package cli_test

import (
	"bytes"
	"os"
	"os/user"
	"path/filepath"
	"strconv"
	"strings"
	"testing"

	"sneak.berlin/go/netwatch/internal/cli"
	"sneak.berlin/go/netwatch/internal/reportbuf"
)

// TestMainRunsCheckCIDR: Main given check-cidr returns 0 for a CIDR the
// server takes in its TRUSTED_PROXIES and 1 for one it refuses, and
// does not start the server.
func TestMainRunsCheckCIDR(t *testing.T) {
	t.Parallel()

	for cidr, want := range map[string]int{"10.0.0.0/8": 0, "1.2.3/32": 1} {
		code := cli.Main("netwatch", "test", []string{"check-cidr", cidr},
			failIfServerStarts(t))
		if code != want {
			t.Errorf("check-cidr %q: exit %d, want %d", cidr, code, want)
		}
	}
}

// TestMainRunsPrepareDataDir: Main given prepare-data-dir returns 1 for
// a DATA_DIR outside /data, and does not start the server. The test
// image has no netwatch user, so there the 1 comes from looking that
// user up; TestPrepareDataDirRefusesPathOutsideVolume checks the path.
func TestMainRunsPrepareDataDir(t *testing.T) {
	t.Parallel()

	code := cli.Main("netwatch", "test", []string{"prepare-data-dir", "/etc"},
		failIfServerStarts(t))
	if code != 1 {
		t.Errorf("prepare-data-dir /etc: exit %d, want 1", code)
	}
}

// TestCheckCIDRTakesCIDR: check-cidr exits 0, writing nothing, for a
// CIDR the server takes in its TRUSTED_PROXIES.
func TestCheckCIDRTakesCIDR(t *testing.T) {
	t.Parallel()

	for _, cidr := range []string{"10.0.0.0/8", "192.0.2.1/32", "2001:db8::/32"} {
		var stderr bytes.Buffer

		code := cli.CheckCIDR(&stderr, cidr)
		if code != 0 || stderr.Len() != 0 {
			t.Errorf("%q: exit %d, stderr %q; want exit 0 and no output",
				cidr, code, stderr.String())
		}
	}
}

// TestCheckCIDRRefusesOtherInput: check-cidr exits 1, with an error
// naming TRUSTED_PROXIES and the input, for anything the server would
// refuse in its TRUSTED_PROXIES, such as 1.2.3/32, which nginx would
// look up as a hostname.
func TestCheckCIDRRefusesOtherInput(t *testing.T) {
	t.Parallel()

	for _, cidr := range []string{
		"1.2.3/32", "example.com/32", "10.0.0.0/33", "10.0.0.1", "",
	} {
		var stderr bytes.Buffer

		code := cli.CheckCIDR(&stderr, cidr)

		want := "TRUSTED_PROXIES " + strconv.Quote(cidr) + ": "
		if code != 1 || !strings.HasPrefix(stderr.String(), want) {
			t.Errorf("%q: exit %d, stderr %q; want exit 1 and %q...",
				cidr, code, stderr.String(), want)
		}
	}
}

// TestPrepareDataDirTakesPathInVolume: prepare-data-dir exits 0,
// writing nothing, for a DATA_DIR below the volume, and creates it.
func TestPrepareDataDirTakesPathInVolume(t *testing.T) {
	t.Parallel()

	volume := t.TempDir()
	dataDir := filepath.Join(volume, "reports")

	var stderr bytes.Buffer

	code := cli.PrepareDataDir(&stderr, volume, dataDir, currentUsername(t))
	if code != 0 || stderr.Len() != 0 {
		t.Errorf("exit %d, stderr %q; want exit 0 and no output",
			code, stderr.String())
	}

	info, err := os.Stat(dataDir)
	if err != nil || !info.IsDir() {
		t.Errorf("DATA_DIR not created: %v", err)
	}
}

// TestPrepareDataDirRefusesPathOutsideVolume: prepare-data-dir exits
// 1, with an error naming DATA_DIR and its value, for a DATA_DIR
// outside the volume.
func TestPrepareDataDirRefusesPathOutsideVolume(t *testing.T) {
	t.Parallel()

	volume := t.TempDir()

	var stderr bytes.Buffer

	code := cli.PrepareDataDir(&stderr, volume, "/etc", currentUsername(t))

	want := "DATA_DIR '/etc': " + reportbuf.ErrDataDirOutsideVolume.Error() + "\n"
	if code != 1 || stderr.String() != want {
		t.Errorf("exit %d, stderr %q; want exit 1 and %q",
			code, stderr.String(), want)
	}
}

// currentUsername is the name of the user the test runs as, the only
// owner a test not run as root can give files to.
func currentUsername(t *testing.T) string {
	t.Helper()

	current, err := user.Current()
	if err != nil {
		t.Fatal(err)
	}

	return current.Username
}

// failIfServerStarts is what the tests give Main in place of
// cli.RunServer: it fails the test instead of starting the server.
func failIfServerStarts(t *testing.T) func(appname, version string) {
	t.Helper()

	return func(string, string) {
		t.Error("Main started the server")
	}
}