package instrumental

import (
	"bufio"
	"errors"
	"io"
	"net"
	"net/textproto"
	"sync"
	"testing"
	"time"

	"github.com/stretchr/testify/require"

	"github.com/influxdata/telegraf"
	"github.com/influxdata/telegraf/config"
	"github.com/influxdata/telegraf/metric"
)

func TestWrite(t *testing.T) {
	var wg sync.WaitGroup
	wg.Add(1)
	port := TCPServer(t, &wg)

	i := Instrumental{
		Host:     "127.0.0.1",
		Port:     port,
		APIToken: config.NewSecret([]byte("abc123token")),
		Prefix:   "my.prefix",
	}
	require.NoError(t, i.Init())

	// Default to gauge
	m1 := metric.New(
		"mymeasurement",
		map[string]string{"host": "192.168.0.1"},
		map[string]interface{}{"myfield": float64(3.14)},
		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
	)
	m2 := metric.New(
		"mymeasurement",
		map[string]string{"host": "192.168.0.1", "metric_type": "set"},
		map[string]interface{}{"value": float64(3.14)},
		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
	)

	metrics := []telegraf.Metric{m1, m2}
	err := i.Write(metrics)
	require.NoError(t, err)

	// Counter and Histogram are increments
	m3 := metric.New(
		"my_histogram",
		map[string]string{"host": "192.168.0.1", "metric_type": "histogram"},
		map[string]interface{}{"value": float64(3.14)},
		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
	)
	// We will modify metric names that won't be accepted by Instrumental
	m4 := metric.New(
		"bad_metric_name",
		map[string]string{"host": "192.168.0.1:8888::123", "metric_type": "counter"},
		map[string]interface{}{"value": 1},
		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
	)
	// We will drop metric values that won't be accepted by Instrumental
	m5 := metric.New(
		"bad_values",
		map[string]string{"host": "192.168.0.1", "metric_type": "counter"},
		map[string]interface{}{"value": "\" 3:30\""},
		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
	)
	m6 := metric.New(
		"my_counter",
		map[string]string{"host": "192.168.0.1", "metric_type": "counter"},
		map[string]interface{}{"value": float64(3.14)},
		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
	)

	metrics = []telegraf.Metric{m3, m4, m5, m6}
	err = i.Write(metrics)
	require.NoError(t, err)

	wg.Wait()
}

func TCPServer(t *testing.T, wg *sync.WaitGroup) int {
	tcpServer, err := net.Listen("tcp", "127.0.0.1:0")
	require.NoError(t, err)

	go func() {
		defer wg.Done()
		defer tcpServer.Close()

		conn, err := tcpServer.Accept()
		if err != nil {
			t.Error(err)
			return
		}
		defer func() {
			if err := conn.Close(); err != nil {
				t.Error(err)
			}
		}()

		err = conn.SetDeadline(time.Now().Add(1 * time.Second))
		if err != nil {
			t.Error(err)
			return
		}

		reader := bufio.NewReader(conn)
		tp := textproto.NewReader(reader)

		helloExpected := "hello version go/telegraf/1.1"
		hello, err := tp.ReadLine()
		if err != nil {
			t.Error(err)
			return
		} else if hello != helloExpected {
			t.Errorf("expected %q, got %q", helloExpected, hello)
			return
		}

		authExpected := "authenticate abc123token"
		auth, err := tp.ReadLine()
		if err != nil {
			t.Error(err)
			return
		} else if auth != authExpected {
			t.Errorf("expected %q, got %q", authExpected, auth)
			return
		}

		_, err = conn.Write([]byte("ok\nok\n"))
		if err != nil {
			t.Error(err)
			return
		}

		data1Expected := "gauge my.prefix.192_168_0_1.mymeasurement.myfield 3.14 1289430000"
		data1, err := tp.ReadLine()
		if err != nil {
			t.Error(err)
			return
		} else if data1 != data1Expected {
			t.Errorf("expected %q, got %q", data1Expected, data1)
			return
		}

		data2Expected := "gauge my.prefix.192_168_0_1.mymeasurement 3.14 1289430000"
		data2, err := tp.ReadLine()
		if err != nil {
			t.Error(err)
			return
		} else if data2 != data2Expected {
			t.Errorf("expected %q, got %q", data2Expected, data2)
			return
		}

		conn, err = tcpServer.Accept()
		if err != nil {
			t.Error(err)
			return
		}

		err = conn.SetDeadline(time.Now().Add(1 * time.Second))
		if err != nil {
			t.Error(err)
			return
		}

		reader = bufio.NewReader(conn)
		tp = textproto.NewReader(reader)

		helloExpected = "hello version go/telegraf/1.1"
		hello, err = tp.ReadLine()
		if err != nil {
			t.Error(err)
			return
		} else if hello != helloExpected {
			t.Errorf("expected %q, got %q", helloExpected, hello)
			return
		}

		authExpected = "authenticate abc123token"
		auth, err = tp.ReadLine()
		if err != nil {
			t.Error(err)
			return
		} else if auth != authExpected {
			t.Errorf("expected %q, got %q", authExpected, auth)
			return
		}

		_, err = conn.Write([]byte("ok\nok\n"))
		if err != nil {
			t.Error(err)
			return
		}

		data3Expected := "increment my.prefix.192_168_0_1.my_histogram 3.14 1289430000"
		data3, err := tp.ReadLine()
		if err != nil {
			t.Error(err)
			return
		} else if data3 != data3Expected {
			t.Errorf("expected %q, got %q", data3Expected, data3)
			return
		}

		data4Expected := "increment my.prefix.192_168_0_1_8888_123.bad_metric_name 1 1289430000"
		data4, err := tp.ReadLine()
		if err != nil {
			t.Error(err)
			return
		} else if data4 != data4Expected {
			t.Errorf("expected %q, got %q", data4Expected, data4)
			return
		}

		data5Expected := "increment my.prefix.192_168_0_1.my_counter 3.14 1289430000"
		data5, err := tp.ReadLine()
		if err != nil {
			t.Error(err)
			return
		} else if data5 != data5Expected {
			t.Errorf("expected %q, got %q", data5Expected, data5)
			return
		}

		data6Expected := ""
		data6, err := tp.ReadLine()
		if !errors.Is(err, io.EOF) {
			t.Error(err)
			return
		} else if data6 != data6Expected {
			t.Errorf("expected %q, got %q", data6Expected, data6)
			return
		}
	}()

	return tcpServer.Addr().(*net.TCPAddr).Port
}