package reachable

import (
	"context"
	"os"
	"strings"
	"testing"
)

// Defends novox/hq ADR 0100: converging previews every listening socket and every published
// container port. Fixtures are captured from a real machine.

func fixture(t *testing.T, name string) string {
	t.Helper()
	raw, err := os.ReadFile("testdata/" + name)
	if err != nil {
		t.Fatal(err)
	}
	return string(raw)
}

func find(rs []Reach, protocol, address string, port int) (Reach, bool) {
	for _, r := range rs {
		if r.Protocol == protocol && r.Address == address && r.Port == port {
			return r, true
		}
	}
	return Reach{}, false
}

func TestSocketsAreReadWithWhatHoldsThem(t *testing.T) {
	got := Sockets(fixture(t, "ss.txt"))
	if r, ok := find(got, "tcp", "0.0.0.0", 22); !ok || r.By != "sshd" {
		t.Errorf("ssh not read: %+v", r)
	}
	if r, ok := find(got, "tcp", "::", 445); !ok || r.By != "smbd" {
		t.Errorf("an IPv6 wildcard listener not read: %+v", r)
	}
	if _, ok := find(got, "udp", "fe80::849e:ccff:fea8:24c7", 123); !ok {
		t.Error("a link-local address with a scope was not read")
	}
	if r, ok := find(got, "udp", "127.0.0.1", 53); !ok || r.By != "dnsmasq" {
		t.Errorf("a loopback udp socket not read: %+v", r)
	}
}

func TestPublishedPortsNameTheirContainerAndItsPort(t *testing.T) {
	got := Published(fixture(t, "docker-ps.txt"))
	if r, ok := find(got, "tcp", "0.0.0.0", 8770); !ok || r.By != "whisper" || r.ContainerPort != 8000 || !r.Published {
		t.Errorf("a published port: %+v", r)
	}
	if r, ok := find(got, "tcp", "0.0.0.0", 9001); !ok || r.ContainerPort != 9001 {
		t.Errorf("a published range was not expanded: %+v", r)
	}
	if r, ok := find(got, "tcp", "127.0.0.1", 15673); !ok || r.ContainerPort != 15672 {
		t.Errorf("a loopback-published port: %+v", r)
	}
	for _, r := range got {
		if r.By == "umami_db" {
			t.Errorf("an exposed and unpublished port was reported reachable: %+v", r)
		}
	}
}

func TestAPublishedPortIsReportedOnceAsPublished(t *testing.T) {
	merged := Merge(Sockets(fixture(t, "ss.txt")), Published(fixture(t, "docker-ps.txt")))
	n := 0
	for _, r := range merged {
		if r.Protocol == "tcp" && r.Address == "0.0.0.0" && r.Port == 8770 {
			n++
			if !r.Published {
				t.Errorf("the runtime's proxy was reported instead of the published port: %+v", r)
			}
		}
	}
	if n != 1 {
		t.Errorf("port 8770 reported %d times", n)
	}
	if _, ok := find(merged, "tcp", "0.0.0.0", 22); !ok {
		t.Error("a socket was lost in the merge")
	}
}

func TestCollectAsksSsAndTheRuntime(t *testing.T) {
	var asked []string
	run := func(_ context.Context, name string, args ...string) (string, error) {
		asked = append(asked, name+" "+strings.Join(args, " "))
		if name == "ss" {
			return fixture(t, "ss.txt"), nil
		}
		return fixture(t, "docker-ps.txt"), nil
	}
	got, err := Collect(context.Background(), run)
	if err != nil || len(got) == 0 {
		t.Fatalf("%v %v", got, err)
	}
	if len(asked) != 2 {
		t.Errorf("asked %v", asked)
	}
}