// Copyright 2015 CoreOS, Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

package activation

import (

	"crypto/tls"

	"net"

)

// Listeners returns a slice containing a net.Listener for each matching socket type

// passed to this process.

//

// The order of the file descriptors is preserved in the returned slice.

// Nil values are used to fill any gaps. For example if systemd were to return file descriptors

// corresponding with "udp, tcp, tcp", then the slice would contain {nil, net.Listener, net.Listener}

func Listeners() ([]net.Listener, error) {

	files := Files(true)

	listeners := make([]net.Listener, len(files))

	for i, f := range files {

		if pc, err := net.FileListener(f); err == nil {

			listeners[i] = pc

			f.Close()

		}

	}

	return listeners, nil

}

// ListenersWithNames maps a listener name to a set of net.Listener instances.

func ListenersWithNames() (map[string][]net.Listener, error) {

	files := Files(true)

	listeners := map[string][]net.Listener{}

	for _, f := range files {

		if pc, err := net.FileListener(f); err == nil {

			current, ok := listeners[f.Name()]

			if !ok {

				listeners[f.Name()] = []net.Listener{pc}

			} else {

				listeners[f.Name()] = append(current, pc)

			}

			f.Close()

		}

	}

	return listeners, nil

}

// TLSListeners returns a slice containing a net.listener for each matching TCP socket type

// passed to this process.

// It uses default Listeners func and forces TCP sockets handlers to use TLS based on tlsConfig.

func TLSListeners(tlsConfig *tls.Config) ([]net.Listener, error) {

	listeners, err := Listeners()

	if listeners == nil || err != nil {

		return nil, err

	}

	if tlsConfig != nil {

		for i, l := range listeners {

			// Activate TLS only for TCP sockets

			if l.Addr().Network() == "tcp" {

				listeners[i] = tls.NewListener(l, tlsConfig)

			}

		}

	}

	return listeners, err

}

// TLSListenersWithNames maps a listener name to a net.Listener with

// the associated TLS configuration.

func TLSListenersWithNames(tlsConfig *tls.Config) (map[string][]net.Listener, error) {

	listeners, err := ListenersWithNames()

	if listeners == nil || err != nil {

		return nil, err

	}

	if tlsConfig != nil {

		for _, ll := range listeners {

			// Activate TLS only for TCP sockets

			for i, l := range ll {

				if l.Addr().Network() == "tcp" {

					ll[i] = tls.NewListener(l, tlsConfig)

				}

			}

		}

	}

	return listeners, err

}