package controller

import (
	"context"
	"errors"
	"sync"
	"testing"
)

func TestParseSelectionDefaultsToAll(t *testing.T) {
	for _, input := range []string{"", "all"} {
		selection, err := ParseSelection(input)
		if err != nil {
			t.Fatal(err)
		}
		if len(selection) != 3 || selection[0] != Scheduler || selection[1] != PodWorker || selection[2] != VMWorker {
			t.Fatalf("selection = %v", selection)
		}
	}
}

func TestParseSelectionAllowsOneOrMoreComponents(t *testing.T) {
	selection, err := ParseSelection("vm-worker,scheduler,vm-worker")
	if err != nil {
		t.Fatal(err)
	}
	if len(selection) != 2 || selection[0] != VMWorker || selection[1] != Scheduler {
		t.Fatalf("selection = %v", selection)
	}
	if _, err := ParseSelection("webhook"); err == nil {
		t.Fatal("expected obsolete component to be rejected")
	}
}

type componentFunc func(context.Context) error

func (f componentFunc) Run(ctx context.Context) error { return f(ctx) }

func TestRunStartsSelectedComponentsAndCancelsPeers(t *testing.T) {
	started := make(chan ComponentName, 2)
	peerStopped := make(chan struct{})
	var once sync.Once
	registry := Registry{
		Scheduler: componentFunc(func(context.Context) error {
			started <- Scheduler
			return errors.New("poll failed")
		}),
		PodWorker: componentFunc(func(ctx context.Context) error {
			started <- PodWorker
			<-ctx.Done()
			once.Do(func() { close(peerStopped) })
			return ctx.Err()
		}),
	}
	err := Run(context.Background(), Selection{Scheduler, PodWorker}, registry)
	if err == nil || !errors.Is(err, context.Canceled) && err.Error() != "component scheduler: poll failed" {
		t.Fatalf("Run() error = %v", err)
	}
	<-peerStopped
	if len(started) != 2 {
		t.Fatalf("started components = %d", len(started))
	}
}