package authproxy

import (
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"testing"
	"time"
)

// writeAppLists lays out one app's config the way the dokku plugin does.
func writeAppLists(t *testing.T, dir, app string, files map[string]string) {
	t.Helper()
	appDir := filepath.Join(dir, app)
	if err := os.MkdirAll(appDir, 0o755); err != nil {
		t.Fatal(err)
	}
	for name, content := range files {
		if err := os.WriteFile(filepath.Join(appDir, name), []byte(content), 0o644); err != nil {
			t.Fatal(err)
		}
	}
}

func TestAppStoreReadsLists(t *testing.T) {
	dir := t.TempDir()
	writeAppLists(t, dir, "my-app", map[string]string{
		"allowed-domains": "Signal.org\n@example.com\n",
		"allowed-emails":  "Guest@Partner.com\n",
		"denied-emails":   "former@signal.org\n",
	})
	store := newAppStore(dir)

	got := store.lists("my-app")
	if len(got.AllowedDomains) != 2 || got.AllowedDomains[0] != "signal.org" || got.AllowedDomains[1] != "example.com" {
		t.Errorf("AllowedDomains = %v", got.AllowedDomains)
	}
	if len(got.AllowedEmails) != 1 || got.AllowedEmails[0] != "guest@partner.com" {
		t.Errorf("AllowedEmails = %v", got.AllowedEmails)
	}
	if len(got.DeniedEmails) != 1 || got.DeniedEmails[0] != "former@signal.org" {
		t.Errorf("DeniedEmails = %v", got.DeniedEmails)
	}

	// An app with no directory, and a disabled store, both mean "inherit".
	if store.lists("other-app").hasAllowRules() {
		t.Error("an app with no config should have no allow rules")
	}
	if newAppStore("").lists("my-app").hasAllowRules() {
		t.Error("an empty config dir should disable per-app lists")
	}
}

// A list file the service cannot read leaves the app's real rules unknown.
// Inheriting the global list there would hand out access the app's own list was
// written to withhold, so the app denies instead.
func TestUnreadableListDeniesInsteadOfInheriting(t *testing.T) {
	if os.Geteuid() == 0 {
		t.Skip("root reads files regardless of mode")
	}
	dir := t.TempDir()
	writeAppLists(t, dir, "locked", map[string]string{"allowed-emails": "ceo@signal.org\n"})
	if err := os.Chmod(filepath.Join(dir, "locked", "allowed-emails"), 0o000); err != nil {
		t.Fatal(err)
	}

	s := newTestServer(t, "http://unused.invalid") // global list allows all of signal.org
	s.cfg.AppConfigDir = dir
	s.apps = newAppStore(dir)

	if !s.apps.lists("locked").Unreadable {
		t.Error("an unreadable list file should mark the app's lists unreadable")
	}
	for _, email := range []string{"ceo@signal.org", "anyone@signal.org"} {
		if s.emailAllowedFor("locked", email) {
			t.Errorf("emailAllowedFor(locked, %q) = true; an app whose list cannot be read must deny", email)
		}
	}
	// Only that app is affected: everyone else still uses the global list.
	if !s.emailAllowedFor("inherits", "anyone@signal.org") {
		t.Error("an app with no config of its own should still inherit the global list")
	}
}

// The app name reaches the service in a header, so it must never be able to
// walk out of the config directory.
func TestAppStoreRejectsUnusableNames(t *testing.T) {
	dir := t.TempDir()
	writeAppLists(t, dir, "escaped", map[string]string{"allowed-emails": "attacker@evil.com\n"})
	store := newAppStore(dir)

	for _, name := range []string{
		"", ".", "..", "../escaped", "..%2fescaped", "/escaped", "sub/escaped",
		".hidden", "app name", "app;rm", "app\x00", "app\n",
	} {
		if got := store.lists(name); got.hasAllowRules() || len(got.DeniedEmails) > 0 {
			t.Errorf("lists(%q) returned rules; want empty", name)
		}
		if validAppName(name) {
			t.Errorf("validAppName(%q) = true, want false", name)
		}
	}
	for _, name := range []string{"my-app", "my_app", "app.example", "App2"} {
		if !validAppName(name) {
			t.Errorf("validAppName(%q) = false, want true", name)
		}
	}
}

func TestAppStoreCachesUntilTTL(t *testing.T) {
	dir := t.TempDir()
	writeAppLists(t, dir, "my-app", map[string]string{"allowed-emails": "first@signal.org\n"})

	now := time.Unix(1700000000, 0)
	store := newAppStore(dir)
	store.now = func() time.Time { return now }

	if got := store.lists("my-app").AllowedEmails[0]; got != "first@signal.org" {
		t.Fatalf("first read = %q", got)
	}
	writeAppLists(t, dir, "my-app", map[string]string{"allowed-emails": "second@signal.org\n"})
	if got := store.lists("my-app").AllowedEmails[0]; got != "first@signal.org" {
		t.Errorf("within the TTL the cached value should stand, got %q", got)
	}
	now = now.Add(store.ttl + time.Second)
	if got := store.lists("my-app").AllowedEmails[0]; got != "second@signal.org" {
		t.Errorf("after the TTL the change should be picked up, got %q", got)
	}
}

// newPerAppServer is a server whose global list allows all of signal.org, plus
// per-app overrides on disk.
func newPerAppServer(t *testing.T, apps map[string]map[string]string) *Server {
	t.Helper()
	dir := t.TempDir()
	for app, files := range apps {
		writeAppLists(t, dir, app, files)
	}
	s := newTestServer(t, "http://unused.invalid")
	s.cfg.AppConfigDir = dir
	s.apps = newAppStore(dir)
	return s
}

func TestPerAppAllowReplacesGlobal(t *testing.T) {
	s := newPerAppServer(t, map[string]map[string]string{
		"narrowed": {"allowed-emails": "ceo@signal.org\n"},
		"widened":  {"allowed-emails": "guest@partner.com\n"},
	})

	cases := []struct {
		app, email string
		want       bool
	}{
		// No per-app config: the global list applies.
		{"inherits", "anyone@signal.org", true},
		{"inherits", "guest@partner.com", false},
		{"", "anyone@signal.org", true},
		// Own allow list: it replaces the global one entirely.
		{"narrowed", "ceo@signal.org", true},
		{"narrowed", "anyone@signal.org", false},
		// An app may admit someone the global list does not cover.
		{"widened", "guest@partner.com", true},
		{"widened", "anyone@signal.org", false},
		// An unknown app name falls back to global rather than failing open.
		{"no-such-app", "anyone@signal.org", true},
		{"../narrowed", "anyone@signal.org", true},
	}
	for _, c := range cases {
		if got := s.emailAllowedFor(c.app, c.email); got != c.want {
			t.Errorf("emailAllowedFor(%q, %q) = %v, want %v", c.app, c.email, got, c.want)
		}
	}
}

func TestPerAppDenyCombinesWithGlobal(t *testing.T) {
	s := newPerAppServer(t, map[string]map[string]string{
		"app-a": {"denied-emails": "bob@signal.org\n"},
		// An app's own deny list must not resurrect a globally denied account.
		"app-b": {"denied-emails": "someone@signal.org\n"},
		// Nor may an app's allow list override a global denial.
		"app-c": {"allowed-emails": "gone@signal.org\n"},
	})
	s.cfg.DeniedEmails = []string{"gone@signal.org"}

	cases := []struct {
		app, email string
		want       bool
	}{
		{"app-a", "bob@signal.org", false},  // denied for this app
		{"app-b", "bob@signal.org", true},   // ...but not for another
		{"app-a", "gone@signal.org", false}, // global denial still applies
		{"app-b", "gone@signal.org", false}, // even with its own deny list
		{"app-c", "gone@signal.org", false}, // even when the app allows them
		{"inherits", "gone@signal.org", false},
	}
	for _, c := range cases {
		if got := s.emailAllowedFor(c.app, c.email); got != c.want {
			t.Errorf("emailAllowedFor(%q, %q) = %v, want %v", c.app, c.email, got, c.want)
		}
	}
}

// The plugin reads healthz to find out whether the running binary honours
// per-app lists at all — docker metadata cannot tell a current container from
// one recreated from a stale image. Changing this shape breaks that check.
func TestHealthzReportsAppConfigDir(t *testing.T) {
	s := newPerAppServer(t, nil)
	s.cfg.AppConfigDir = "/data/apps"

	r := httptest.NewRequest("GET", "http://"+appHost+RoutePrefix+"/healthz", nil)
	w := do(s.Routes(), r)
	if w.Code != http.StatusOK {
		t.Fatalf("healthz = %d, want 200", w.Code)
	}
	if got, want := w.Body.String(), `{"ok":true,"app_config_dir":"/data/apps"}`; got != want {
		t.Errorf("healthz body = %s, want %s", got, want)
	}

	// Per-app config off: the field is present but empty, so the plugin can
	// tell "configured with no directory" from "too old to answer".
	s.cfg.AppConfigDir = ""
	if got, want := do(s.Routes(), r).Body.String(), `{"ok":true,"app_config_dir":""}`; got != want {
		t.Errorf("healthz body with per-app config off = %s, want %s", got, want)
	}
}

// The app name is read from a header, so verify must use the value nginx set
// and a session must not be portable to an app with stricter rules.
func TestVerifyUsesAppHeader(t *testing.T) {
	s := newPerAppServer(t, map[string]map[string]string{
		"strict": {"allowed-emails": "ceo@signal.org\n"},
	})
	sess := sessionClaims{Email: "dev@signal.org", User: "1", Host: appHost,
		Exp: time.Now().Add(time.Hour).Unix()}
	val, err := s.box.seal("session", sess)
	if err != nil {
		t.Fatal(err)
	}
	verify := func(app string) int {
		r := httptest.NewRequest("GET", "http://"+appHost+RoutePrefix+"/verify", nil)
		r.AddCookie(&http.Cookie{Name: "_google_auth", Value: val})
		if app != "" {
			r.Header.Set(AppHeader, app)
		}
		return do(s.Routes(), r).Code
	}

	if got := verify("lenient"); got != http.StatusOK {
		t.Errorf("app inheriting the global list: got %d, want 200", got)
	}
	if got := verify("strict"); got != http.StatusUnauthorized {
		t.Errorf("app whose list excludes the user: got %d, want 401", got)
	}
	if got := verify(""); got != http.StatusOK {
		t.Errorf("no app header: got %d, want 200 (global rules)", got)
	}
}

// The callback runs on the auth host, which may serve a different app than the
// one being signed in to. Authorization must follow the destination app.
func TestCallbackAuthorizesAgainstDestinationApp(t *testing.T) {
	google := fakeGoogle(t, goodClaims()) // signs in greyson@signal.org
	defer google.Close()
	s := newPerAppServer(t, map[string]map[string]string{
		"strict": {"allowed-emails": "ceo@signal.org\n"},
	})
	s.cfg.TokenURL = google.URL

	callback := func(app string) *httptest.ResponseRecorder {
		tok, err := s.box.seal("state", stateClaims{
			Host: appHost, App: app, RD: "/", Proto: "https", Nonce: randToken(),
			Exp: time.Now().Add(10 * time.Minute).Unix(),
		})
		if err != nil {
			t.Fatal(err)
		}
		r := httptest.NewRequest("GET",
			"http://"+authHost+RoutePrefix+"/callback?code=good-code&state="+url.QueryEscape(tok), nil)
		// The auth host's own app name, which must not be what decides.
		r.Header.Set(AppHeader, "auth-host-app")
		return do(s.Routes(), r)
	}

	if w := callback("lenient"); w.Code != http.StatusFound {
		t.Errorf("destination inheriting the global list: got %d, want 302; body: %s", w.Code, w.Body.String())
	}
	if w := callback("strict"); w.Code != http.StatusForbidden {
		t.Errorf("destination whose list excludes the user: got %d, want 403", w.Code)
	}
}

// The hd hint should follow the app's effective domain list, not the global one.
func TestStartHintsAppDomain(t *testing.T) {
	s := newPerAppServer(t, map[string]map[string]string{
		"partner-app": {"allowed-domains": "partner.com\n"},
	})
	start := func(app string) string {
		r := httptest.NewRequest("GET", "http://"+appHost+RoutePrefix+"/start", nil)
		r.Header.Set("Accept", "text/html")
		r.Header.Set(AppHeader, app)
		loc, err := url.Parse(do(s.Routes(), r).Header().Get("Location"))
		if err != nil {
			t.Fatal(err)
		}
		return loc.Query().Get("hd")
	}
	if got := start("inherits"); got != "signal.org" {
		t.Errorf("hd for an inheriting app = %q, want signal.org", got)
	}
	if got := start("partner-app"); got != "partner.com" {
		t.Errorf("hd for an app with its own domain = %q, want partner.com", got)
	}
}