package server

import (
	"context"
	"errors"
	"net"
	"net/http"
	"net/http/httptest"
	"os"
	"os/user"
	"path/filepath"
	"strings"
	"testing"

	"jarl/internal/api"
	"jarl/internal/client"
)

// serveTestSocket serves e's API on a unix socket, as jarld does.
func serveTestSocket(t *testing.T, e *apiEnv) string {
	t.Helper()
	path := filepath.Join(t.TempDir(), "jarl.sock")
	ln, err := listenSocket(path)
	if err != nil {
		t.Fatal(err)
	}
	srv := &http.Server{Handler: e.srv.Handler(), ConnContext: socketConnContext}
	go srv.Serve(ln)
	t.Cleanup(func() { srv.Close() })
	return path
}

func TestSocketTrustedUser(t *testing.T) {
	e := newAPIEnv(t)
	path := serveTestSocket(t, e)
	if fi, err := os.Stat(path); err != nil || fi.Mode().Perm() != 0o600 {
		t.Fatalf("socket mode: %v %v", fi.Mode(), err)
	}
	// The test runs as the same user as the server: an administrator
	// without a token.
	c, err := client.New(client.Options{Server: "unix://" + path})
	if err != nil {
		t.Fatal(err)
	}
	var who api.Whoami
	if err := c.Get(context.Background(), "/auth/whoami", nil, &who); err != nil {
		t.Fatal(err)
	}
	me, _ := user.Current()
	if !who.Admin || who.Method != "socket" || who.User.Username != me.Username || who.Token != nil {
		t.Errorf("whoami over the socket = %+v", who)
	}
	// It can change things, and the history and audit log name the
	// system user.
	if err := c.Do(context.Background(), "POST", "/zones", nil, map[string]any{"name": "sock.example", "records": []map[string]any{{"name": "ns1", "type": "A", "data": "192.0.2.1"}}}, nil); err != nil {
		t.Fatal(err)
	}
	var events []map[string]any
	c.Get(context.Background(), "/audit", nil, &events)
	found := false
	for _, ev := range events {
		if ev["action"] == "changeset.apply" && ev["username"] == me.Username && ev["auth"] == "socket" && ev["ip"] == "local" {
			found = true
		}
	}
	if !found {
		t.Errorf("no audit event for the socket user: %v", events)
	}
	// A token sent over the socket is used as such.
	c.Token = e.token
	if err := c.Get(context.Background(), "/auth/whoami", nil, &who); err != nil || who.Method != "token" {
		t.Errorf("token over the socket: %+v %v", who, err)
	}
	// The socket's user isn't a Jarl user, so it has no tokens of its own.
	c.Token = ""
	err = c.Do(context.Background(), "POST", "/me/tokens", nil, map[string]any{"name": "x"}, nil)
	var ae *client.Error
	if !errors.As(err, &ae) || ae.Status != 400 {
		t.Errorf("own token over the socket: %v", err)
	}
}

func TestSocketOtherUserNeedsToken(t *testing.T) {
	e := newAPIEnv(t)
	req := func(uid int, token string) *httptest.ResponseRecorder {
		r := httptest.NewRequest("GET", api.Prefix+"/auth/whoami", nil)
		r = r.WithContext(context.WithValue(r.Context(), peerKey{}, &peer{UID: uid}))
		if token != "" {
			r.Header.Set("Authorization", "Bearer "+token)
		}
		w := httptest.NewRecorder()
		e.srv.Handler().ServeHTTP(w, r)
		return w
	}
	other := os.Getuid() + 4242
	if w := req(other, ""); w.Code != 401 || !strings.Contains(w.Body.String(), "only to root and jarld's own user") {
		t.Errorf("untrusted user without a token: %d %s", w.Code, w.Body)
	}
	if w := req(-1, ""); w.Code != 401 {
		t.Errorf("unknown peer without a token: %d", w.Code)
	}
	if w := req(other, e.token); w.Code != 200 {
		t.Errorf("untrusted user with a token: %d %s", w.Code, w.Body)
	}
	if w := req(0, ""); w.Code != 200 || !strings.Contains(w.Body.String(), `"method":"socket"`) {
		t.Errorf("root: %d %s", w.Code, w.Body)
	}
	// Network requests never get this treatment.
	r := httptest.NewRequest("GET", api.Prefix+"/auth/whoami", nil)
	w := httptest.NewRecorder()
	e.srv.Handler().ServeHTTP(w, r)
	if w.Code != 401 {
		t.Errorf("network request without a token: %d", w.Code)
	}
}

func TestListenSocketStale(t *testing.T) {
	path := filepath.Join(t.TempDir(), "jarl.sock")
	// A socket left by a process that is gone is replaced.
	old, err := net.Listen("unix", path)
	if err != nil {
		t.Fatal(err)
	}
	old.(*net.UnixListener).SetUnlinkOnClose(false)
	old.Close()
	ln, err := listenSocket(path)
	if err != nil {
		t.Fatalf("stale socket not replaced: %v", err)
	}
	// One that is in use isn't.
	if _, err := listenSocket(path); err == nil || !strings.Contains(err.Error(), "in use") {
		t.Errorf("second jarld on the same socket: %v", err)
	}
	ln.Close()
	// A file that isn't a socket is never removed.
	os.WriteFile(path, []byte("x"), 0o600)
	if _, err := listenSocket(path); err == nil {
		t.Error("replaced a regular file")
	}
}