package app

import (
	"context"
	"sync"
	"testing"
	"time"

	"galaxy/mail/internal/config"

	"github.com/stretchr/testify/require"
)

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

	component := &blockingComponent{}
	app := New(config.Config{ShutdownTimeout: time.Second}, component)

	ctx, cancel := context.WithCancel(context.Background())
	done := make(chan error, 1)
	go func() {
		done <- app.Run(ctx)
	}()

	require.Eventually(t, func() bool {
		component.mu.Lock()
		defer component.mu.Unlock()
		return component.runStarted
	}, time.Second, 10*time.Millisecond)

	cancel()

	require.Eventually(t, func() bool {
		select {
		case err := <-done:
			return err == nil
		default:
			return false
		}
	}, time.Second, 10*time.Millisecond)
	require.Equal(t, 1, component.shutdownCalls)
}

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

	app := New(config.Config{ShutdownTimeout: time.Second}, componentFunc(func(context.Context) error {
		return nil
	}))

	err := app.Run(context.Background())
	require.Error(t, err)
	require.Contains(t, err.Error(), "exited without error before shutdown")
}

type blockingComponent struct {
	mu            sync.Mutex
	runStarted    bool
	shutdownCalls int
}

func (component *blockingComponent) Run(ctx context.Context) error {
	component.mu.Lock()
	component.runStarted = true
	component.mu.Unlock()

	<-ctx.Done()
	return ctx.Err()
}

func (component *blockingComponent) Shutdown(context.Context) error {
	component.shutdownCalls++
	return nil
}

type componentFunc func(context.Context) error

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

func (fn componentFunc) Shutdown(context.Context) error {
	return nil
}