// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: MIT

package main

import (
	"net"
	"path/filepath"
	"testing"
	"time"
)

// TestNotifyReadyWithoutSocket covers the quiet path: no NOTIFY_SOCKET,
// no notification, no error. This is every run outside a Type=notify
// unit.
func TestNotifyReadyWithoutSocket(t *testing.T) {
	t.Setenv("NOTIFY_SOCKET", "")
	if err := notifyReady(); err != nil {
		t.Fatalf("notify without a socket: %v", err)
	}
}

// expectReady reads one datagram and reports whether it is READY=1.
func expectReady(t *testing.T, ln *net.UnixConn) {
	t.Helper()
	buf := make([]byte, 64)
	ln.SetReadDeadline(time.Now().Add(2 * time.Second))
	n, _, err := ln.ReadFrom(buf)
	if err != nil {
		t.Fatalf("read: %v", err)
	}
	if string(buf[:n]) != "READY=1" {
		t.Fatalf("message %q, want READY=1", buf[:n])
	}
}

// TestNotifyReadyDelivers covers the pathname socket form.
func TestNotifyReadyDelivers(t *testing.T) {
	sock := filepath.Join(t.TempDir(), "notify.sock")
	ln, err := net.ListenUnixgram("unixgram", &net.UnixAddr{Name: sock, Net: "unixgram"})
	if err != nil {
		t.Fatalf("listen: %v", err)
	}
	defer ln.Close()
	t.Setenv("NOTIFY_SOCKET", sock)
	if err := notifyReady(); err != nil {
		t.Fatalf("notify: %v", err)
	}
	expectReady(t, ln)
}

// TestNotifyReadyAbstract covers the abstract namespace form, the one
// systemd hands over on Linux.
func TestNotifyReadyAbstract(t *testing.T) {
	addr := "@" + filepath.Base(t.TempDir()) + "-notify"
	ln, err := net.ListenUnixgram("unixgram", &net.UnixAddr{Name: addr, Net: "unixgram"})
	if err != nil {
		t.Skipf("abstract unix sockets are unavailable: %v", err)
	}
	defer ln.Close()
	t.Setenv("NOTIFY_SOCKET", addr)
	if err := notifyReady(); err != nil {
		t.Fatalf("notify: %v", err)
	}
	expectReady(t, ln)
}