#!/usr/bin/env bash
# Copyright (C) 2016-2017 Luke Shumaker <lukeshu@sbcglobal.net>
#
# 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.

{
	printf '//'
	printf ' %q' "$0" "$@"
	printf '\n// MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT\n\n'

	cat <<EOF
package sd_login

import (
	"net"

	"golang.org/x/sys/unix"
)

// A PID represents a process.
//
// As a special case, PID(0) refers to the current process.
type PID int

func (pid PID) isValid() bool {
	return pid >= 0
}

func GetPeer(conn *net.UnixConn) (PID, error) {
	ucred, err := getpeercred(conn)
	if err != nil {
		return -1, err
	}
	return PID(ucred.Pid), nil
}

EOF

	data=(
		'GetSession Session'
		'GetOwnerUser User'
		'GetMachine Machine'

		'GetUnit string'
		'GetUserUnit string'
		'GetSlice string'
		'GetUserSlice string'
	)
	for item in "${data[@]}"; do
		read Func Type <<<"$item"
		cat <<EOF

func (pid PID) ${Func}() (v ${Type}, err error) {
	if !pid.isValid() {
		err = unix.EINVAL
		return
	}
	cgroup, err := pid.getCgroup()
	if err != nil {
		return
	}
	return cgroup.MustSkipSystemPrefix().${Func}(), nil
}
EOF
	done
} | gofmt