package ci

import (
	"fmt"
	"testing"
)

// pkt builds one pkt-line with its 4-digit hex length prefix.
func pkt(payload string) string {
	return fmt.Sprintf("%04x%s", len(payload)+4, payload)
}

func TestParsePktLineRefUpdates(t *testing.T) {
	const zero = "0000000000000000000000000000000000000000"
	const shaA = "5f4dcc3b5aa765d61d8327deb882cf99aaaaaaaa"
	const shaB = "aabbccddeeff00112233445566778899aabbccdd"

	// A real push sends capabilities after a NUL on the first line, then a
	// flush packet, then the pack data.
	stream := pkt(zero+" "+shaA+" refs/heads/main\x00report-status side-band-64k agent=git/2.43.0\n") +
		pkt(shaA+" "+shaB+" refs/tags/v1.0\n") +
		pkt(shaB+" "+zero+" refs/heads/old\n") +
		"0000PACK\x00\x02\x00junk"

	got := parsePktLineRefUpdates(stream)
	want := []refUpdate{
		{zero, shaA, "refs/heads/main"},
		{shaA, shaB, "refs/tags/v1.0"},
		{shaB, zero, "refs/heads/old"},
	}
	if len(got) != len(want) {
		t.Fatalf("got %d refs, want %d: %+v", len(got), len(want), got)
	}
	for i := range want {
		if got[i] != want[i] {
			t.Errorf("ref %d = %+v, want %+v", i, got[i], want[i])
		}
	}
}

func TestParsePktLineRefUpdatesTruncated(t *testing.T) {
	const shaA = "5f4dcc3b5aa765d61d8327deb882cf99aaaaaaaa"
	full := pkt(shaA + " " + shaA + " refs/heads/main\n")
	// Cut the stream mid-line, as the 4 KB preamble cap can do.
	got := parsePktLineRefUpdates(full[:len(full)-5])
	if len(got) != 0 {
		t.Fatalf("truncated line should be dropped, got %+v", got)
	}
}

func TestParsePktLineRefUpdatesGarbage(t *testing.T) {
	for _, in := range []string{"", "zz", "zzzzhello", "0001", "0002ab"} {
		if got := parsePktLineRefUpdates(in); len(got) != 0 {
			t.Errorf("input %q: got %+v, want none", in, got)
		}
	}
}