func populateStateFromInstalled() error {
	all, err := (&snappy.Overlord{}).Installed()
	if err != nil {
		return err
	}

	if osutil.FileExists(dirs.SnapStateFile) {
		return fmt.Errorf("cannot create state: state %q already exists", dirs.SnapStateFile)
	}

	st := state.New(&overlordStateBackend{
		path: dirs.SnapStateFile,
	})
	st.Lock()
	defer st.Unlock()

	for _, sn := range all {
		// no need to do a snapstate.Get() because this is firstboot
		info := sn.Info()

		var snapst snapstate.SnapState
		snapst.Sequence = append(snapst.Sequence, &info.SideInfo)
		snapst.Channel = info.Channel
		snapst.Active = sn.IsActive()
		snapstate.Set(st, sn.Name(), &snapst)
	}

	return nil
}

func (s *interfaceManagerSuite) undoDevModeCheck(c *C, flags snappy.InstallFlags, devMode bool) {
	// Put the OS and sample snaps in place.
	s.mockSnap(c, osSnapYaml)
	snapInfo := s.mockSnap(c, sampleSnapYaml)

	// Initialize the manager. This registers both snaps.
	mgr := s.manager(c)

	// Run the setup-profiles task in UndoMode and let it finish.
	change := s.addSetupSnapSecurityChange(c, &snapstate.SnapSetup{
		Name: snapInfo.Name(), Flags: int(flags), Revision: snapInfo.Revision})
	s.state.Lock()
	task := change.Tasks()[0]
	// Inject the old value of DevMode flag for the task handler to restore
	task.Set("old-devmode", devMode)
	task.SetStatus(state.UndoStatus)
	s.state.Unlock()
	mgr.Ensure()
	mgr.Wait()
	mgr.Stop()

	// Change succeeds
	s.state.Lock()
	defer s.state.Unlock()
	c.Check(change.Status(), Equals, state.UndoneStatus)

	// SnapState.Flags now holds the original value of DevMode
	var snapState snapstate.SnapState
	err := snapstate.Get(s.state, snapInfo.Name(), &snapState)
	c.Assert(err, IsNil)
	c.Check(snapState.DevMode(), Equals, devMode)
}

func setupSnapSecurity(task *state.Task, snapInfo *snap.Info, repo *interfaces.Repository) error {
	st := task.State()
	var snapState snapstate.SnapState
	snapName := snapInfo.Name()
	if err := snapstate.Get(st, snapName, &snapState); err != nil {
		task.Errorf("cannot get state of snap %q: %s", snapName, err)
		return err
	}
	for _, backend := range securityBackends {
		st.Unlock()
		err := backend.Setup(snapInfo, snapState.DevMode(), repo)
		st.Lock()
		if err != nil {
			task.Errorf("cannot setup %s for snap %q: %s", backend.Name(), snapName, err)
			return err
		}
	}
	return nil
}

// The setup-profiles task will honor snappy.DeveloperMode flag by storing it
// in the SnapState.Flags (as DevMode) and by actually setting up security
// using that flag. Old copy of SnapState.Flag's DevMode is saved for the undo
// handler under `old-devmode`.
func (s *interfaceManagerSuite) TestSetupProfilesHonorsDevMode(c *C) {
	// Put the OS snap in place.
	mgr := s.manager(c)

	// Initialize the manager. This registers the OS snap.
	snapInfo := s.mockSnap(c, sampleSnapYaml)

	// Run the setup-profiles task and let it finish.
	// Note that the task will see SnapSetup.Flags equal to DeveloperMode.
	change := s.addSetupSnapSecurityChange(c, &snapstate.SnapSetup{
		Name: snapInfo.Name(), Flags: int(snappy.DeveloperMode), Revision: snapInfo.Revision})
	mgr.Ensure()
	mgr.Wait()
	mgr.Stop()

	s.state.Lock()
	defer s.state.Unlock()

	// Ensure that the task succeeded.
	c.Check(change.Status(), Equals, state.DoneStatus)

	// The snap was setup with DevMode equal to true.
	c.Assert(s.secBackend.SetupCalls, HasLen, 1)
	c.Assert(s.secBackend.RemoveCalls, HasLen, 0)
	c.Check(s.secBackend.SetupCalls[0].SnapInfo.Name(), Equals, "snap")
	c.Check(s.secBackend.SetupCalls[0].DevMode, Equals, true)

	// SnapState stored the value of DevMode
	var snapState snapstate.SnapState
	err := snapstate.Get(s.state, snapInfo.Name(), &snapState)
	c.Assert(err, IsNil)
	c.Check(snapState.DevMode(), Equals, true)

	// The old value of DevMode was saved in the task in case undo is needed.
	task := change.Tasks()[0]
	var oldDevMode bool
	err = task.Get("old-devmode", &oldDevMode)
	c.Assert(err, IsNil)
	c.Check(oldDevMode, Equals, false)
}

// localSnapInfo returns the information about the current snap for the given name plus the SnapState with the active flag and other snap revisions.
func localSnapInfo(st *state.State, name string) (info *snap.Info, active bool, err error) {
	st.Lock()
	defer st.Unlock()

	var snapst snapstate.SnapState
	err = snapstate.Get(st, name, &snapst)
	if err != nil && err != state.ErrNoState {
		return nil, false, fmt.Errorf("cannot consult state: %v", err)
	}

	cur := snapst.Current()
	if cur == nil {
		return nil, false, nil
	}

	info, err = snap.ReadInfo(name, cur)
	if err != nil {
		return nil, false, fmt.Errorf("cannot read snap details: %v", err)
	}

	return info, snapst.Active, nil
}

func (s *snapmgrQuerySuite) TestAll(c *C) {
	st := s.st
	st.Lock()
	defer st.Unlock()

	snapStates, err := snapstate.All(st)
	c.Assert(err, IsNil)

	c.Check(snapStates, HasLen, 1)

	var snapst *snapstate.SnapState

	for name, sst := range snapStates {
		c.Assert(name, Equals, "name1")
		snapst = sst
	}

	c.Check(snapst.Active, Equals, true)
	c.Check(snapst.Current(), NotNil)

	info12, err := snap.ReadInfo("name1", snapst.Current())
	c.Assert(err, IsNil)

	c.Check(info12.Name(), Equals, "name1")
	c.Check(info12.Revision, Equals, 12)
	c.Check(info12.Summary(), Equals, "s12")
	c.Check(info12.Version, Equals, "1.2")
	c.Check(info12.Description(), Equals, "Lots of text")

	info11, err := snap.ReadInfo("name1", snapst.Sequence[0])
	c.Assert(err, IsNil)

	c.Check(info11.Name(), Equals, "name1")
	c.Check(info11.Revision, Equals, 11)
	c.Check(info11.Version, Equals, "1.1")
}

func (s *snapmgrTestSuite) TestInstallSubequentLocalIntegration(c *C) {
	s.state.Lock()
	defer s.state.Unlock()

	snapstate.Set(s.state, "mock", &snapstate.SnapState{
		Active:        true,
		Sequence:      []*snap.SideInfo{{Revision: 100002}},
		LocalRevision: 100002,
	})

	mockSnap := makeTestSnap(c, `name: mock
version: 1.0`)
	chg := s.state.NewChange("install", "install a local snap")
	ts, err := snapstate.InstallPath(s.state, mockSnap, "", 0)
	c.Assert(err, IsNil)
	chg.AddAll(ts)

	s.state.Unlock()
	defer s.snapmgr.Stop()
	s.settle()
	s.state.Lock()

	// ensure only local install was run, i.e. first action is check-snap
	c.Assert(s.fakeBackend.ops, HasLen, 6)
	c.Check(s.fakeBackend.ops[0].op, Equals, "check-snap")
	c.Check(s.fakeBackend.ops[0].name, Matches, `.*/mock_1.0_all.snap`)

	c.Check(s.fakeBackend.ops[2].op, Equals, "unlink-snap")
	c.Check(s.fakeBackend.ops[2].name, Equals, "/snap/mock/100002")

	c.Check(s.fakeBackend.ops[3].op, Equals, "copy-data")
	c.Check(s.fakeBackend.ops[3].name, Equals, "/snap/mock/100003")
	c.Check(s.fakeBackend.ops[3].old, Equals, "/snap/mock/100002")

	c.Check(s.fakeBackend.ops[4].op, Equals, "candidate")
	c.Check(s.fakeBackend.ops[4].sinfo, DeepEquals, snap.SideInfo{Revision: 100003})
	c.Check(s.fakeBackend.ops[5].op, Equals, "link-snap")
	c.Check(s.fakeBackend.ops[5].name, Equals, "/snap/mock/100003")

	// verify snapSetup info
	var ss snapstate.SnapSetup
	task := ts.Tasks()[0]
	err = task.Get("snap-setup", &ss)
	c.Assert(err, IsNil)
	c.Assert(ss, DeepEquals, snapstate.SnapSetup{
		Name:     "mock",
		Revision: 100003,
		SnapPath: mockSnap,
	})

	// verify snaps in the system state
	var snapst snapstate.SnapState
	err = snapstate.Get(s.state, "mock", &snapst)
	c.Assert(err, IsNil)

	c.Assert(snapst.Active, Equals, true)
	c.Assert(snapst.Candidate, IsNil)
	c.Assert(snapst.Sequence, HasLen, 2)
	c.Assert(snapst.Current(), DeepEquals, &snap.SideInfo{
		OfficialName: "",
		Channel:      "",
		Revision:     100003,
	})
	c.Assert(snapst.LocalRevision, Equals, 100003)
}

func (m *InterfaceManager) doSetupProfiles(task *state.Task, _ *tomb.Tomb) error {
	task.State().Lock()
	defer task.State().Unlock()

	// Get snap.Info from bits handed by the snap manager.
	ss, err := snapstate.TaskSnapSetup(task)
	if err != nil {
		return err
	}
	snapInfo, err := snapstate.Info(task.State(), ss.Name, ss.Revision)
	if err != nil {
		return err
	}
	snap.AddImplicitSlots(snapInfo)
	snapName := snapInfo.Name()
	var snapState snapstate.SnapState
	if err := snapstate.Get(task.State(), snapName, &snapState); err != nil {
		task.Errorf("cannot get state of snap %q: %s", snapName, err)
		return err
	}

	// Set DevMode flag if SnapSetup.Flags indicates it should be done
	// but remember the old value in the task in case we undo.
	task.Set("old-devmode", snapState.DevMode())
	if ss.DevMode() {
		snapState.Flags |= snapstate.DevMode
	} else {
		snapState.Flags &= ^snapstate.DevMode
	}
	snapstate.Set(task.State(), snapName, &snapState)

	// The snap may have been updated so perform the following operation to
	// ensure that we are always working on the correct state:
	//
	// - disconnect all connections to/from the given snap
	//   - remembering the snaps that were affected by this operation
	// - remove the (old) snap from the interfaces repository
	// - add the (new) snap to the interfaces repository
	// - restore connections based on what is kept in the state
	//   - if a connection cannot be restored then remove it from the state
	// - setup the security of all the affected snaps
	blacklist := m.repo.AutoConnectBlacklist(snapName)
	affectedSnaps, err := m.repo.DisconnectSnap(snapName)
	if err != nil {
		return err
	}
	// XXX: what about snap renames? We should remove the old name (or switch
	// to IDs in the interfaces repository)
	if err := m.repo.RemoveSnap(snapName); err != nil {
		return err
	}
	if err := m.repo.AddSnap(snapInfo); err != nil {
		if _, ok := err.(*interfaces.BadInterfacesError); ok {
			logger.Noticef("%s", err)
		} else {
			return err
		}
	}
	if err := m.reloadConnections(snapName); err != nil {
		return err
	}
	if err := m.autoConnect(task, snapName, blacklist); err != nil {
		return err
	}
	if len(affectedSnaps) == 0 {
		affectedSnaps = append(affectedSnaps, snapInfo)
	}
	for _, snapInfo := range affectedSnaps {
		if err := setupSnapSecurity(task, snapInfo, m.repo); err != nil {
			return state.Retry
		}
	}
	return nil
}

func (m *InterfaceManager) doRemoveProfiles(task *state.Task, _ *tomb.Tomb) error {
	st := task.State()
	st.Lock()
	defer st.Unlock()

	// Get SnapSetup for this snap. This is gives us the name of the snap.
	snapSetup, err := snapstate.TaskSnapSetup(task)
	if err != nil {
		return err
	}
	snapName := snapSetup.Name

	// Get SnapState for this snap
	var snapState snapstate.SnapState
	err = snapstate.Get(st, snapName, &snapState)
	if err != nil && err != state.ErrNoState {
		return err
	}

	// Get the old-devmode flag from the task.
	// This flag is set by setup-profiles in case we have to undo.
	var oldDevMode bool
	err = task.Get("old-devmode", &oldDevMode)
	if err != nil && err != state.ErrNoState {
		return err
	}
	// Restore the state of DevMode flag if old-devmode was saved in the task.
	if err == nil {
		if oldDevMode {
			snapState.Flags |= snapstate.DevMode
		} else {
			snapState.Flags &= ^snapstate.DevMode
		}
		snapstate.Set(st, snapName, &snapState)
	}

	// Disconnect the snap entirely.
	// This is required to remove the snap from the interface repository.
	// The returned list of affected snaps will need to have its security setup
	// to reflect the change.
	affectedSnaps, err := m.repo.DisconnectSnap(snapName)
	if err != nil {
		return err
	}

	// Setup security of the affected snaps.
	for _, snapInfo := range affectedSnaps {
		if snapInfo.Name() == snapName {
			// Skip setup for the snap being removed as this is handled below.
			continue
		}
		if err := setupSnapSecurity(task, snapInfo, m.repo); err != nil {
			return state.Retry
		}
	}

	// Remove the snap from the interface repository.
	// This discards all the plugs and slots belonging to that snap.
	if err := m.repo.RemoveSnap(snapName); err != nil {
		return err
	}

	// Remove security artefacts of the snap.
	if err := removeSnapSecurity(task, snapName); err != nil {
		return state.Retry
	}

	return nil
}