package manager

import (
	"context"
	"net"
	"time"

	"github.com/go-logr/logr"

	"edge-infra.dev/pkg/lib/runtime/healthz"
)

type Manager interface {
	// Add will set requested dependencies on the component, and cause the component to be
	// started when Start is called.  Add will inject any dependencies for which the argument
	// implements the inject interface - e.g. inject.Client.
	// Depending on if a Runnable implements LeaderElectionRunnable interface, a Runnable can be run in either
	// non-leaderelection mode (always running) or leader election mode (managed by leader election if enabled).
	Add(Runnable) error

	// AddLivezCheck allows you to add Livez checker
	AddLivezCheck(name string, check healthz.Checker) error

	// AddReadyzCheck allows you to add Readyz checker
	AddReadyzCheck(name string, check healthz.Checker) error

	// Start starts all registered Controllers and blocks until the context is cancelled.
	// Returns an error if there is an error starting any controller.
	//
	// If LeaderElection is used, the binary must be exited immediately after this returns,
	// otherwise components that need leader election might continue to run after the leader
	// lock was lost.
	Start(ctx context.Context) error

	// GetLogger returns this manager's logger.
	GetLogger() logr.Logger
}

type Options struct {
	// Logger is the logger that should be used by this manager.
	// If none is set, it defaults to log.Log global logger.
	Logger *logr.Logger

	// MetricsBindAddress is the TCP address that the controller should bind to
	// for serving prometheus metrics.
	// It can be set to "0" to disable the metrics serving.
	MetricsBindAddress string

	// HealthProbeBindAddress is the TCP address that the controller should bind to
	// for serving health probes
	HealthProbeBindAddress string

	// Readiness probe endpoint name, defaults to "/readyz"
	ReadinessEndpointName string

	// Liveness probe endpoint name, defaults to "/livez"
	LivenessEndpointName string

	// BaseContext is the function that provides Context values to Runnables
	// managed by the Manager. If a BaseContext function isn't provided, Runnables
	// will receive a new Background Context instead.
	BaseContext BaseContextFunc

	// GracefulShutdownTimeout is the duration given to runnable to stop before the manager actually returns on stop.
	// To disable graceful shutdown, set to time.Duration(0)
	// To use graceful shutdown without timeout, set to a negative duration, e.G. time.Duration(-1)
	// The graceful shutdown is skipped for safety reasons in case the leader election lease is lost.
	GracefulShutdownTimeout *time.Duration

	// Dependency injection for testing
	newMetricsListener     func(addr string) (net.Listener, error)
	newHealthProbeListener func(addr string) (net.Listener, error)
}