package lifecycle_test

import (
	"context"
	"log/slog"
	"sync"
	"testing"
	"time"

	"github.com/stretchr/testify/require"
	"sneak.berlin/go/webhooker/internal/lifecycle"
)

// waitTimeout is the stop budget the timeout case gives a
// goroutine that never returns. The test's own patience is the
// go test deadline, so the only thing this value affects is how
// long the case takes.
const waitTimeout = 100 * time.Millisecond

func discardLogger() *slog.Logger {
	return slog.New(slog.DiscardHandler)
}

func TestWaitForShutdown_DrainedGroup(t *testing.T) {
	t.Parallel()

	var wg sync.WaitGroup

	wg.Go(func() {})

	require.NoError(
		t,
		lifecycle.WaitForShutdown(
			context.Background(), discardLogger(),
			"test component", &wg,
		),
	)
}

func TestWaitForShutdown_ContextExpires(t *testing.T) {
	t.Parallel()

	release := make(chan struct{})

	t.Cleanup(func() { close(release) })

	var wg sync.WaitGroup

	wg.Go(func() { <-release })

	ctx, cancel := context.WithTimeout(
		context.Background(), waitTimeout,
	)
	defer cancel()

	err := lifecycle.WaitForShutdown(
		ctx, discardLogger(), "test component", &wg,
	)

	require.ErrorIs(t, err, context.DeadlineExceeded)
	require.ErrorContains(t, err, "test component")
}