// 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.

package sd_login

import (
	"strconv"
	"strings"
)

func (cgroup _Cgroup) SkipPath(prefix _Cgroup) (_Cgroup, bool) {
	//skip: SkipPath(prefix _Cgroup) : SkipPath(prefix)
	rest, ok := path_startswith(string(cgroup), string(prefix))
	if ok {
		return _Cgroup(rest), true
	} else {
		return cgroup, false
	}
}

// Skip (*.slice){1,}
func (cgroup _Cgroup) SkipSlices() (_Cgroup, bool) {
	//skip: SkipSlices() : SkipSlices()
	cg := string(cgroup)
	skipped := false
	for {
		cg = strings.TrimLeft(cg, "/")
		part, rest := split2(cg, '/')
		if !valid_slice_name(part) {
			return _Cgroup(cg), skipped
		}
		skipped = true
		cg = rest
	}
}

// Skip user@*.service
func (cgroup _Cgroup) SkipUserManager() (_Cgroup, bool) {
	//skip: SkipUserManager() : SkipUserManager()
	part, rest := split2(strings.TrimLeft(string(cgroup), "/"), '/')
	uid_str, ok := trimPrefixSuffix(part, "user@", ".service")
	if !ok {
		return cgroup, false
	}
	_, err := strconv.Atoi(uid_str)
	if err != nil {
		return cgroup, false
	}
	return _Cgroup(rest), true
}

// Skip session-*.scope
func (cgroup _Cgroup) SkipSession() (_Cgroup, bool) {
	//skip: SkipSession() : SkipSession()
	part, rest := split2(strings.TrimLeft(string(cgroup), "/"), '/')
	session, ok := trimPrefixSuffix(part, "session-", ".scope")
	if !ok {
		return cgroup, false
	}
	if !valid_session_name(session) {
		return cgroup, false
	}
	return _Cgroup(rest), true
}

// Skip (/*.slice){0,}/(user@*.service|session-*.scope)
func (cgroup _Cgroup) SkipUserPrefix() (_Cgroup, bool) {
	//skip: SkipUserPrefix() : SkipUserPrefix()
	cgroup, _ = cgroup.SkipSlices()
	cgroup, ok := cgroup.SkipUserManager()
	if ok {
		return cgroup, ok
	}
	return cgroup.SkipSession()
}

// Skip cgGetRootPath
func (cgroup _Cgroup) SkipSystemPrefix() (_Cgroup, bool) {
	//skip: SkipSystemPrefix() : SkipSystemPrefix()

	rootpath, err := cgGetRootPath()
	if err != nil {
		return cgroup, false
	}

	return cgroup.SkipPath(rootpath)
}