package probe

import (
	"net"
	"testing"
)

func TestHumanizeBitsPerSecond(t *testing.T) {
	tests := []struct {
		name string
		rate float64
		want string
	}{
		{name: "bits", rate: 999, want: "999 bit/s"},
		{name: "kilobits", rate: 1500, want: "1.50 kbit/s"},
		{name: "megabits", rate: 2500000, want: "2.50 Mbit/s"},
		{name: "gigabits", rate: 4200000000, want: "4.20 Gbit/s"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := HumanizeBitsPerSecond(tt.rate); got != tt.want {
				t.Fatalf("HumanizeBitsPerSecond(%v) = %q, want %q", tt.rate, got, tt.want)
			}
		})
	}
}

func TestParseNetDev(t *testing.T) {
	data := []byte(`Inter-|   Receive                                                |  Transmit
 face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
    lo: 1000 0 0 0 0 0 0 0 2000 0 0 0 0 0 0 0
  eth0: 12345 1 0 0 0 0 0 0 67890 2 0 0 0 0 0 0
`)

	stats, err := parseNetDev(data, "eth0")
	if err != nil {
		t.Fatalf("parseNetDev() error = %v", err)
	}
	if stats.RXBytes != 12345 || stats.TXBytes != 67890 {
		t.Fatalf("stats = %+v, want rx 12345 tx 67890", stats)
	}
}

func TestLittleEndianHexIPv4(t *testing.T) {
	ip, err := littleEndianHexIPv4("0102A8C0")
	if err != nil {
		t.Fatalf("littleEndianHexIPv4() error = %v", err)
	}
	if !ip.Equal(net.IPv4(192, 168, 2, 1)) {
		t.Fatalf("ip = %v, want 192.168.2.1", ip)
	}
}

func TestParseLinuxDefaultGateway(t *testing.T) {
	t.Run("explicit gateway default route", func(t *testing.T) {
		data := []byte(`Iface	Destination	Gateway 	Flags	RefCnt	Use	Metric	Mask		MTU	Window	IRTT
eth0	00000000	0102A8C0	0003	0	0	100	00000000	0	0	0
`)

		ip, err := parseLinuxDefaultGateway(data, "eth0")
		if err != nil {
			t.Fatalf("parseLinuxDefaultGateway() error = %v", err)
		}
		if !ip.Equal(net.IPv4(192, 168, 2, 1)) {
			t.Fatalf("ip = %v, want 192.168.2.1", ip)
		}
	})

	t.Run("point to point peer route", func(t *testing.T) {
		data := []byte(`Iface	Destination	Gateway 	Flags	RefCnt	Use	Metric	Mask		MTU	Window	IRTT
ppp0	00000000	00000000	0001	0	0	0	00000000	0	0	0
ppp0	0100400A	00000000	0005	0	0	0	FFFFFFFF	0	0	0
`)

		ip, err := parseLinuxDefaultGateway(data, "ppp0")
		if err != nil {
			t.Fatalf("parseLinuxDefaultGateway() error = %v", err)
		}
		if !ip.Equal(net.IPv4(10, 64, 0, 1)) {
			t.Fatalf("ip = %v, want 10.64.0.1", ip)
		}
	})

	t.Run("prefers explicit gateway over peer route", func(t *testing.T) {
		data := []byte(`Iface	Destination	Gateway 	Flags	RefCnt	Use	Metric	Mask		MTU	Window	IRTT
ppp0	00000000	FE00400A	0003	0	0	0	00000000	0	0	0
ppp0	0100400A	00000000	0005	0	0	0	FFFFFFFF	0	0	0
`)

		ip, err := parseLinuxDefaultGateway(data, "ppp0")
		if err != nil {
			t.Fatalf("parseLinuxDefaultGateway() error = %v", err)
		}
		if !ip.Equal(net.IPv4(10, 64, 0, 254)) {
			t.Fatalf("ip = %v, want 10.64.0.254", ip)
		}
	})
}