/*
Copyright 2019 The Jetstack cert-manager contributors.

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 controller

// This file defines types for controllers to register themselves with the
// controller package.

// Interface represents a controller that can be run.
type Interface interface {
	// Run will start a controller. 'workers' should be the  number of
	// independent goroutines for this controller in question that are to be
	// run, and the workers should shut down upon a signal on stopCh.
	// This method should block until all workers have exited cleanly, thus
	// allowing for graceful shutdown of control loops.
	Run(workers int, stopCh <-chan struct{}) error

	// AdditionalInformers is a list of additional informer 'Run' functions
	// that will be started when the shared informer factories 'Start' function
	// is called.
	AdditionalInformers() []RunFunc
}

// Constructor is a function that creates a new control loop given a
// controller Context.
type Constructor func(ctx *Context) (Interface, error)

var (
	known = make(map[string]Constructor, 0)
)

// Known returns a map of the registered controller Constructors
func Known() map[string]Constructor {
	return known
}

// Register registers a controller constructor with the controller package
func Register(name string, fn Constructor) {
	known[name] = fn
}
