package profile

import (
	"errors"
	"os"
	"os/exec"
	"path/filepath"
	"syscall"
	"testing"
	"time"
)

type fakeIdentityEnvironment struct {
	current UserIdentity
	users   map[string]UserIdentity
	env     map[string]string
}

func (f fakeIdentityEnvironment) CurrentUser() (UserIdentity, error) { return f.current, nil }
func (f fakeIdentityEnvironment) LookupUser(name string) (UserIdentity, error) {
	identity, ok := f.users[name]
	if !ok {
		return UserIdentity{}, errors.New("not found")
	}
	return identity, nil
}
func (f fakeIdentityEnvironment) LookupEnv(name string) (string, bool) {
	value, ok := f.env[name]
	return value, ok
}

func TestFileStoreLockSerializesAcrossProcesses(t *testing.T) {
	if path := os.Getenv("PROXYCTL_LOCK_HELPER_PATH"); path != "" {
		store := NewFileStore(path)
		_, err := store.Mutate(func(state State) (State, error) {
			state.Profiles = append(state.Profiles, Profile{Name: "child"})
			return state, nil
		})
		if err != nil {
			t.Fatal(err)
		}
		return
	}

	path := filepath.Join(t.TempDir(), "proxyctl", "profiles.json")
	store := NewFileStore(path)
	if _, err := store.Mutate(func(state State) (State, error) { return state, nil }); err != nil {
		t.Fatal(err)
	}
	lock, err := os.OpenFile(path+".lock", os.O_RDWR, 0o600)
	if err != nil {
		t.Fatal(err)
	}
	defer lock.Close()
	if err := syscall.Flock(int(lock.Fd()), syscall.LOCK_EX); err != nil {
		t.Fatal(err)
	}

	command := exec.Command(os.Args[0], "-test.run=^TestFileStoreLockSerializesAcrossProcesses$")
	command.Env = append(os.Environ(), "PROXYCTL_LOCK_HELPER_PATH="+path)
	done := make(chan error, 1)
	go func() { done <- command.Run() }()
	select {
	case err := <-done:
		t.Fatalf("child mutation did not wait for lock: %v", err)
	case <-time.After(100 * time.Millisecond):
	}
	if err := syscall.Flock(int(lock.Fd()), syscall.LOCK_UN); err != nil {
		t.Fatal(err)
	}
	select {
	case err := <-done:
		if err != nil {
			t.Fatalf("child mutation after unlock: %v", err)
		}
	case <-time.After(5 * time.Second):
		_ = command.Process.Kill()
		t.Fatal("child mutation remained blocked after unlock")
	}
	state, err := store.Load()
	if err != nil {
		t.Fatal(err)
	}
	if len(state.Profiles) != 1 || state.Profiles[0].Name != "child" {
		t.Fatalf("state after serialized child mutation = %#v", state)
	}
}

func TestConfigPathUsesInvokingUserIdentityUnderSudo(t *testing.T) {
	environment := fakeIdentityEnvironment{
		current: UserIdentity{Username: "root", HomeDir: "/root"},
		users:   map[string]UserIdentity{"alice": {Username: "alice", HomeDir: "/home/alice"}},
		env: map[string]string{
			"SUDO_USER":       "alice",
			"XDG_CONFIG_HOME": "/home/alice/.xdg/config",
		},
	}
	path, err := ConfigPathWith(environment)
	if err != nil {
		t.Fatal(err)
	}
	want := filepath.Join("/home/alice/.xdg/config", "proxyctl", "profiles.json")
	if path != want {
		t.Fatalf("configuration path = %q, want invoking user's XDG path %q", path, want)
	}
}

func TestConfigPathDoesNotReuseRootXDGForInvokingUser(t *testing.T) {
	environment := fakeIdentityEnvironment{
		current: UserIdentity{Username: "root", HomeDir: "/root"},
		users:   map[string]UserIdentity{"alice": {Username: "alice", HomeDir: "/home/alice"}},
		env: map[string]string{
			"SUDO_USER":       "alice",
			"XDG_CONFIG_HOME": "/root/.config",
		},
	}
	path, err := ConfigPathWith(environment)
	if err != nil {
		t.Fatal(err)
	}
	want := filepath.Join("/home/alice/.config", "proxyctl", "profiles.json")
	if path != want {
		t.Fatalf("configuration path = %q, want invoking user's fallback %q", path, want)
	}
}

func TestConfigPathUsesRootForDirectRootLogin(t *testing.T) {
	environment := fakeIdentityEnvironment{
		current: UserIdentity{Username: "root", HomeDir: "/root"},
		users:   map[string]UserIdentity{},
		env:     map[string]string{"XDG_CONFIG_HOME": "/root/custom-config"},
	}
	path, err := ConfigPathWith(environment)
	if err != nil {
		t.Fatal(err)
	}
	want := filepath.Join("/root/custom-config", "proxyctl", "profiles.json")
	if path != want {
		t.Fatalf("configuration path = %q, want direct root path %q", path, want)
	}
}