package stario

import (
	"context"
	"errors"
	"testing"
	"time"
)

func TestWaitUntilContextReturnsWorkerError(t *testing.T) {
	want := errors.New("worker failed")
	err := WaitUntilContext(context.Background(), func(ctx context.Context) error {
		return want
	})
	if !errors.Is(err, want) {
		t.Fatalf("unexpected error: got %v want %v", err, want)
	}
}

func TestWaitUntilContextReturnsDeadlineExceeded(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Millisecond)
	defer cancel()
	workerReturned := make(chan struct{})
	err := WaitUntilContext(ctx, func(ctx context.Context) error {
		<-ctx.Done()
		close(workerReturned)
		return nil
	})
	if !errors.Is(err, context.DeadlineExceeded) {
		t.Fatalf("unexpected context error: %v", err)
	}
	select {
	case <-workerReturned:
	case <-time.After(200 * time.Millisecond):
		t.Fatal("worker did not return after context deadline")
	}
}

func TestWaitUntilContextFinishedReturnsCanceled(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	result := WaitUntilContextFinished(ctx, func(ctx context.Context) error {
		<-ctx.Done()
		return nil
	})
	err, ok := <-result
	if !ok {
		t.Fatal("result channel closed without value")
	}
	if !errors.Is(err, context.Canceled) {
		t.Fatalf("unexpected context error: %v", err)
	}
	if _, ok := <-result; ok {
		t.Fatal("result channel should be closed after delivering the outcome")
	}
}

func TestWaitUntilContextDoneBridgesDoneChannel(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	doneClosed := make(chan struct{})
	go func() {
		time.Sleep(20 * time.Millisecond)
		cancel()
	}()
	err := WaitUntilContextDone(ctx, func(done <-chan struct{}) error {
		<-done
		close(doneClosed)
		return nil
	})
	if !errors.Is(err, context.Canceled) {
		t.Fatalf("unexpected context error: %v", err)
	}
	select {
	case <-doneClosed:
	case <-time.After(200 * time.Millisecond):
		t.Fatal("done channel was not closed when context canceled")
	}
}

func TestWaitUntilContextDoneFinishedReturnsCanceled(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	doneClosed := make(chan struct{})
	go func() {
		time.Sleep(20 * time.Millisecond)
		cancel()
	}()
	result := WaitUntilContextDoneFinished(ctx, func(done <-chan struct{}) error {
		<-done
		close(doneClosed)
		return nil
	})
	err, ok := <-result
	if !ok {
		t.Fatal("result channel closed without value")
	}
	if !errors.Is(err, context.Canceled) {
		t.Fatalf("unexpected context error: %v", err)
	}
	select {
	case <-doneClosed:
	case <-time.After(200 * time.Millisecond):
		t.Fatal("done channel was not closed when context canceled")
	}
	if _, ok := <-result; ok {
		t.Fatal("result channel should be closed after delivering the outcome")
	}
}

func TestWaitUntilTimeoutReturnsWorkerError(t *testing.T) {
	want := errors.New("worker failed")
	err := WaitUntilTimeout(time.Second, func(stop chan struct{}) error {
		return want
	})
	if !errors.Is(err, want) {
		t.Fatalf("unexpected error: got %v want %v", err, want)
	}
}

func TestWaitUntilTimeoutTimesOutWithoutBlockingWorkerReturn(t *testing.T) {
	workerReturned := make(chan struct{})
	err := WaitUntilTimeout(20*time.Millisecond, func(stop chan struct{}) error {
		<-stop
		close(workerReturned)
		return nil
	})
	if !errors.Is(err, ERR_TIMEOUT) {
		t.Fatalf("unexpected timeout error: %v", err)
	}
	select {
	case <-workerReturned:
	case <-time.After(200 * time.Millisecond):
		t.Fatal("worker did not return after timeout signal")
	}
}

func TestWaitUntilFinishedReturnsWorkerError(t *testing.T) {
	want := errors.New("worker failed")
	err := <-WaitUntilFinished(func() error {
		return want
	})
	if !errors.Is(err, want) {
		t.Fatalf("unexpected error: got %v want %v", err, want)
	}
}

func TestWaitUntilTimeoutFinishedReturnsTimeout(t *testing.T) {
	result := WaitUntilTimeoutFinished(20*time.Millisecond, func(stop chan struct{}) error {
		<-stop
		return nil
	})
	err, ok := <-result
	if !ok {
		t.Fatal("result channel closed without value")
	}
	if !errors.Is(err, ERR_TIMEOUT) {
		t.Fatalf("unexpected timeout error: %v", err)
	}
	if _, ok := <-result; ok {
		t.Fatal("result channel should be closed after delivering the outcome")
	}
}

func TestWaitUntilTimeoutFinishedReturnsWorkerError(t *testing.T) {
	want := errors.New("worker failed")
	err, ok := <-WaitUntilTimeoutFinished(time.Second, func(stop chan struct{}) error {
		return want
	})
	if !ok {
		t.Fatal("result channel closed without value")
	}
	if !errors.Is(err, want) {
		t.Fatalf("unexpected error: got %v want %v", err, want)
	}
}