//go:build integration

package builder

import (
	"bytes"
	"context"
	"os"
	"os/exec"
	"path/filepath"
	"testing"
)

func TestAnXzFileOfAFewDeltaBlocksAndTwoStreamsIsRead(t *testing.T) {
	// The streams this test builds are ones the reader decodes, so what the walk refuses below is the
	// same framing the reader follows.
	body := bytes.Repeat([]byte("betterbird "), 300)
	whole := tarHolding(t, body)
	half := len(whole) / 2
	for name, file := range map[string][]byte{
		"one stream of delta blocks": xzStream(whole, 512, true, -1),
		"two streams with padding": append(append(xzStream(whole[:half], 700, true, -1), 0, 0, 0, 0),
			xzStream(whole[half:], 100, false, -1)...),
	} {
		path := writeTemp(t, file)
		if xzPath, err := exec.LookPath("xz"); err == nil {
			if out, err := exec.Command(xzPath, "-t", path).CombinedOutput(); err != nil {
				t.Fatalf("%s: xz itself refuses the built stream: %v %s", name, err, out)
			}
		}
		into := t.TempDir()
		if err := unpackUpstream(context.Background(), path, into, "betterbird"); err != nil {
			t.Fatalf("%s: %v", name, err)
		}
		got, err := os.ReadFile(filepath.Join(into, "data"))
		if err != nil || !bytes.Equal(got, body) {
			t.Fatalf("%s: unpacked %d bytes, want %d: %v", name, len(got), len(body), err)
		}
	}
}