<?php

declare(strict_types = 1);

namespace Fgm\Drupal\Composer;

use Composer\Composer;
use Composer\EventDispatcher\EventSubscriberInterface;
use Composer\IO\IOInterface;
use Composer\Plugin\Capability\Capability;
use Composer\Plugin\Capability\CommandProvider;
use Composer\Plugin\Capable;
use Composer\Plugin\PluginInterface;
use Composer\Script\Event as ScriptEvent;
use Composer\Script\ScriptEvents;

/**
 * Class Builder is the Composer plugin entry point.
 *
 * @package Fgm\Drupal\Composer
 */
class Builder implements Capable, Capability, EventSubscriberInterface, PluginInterface {

  const NAME = "composer_builder";

  /**
   * The currently running Composer instance.
   *
   * @var \Composer\Composer
   */
  protected $composer;

  /**
   * The Composer I/O.
   *
   * @var \Composer\IO\IOInterface
   */
  protected $io;

  /**
   * {@inheritdoc}
   *
   * Available events:
   *
   * - Composer\Installer\InstallerEvents::*
   *    -> Composer\Installer\InstallerEvent
   * - Composer\Installer\PackageEvents::* -> Composer\Installer\PackageEvent
   * - Composer\Installer\PluginEvents::INIT -> Composer\EventDispatcher\Event
   * - Composer\Installer\PluginEvents::COMMAND -> Composer\Plugin\CommandEvent
   * - Composer\Installer\PluginEvents::PRE_FILE_DOWNLOAD
   *     -> Composer\Plugin\PreFileDownloadEvent
   * - Composer\Script\ScriptEvents::* -> Composer\Script\Event
   */
  public static function getSubscribedEvents() {
    return [
      ScriptEvents::POST_INSTALL_CMD => 'onScriptEvent',
      ScriptEvents::POST_UPDATE_CMD => 'onScriptEvent',
    ];
  }

  /**
   * Apply plugin modifications to Composer.
   *
   * @param \Composer\Composer $composer
   *   The currently running Composer instance.
   * @param \Composer\IO\IOInterface $io
   *   The Composer I/O.
   */
  public function activate(Composer $composer, IOInterface $io) {
    $this->composer = $composer;
    $this->io = $io;
  }

  /**
   * Composer plugin API: describe the plugin capabilities.
   */
  public function getCapabilities() {
    return [
      CommandProvider::class => BuilderCommandProvider::class,
    ];
  }

  protected function showCommands() {
    $capabilities = $this->getCapabilities();
    if (empty($capabilities[CommandProvider::class])) {
      return;
    }
    $providerClass = $capabilities[CommandProvider::class];
    /** @var \Composer\Plugin\Capability\CommandProvider $provider */
    $provider = new $providerClass([
      'composer' => $this->composer,
      'io' => $io = $this->io,
      'plugin' => NULL,
    ]);
    $commands = $provider->getCommands();
    $io->write("Available build commands:");
    foreach ($commands as $command) {
      $io->write("- " . $command->getName());
    }
  }

  /**
   * Event callback: run build:settings  on post-install|update only.
   *
   * @param \Composer\Script\Event $event
   *   The subscribed event triggering this callback.
   *
   * @throws \Exception
   */
  public function onScriptEvent(ScriptEvent $event) {
    if (in_array($event->getName(), [
      ScriptEvents::POST_INSTALL_CMD,
      ScriptEvents::POST_UPDATE_CMD,
    ])) {
      // FIXME without an argument, the command should build all templates.
      // $buildCommand = new BuildSettingsCommand($event->getName());
      // $buildCommand->run(new ArgvInput([]), new ConsoleOutput());

      // Verbosity seems limited to 32, while the test expects 64 or 128.
      if ($event->getIO()->isVerbose()) {
        $this->showCommands();
      }
    }
  }

}