package pktline

import (
	"bytes"
	"errors"
	"strings"
	"testing"
)

func TestRoundTrip(t *testing.T) {
	var buf bytes.Buffer
	w := NewWriter(&buf)
	for _, s := range []string{"version=1", "ok refs/proposals/47", strings.Repeat("x", 1000)} {
		if err := w.Write(s); err != nil {
			t.Fatal(err)
		}
	}
	if err := w.Flush(); err != nil {
		t.Fatal(err)
	}
	r := NewReader(&buf)
	for _, want := range []string{"version=1", "ok refs/proposals/47", strings.Repeat("x", 1000)} {
		got, err := r.Read()
		if err != nil || got != want {
			t.Fatalf("Read = %q, %v; want %q", got, err, want)
		}
	}
	if _, err := r.Read(); !errors.Is(err, ErrFlush) {
		t.Errorf("expected a flush packet, got %v", err)
	}
}

// The exact framing matters: git is on the other end of it.
func TestFraming(t *testing.T) {
	var buf bytes.Buffer
	NewWriter(&buf).Write("a")
	if got := buf.String(); got != "0006a\n" {
		t.Errorf("wrote %q, want %q", got, "0006a\n")
	}
}

func TestReadRejectsGarbage(t *testing.T) {
	for _, in := range []string{"", "zzzz", "0003", "0010short"} {
		if _, err := NewReader(strings.NewReader(in)).Read(); err == nil {
			t.Errorf("Read(%q) returned no error", in)
		}
	}
}