// stateServerAddresses returns the list of internal addresses of the state
// server machines.
func (st *State) stateServerAddresses() ([]string, error) {
	type addressMachine struct {
		Addresses []address
	}
	var allAddresses []addressMachine
	// TODO(rog) 2013/10/14 index machines on jobs.
	err := st.machines.Find(bson.D{{"jobs", JobManageEnviron}}).All(&allAddresses)
	if err != nil {
		return nil, err
	}
	if len(allAddresses) == 0 {
		return nil, fmt.Errorf("no state server machines found")
	}
	apiAddrs := make([]string, 0, len(allAddresses))
	for _, addrs := range allAddresses {
		instAddrs := addressesToInstanceAddresses(addrs.Addresses)
		addr := network.SelectInternalAddress(instAddrs, false)
		if addr != "" {
			apiAddrs = append(apiAddrs, addr)
		}
	}
	if len(apiAddrs) == 0 {
		return nil, fmt.Errorf("no state server machines with addresses found")
	}
	return apiAddrs, nil
}

// PrivateAddress implements the server side of Client.PrivateAddress.
func (c *Client) PrivateAddress(p params.PrivateAddress) (results params.PrivateAddressResults, err error) {
	switch {
	case names.IsValidMachine(p.Target):
		machine, err := c.api.state.Machine(p.Target)
		if err != nil {
			return results, err
		}
		addr := network.SelectInternalAddress(machine.Addresses(), false)
		if addr == "" {
			return results, fmt.Errorf("machine %q has no internal address", machine)
		}
		return params.PrivateAddressResults{PrivateAddress: addr}, nil

	case names.IsValidUnit(p.Target):
		unit, err := c.api.state.Unit(p.Target)
		if err != nil {
			return results, err
		}
		addr, ok := unit.PrivateAddress()
		if !ok {
			return results, fmt.Errorf("unit %q has no internal address", unit)
		}
		return params.PrivateAddressResults{PrivateAddress: addr}, nil
	}
	return results, fmt.Errorf("unknown unit or machine %q", p.Target)
}

func (st *State) machineDocForTemplate(template MachineTemplate, id string) *machineDoc {
	// We ignore the error from Select*Address as an error indicates
	// no address is available, in which case the empty address is returned
	// and setting the preferred address to an empty one is the correct
	// thing to do when none is available.
	privateAddr, _ := network.SelectInternalAddress(template.Addresses, false)
	publicAddr, _ := network.SelectPublicAddress(template.Addresses)
	logger.Infof(
		"new machine %q has preferred addresses: private %q, public %q",
		id, privateAddr, publicAddr,
	)
	return &machineDoc{
		DocID:                   st.docID(id),
		Id:                      id,
		ModelUUID:               st.ModelUUID(),
		Series:                  template.Series,
		Jobs:                    template.Jobs,
		Clean:                   !template.Dirty,
		Principals:              template.principals,
		Life:                    Alive,
		Nonce:                   template.Nonce,
		Addresses:               fromNetworkAddresses(template.Addresses, OriginMachine),
		PreferredPrivateAddress: fromNetworkAddress(privateAddr, OriginMachine),
		PreferredPublicAddress:  fromNetworkAddress(publicAddr, OriginMachine),
		NoVote:                  template.NoVote,
		Placement:               template.Placement,
	}
}

// Restore implements the server side of Backups.Restore.
func (a *API) Restore(p params.RestoreArgs) error {

	// Get hold of a backup file Reader
	backup, closer := newBackups(a.st)
	defer closer.Close()

	// Obtain the address of current machine, where we will be performing restore.
	machine, err := a.st.Machine(a.machineID)
	if err != nil {
		return errors.Trace(err)
	}

	addr := network.SelectInternalAddress(machine.Addresses(), false)
	if addr == "" {
		return errors.Errorf("machine %q has no internal address", machine)
	}

	publicAddress := network.SelectPublicAddress(machine.Addresses())
	if publicAddress == "" {
		return errors.Errorf("machine %q has no public address", machine)
	}

	info, err := a.st.RestoreInfoSetter()
	if err != nil {
		return errors.Trace(err)
	}
	// Signal to current state and api server that restore will begin
	err = info.SetStatus(state.RestoreInProgress)
	if err != nil {
		return errors.Annotatef(err, "cannot set the server to %q mode", state.RestoreInProgress)
	}
	// Any abnormal termination of this function will mark restore as failed,
	// succesful termination will call Exit and never run this.
	defer info.SetStatus(state.RestoreFailed)

	instanceId, err := machine.InstanceId()
	if err != nil {
		return errors.Annotate(err, "cannot obtain instance id for machine to be restored")
	}

	logger.Infof("beginning server side restore of backup %q", p.BackupId)
	// Restore
	restoreArgs := backups.RestoreArgs{
		PrivateAddress: addr,
		PublicAddress:  publicAddress,
		NewInstId:      instanceId,
		NewInstTag:     machine.Tag(),
		NewInstSeries:  machine.Series(),
	}
	if err := backup.Restore(p.BackupId, restoreArgs); err != nil {
		return errors.Annotate(err, "restore failed")
	}

	// After restoring, the api server needs a forced restart, tomb will not work
	// this is because we change all of juju configuration files and mongo too.
	// Exiting with 0 would prevent upstart to respawn the process
	os.Exit(1)
	return nil
}

func (s *AddressSuite) TestSelectInternalMachineAddress(c *gc.C) {
	for i, t := range selectInternalMachineTests {
		c.Logf("test %d: %s", i, t.about)
		expectAddr, expectOK := t.expected()
		actualAddr, actualOK := network.SelectInternalAddress(t.addresses, true)
		c.Check(actualOK, gc.Equals, expectOK)
		c.Check(actualAddr, gc.Equals, expectAddr)
	}
}

func (s *AddressSuite) TestSelectInternalMachineAddress(c *gc.C) {
	oldValue := network.GetPreferIPv6()
	defer func() {
		network.SetPreferIPv6(oldValue)
	}()
	for i, t := range selectInternalMachineTests {
		c.Logf("test %d: %s", i, t.about)
		network.SetPreferIPv6(t.preferIPv6)
		c.Check(network.SelectInternalAddress(t.addresses, true), gc.Equals, t.expected())
	}
}

func (s *AddressSuite) TestSelectInternalAddress(c *gc.C) {
	oldValue := network.PreferIPv6()
	defer func() {
		network.SetPreferIPv6(oldValue)
	}()
	for i, t := range selectInternalTests {
		c.Logf("test %d: %s", i, t.about)
		network.SetPreferIPv6(t.preferIPv6)
		expectAddr, expectOK := t.expected()
		actualAddr, actualOK := network.SelectInternalAddress(t.addresses, false)
		c.Check(actualOK, gc.Equals, expectOK)
		c.Check(actualAddr, gc.Equals, expectAddr)
	}
}

// remoteParamsForMachine returns a filled in RemoteExec instance
// based on the machine, command and timeout params.  If the machine
// does not have an internal address, the Host is empty. This is caught
// by the function that actually tries to execute the command.
func remoteParamsForMachine(machine *state.Machine, command string, timeout time.Duration) *RemoteExec {
	// magic boolean parameters are bad :-(
	address, ok := network.SelectInternalAddress(machine.Addresses(), false)
	execParams := &RemoteExec{
		ExecParams: ssh.ExecParams{
			Command: command,
			Timeout: timeout,
		},
		MachineId: machine.Id(),
	}
	if ok {
		execParams.Host = fmt.Sprintf("[email protected]%s", address.Value)
	}
	return execParams
}

// stateServerAddresses returns the list of internal addresses of the state
// server machines.
func (st *State) stateServerAddresses() ([]string, error) {
	ssState := st
	env, err := st.StateServerEnvironment()
	if err != nil {
		return nil, errors.Trace(err)
	}
	if st.EnvironTag() != env.EnvironTag() {
		// We are not using the state server environment, so get one.
		logger.Debugf("getting a state server state connection, current env: %s", st.EnvironTag())
		ssState, err = st.ForEnviron(env.EnvironTag())
		if err != nil {
			return nil, errors.Trace(err)
		}
		defer ssState.Close()
		logger.Debugf("ssState env: %s", ssState.EnvironTag())
	}

	type addressMachine struct {
		Addresses []address
	}
	var allAddresses []addressMachine
	// TODO(rog) 2013/10/14 index machines on jobs.
	machines, closer := ssState.getCollection(machinesC)
	defer closer()
	err = machines.Find(bson.D{{"jobs", JobManageEnviron}}).All(&allAddresses)
	if err != nil {
		return nil, err
	}
	if len(allAddresses) == 0 {
		return nil, errors.New("no state server machines found")
	}
	apiAddrs := make([]string, 0, len(allAddresses))
	for _, addrs := range allAddresses {
		naddrs := networkAddresses(addrs.Addresses)
		addr := network.SelectInternalAddress(naddrs, false)
		if addr != "" {
			apiAddrs = append(apiAddrs, addr)
		}
	}
	if len(apiAddrs) == 0 {
		return nil, errors.New("no state server machines with addresses found")
	}
	return apiAddrs, nil
}

// controllerAddresses returns the list of internal addresses of the state
// server machines.
func (st *State) controllerAddresses() ([]string, error) {
	ssState := st
	model, err := st.ControllerModel()
	if err != nil {
		return nil, errors.Trace(err)
	}
	if st.ModelTag() != model.ModelTag() {
		// We are not using the controller model, so get one.
		logger.Debugf("getting a controller state connection, current env: %s", st.ModelTag())
		ssState, err = st.ForModel(model.ModelTag())
		if err != nil {
			return nil, errors.Trace(err)
		}
		defer ssState.Close()
		logger.Debugf("ssState env: %s", ssState.ModelTag())
	}

	type addressMachine struct {
		Addresses []address
	}
	var allAddresses []addressMachine
	// TODO(rog) 2013/10/14 index machines on jobs.
	machines, closer := ssState.getCollection(machinesC)
	defer closer()
	err = machines.Find(bson.D{{"jobs", JobManageModel}}).All(&allAddresses)
	if err != nil {
		return nil, err
	}
	if len(allAddresses) == 0 {
		return nil, errors.New("no controller machines found")
	}
	apiAddrs := make([]string, 0, len(allAddresses))
	for _, addrs := range allAddresses {
		naddrs := networkAddresses(addrs.Addresses)
		addr, ok := network.SelectInternalAddress(naddrs, false)
		if ok {
			apiAddrs = append(apiAddrs, addr.Value)
		}
	}
	if len(apiAddrs) == 0 {
		return nil, errors.New("no controller machines with addresses found")
	}
	return apiAddrs, nil
}

// SelectPeerAddress returns the address to use as the
// mongo replica set peer address by selecting it from the given addresses.
func SelectPeerAddress(addrs []network.Address) string {
	return network.SelectInternalAddress(addrs, false)
}

// SelectPeerAddress returns the address to use as the
// mongo replica set peer address by selecting it from the given addresses. If
// no addresses are available an empty string is returned.
func SelectPeerAddress(addrs []network.Address) string {
	addr, _ := network.SelectInternalAddress(addrs, true)
	return addr.Value
}

func (s *AddressSuite) TestSelectInternalAddress(c *gc.C) {
	for i, t := range selectInternalTests {
		c.Logf("test %d: %s", i, t.about)
		c.Check(network.SelectInternalAddress(t.addresses, false), gc.Equals, t.expected())
	}
}