<?php

namespace BlaxSoftware\LaravelWebSockets\Test\Commands;

use BlaxSoftware\LaravelWebSockets\Console\Commands\StartServer;
use BlaxSoftware\LaravelWebSockets\Contracts\ChannelManager;
use BlaxSoftware\LaravelWebSockets\Helpers;
use BlaxSoftware\LaravelWebSockets\Server\ChildProcesses;
use BlaxSoftware\LaravelWebSockets\Test\TestCase;
use Illuminate\Console\OutputStyle;
use React\EventLoop\Factory as LoopFactory;
use React\Promise\PromiseInterface;
use Symfony\Component\Console\Input\ArrayInput;
use Symfony\Component\Console\Output\BufferedOutput;

/**
 * Both shutdown paths of websockets:serve stop the message children that are
 * still running (#2465). A child that outlived the server used to keep the
 * listening port bound, and the restarted server failed with EADDRINUSE.
 */
class ShutdownStopsChildrenTest extends TestCase
{
    /** @var int[] */
    private array $spawned = [];

    public function setUp(): void
    {
        parent::setUp();

        if (! function_exists('pcntl_fork') || ! function_exists('posix_kill')) {
            $this->markTestSkipped('pcntl and posix are required');
        }

        ChildProcesses::flush();
    }

    public function tearDown(): void
    {
        foreach ($this->spawned as $pid) {
            @posix_kill($pid, SIGKILL);
            @pcntl_waitpid($pid, $status);
        }
        ChildProcesses::flush();

        parent::tearDown();
    }

    public function test_hard_shutdown_stops_running_children()
    {
        $pid = $this->spawnTrackedChild();

        $command = $this->command(LoopFactory::create());
        (new \ReflectionMethod(StartServer::class, 'triggerHardShutdown'))->invoke($command);

        $this->assertFalse(@posix_kill($pid, 0), 'The child must not outlive the server.');
        $this->assertSame(0, ChildProcesses::count());
    }

    public function test_soft_shutdown_stops_running_children()
    {
        $pid = $this->spawnTrackedChild();

        $loop = LoopFactory::create();
        $this->app->instance(ChannelManager::class, new class {
            public function declineNewConnections(): void {}

            public function getLocalConnections(): PromiseInterface
            {
                return Helpers::createFulfilledPromise([]);
            }
        });
        $command = $this->command($loop);

        $loop->addTimer(8, fn () => $loop->stop());
        $loop->futureTick(fn () => (new \ReflectionMethod(StartServer::class, 'triggerSoftShutdown'))->invoke($command));
        $loop->run();

        $this->assertFalse(@posix_kill($pid, 0), 'The child must not outlive the server.');
        $this->assertSame(0, ChildProcesses::count());
    }

    public function test_the_server_registers_its_listening_socket_for_children_to_close()
    {
        // No broadcast socket file left behind in /tmp by this test.
        config(['websockets.broadcast_socket_enabled' => false]);

        $registered = null;
        $this->loop->futureTick(function () use (&$registered) {
            $registered = ChildProcesses::listenerCount();
            $this->loop->stop();
        });

        $this->artisan('websockets:serve', ['--loop' => $this->loop, '--host' => '127.0.0.1', '--port' => 0]);

        $this->assertSame(1, $registered);
    }

    public function test_children_are_left_alone_when_disabled()
    {
        config(['websockets.shutdown.terminate_children' => false]);
        $pid = $this->spawnTrackedChild();

        $command = $this->command(LoopFactory::create());
        (new \ReflectionMethod(StartServer::class, 'triggerHardShutdown'))->invoke($command);

        $this->assertTrue(posix_kill($pid, 0), 'Opted out: the child keeps running.');
    }

    private function command($loop): StartServer
    {
        $command = $this->app->make(StartServer::class);
        $command->setLaravel($this->app);
        $command->setOutput(new OutputStyle(new ArrayInput([]), new BufferedOutput));
        (new \ReflectionProperty(StartServer::class, 'loop'))->setValue($command, $loop);

        return $command;
    }

    private function spawnTrackedChild(): int
    {
        $pid = pcntl_fork();
        $this->assertNotSame(-1, $pid);

        if ($pid === 0) {
            // A busy message child: default SIGTERM disposition, as after
            // ChildProcesses::prepareChild(). Never returns into PHPUnit.
            ChildProcesses::restoreDefaultSignals();
            while (true) {
                usleep(50_000);
            }
        }

        $this->spawned[] = $pid;
        ChildProcesses::track($pid, 'child-crash.hold');

        return $pid;
    }
}