package notify

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

func TestBulkOwnedChunkReleaseAfterRead(t *testing.T) {
	bulk := newBulkHandle(context.Background(), newBulkRuntime("buffer-release-read"), clientFileScope(), BulkOpenRequest{
		BulkID: "buffer-release-read",
		DataID: 1,
	}, 0, nil, nil, 0, nil, nil, nil, nil, nil)

	released := 0
	if err := bulk.pushOwnedChunkWithReleaseNoReset([]byte("hello"), func() {
		released++
	}); err != nil {
		t.Fatalf("pushOwnedChunkWithReleaseNoReset failed: %v", err)
	}

	buf := make([]byte, 5)
	n, err := bulk.Read(buf)
	if err != nil {
		t.Fatalf("Read failed: %v", err)
	}
	if n != 5 || string(buf[:n]) != "hello" {
		t.Fatalf("Read = %d %q, want 5 hello", n, string(buf[:n]))
	}
	if released != 1 {
		t.Fatalf("release count = %d, want 1", released)
	}
}

func TestBulkOwnedChunkReleaseOnReset(t *testing.T) {
	bulk := newBulkHandle(context.Background(), newBulkRuntime("buffer-release-reset"), clientFileScope(), BulkOpenRequest{
		BulkID: "buffer-release-reset",
		DataID: 1,
	}, 0, nil, nil, 0, nil, nil, nil, nil, nil)

	released := 0
	if err := bulk.pushOwnedChunkWithReleaseNoReset([]byte("hello"), func() {
		released++
	}); err != nil {
		t.Fatalf("pushOwnedChunkWithReleaseNoReset failed: %v", err)
	}

	bulk.markReset(errors.New("boom"))
	if released != 1 {
		t.Fatalf("release count = %d, want 1", released)
	}
}

func TestBulkReadDoesNotBlockOnAsyncWindowRelease(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	releaseStarted := make(chan struct{})
	releaseUnblock := make(chan struct{})
	bulk := newBulkHandle(ctx, newBulkRuntime("buffer-release-async"), clientFileScope(), BulkOpenRequest{
		BulkID:      "buffer-release-async",
		DataID:      1,
		ChunkSize:   4,
		WindowBytes: 4,
		MaxInFlight: 1,
	}, 0, nil, nil, 0, nil, nil, nil, nil, func(_ *bulkHandle, bytes int64, chunks int) error {
		if bytes != 4 || chunks != 1 {
			t.Fatalf("release = (%d,%d), want (4,1)", bytes, chunks)
		}
		close(releaseStarted)
		<-releaseUnblock
		return nil
	})

	if err := bulk.pushOwnedChunk([]byte("ping")); err != nil {
		t.Fatalf("pushOwnedChunk failed: %v", err)
	}

	buf := make([]byte, 4)
	doneCh := make(chan error, 1)
	go func() {
		n, err := bulk.Read(buf)
		if err != nil {
			doneCh <- err
			return
		}
		if got, want := n, 4; got != want {
			doneCh <- errors.New("unexpected read size")
			return
		}
		doneCh <- nil
	}()

	select {
	case err := <-doneCh:
		if err != nil {
			t.Fatalf("Read failed: %v", err)
		}
	case <-time.After(200 * time.Millisecond):
		t.Fatal("Read should not block on async release sender")
	}

	select {
	case <-releaseStarted:
	case <-time.After(time.Second):
		t.Fatal("window release sender did not start")
	}

	close(releaseUnblock)
	cancel()
	if bulk.releaseWorkerDone != nil {
		select {
		case <-bulk.releaseWorkerDone:
		case <-time.After(time.Second):
			t.Fatal("release worker did not exit")
		}
	}
}