<?php

declare(strict_types=1);

namespace Fgm\Drupal\Composer;

use Composer\Package\PackageInterface;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputDefinition;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;

/**
 * Class Installer sets up PhpMemcacheAdmin in vendor/phpmemcacheadmin/Config.
 *
 * Unlike the default configuration:
 * - it does not require making part of vendor/ writable.
 * - it builds the Memcache.php configuration class from a non-repository
 *   configuration file.
 *
 * Configuration:
 * - add a "phpmemcacheadmin" subsection in settings/params.local.yml.
 *   Available keys:
 *   - basic: a hash with the most commonly changed settings
 *   - advanced: a hash with the least commonly changed settings
 * - the memcache.servers section is used to chose manageed instances.
 *
 * @package Fgm\Drupal\Composer
 */
class PhpMemcacheAdminConfigCommand extends BaseBuilderCommand {

  /**
   * Machine name of current building process.
   *
   * Used as file name if none provided.
   */
  const BUILD_NAME = 'phpmemcacheadmin';

  /**
   * PHPMemCacheAdminn package name.
   */
  const PACKAGE = 'elijaa/phpmemcacheadmin';

  /**
   * PHPMemCacheAdmin configuration file path.
   *
   * Path of PHPMemCacheAdmin configuration file relative to
   * directory of elijaa/phpmemcacheadmin package.
   */
  const TARGET = 'Config/Memcache.php';

  /**
   * The event triggering this command.
   *
   * @var string
   */
  protected $eventName;

  /**
   * Configures the current command.
   */
  public function configure() {
    parent::configure();
    $this->eventName = $this->getName();
    $this
      ->setName('build:phpmemcacheadmin')
      ->setDescription('Build the PhpMemcacheAdmin configuration.')
      ->setDefinition(
        new InputDefinition([
          new InputArgument(static::ARG_FILE, InputArgument::OPTIONAL, '', static::BUILD_NAME),
        ])
      )
      ->setHelp(
        <<<EOT
The build:phpmemcacheadmin command uses the memcache section of the site parameters
to build the vendor/elijaa/phpmemcacheamin/Config/Memcache.php file.
EOT
      );
  }

  /**
   * Executes the current command.
   *
   * {@inheritDoc}
   */
  public function execute(InputInterface $input, OutputInterface $output): int {
    [
      $wrapper,
      $params,
      $msg,
      $err,
    ] = $this->prepare($input, $output, static::BUILD_NAME);
    if ($err != 0) {
      $output->writeln($msg);
      return $err;
    }

    $context = $this->buildConfig($wrapper, $params);
    $target = $this->getTarget();
    echo "Generating $target\n";

    [$msg, $error] = $this->render($wrapper, $context, $target);
    if ($error) {
      $output->writeln(sprintf("Failed rendering doc configuration: %s", $msg));
      return 5;
    }

    return 0;
  }

  /**
   * Render the config from params.local.yml and the template.
   *
   * @param \Twig_TemplateWrapper $template
   *   The template used to format the parameters.
   * @param array $params
   *   The parameters loaded from the local params file.
   *
   * @return array
   *   An array made of the relevant parameters.
   */
  protected function buildConfig(\Twig_TemplateWrapper $template, array $params) {
    $params[static::BUILD_NAME]['basic']['file_path'] = realpath($params[static::BUILD_NAME]['basic']['file_path']);
    $variables = array_merge(
      $params[static::BUILD_NAME]['basic'],
      $params[static::BUILD_NAME]['advanced'], [
        'servers' => $params['memcache']['servers'],
      ],
      ['local_params_path' => realpath($this->getSettingsPath() . "/params.local.yml")]
    );
    return $variables;
  }

  /**
   * Get the actual path where the configuration file needs to be generated.
   *
   * @return string
   *   The path.
   */
  protected function getTarget(): string {
    $composer = $this->getComposer();
    $packages = $composer
      ->getRepositoryManager()
      ->getLocalRepository()
      ->getPackages();
    $package = current(array_filter($packages, function (PackageInterface $package) {
      return $package->getName() === static::PACKAGE;
    }));
    $targetBase = $composer
      ->getInstallationManager()
      ->getInstallPath($package);
    $target = "{$targetBase}/" . static::TARGET;
    return $target;
  }

}