package cloudwatch

import (
	"testing"
	"time"

	"github.com/grafana/grafana-plugin-sdk-go/backend"
	"github.com/grafana/grafana/pkg/components/simplejson"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestRequestParser(t *testing.T) {
	t.Run("Query migration ", func(t *testing.T) {
		t.Run("legacy statistics field is migrated", func(t *testing.T) {
			startTime := time.Now()
			endTime := startTime.Add(2 * time.Hour)
			oldQuery := &backend.DataQuery{
				MaxDataPoints: 0,
				QueryType:     "timeSeriesQuery",
				Interval:      0,
			}
			oldQuery.RefID = "A"
			oldQuery.JSON = []byte(`{
				"region": "us-east-1",
				"namespace": "ec2",
				"metricName": "CPUUtilization",
				"dimensions": {
				  "InstanceId": ["test"]
				},
				"statistics": ["Average", "Sum"],
				"period": "600",
				"hide": false
			  }`)
			migratedQueries, err := migrateLegacyQuery([]backend.DataQuery{*oldQuery}, startTime, endTime)
			require.NoError(t, err)
			assert.Equal(t, 1, len(migratedQueries))

			migratedQuery := migratedQueries[0]
			assert.Equal(t, "A", migratedQuery.RefID)
			model, err := simplejson.NewJson(migratedQuery.JSON)
			require.NoError(t, err)
			assert.Equal(t, "Average", model.Get("statistic").MustString())
			res, err := model.Get("statistic").Array()
			assert.Error(t, err)
			assert.Nil(t, res)
		})
	})

	t.Run("New dimensions structure", func(t *testing.T) {
		query := simplejson.NewFromAny(map[string]interface{}{
			"refId":      "ref1",
			"region":     "us-east-1",
			"namespace":  "ec2",
			"metricName": "CPUUtilization",
			"id":         "",
			"expression": "",
			"dimensions": map[string]interface{}{
				"InstanceId":   []interface{}{"test"},
				"InstanceType": []interface{}{"test2", "test3"},
			},
			"statistic": "Average",
			"period":    "600",
			"hide":      false,
		})

		res, err := parseRequestQuery(query, "ref1", time.Now().Add(-2*time.Hour), time.Now().Add(-time.Hour))
		require.NoError(t, err)
		assert.Equal(t, "us-east-1", res.Region)
		assert.Equal(t, "ref1", res.RefId)
		assert.Equal(t, "ec2", res.Namespace)
		assert.Equal(t, "CPUUtilization", res.MetricName)
		assert.Equal(t, "queryref1", res.Id)
		assert.Empty(t, res.Expression)
		assert.Equal(t, 600, res.Period)
		assert.True(t, res.ReturnData)
		assert.Len(t, res.Dimensions, 2)
		assert.Len(t, res.Dimensions["InstanceId"], 1)
		assert.Len(t, res.Dimensions["InstanceType"], 2)
		assert.Equal(t, "test3", res.Dimensions["InstanceType"][1])
		assert.Equal(t, "Average", res.Statistic)
	})

	t.Run("Old dimensions structure (backwards compatibility)", func(t *testing.T) {
		query := simplejson.NewFromAny(map[string]interface{}{
			"refId":      "ref1",
			"region":     "us-east-1",
			"namespace":  "ec2",
			"metricName": "CPUUtilization",
			"id":         "",
			"expression": "",
			"dimensions": map[string]interface{}{
				"InstanceId":   "test",
				"InstanceType": "test2",
			},
			"statistic": "Average",
			"period":    "600",
			"hide":      false,
		})

		res, err := parseRequestQuery(query, "ref1", time.Now().Add(-2*time.Hour), time.Now().Add(-time.Hour))
		require.NoError(t, err)
		assert.Equal(t, "us-east-1", res.Region)
		assert.Equal(t, "ref1", res.RefId)
		assert.Equal(t, "ec2", res.Namespace)
		assert.Equal(t, "CPUUtilization", res.MetricName)
		assert.Equal(t, "queryref1", res.Id)
		assert.Empty(t, res.Expression)
		assert.Equal(t, 600, res.Period)
		assert.True(t, res.ReturnData)
		assert.Len(t, res.Dimensions, 2)
		assert.Len(t, res.Dimensions["InstanceId"], 1)
		assert.Len(t, res.Dimensions["InstanceType"], 1)
		assert.Equal(t, "test2", res.Dimensions["InstanceType"][0])
		assert.Equal(t, "Average", res.Statistic)
	})

	t.Run("Period defined in the editor by the user is being used when time range is short", func(t *testing.T) {
		query := simplejson.NewFromAny(map[string]interface{}{
			"refId":      "ref1",
			"region":     "us-east-1",
			"namespace":  "ec2",
			"metricName": "CPUUtilization",
			"id":         "",
			"expression": "",
			"dimensions": map[string]interface{}{
				"InstanceId":   "test",
				"InstanceType": "test2",
			},
			"statistic": "Average",
			"hide":      false,
		})
		query.Set("period", "900")

		res, err := parseRequestQuery(query, "ref1", time.Now().Add(-2*time.Hour), time.Now().Add(-time.Hour))
		require.NoError(t, err)
		assert.Equal(t, 900, res.Period)
	})

	t.Run("Period is parsed correctly if not defined by user", func(t *testing.T) {
		query := simplejson.NewFromAny(map[string]interface{}{
			"refId":      "ref1",
			"region":     "us-east-1",
			"namespace":  "ec2",
			"metricName": "CPUUtilization",
			"id":         "",
			"expression": "",
			"dimensions": map[string]interface{}{
				"InstanceId":   "test",
				"InstanceType": "test2",
			},
			"statistic": "Average",
			"hide":      false,
			"period":    "auto",
		})

		t.Run("Time range is 5 minutes", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now()
			from := to.Local().Add(time.Minute * time.Duration(5))

			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 60, res.Period)
		})

		t.Run("Time range is 1 day", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now()
			from := to.AddDate(0, 0, -1)

			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 60, res.Period)
		})

		t.Run("Time range is 2 days", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now()
			from := to.AddDate(0, 0, -2)
			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 300, res.Period)
		})

		t.Run("Time range is 7 days", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now()
			from := to.AddDate(0, 0, -7)

			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 900, res.Period)
		})

		t.Run("Time range is 30 days", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now()
			from := to.AddDate(0, 0, -30)

			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 3600, res.Period)
		})

		t.Run("Time range is 90 days", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now()
			from := to.AddDate(0, 0, -90)

			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 21600, res.Period)
		})

		t.Run("Time range is 1 year", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now()
			from := to.AddDate(-1, 0, 0)

			res, err := parseRequestQuery(query, "ref1", from, to)
			require.Nil(t, err)
			assert.Equal(t, 21600, res.Period)
		})

		t.Run("Time range is 2 years", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now()
			from := to.AddDate(-2, 0, 0)

			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 86400, res.Period)
		})

		t.Run("Time range is 2 days, but 16 days ago", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now().AddDate(0, 0, -14)
			from := to.AddDate(0, 0, -2)
			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 300, res.Period)
		})

		t.Run("Time range is 2 days, but 90 days ago", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now().AddDate(0, 0, -88)
			from := to.AddDate(0, 0, -2)
			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 3600, res.Period)
		})

		t.Run("Time range is 2 days, but 456 days ago", func(t *testing.T) {
			query.Set("period", "auto")
			to := time.Now().AddDate(0, 0, -454)
			from := to.AddDate(0, 0, -2)
			res, err := parseRequestQuery(query, "ref1", from, to)
			require.NoError(t, err)
			assert.Equal(t, 21600, res.Period)
		})
	})

	t.Run("Metric query type, metric editor mode and query api mode", func(t *testing.T) {
		t.Run("when metric query type and metric editor mode is not specified", func(t *testing.T) {
			t.Run("it should be metric search builder", func(t *testing.T) {
				query := getBaseJsonQuery()
				res, err := parseRequestQuery(query, "ref1", time.Now().Add(-2*time.Hour), time.Now().Add(-time.Hour))
				require.NoError(t, err)
				assert.Equal(t, MetricQueryTypeSearch, res.MetricQueryType)
				assert.Equal(t, MetricEditorModeBuilder, res.MetricEditorMode)
				assert.Equal(t, GMDApiModeMetricStat, res.getGMDAPIMode())
			})

			t.Run("and an expression is specified it should be metric search builder", func(t *testing.T) {
				query := getBaseJsonQuery()
				query.Set("expression", "SUM(a)")
				res, err := parseRequestQuery(query, "ref1", time.Now().Add(-2*time.Hour), time.Now().Add(-time.Hour))
				require.NoError(t, err)
				assert.Equal(t, MetricQueryTypeSearch, res.MetricQueryType)
				assert.Equal(t, MetricEditorModeRaw, res.MetricEditorMode)
				assert.Equal(t, GMDApiModeMathExpression, res.getGMDAPIMode())
			})
		})

		t.Run("and an expression is specified it should be metric search builder", func(t *testing.T) {
			query := getBaseJsonQuery()
			query.Set("expression", "SUM(a)")
			res, err := parseRequestQuery(query, "ref1", time.Now().Add(-2*time.Hour), time.Now().Add(-time.Hour))
			require.NoError(t, err)
			assert.Equal(t, MetricQueryTypeSearch, res.MetricQueryType)
			assert.Equal(t, MetricEditorModeRaw, res.MetricEditorMode)
			assert.Equal(t, GMDApiModeMathExpression, res.getGMDAPIMode())
		})
	})

	t.Run("ID is the string `query` appended with refId if refId is a valid MetricData ID", func(t *testing.T) {
		query := getBaseJsonQuery()
		res, err := parseRequestQuery(query, "ref1", time.Now().Add(-2*time.Hour), time.Now().Add(-time.Hour))
		require.NoError(t, err)
		assert.Equal(t, "ref1", res.RefId)
		assert.Equal(t, "queryref1", res.Id)
	})

	t.Run("Valid id is generated if ID is not provided and refId is not a valid MetricData ID", func(t *testing.T) {
		query := getBaseJsonQuery()
		query.Set("refId", "$$")
		res, err := parseRequestQuery(query, "$$", time.Now().Add(-2*time.Hour), time.Now().Add(-time.Hour))
		require.NoError(t, err)
		assert.Equal(t, "$$", res.RefId)
		assert.Regexp(t, validMetricDataID, res.Id)
	})
}

func getBaseJsonQuery() *simplejson.Json {
	return simplejson.NewFromAny(map[string]interface{}{
		"refId":      "ref1",
		"region":     "us-east-1",
		"namespace":  "ec2",
		"metricName": "CPUUtilization",
		"statistic":  "Average",
		"period":     "900",
	})
}