing)
			require.True(t, cr.NoDataFound)
		})

		t.Run("Should be firing when condition is no_value", func(t *testing.T) {
			ctx.evaluator = `{"type": "no_value", "params": []}`
			ctx.series = legacydata.DataTimeSeriesSlice{}
			cr, err := ctx.exec(t)

			require.Nil(t, err)
			require.True(t, cr.Firing)
		})
	})

	t.Run("Empty series", func(t *testing.T) {
		ctx := setup()
		t.Run("Should set Firing if eval match", func(t *testing.T) {
			ctx.evaluator = `{"type": "no_value", "params": []}`
			ctx.series = legacydata.DataTimeSeriesSlice{
				legacydata.DataTimeSeries{Name: "test1", Points: newTimeSeriesPointsFromArgs()},
			}
			cr, err := ctx.exec(t)

			require.Nil(t, err)
			require.True(t, cr.Firing)
		})

		t.Run("Should set NoDataFound both series are empty", func(t *testing.T) {
			ctx.series = legacydata.DataTimeSeriesSlice{
				legacydata.DataTimeSeries{Name: "test1", Points: newTimeSeriesPointsFromArgs()},
				legacydata.DataTimeSeries{Name: "test2", Points: newTimeSeriesPointsFromArgs()},
			}
			cr, err := ctx.exec(t)

			require.Nil(t, err)
			require.True(t, cr.NoDataFound)
		})

		t.Run("Should set NoDataFound both series contains null", func(t *testing.T) {
			ctx.series = legacydata.DataTimeSeriesSlice{
				legacydata.DataTimeSeries{Name: "test1", Points: legacydata.DataTimeSeriesPoints{legacydata.DataTimePoint{null.FloatFromPtr(nil), null.FloatFrom(0)}}},
				legacydata.DataTimeSeries{Name: "test2", Points: legacydata.DataTimeSeriesPoints{legacydata.DataTimePoint{null.FloatFromPtr(nil), null.FloatFrom(0)}}},
			}
			cr, err := ctx.exec(t)

			require.Nil(t, err)
			require.True(t, cr.NoDataFound)
		})

		t.Run("Should not set NoDataFound if one series is empty", func(t *testing.T) {
			ctx.series = legacydata.DataTimeSeriesSlice{
				legacydata.DataTimeSeries{Name: "test1", Points: newTimeSeriesPointsFromArgs()},
				legacydata.DataTimeSeries{Name: "test2", Points: newTimeSeriesPointsFromArgs(120, 0)},
			}
			cr, err := ctx.exec(t)

			require.Nil(t, err)
			require.False(t, cr.NoDataFound)
		})
	})
}

type queryConditionTestContext struct {
	reducer   string
	evaluator string
	series    legacydata.DataTimeSeriesSlice
	frame     *data.Frame
	result    *alerting.EvalContext
	condition *QueryCondition
}

//nolint:staticcheck // legacydata.DataPlugin deprecated
func (ctx *queryConditionTestContext) exec(t *testing.T) (*alerting.ConditionResult, error) {
	jsonModel, err := simplejson.NewJson([]byte(`{
            "type": "query",
            "query":  {
              "params": ["A", "5m", "now"],
              "datasourceId": 1,
              "model": {"target": "aliasByNode(statsd.fakesite.counters.session_start.mobile.count, 4)"}
            },
            "reducer":` + ctx.reducer + `,
            "evaluator":` + ctx.evaluator + `
          }`))
	require.Nil(t, err)

	condition, err := newQueryCondition(jsonModel, 0)
	require.Nil(t, err)

	ctx.condition = condition

	qr := legacydata.DataQueryResult{
		Series: ctx.series,
	}

	if ctx.frame != nil {
		qr = legacydata.DataQueryResult{
			Dataframes: legacydata.NewDecodedDataFrames(data.Frames{ctx.frame}),
		}
	}
	reqHandler := fakeReqHandler{
		response: legacydata.DataResponse{
			Results: map[string]legacydata.DataQueryResult{
				"A": qr,
			},
		},
	}

	return condition.Eval(ctx.result, reqHandler)
}

type fakeReqHandler struct {
	//nolint: staticcheck // legacydata.DataPlugin deprecated
	response legacydata.DataResponse
}

//nolint:staticcheck // legacydata.DataPlugin deprecated
func (rh fakeReqHandler) HandleRequest(context.Context, *datasources.DataSource, legacydata.DataQuery) (
	legacydata.DataResponse, error) {
	return rh.response, nil
}

func TestFrameToSeriesSlice(t *testing.T) {
	tests := []struct {
		name        string
		frame       *data.Frame
		seriesSlice legacydata.DataTimeSeriesSlice
		Err         require.ErrorAssertionFunc
	}{
		{
			name: "a wide series",
			frame: data.NewFrame("",
				data.NewField("Time", nil, []time.Time{
					time.Date(2020, 1, 2, 3, 4, 0, 0, time.UTC),
					time.Date(2020, 1, 2, 3, 4, 30, 0, time.UTC),
				}),
				data.NewField(`Values Int64s`, data.Labels{"Animal Factor": "cat"}, []*int64{
					nil,
					util.Pointer(int64(3)),
				}),
				data.NewField(`Values Floats`, data.Labels{"Animal Factor": "sloth"}, []float64{
					2.0,
					4.0,
				})),

			seriesSlice: legacydata.DataTimeSeriesSlice{
				legacydata.DataTimeSeries{
					Name: "Values Int64s {Animal Factor=cat}",
					Tags: map[string]string{"Animal Factor": "cat"},
					Points: legacydata.DataTimeSeriesPoints{
						legacydata.DataTimePoint{null.FloatFrom(math.NaN()), null.FloatFrom(1577934240000)},
						legacydata.DataTimePoint{null.FloatFrom(3), null.FloatFrom(1577934270000)},
					},
				},
				legacydata.DataTimeSeries{
					Name: "Values Floats {Animal Factor=sloth}",
					Tags: map[string]string{"Animal Factor": "sloth"},
					Points: legacydata.DataTimeSeriesPoints{
						legacydata.DataTimePoint{null.FloatFrom(2), null.FloatFrom(1577934240000)},
						legacydata.DataTimePoint{null.FloatFrom(4), null.FloatFrom(1577934270000)},
					},
				},
			},
			Err: require.NoError,
		},
		{
			name: "empty wide series",
			frame: data.NewFrame("",
				data.NewField("Time", nil, []time.Time{}),
				data.NewField(`Values Int64s`, data.Labels{"Animal Factor": "cat"}, []*int64{}),
				data.NewField(`Values Floats`, data.Labels{"Animal Factor": "sloth"}, []float64{})),

			seriesSlice: legacydata.DataTimeSeriesSlice{
				legacydata.DataTimeSeries{
					Name:   "Values Int64s {Animal Factor=cat}",
					Tags:   map[string]string{"Animal Factor": "cat"},
					Points: legacydata.DataTimeSeriesPoints{},
				},
				legacydata.DataTimeSeries{
					Name:   "Values Floats {Animal Factor=sloth}",
					Tags:   map[string]string{"Animal Factor": "sloth"},
					Points: legacydata.DataTimeSeriesPoints{},
				},
			},
			Err: require.NoError,
		},
		{
			name: "empty labels",
			frame: data.NewFrame("",
				data.NewField("Time", data.Labels{}, []time.Time{}),
				data.NewField(`Values`, data.Labels{}, []float64{})),

			seriesSlice: legacydata.DataTimeSeriesSlice{
				legacydata.DataTimeSeries{
					Name:   "Values",
					Points: legacydata.DataTimeSeriesPoints{},
				},
			},
			Err: require.NoError,
		},
		{
			name: "display name from data source",
			frame: data.NewFrame("",
				data.NewField("Time", data.Labels{}, []time.Time{}),
				data.NewField(`Values`, data.Labels{"Rating": "10"}, []*int64{}).SetConfig(&data.FieldConfig{
					DisplayNameFromDS: "sloth",
				})),

			seriesSlice: legacydata.DataTimeSeriesSlice{
				legacydata.DataTimeSeries{
					Name:   "sloth",
					Points: legacydata.DataTimeSeriesPoints{},
					Tags:   map[string]string{"Rating": "10"},
				},
			},
			Err: require.NoError,
		},
		{
			name: "prefer display name over data source display name",
			frame: data.NewFrame("",
				data.NewField("Time", data.Labels{}, []time.Time{}),
				data.NewField(`Values`, data.Labels{}, []*int64{}).SetConfig(&data.FieldConfig{
					DisplayName:       "sloth #1",
					DisplayNameFromDS: "sloth #2",
				})),

			seriesSlice: legacydata.DataTimeSeriesSlice{
				legacydata.DataTimeSeries{
					Name:   "sloth #1",
					Points: legacydata.DataTimeSeriesPoints{},
				},
			},
			Err: require.NoError,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			seriesSlice, err := FrameToSeriesSlice(tt.frame)
			tt.Err(t, err)
			if diff := cmp.Diff(tt.seriesSlice, seriesSlice, cmpopts.EquateNaNs()); diff != "" {
				t.Errorf("Result mismatch (-want +got):\n%s", diff)
			}
		})
	}
}