// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package collector

import (
	"context"
	"fmt"
	"testing"

	"github.com/DATA-DOG/go-sqlmock"
	"github.com/alecthomas/kingpin/v2"
	"github.com/prometheus/client_golang/prometheus"
	dto "github.com/prometheus/client_model/go"
	"github.com/prometheus/common/promslog"
	"github.com/smartystreets/goconvey/convey"
)

type ScrapeHeartbeatTestCase struct {
	Args    []string
	Columns []string
	Query   string
}

var ScrapeHeartbeatTestCases = []ScrapeHeartbeatTestCase{
	{
		[]string{
			"--collect.heartbeat.database", "heartbeat-test",
			"--collect.heartbeat.table", "heartbeat-test",
		},
		[]string{"UNIX_TIMESTAMP(ts)", "UNIX_TIMESTAMP(NOW(6))", "server_id"},
		"SELECT UNIX_TIMESTAMP(ts), UNIX_TIMESTAMP(NOW(6)), server_id from `heartbeat-test`.`heartbeat-test`",
	},
	{
		[]string{
			"--collect.heartbeat.database", "heartbeat-test",
			"--collect.heartbeat.table", "heartbeat-test",
			"--collect.heartbeat.utc",
		},
		[]string{"UNIX_TIMESTAMP(ts)", "UNIX_TIMESTAMP(UTC_TIMESTAMP(6))", "server_id"},
		"SELECT UNIX_TIMESTAMP(ts), UNIX_TIMESTAMP(UTC_TIMESTAMP(6)), server_id from `heartbeat-test`.`heartbeat-test`",
	},
}

func TestScrapeHeartbeat(t *testing.T) {
	for _, tt := range ScrapeHeartbeatTestCases {
		t.Run(fmt.Sprint(tt.Args), func(t *testing.T) {
			_, err := kingpin.CommandLine.Parse(tt.Args)
			if err != nil {
				t.Fatal(err)
			}

			db, mock, err := sqlmock.New()
			if err != nil {
				t.Fatalf("error opening a stub database connection: %s", err)
			}
			defer db.Close()
			inst := &instance{db: db}

			rows := sqlmock.NewRows(tt.Columns).
				AddRow("1487597613.001320", "1487598113.448042", 1)
			mock.ExpectQuery(sanitizeQuery(tt.Query)).WillReturnRows(rows)

			ch := make(chan prometheus.Metric)
			go func() {
				if err = (ScrapeHeartbeat{}).Scrape(context.Background(), inst, ch, promslog.NewNopLogger()); err != nil {
					t.Errorf("error calling function on test: %s", err)
				}
				close(ch)
			}()

			counterExpected := []MetricResult{
				{labels: labelMap{"server_id": "1"}, value: 1487598113.448042, metricType: dto.MetricType_GAUGE},
				{labels: labelMap{"server_id": "1"}, value: 1487597613.00132, metricType: dto.MetricType_GAUGE},
			}
			convey.Convey("Metrics comparison", t, func() {
				for _, expect := range counterExpected {
					got := readMetric(<-ch)
					convey.So(got, convey.ShouldResemble, expect)
				}
			})

			// Ensure all SQL queries were executed
			if err := mock.ExpectationsWereMet(); err != nil {
				t.Errorf("there were unfulfilled exceptions: %s", err)
			}
		})
	}
}