// Copyright 2023 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.

package subsystem

import "fmt"

// In general, it's not correct to assume that subsystems are only determined by target.OS,
// because subsystems are related not to the user interface of the OS kernel, but rather to
// the OS kernel implementation.
//
// For example, during fuzzing we can treat gVisor in the same way as any other Linux kernel.
// In reality, however, not a single MAINTAINERS-based rule will work on the gVisor codebase.
//
// Therefore, subsystem lists have to be a completely different entity.

var (
	lists = make(map[string]registeredSubsystem)
)

type registeredSubsystem struct {
	list     []*Subsystem
	revision int
}

func RegisterList(name string, list []*Subsystem, revision int) {
	if _, ok := lists[name]; ok {
		panic(name + " subsystem list already exists!")
	}
	lists[name] = registeredSubsystem{
		list:     list,
		revision: revision,
	}
}

func GetList(name string) []*Subsystem {
	info, ok := lists[name]
	if !ok {
		panic(fmt.Sprintf("list %q is not registered", name))
	}
	return info.list
}

func ListService(name string) *Service {
	info, ok := lists[name]
	if !ok {
		panic(fmt.Sprintf("list %q is not registered", name))
	}
	return MustMakeService(info.list, info.revision)
}