package stario

import (
	"bytes"
	"errors"
	"io"
	"testing"
)

func TestStarPipeRoundTrip(t *testing.T) {
	reader, writer, err := NewStarPipe(16)
	if err != nil {
		t.Fatal(err)
	}
	want := []byte("hello world")
	go func() {
		_, _ = writer.Write(want)
		_ = writer.Close()
	}()

	got, err := io.ReadAll(reader)
	if err != nil {
		t.Fatalf("ReadAll failed: %v", err)
	}
	if !bytes.Equal(got, want) {
		t.Fatalf("unexpected payload: got %q want %q", got, want)
	}
}

func TestStarPipeReaderCloseAbortsWriter(t *testing.T) {
	reader, writer, err := NewStarPipe(4)
	if err != nil {
		t.Fatal(err)
	}
	if err := reader.Close(); err != nil {
		t.Fatal(err)
	}
	if _, err := writer.Write([]byte("x")); !errors.Is(err, ErrStarBufferClosed) {
		t.Fatalf("unexpected writer error after reader close: %v", err)
	}
}

func TestStarPipeNilEndsReportClosedPipe(t *testing.T) {
	var reader *StarPipeReader
	var writer *StarPipeWriter

	if _, err := reader.Read(make([]byte, 1)); !errors.Is(err, io.ErrClosedPipe) {
		t.Fatalf("unexpected nil reader error: %v", err)
	}
	if _, err := writer.Write([]byte("x")); !errors.Is(err, io.ErrClosedPipe) {
		t.Fatalf("unexpected nil writer error: %v", err)
	}
}