package postgres

import (
	"encoding/json"
	"fmt"
	"math/rand"
	"strings"
	"testing"
	"time"

	"github.com/grafana/grafana-plugin-sdk-go/backend"
	"github.com/grafana/grafana-plugin-sdk-go/data"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/grafana/grafana/pkg/tsdb/grafana-postgresql-datasource/sqleng"

	"github.com/grafana/grafana/pkg/util/testutil"
	_ "github.com/lib/pq"
)

// Test generateConnectionString.
func TestIntegrationGenerateConnectionStringPGX(t *testing.T) {
	testutil.SkipIntegrationTestInShortMode(t)

	testCases := []struct {
		desc        string
		host        string
		user        string
		password    string
		database    string
		tlsSettings tlsSettings
		expConnStr  string
		expErr      string
		uid         string
	}{
		{
			desc:        "Unix socket host",
			host:        "/var/run/postgresql",
			user:        "user",
			password:    "password",
			database:    "database",
			tlsSettings: tlsSettings{Mode: "verify-full"},
			expConnStr:  "user='user' password='password' host='/var/run/postgresql' dbname='database' sslmode='verify-full'",
		},
		{
			desc:        "TCP host",
			host:        "host",
			user:        "user",
			password:    "password",
			database:    "database",
			tlsSettings: tlsSettings{Mode: "verify-full"},
			expConnStr:  "user='user' password='password' host='host' dbname='database' sslmode='verify-full'",
		},
		{
			desc:        "verify-ca automatically adds disable-sni",
			host:        "host:1234",
			user:        "user",
			password:    "password",
			database:    "database",
			tlsSettings: tlsSettings{Mode: "verify-ca"},
			expConnStr:  "user='user' password='password' host='host' dbname='database' port=1234 sslmode='verify-ca' sslsni=0",
		},
		{
			desc:        "TCP/port host",
			host:        "host:1234",
			user:        "user",
			password:    "password",
			database:    "database",
			tlsSettings: tlsSettings{Mode: "verify-full"},
			expConnStr:  "user='user' password='password' host='host' dbname='database' port=1234 sslmode='verify-full'",
		},
		{
			desc:        "Ipv6 host",
			host:        "[::1]",
			user:        "user",
			password:    "password",
			database:    "database",
			tlsSettings: tlsSettings{Mode: "verify-full"},
			expConnStr:  "user='user' password='password' host='::1' dbname='database' sslmode='verify-full'",
		},
		{
			desc:        "Ipv6/port host",
			host:        "[::1]:1234",
			user:        "user",
			password:    "password",
			database:    "database",
			tlsSettings: tlsSettings{Mode: "verify-full"},
			expConnStr:  "user='user' password='password' host='::1' dbname='database' port=1234 sslmode='verify-full'",
		},
		{
			desc:        "Invalid port",
			host:        "host:invalid",
			user:        "user",
			database:    "database",
			tlsSettings: tlsSettings{},
			expErr:      "error parsing postgres url",
		},
		{
			desc:        "Password with single quote and backslash",
			host:        "host",
			user:        "user",
			password:    `p'\assword`,
			database:    "database",
			tlsSettings: tlsSettings{Mode: "verify-full"},
			expConnStr:  `user='user' password='p\'\\assword' host='host' dbname='database' sslmode='verify-full'`,
		},
		{
			desc:        "User/DB with single quote and backslash",
			host:        "host",
			user:        `u'\ser`,
			password:    `password`,
			database:    `d'\atabase`,
			tlsSettings: tlsSettings{Mode: "verify-full"},
			expConnStr:  `user='u\'\\ser' password='password' host='host' dbname='d\'\\atabase' sslmode='verify-full'`,
		},
		{
			desc:        "Custom TLS mode disabled",
			host:        "host",
			user:        "user",
			password:    "password",
			database:    "database",
			tlsSettings: tlsSettings{Mode: "disable"},
			expConnStr:  "user='user' password='password' host='host' dbname='database' sslmode='disable'",
		},
		{
			desc:     "Custom TLS mode verify-full with certificate files",
			host:     "host",
			user:     "user",
			password: "password",
			database: "database",
			tlsSettings: tlsSettings{
				Mode:         "verify-full",
				RootCertFile: "i/am/coding/ca.crt",
				CertFile:     "i/am/coding/client.crt",
				CertKeyFile:  "i/am/coding/client.key",
			},
			expConnStr: "user='user' password='password' host='host' dbname='database' sslmode='verify-full' " +
				"sslrootcert='i/am/coding/ca.crt' sslcert='i/am/coding/client.crt' sslkey='i/am/coding/client.key'",
		},
	}
	for _, tt := range testCases {
		t.Run(tt.desc, func(t *testing.T) {
			svc := Service{
				logger: backend.NewLoggerWith("logger", "tsdb.postgres"),
			}

			ds := sqleng.DataSourceInfo{
				URL:                     tt.host,
				User:                    tt.user,
				DecryptedSecureJSONData: map[string]string{"password": tt.password},
				Database:                tt.database,
				UID:                     tt.uid,
			}

			connStr, err := svc.generateConnectionString(ds, tt.tlsSettings, false)

			if tt.expErr == "" {
				require.NoError(t, err, tt.desc)
				assert.Equal(t, tt.expConnStr, connStr)
			} else {
				require.Error(t, err, tt.desc)
				assert.True(t, strings.HasPrefix(err.Error(), tt.expErr),
					fmt.Sprintf("%s: %q doesn't start with %q", tt.desc, err, tt.expErr))
			}
		})
	}
}

// To run this test, set runPostgresTests=true
// Or from the commandline: GRAFANA_TEST_DB=postgres go test -tags=integration -v ./pkg/tsdb/grafana-postgresql-datasource
// The tests require a PostgreSQL db named grafanadstest and a user/password grafanatest/grafanatest!
// Use the docker/blocks/postgres_tests/docker-compose.yaml to spin up a
// preconfigured Postgres server suitable for running these tests.
// There is also a datasource and dashboard provisioned by devenv scripts that you can
// use to verify that the generated data are visualized as expected, see
// devenv/README.md for setup instructions.
func TestIntegrationPostgresPGX(t *testing.T) {
	testutil.SkipIntegrationTestInShortMode(t)

	// change to true to run the PostgreSQL tests
	const runPostgresTests = false

	if !isTestDbPostgres() && !runPostgresTests {
		t.Skip()
	}

	origInterpolate := sqleng.Interpolate
	t.Cleanup(func() {
		sqleng.Interpolate = origInterpolate
	})
	sqleng.Interpolate = func(query backend.DataQuery, timeRange backend.TimeRange, timeInterval string, sql string) string {
		return sql
	}

	jsonData := sqleng.JsonData{
		MaxOpenConns:        10,
		MaxIdleConns:        2,
		ConnMaxLifetime:     14400,
		Timescaledb:         false,
		Mode:                "disable",
		ConfigurationMethod: "file-path",
	}

	dsInfo := sqleng.DataSourceInfo{
		JsonData:                jsonData,
		DecryptedSecureJSONData: map[string]string{},
	}

	logger := backend.NewLoggerWith("logger", "postgres.test")

	cnnstr := postgresTestDBConnString()

	p, exe, err := newPostgresPGX(t.Context(), "error", 10000, dsInfo, cnnstr, logger, backend.DataSourceInstanceSettings{})

	require.NoError(t, err)

	fromStart := time.Date(2018, 3, 15, 13, 0, 0, 0, time.UTC).In(time.Local)

	t.Run("Given a table with different native data types", func(t *testing.T) {
		sql := `
			DROP TABLE IF EXISTS postgres_types;
			CREATE TABLE postgres_types(
				c00_smallint smallint,
				c01_integer integer,
				c02_bigint bigint,

				c03_real real,
				c04_double double precision,
				c05_decimal decimal(10,2),
				c06_numeric numeric(10,2),

				c07_char char(10),
				c08_varchar varchar(10),
				c09_text text,

				c10_timestamp timestamp without time zone,
				c11_timestamptz timestamp with time zone,
				c12_date date,
				c13_time time without time zone,
				c14_timetz time with time zone,
				time date,
				c15_interval interval,
				c16_smallint smallint,

				c17_json json,
				c18_jsonb jsonb
			);
		`
		_, err := p.Exec(t.Context(), sql)
		require.NoError(t, err)

		sql = `
			INSERT INTO postgres_types VALUES(
				1,2,3,
				4.5,6.7,1.1,1.2,
				'char10','varchar10','text',
				now(),now(),now(),now(),now(),now(),'15m'::interval,null,
			    '{"key1": "value1"}'::json, '{"key2": "value2"}'::jsonb
			);
		`
		_, err = p.Exec(t.Context(), sql)
		require.NoError(t, err)

		t.Run("When doing a table query should map Postgres column types to Go types", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT * FROM postgres_types",
							"format": "table"
						}`),
						RefID: "A",
					},
				},
			}
			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Len(t, frames, 1)
			require.Len(t, frames[0].Fields, 20)

			require.Equal(t, int16(1), *frames[0].Fields[0].At(0).(*int16))
			require.Equal(t, int32(2), *frames[0].Fields[1].At(0).(*int32))
			require.Equal(t, int64(3), *frames[0].Fields[2].At(0).(*int64))

			require.Equal(t, float64(4.5), *frames[0].Fields[3].At(0).(*float64))
			require.Equal(t, float64(6.7), *frames[0].Fields[4].At(0).(*float64))
			require.Equal(t, float64(1.1), *frames[0].Fields[5].At(0).(*float64))
			require.Equal(t, float64(1.2), *frames[0].Fields[6].At(0).(*float64))

			require.Equal(t, "char10    ", *frames[0].Fields[7].At(0).(*string))
			require.Equal(t, "varchar10", *frames[0].Fields[8].At(0).(*string))
			require.Equal(t, "text", *frames[0].Fields[9].At(0).(*string))

			_, ok := frames[0].Fields[10].At(0).(*time.Time)
			require.True(t, ok)
			_, ok = frames[0].Fields[11].At(0).(*time.Time)
			require.True(t, ok)
			_, ok = frames[0].Fields[12].At(0).(*time.Time)
			require.True(t, ok)
			_, ok = frames[0].Fields[13].At(0).(*string)
			require.True(t, ok)
			_, ok = frames[0].Fields[14].At(0).(*string)
			require.True(t, ok)
			_, ok = frames[0].Fields[15].At(0).(*time.Time)
			require.True(t, ok)
			require.Equal(t, "00:15:00", *frames[0].Fields[16].At(0).(*string))
			require.Nil(t, frames[0].Fields[17].At(0))

			_, ok = frames[0].Fields[18].At(0).(*json.RawMessage)
			require.True(t, ok)
			require.Equal(t, json.RawMessage(`{"key1": "value1"}`), *frames[0].Fields[18].At(0).(*json.RawMessage))
			_, ok = frames[0].Fields[19].At(0).(*json.RawMessage)
			require.True(t, ok)
			require.Equal(t, json.RawMessage(`{"key2": "value2"}`), *frames[0].Fields[19].At(0).(*json.RawMessage))
		})
	})

	t.Run("Given a table with metrics that lacks data for some series ", func(t *testing.T) {
		sql := `
				DROP TABLE IF EXISTS metric;
				CREATE TABLE metric (
					time timestamp,
					value integer
				)
			`

		_, err := p.Exec(t.Context(), sql)
		require.NoError(t, err)

		type metric struct {
			Time  time.Time
			Value int64
		}

		series := []*metric{}
		firstRange := genTimeRangeByInterval(fromStart, 10*time.Minute, 10*time.Second)
		secondRange := genTimeRangeByInterval(fromStart.Add(20*time.Minute), 10*time.Minute, 10*time.Second)

		for _, t := range firstRange {
			series = append(series, &metric{
				Time:  t,
				Value: 15,
			})
		}

		for _, t := range secondRange {
			series = append(series, &metric{
				Time:  t,
				Value: 20,
			})
		}

		for _, m := range series {
			_, err := p.Exec(t.Context(), `INSERT INTO metric ("time", value) VALUES ($1, $2)`, m.Time.UTC(), m.Value)
			require.NoError(t, err)
		}

		t.Run("When doing a metric query using timeGroup", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
								"rawSql": "SELECT $__timeGroup(time, '5m') AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
								"format": "time_series"
							}`),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Len(t, frames, 1)
			require.Equal(t, 4, frames[0].Fields[0].Len())

			// without fill this should result in 4 buckets

			dt := fromStart

			for i := 0; i < 2; i++ {
				aValue := *frames[0].Fields[1].At(i).(*float64)
				aTime := *frames[0].Fields[0].At(i).(*time.Time)
				require.Equal(t, float64(15), aValue)
				require.Equal(t, dt, aTime)
				dt = dt.Add(5 * time.Minute)
			}

			// adjust for 10 minute gap between first and second set of points
			dt = dt.Add(10 * time.Minute)
			for i := 2; i < 4; i++ {
				aValue := *frames[0].Fields[1].At(i).(*float64)
				aTime := *frames[0].Fields[0].At(i).(*time.Time)
				require.Equal(t, float64(20), aValue)
				require.Equal(t, dt, aTime)
				dt = dt.Add(5 * time.Minute)
			}
		})

		t.Run("When doing a query without a format should default to time_series", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT $__timeGroup(time, '5m') AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1 "
						}`),
						RefID: "A",
					},
				},
			}
			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Len(t, frames, 1)
			require.Len(t, frames[0].Fields, 2)
		})

		t.Run("When doing a metric query using timeGroup and $__interval", func(t *testing.T) {
			mockInterpolate := sqleng.Interpolate
			sqleng.Interpolate = origInterpolate
			t.Cleanup(func() {
				sqleng.Interpolate = mockInterpolate
			})

			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT $__timeGroup(time, $__interval) AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
							"format": "time_series"
						}`),
						RefID:    "A",
						Interval: time.Second * 60,
						TimeRange: backend.TimeRange{
							From: fromStart,
							To:   fromStart.Add(30 * time.Minute),
						},
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			frames := queryResult.Frames

			require.NoError(t, queryResult.Error)
			require.Equal(t,
				"SELECT floor(extract(epoch from time)/60)*60 AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
				frames[0].Meta.ExecutedQueryString)
		})

		t.Run("When doing a metric query using timeGroup with NULL fill enabled", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT $__timeGroup(time, '5m', NULL) AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
							"format": "time_series"
						}`),
						RefID: "A",
						TimeRange: backend.TimeRange{
							From: fromStart,
							To:   fromStart.Add(34 * time.Minute),
						},
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 7, frames[0].Fields[0].Len())

			dt := fromStart

			for i := 0; i < 2; i++ {
				aValue := *frames[0].Fields[1].At(i).(*float64)
				aTime := *frames[0].Fields[0].At(i).(*time.Time)
				require.Equal(t, float64(15), aValue)
				require.True(t, aTime.Equal(dt))
				dt = dt.Add(5 * time.Minute)
			}

			// check for NULL values inserted by fill
			require.Nil(t, frames[0].Fields[1].At(2))
			require.Nil(t, frames[0].Fields[1].At(3))

			// adjust for 10 minute gap between first and second set of points
			dt = dt.Add(10 * time.Minute)
			for i := 4; i < 6; i++ {
				aValue := *frames[0].Fields[1].At(i).(*float64)
				aTime := *frames[0].Fields[0].At(i).(*time.Time)
				require.Equal(t, float64(20), aValue)
				require.True(t, aTime.Equal(dt))
				dt = dt.Add(5 * time.Minute)
			}

			// check for NULL values inserted by fill
			require.Nil(t, frames[0].Fields[1].At(6))
		})

		t.Run("When doing a metric query using timeGroup with value fill enabled", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT $__timeGroup(time, '5m', 1.5) AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
							"format": "time_series"
						}`),
						RefID: "A",
						TimeRange: backend.TimeRange{
							From: fromStart,
							To:   fromStart.Add(34 * time.Minute),
						},
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 1.5, *frames[0].Fields[1].At(3).(*float64))
		})
	})

	t.Run("Given a table with one data point", func(t *testing.T) {
		type metric struct {
			Time  time.Time
			Value int64
		}

		startTime := time.Now().UTC().Add(-time.Minute * 5)
		series := []*metric{
			{
				Time:  startTime,
				Value: 33,
			},
		}

		for _, m := range series {
			_, err := p.Exec(t.Context(), `INSERT INTO metric ("time", value) VALUES ($1, $2)`, m.Time.UTC(), m.Value)
			require.NoError(t, err)
		}

		t.Run("querying with time group with default value", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "WITH data AS (SELECT now()-'3m'::interval AS ts, 42 AS n) SELECT $__timeGroup(ts, '1m', 0), n FROM data",
							"format": "time_series"
						}`),
						RefID: "A",
						TimeRange: backend.TimeRange{
							From: startTime,
							To:   startTime.Add(5 * time.Minute),
						},
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, "Time", frames[0].Fields[0].Name)
			require.Equal(t, "n", frames[0].Fields[1].Name)
			require.Equal(t, float64(0), *frames[0].Fields[1].At(0).(*float64))
			require.Equal(t, float64(0), *frames[0].Fields[1].At(1).(*float64))
			require.Equal(t, float64(42), *frames[0].Fields[1].At(2).(*float64))
			require.Equal(t, float64(0), *frames[0].Fields[1].At(3).(*float64))
			require.Equal(t, float64(0), *frames[0].Fields[1].At(4).(*float64))
			require.Equal(t, float64(0), *frames[0].Fields[1].At(5).(*float64))
		})
	})

	t.Run("When doing a metric query using timeGroup with previous fill enabled", func(t *testing.T) {
		query := &backend.QueryDataRequest{
			Queries: []backend.DataQuery{
				{
					JSON: []byte(`{
						"rawSql": "SELECT $__timeGroup(time, '5m', previous), avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
						"format": "time_series"
					}`),
					RefID: "A",
					TimeRange: backend.TimeRange{
						From: fromStart,
						To:   fromStart.Add(34 * time.Minute),
					},
				},
			},
		}

		resp, err := exe.QueryDataPGX(t.Context(), query)
		require.NoError(t, err)
		queryResult := resp.Responses["A"]
		require.NoError(t, queryResult.Error)

		frames := queryResult.Frames
		require.Equal(t, 1, len(frames))
		require.Equal(t, float64(15.0), *frames[0].Fields[1].At(2).(*float64))
		require.Equal(t, float64(15.0), *frames[0].Fields[1].At(3).(*float64))
		require.Equal(t, float64(20.0), *frames[0].Fields[1].At(6).(*float64))
	})

	t.Run("Given a table with metrics having multiple values and measurements", func(t *testing.T) {
		type metric_values struct {
			Time                time.Time
			TimeInt64           int64
			TimeInt64Nullable   *int64
			TimeFloat64         float64
			TimeFloat64Nullable *float64
			TimeInt32           int32
			TimeInt32Nullable   *int32
			TimeFloat32         float32
			TimeFloat32Nullable *float32
			Measurement         string
			ValueOne            int64
			ValueTwo            int64
		}

		_, err := p.Exec(t.Context(), "DROP TABLE IF EXISTS metric_values")
		require.NoError(t, err)

		_, err = p.Exec(t.Context(), `CREATE TABLE metric_values (
			"time" TIMESTAMP NULL,
			"timeInt64" BIGINT NOT NULL, "timeInt64Nullable" BIGINT NULL,
			"timeFloat64" DOUBLE PRECISION NOT NULL, "timeFloat64Nullable" DOUBLE PRECISION NULL,
			"timeInt32" INTEGER NOT NULL, "timeInt32Nullable" INTEGER NULL,
			"timeFloat32" DOUBLE PRECISION NOT NULL, "timeFloat32Nullable" DOUBLE PRECISION NULL,
			measurement VARCHAR(255) NULL,
			"valueOne" INTEGER NULL, "valueTwo" INTEGER NULL
		)`)
		require.NoError(t, err)

		rng := rand.New(rand.NewSource(time.Now().Unix()))
		rnd := func(min, max int64) int64 {
			return rng.Int63n(max-min) + min
		}

		var tInitial time.Time

		series := []*metric_values{}
		for i, t := range genTimeRangeByInterval(fromStart.Add(-30*time.Minute), 90*time.Minute, 5*time.Minute) {
			if i == 0 {
				tInitial = t
			}
			tSeconds := t.Unix()
			tSecondsInt32 := int32(tSeconds)
			tSecondsFloat32 := float32(tSeconds)
			tMilliseconds := tSeconds * 1e3
			tMillisecondsFloat := float64(tMilliseconds)
			first := metric_values{
				Time:                t,
				TimeInt64:           tMilliseconds,
				TimeInt64Nullable:   &(tMilliseconds),
				TimeFloat64:         tMillisecondsFloat,
				TimeFloat64Nullable: &tMillisecondsFloat,
				TimeInt32:           tSecondsInt32,
				TimeInt32Nullable:   &tSecondsInt32,
				TimeFloat32:         tSecondsFloat32,
				TimeFloat32Nullable: &tSecondsFloat32,
				Measurement:         "Metric A",
				ValueOne:            rnd(0, 100),
				ValueTwo:            rnd(0, 100),
			}
			second := first
			second.Measurement = "Metric B"
			second.ValueOne = rnd(0, 100)
			second.ValueTwo = rnd(0, 100)

			series = append(series, &first)
			series = append(series, &second)
		}

		// _, err = session.InsertMulti(series)
		for _, m := range series {
			_, err := p.Exec(t.Context(), `INSERT INTO "metric_values" (
				time,
				"timeInt64", "timeInt64Nullable",
				"timeFloat64", "timeFloat64Nullable",
				"timeInt32", "timeInt32Nullable",
				"timeFloat32", "timeFloat32Nullable",
				measurement, "valueOne", "valueTwo"
			) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12)`,
				m.Time,
				m.TimeInt64, m.TimeInt64Nullable,
				m.TimeFloat64, m.TimeFloat64Nullable,
				m.TimeInt32, m.TimeInt32Nullable,
				m.TimeFloat32, m.TimeFloat32Nullable,
				m.Measurement, m.ValueOne, m.ValueTwo,
			)
			require.NoError(t, err)
		}

		t.Run(
			"When doing a metric query using epoch (int64) as time column and value column (int64) should return metric with time in time.Time",
			func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
								"rawSql": "SELECT \"timeInt64\" as time, \"timeInt64\" FROM metric_values ORDER BY time LIMIT 1",
								"format": "time_series"
							}`),
							RefID: "A",
						},
					},
				}

				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)

				frames := queryResult.Frames
				require.Len(t, frames, 1)
				require.True(t, tInitial.Equal(*frames[0].Fields[0].At(0).(*time.Time)))
			})

		t.Run("When doing a metric query using epoch (int64 nullable) as time column and value column (int64 nullable,) should return metric with time in time.Time",
			func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
								"rawSql": "SELECT \"timeInt64Nullable\" as time, \"timeInt64Nullable\" FROM metric_values ORDER BY time LIMIT 1",
								"format": "time_series"
							}`),
							RefID: "A",
						},
					},
				}

				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)

				frames := queryResult.Frames
				require.Len(t, frames, 1)
				require.True(t, tInitial.Equal(*frames[0].Fields[0].At(0).(*time.Time)))
			})

		t.Run("When doing a metric query using epoch (float64) as time column and value column (float64), should return metric with time in time.Time",
			func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
								"rawSql": "SELECT \"timeFloat64\" as time, \"timeFloat64\" FROM metric_values ORDER BY time LIMIT 1",
								"format": "time_series"
							}`),
							RefID: "A",
						},
					},
				}

				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)

				frames := queryResult.Frames
				require.Len(t, frames, 1)
				require.True(t, tInitial.Equal(*frames[0].Fields[0].At(0).(*time.Time)))
			})

		t.Run("When doing a metric query using epoch (float64 nullable) as time column and value column (float64 nullable), should return metric with time in time.Time",
			func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
								"rawSql": "SELECT \"timeFloat64Nullable\" as time, \"timeFloat64Nullable\" FROM metric_values ORDER BY time LIMIT 1",
								"format": "time_series"
							}`),
							RefID: "A",
						},
					},
				}

				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)

				frames := queryResult.Frames
				require.Equal(t, 1, len(frames))
				require.True(t, tInitial.Equal(*frames[0].Fields[0].At(0).(*time.Time)))
			})

		t.Run("When doing a metric query using epoch (int32) as time column and value column (int32), should return metric with time in time.Time",
			func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
								"rawSql": "SELECT \"timeInt32\" as time, \"timeInt32\" FROM metric_values ORDER BY time LIMIT 1",
								"format": "time_series"
							}`),
							RefID: "A",
						},
					},
				}

				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)

				frames := queryResult.Frames
				require.Equal(t, 1, len(frames))
				require.True(t, tInitial.Equal(*frames[0].Fields[0].At(0).(*time.Time)))
			})

		t.Run("When doing a metric query using epoch (int32 nullable) as time column and value column (int32 nullable), should return metric with time in time.Time",
			func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
								"rawSql": "SELECT \"timeInt32Nullable\" as time, \"timeInt32Nullable\" FROM metric_values ORDER BY time LIMIT 1",
								"format": "time_series"
							}`),
							RefID: "A",
						},
					},
				}

				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)

				frames := queryResult.Frames
				require.Equal(t, 1, len(frames))
				require.True(t, tInitial.Equal(*frames[0].Fields[0].At(0).(*time.Time)))
			})

		t.Run("When doing a metric query using epoch (float32) as time column and value column (float32), should return metric with time in time.Time",
			func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
								"rawSql": "SELECT \"timeFloat32\" as time, \"timeFloat32\" FROM metric_values ORDER BY time LIMIT 1",
								"format": "time_series"
							}`),
							RefID: "A",
						},
					},
				}

				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)

				frames := queryResult.Frames
				require.Equal(t, 1, len(frames))
				aTime := time.Unix(0, int64(float64(float32(tInitial.Unix()))*1e3)*int64(time.Millisecond))
				require.True(t, aTime.Equal(*frames[0].Fields[0].At(0).(*time.Time)))
			})

		t.Run("When doing a metric query using epoch (float32 nullable) as time column and value column (float32 nullable), should return metric with time in time.Time",
			func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
								"rawSql": "SELECT \"timeFloat32Nullable\" as time, \"timeFloat32Nullable\" FROM metric_values ORDER BY time LIMIT 1",
								"format": "time_series"
							}`),
							RefID: "A",
						},
					},
				}

				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)

				frames := queryResult.Frames
				require.Equal(t, 1, len(frames))
				aTime := time.Unix(0, int64(float64(float32(tInitial.Unix()))*1e3)*int64(time.Millisecond))
				require.True(t, aTime.Equal(*frames[0].Fields[0].At(0).(*time.Time)))
			})

		t.Run("When doing a metric query grouping by time and select metric column should return correct series", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT $__timeEpoch(time), measurement || ' - value one' as metric, \"valueOne\" FROM metric_values ORDER BY 1",
							"format": "time_series"
						}`),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 3, len(frames[0].Fields))
			require.Equal(t, "Metric A - value one", frames[0].Fields[1].Name)
			require.Equal(t, "Metric B - value one", frames[0].Fields[2].Name)
		})

		t.Run("When doing a metric query with metric column and multiple value columns", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT $__timeEpoch(time), measurement as metric, \"valueOne\", \"valueTwo\" FROM metric_values ORDER BY 1",
							"format": "time_series"
						}`),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.NoError(t, err)
			require.Equal(t, 1, len(frames))
			require.Equal(t, 5, len(frames[0].Fields))
			require.Equal(t, "valueOne", frames[0].Fields[1].Name)
			require.Equal(t, data.Labels{"metric": "Metric A"}, frames[0].Fields[1].Labels)
			require.Equal(t, "valueOne", frames[0].Fields[2].Name)
			require.Equal(t, data.Labels{"metric": "Metric B"}, frames[0].Fields[2].Labels)
			require.Equal(t, "valueTwo", frames[0].Fields[3].Name)
			require.Equal(t, data.Labels{"metric": "Metric A"}, frames[0].Fields[3].Labels)
			require.Equal(t, "valueTwo", frames[0].Fields[4].Name)
			require.Equal(t, data.Labels{"metric": "Metric B"}, frames[0].Fields[4].Labels)
		})

		t.Run("When doing a metric query grouping by time should return correct series", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT $__timeEpoch(time), \"valueOne\", \"valueTwo\" FROM metric_values ORDER BY 1",
							"format": "time_series"
						}`),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 3, len(frames[0].Fields))
			require.Equal(t, "valueOne", frames[0].Fields[1].Name)
			require.Equal(t, "valueTwo", frames[0].Fields[2].Name)
		})

		t.Run("When doing a query with timeFrom,timeTo,unixEpochFrom,unixEpochTo macros", func(t *testing.T) {
			fakeInterpolate := sqleng.Interpolate
			t.Cleanup(func() {
				sqleng.Interpolate = fakeInterpolate
			})
			sqleng.Interpolate = origInterpolate

			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT time FROM metric_values WHERE time > $__timeFrom() OR time < $__timeFrom() OR 1 < $__unixEpochFrom() OR $__unixEpochTo() > 1 ORDER BY 1",
							"format": "time_series"
						}`),
						RefID: "A",
						TimeRange: backend.TimeRange{
							From: fromStart.Add(-5 * time.Minute),
							To:   fromStart,
						},
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)
			frames := queryResult.Frames
			require.Len(t, frames, 1)
			require.Equal(t,
				"SELECT time FROM metric_values WHERE time > '2018-03-15T12:55:00Z' OR time < '2018-03-15T12:55:00Z' OR 1 < 1521118500 OR 1521118800 > 1 ORDER BY 1",
				frames[0].Meta.ExecutedQueryString)
		})
	})

	t.Run("Given a table with event data", func(t *testing.T) {
		type event struct {
			TimeSec     int64
			Description string
			Tags        string
		}

		_, err := p.Exec(t.Context(), "DROP TABLE IF EXISTS event")
		require.NoError(t, err)
		_, err = p.Exec(t.Context(), `CREATE TABLE event (time_sec BIGINT NULL, description VARCHAR(255) NULL, tags VARCHAR(255) NULL)`)
		require.NoError(t, err)

		events := []*event{}
		for _, t := range genTimeRangeByInterval(fromStart.Add(-20*time.Minute), time.Hour, 25*time.Minute) {
			events = append(events, &event{
				TimeSec:     t.Unix(),
				Description: "Someone deployed something",
				Tags:        "deploy",
			})
			events = append(events, &event{
				TimeSec:     t.Add(5 * time.Minute).Unix(),
				Description: "New support ticket registered",
				Tags:        "ticket",
			})
		}

		for _, e := range events {
			_, err := p.Exec(t.Context(), "INSERT INTO event (time_sec, description, tags) VALUES ($1, $2, $3)", e.TimeSec, e.Description, e.Tags)
			require.NoError(t, err)
		}

		t.Run("When doing an annotation query of deploy events should return expected result", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT \"time_sec\" as time, description as text, tags FROM event WHERE $__unixEpochFilter(time_sec) AND tags='deploy' ORDER BY 1 ASC",
							"format": "table"
						}`),
						RefID: "Deploys",
						TimeRange: backend.TimeRange{
							From: fromStart.Add(-20 * time.Minute),
							To:   fromStart.Add(40 * time.Minute),
						},
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)

			queryResult := resp.Responses["Deploys"]

			frames := queryResult.Frames
			require.Len(t, frames, 1)
			require.Len(t, frames[0].Fields, 3)
		})

		t.Run("When doing an annotation query of ticket events should return expected result", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT \"time_sec\" as time, description as text, tags FROM event WHERE $__unixEpochFilter(time_sec) AND tags='ticket' ORDER BY 1 ASC",
							"format": "table"
						}`),
						RefID: "Tickets",
						TimeRange: backend.TimeRange{
							From: fromStart.Add(-20 * time.Minute),
							To:   fromStart.Add(40 * time.Minute),
						},
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)

			queryResult := resp.Responses["Tickets"]
			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 3, len(frames[0].Fields))
		})

		t.Run("When doing an annotation query with a time column in datetime format", func(t *testing.T) {
			dt := time.Date(2018, 3, 14, 21, 20, 6, 527e6, time.UTC)
			dtFormat := "2006-01-02 15:04:05.999999999"

			queryjson := fmt.Sprintf("{\"rawSql\": \"SELECT CAST('%s' AS TIMESTAMP) as time, 'message' as text, 'tag1,tag2' as tags\", \"format\": \"table\" }", dt.Format(dtFormat))
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON:  []byte(queryjson),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)
			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 3, len(frames[0].Fields))

			// Should be in time.Time
			require.Equal(t, dt.Unix(), (*frames[0].Fields[0].At(0).(*time.Time)).Unix())
		})

		t.Run("When doing an annotation query with a time column in epoch second format should return time.Time", func(t *testing.T) {
			dt := time.Date(2018, 3, 14, 21, 20, 6, 527e6, time.UTC)

			queryjson := fmt.Sprintf("{\"rawSql\": \"SELECT %d as time, 'message' as text, 'tag1,tag2' as tags\", \"format\": \"table\"}", dt.Unix())
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON:  []byte(queryjson),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 3, len(frames[0].Fields))

			// Should be in time.Time
			require.Equal(t, dt.Unix(), (*frames[0].Fields[0].At(0).(*time.Time)).Unix())
		})

		t.Run("When doing an annotation query with a time column in epoch second format (t *testing.Tint) should return time.Time", func(t *testing.T) {
			dt := time.Date(2018, 3, 14, 21, 20, 6, 527e6, time.UTC)
			queryjson := fmt.Sprintf("{\"rawSql\": \"SELECT cast(%d as bigint) as time, 'message' as text, 'tag1,tag2' as tags\", \"format\": \"table\"}", dt.Unix())
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON:  []byte(queryjson),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 3, len(frames[0].Fields))

			// Should be in time.Time
			require.Equal(t, dt.Unix(), (*frames[0].Fields[0].At(0).(*time.Time)).Unix())
		})

		t.Run("When doing an annotation query with a time column in epoch millisecond format should return time.Time", func(t *testing.T) {
			dt := time.Date(2018, 3, 14, 21, 20, 6, 527e6, time.UTC)

			queryjson := fmt.Sprintf("{\"rawSql\":\"SELECT %d as time, 'message' as text, 'tag1,tag2' as tags\", \"format\": \"table\"}", dt.Unix()*1000)
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON:  []byte(queryjson),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 3, len(frames[0].Fields))

			// Should be in time.Time
			require.Equal(t, dt.Unix(), (*frames[0].Fields[0].At(0).(*time.Time)).Unix())
		})

		t.Run("When doing an annotation query with a time column holding a bigint null value should return nil", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT cast(null as bigint) as time, 'message' as text, 'tag1,tag2' as tags",
							"format": "table"
						}`),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 3, len(frames[0].Fields))

			// Should be in time.Time
			require.Nil(t, frames[0].Fields[0].At(0))
		})

		t.Run("When doing an annotation query with a time column holding a timestamp null value should return nil", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT cast(null as timestamp) as time, 'message' as text, 'tag1,tag2' as tags",
							"format": "table"
						}`),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 3, len(frames[0].Fields))

			// Should be in time.Time
			assert.Nil(t, frames[0].Fields[0].At(0))
		})

		t.Run("When doing an annotation query with a time and timeend column should return two fields of type time", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT 1631053772276 as time, 1631054012276 as timeend, '' as text, '' as tags",
							"format": "table"
						}`),
						RefID: "A",
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Equal(t, 1, len(frames))
			require.Equal(t, 4, len(frames[0].Fields))

			require.Equal(t, data.FieldTypeNullableTime, frames[0].Fields[0].Type())
			require.Equal(t, data.FieldTypeNullableTime, frames[0].Fields[1].Type())
		})

		t.Run("When row limit set to 1", func(t *testing.T) {
			jsonData := sqleng.JsonData{
				MaxOpenConns:        10,
				MaxIdleConns:        2,
				ConnMaxLifetime:     14400,
				Timescaledb:         false,
				Mode:                "disable",
				ConfigurationMethod: "file-path",
			}

			dsInfo := sqleng.DataSourceInfo{
				JsonData:                jsonData,
				DecryptedSecureJSONData: map[string]string{},
			}
			_, handler, err := newPostgresPGX(t.Context(), "error", 1, dsInfo, cnnstr, logger, backend.DataSourceInstanceSettings{})

			require.NoError(t, err)

			t.Run("When doing a table query that returns 2 rows should limit the result to 1 row", func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
							"rawSql": "SELECT 1 as value UNION ALL select 2 as value",
							"format": "table"
						}`),
							RefID: "A",
							TimeRange: backend.TimeRange{
								From: time.Now(),
								To:   time.Now(),
							},
						},
					},
				}

				resp, err := handler.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)
				frames := queryResult.Frames
				require.NoError(t, err)
				require.Equal(t, 1, len(frames))
				require.Equal(t, 1, len(frames[0].Fields))
				require.Equal(t, 1, frames[0].Rows())
				require.Len(t, frames[0].Meta.Notices, 1)
				require.Equal(t, data.NoticeSeverityWarning, frames[0].Meta.Notices[0].Severity)
			})

			t.Run("When doing a time series query that returns 2 rows should limit the result to 1 row", func(t *testing.T) {
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							JSON: []byte(`{
							"rawSql": "SELECT 1 as time, 1 as value UNION ALL select 2 as time, 2 as value",
							"format": "time_series"
						}`),
							RefID: "A",
							TimeRange: backend.TimeRange{
								From: time.Now(),
								To:   time.Now(),
							},
						},
					},
				}

				resp, err := handler.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)
				frames := queryResult.Frames
				require.NoError(t, err)
				require.Equal(t, 1, len(frames))
				require.Equal(t, 2, len(frames[0].Fields))
				require.Equal(t, 1, frames[0].Rows())
				require.Len(t, frames[0].Meta.Notices, 1)
				require.Equal(t, data.NoticeSeverityWarning, frames[0].Meta.Notices[0].Severity)
			})
		})
	})

	t.Run("Given an empty table", func(t *testing.T) {
		_, err := p.Exec(t.Context(), "DROP TABLE IF EXISTS empty_obj")
		require.NoError(t, err)
		_, err = p.Exec(t.Context(), "CREATE TABLE empty_obj (empty_key VARCHAR(255) NULL, empty_val BIGINT NULL)")
		require.NoError(t, err)

		t.Run("When no rows are returned, should return an empty frame", func(t *testing.T) {
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						JSON: []byte(`{
							"rawSql": "SELECT empty_key, empty_val FROM empty_obj",
							"format": "table"
						}`),
						RefID: "A",
						TimeRange: backend.TimeRange{
							From: time.Now(),
							To:   time.Now().Add(1 * time.Minute),
						},
					},
				},
			}

			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]

			frames := queryResult.Frames
			require.Len(t, frames, 1)
			require.Equal(t, 0, frames[0].Rows())
			require.NotNil(t, frames[0].Fields)
			require.Empty(t, frames[0].Fields)
		})

		t.Run("Should handle multiple result sets without panicking", func(t *testing.T) {
			// Create a test table for the panic scenario test
			sql := `
				DROP TABLE IF EXISTS test_multi_results;
				CREATE TABLE test_multi_results(
					id integer,
					name text,
					value numeric
				);
				INSERT INTO test_multi_results VALUES
					(1, 'test1', 10.5),
					(2, 'test2', 20.7),
					(3, 'test3', 30.2);
			`
			_, err := p.Exec(t.Context(), sql)
			require.NoError(t, err)

			t.Run("Should handle compatible multiple result sets", func(t *testing.T) {
				// This query returns multiple result sets with the same structure
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							RefID: "A",
							JSON: []byte(`{
								"rawSql": "SELECT id, name FROM test_multi_results WHERE id <= 2; SELECT id, name FROM test_multi_results WHERE id >= 2;",
								"format": "table"
							}`),
							TimeRange: backend.TimeRange{
								From: fromStart,
								To:   fromStart.Add(1 * time.Hour),
							},
						},
					},
				}

				// This should not panic and should work correctly
				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]
				require.NoError(t, queryResult.Error)

				frames := queryResult.Frames
				require.Len(t, frames, 1)

				// The frame should be properly constructed from both SELECT results
				frame := frames[0]
				require.Equal(t, 2, len(frame.Fields)) // id, name from both queries
				require.Equal(t, "id", frame.Fields[0].Name)
				require.Equal(t, "name", frame.Fields[1].Name)
				require.Equal(t, 4, frame.Rows()) // 2 rows from first result + 2 rows from second result
			})

			t.Run("Should return error for incompatible multiple result sets", func(t *testing.T) {
				// This query returns multiple result sets with different structures - the kind that used to cause panic
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							RefID: "A",
							JSON: []byte(`{
								"rawSql": "SELECT id, name FROM test_multi_results WHERE id <= 2; SELECT id, value FROM test_multi_results WHERE id >= 2;",
								"format": "table"
							}`),
							TimeRange: backend.TimeRange{
								From: fromStart,
								To:   fromStart.Add(1 * time.Hour),
							},
						},
					},
				}

				// This should not panic anymore, but should return an error instead
				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]

				// We expect an error about column mismatch, not a panic
				require.Error(t, queryResult.Error)
				require.Contains(t, queryResult.Error.Error(), "column name mismatch")
			})

			t.Run("Should return error for incompatible number of columns", func(t *testing.T) {
				// This query returns multiple result sets with different number of columns
				// This should fix the error "runtime error: index out of range [1] with length 1"
				query := &backend.QueryDataRequest{
					Queries: []backend.DataQuery{
						{
							RefID: "A",
							JSON: []byte(`{
								"rawSql": "SELECT id, name FROM test_multi_results WHERE id = 1; SELECT id FROM test_multi_results WHERE id = 1;",
								"format": "table"
							}`),
							TimeRange: backend.TimeRange{
								From: fromStart,
								To:   fromStart.Add(1 * time.Hour),
							},
						},
					},
				}

				// This should not panic anymore, but should return an error instead
				resp, err := exe.QueryDataPGX(t.Context(), query)
				require.NoError(t, err)
				queryResult := resp.Responses["A"]

				// We expect an error about incompatible result structure, not a panic
				require.Error(t, queryResult.Error)
				require.Contains(t, queryResult.Error.Error(), "incompatible result structure: expected 2 columns, got 1 columns")
			})
		})

		t.Run("Should handle queries with mixed statement types", func(t *testing.T) {
			// This tests a scenario with UPDATE + SELECT that could cause the original panic
			query := &backend.QueryDataRequest{
				Queries: []backend.DataQuery{
					{
						RefID: "A",
						JSON: []byte(`{
							"rawSql": "UPDATE test_multi_results SET name = 'updated' WHERE id = 1; SELECT id, name FROM test_multi_results WHERE id = 1;",
							"format": "table"
						}`),
						TimeRange: backend.TimeRange{
							From: fromStart,
							To:   fromStart.Add(1 * time.Hour),
						},
					},
				},
			}

			// This should not panic
			resp, err := exe.QueryDataPGX(t.Context(), query)
			require.NoError(t, err)
			queryResult := resp.Responses["A"]
			require.NoError(t, queryResult.Error)

			frames := queryResult.Frames
			require.Len(t, frames, 1)

			// Should only contain data from the SELECT part
			frame := frames[0]
			require.Equal(t, 2, len(frame.Fields)) // id, name
			require.Equal(t, 1, frame.Rows())      // 1 row

			// Verify the update worked
			nameField := frame.Fields[1]
			nameValue := nameField.At(0).(*string)
			require.Equal(t, "updated", *nameValue)
		})
	})
}