<?php
declare(strict_types = 1);

namespace Fgm\Drupal\Composer;

use Drupal\Component\Utility\NestedArray;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputDefinition;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;
use Symfony\Component\Yaml\Exception\ParseException;
use Symfony\Component\Yaml\Yaml;
use Twig\Environment;
use Twig\Extension\DebugExtension;
use Twig\Loader\FilesystemLoader;
use Twig\TemplateWrapper;

class BuildSettingsCommand extends BaseBuilderCommand
{

    /**
     * @var string
     */
    protected $eventName;

    /**
     * {@inheritDoc}
     */
    public function configure()
    {
        parent::configure();
        $this->eventName = $this->getName();
        $this
            ->setName('build:settings')
            ->setDescription('Step 4: build the *.settings.local.php files.')
            ->setDefinition(
                new InputDefinition([
                new InputArgument(static::ARG_FILE, InputArgument::OPTIONAL),
                ])
            )
            ->setHelp(
                <<<EOT
The build:settings command combines shared and per-environment parameters and passes
them to the settings.local.php.twig template to build the settings/(build|run).settings.local.php files.

EOT
            );
    }

    /**
     * {@inheritDoc}
     */
    public function execute(InputInterface $input, OutputInterface $output)
    {
        [$templateName, $err] = $this->validateTemplateName($input, $output);
        if ($err) {
          return 1;
        };

        $settingsPath = $this->getSettingsPath();
        $templatePath = "${settingsPath}/${templateName}";
        $realTemplatePath = realpath($templatePath);
        if (empty($realTemplatePath)) {
            $output->writeln(sprintf("Could not load template %s: no such file", $templateName));
            return 2;
        }

        $paramsPath = "${settingsPath}/merged.params.local.yml";
        $realParamsPath = realpath($paramsPath);
        if (empty($realParamsPath)) {
            $output->writeln(sprintf("Could not load parameters %s: no such file", $paramsPath));
            return 3;
        }

        $yaml = new Yaml();
        try {
            $params = $yaml->parseFile($realParamsPath);
        } catch (ParseException $e) {
            $output->writeln(sprintf("Could not parse %s: %s", $realParamsPath, $e->getMessage()));
            return 4;
        }

        $loader = new FilesystemLoader($settingsPath, $settingsPath);
        $twig = new Environment($loader, [
          'auto_reload' => true,
          'cache' => false,
          'debug' => true,
          'strict_variables' => true,
        ]);
        $twig->addExtension(new DebugExtension());

        $wrapper = $twig->load($templateName);
        foreach ($params['sites'] as $name => $siteParams) {
            foreach (['build', 'run'] as $stage) {
                $stageSettings = NestedArray::mergeDeepArray([
                  $siteParams['settings']['both'] ?? [],
                  $siteParams['settings'][$stage] ?? []
                ], true);
                $stageParams = $siteParams;
                $stageParams['settings'] = $stageSettings;
                $context = [
                  'instance' => $params['instance'],
                  'name' => $name,
                  'stage' => $stage,
                  'site' => $stageParams,
                ];
                $error = $this->render($wrapper, $context, $output);
                if ($error) {
                    $output->writeln(sprintf("Failed rendering %s settings for site %s", $stage, $name));
                    return 5;
                }
            }
        }
    }

    protected function render(TemplateWrapper $wrapper, array $context, OutputInterface $output): int
    {
        $settingsPath = "web/sites/${context['name']}/${context['stage']}.settings.local.php";
        if (file_exists($settingsPath)) {
            $ok = unlink($settingsPath);
            if (!$ok) {
                $output->writeln(sprintf(
                    "Could not remove old %s file",
                    $settingsPath
                ));
                return 1;
            }
        }

        $rendered = $wrapper->render($context);
        $ok = file_put_contents($settingsPath, $rendered, LOCK_EX);
        if (!$ok) {
            $output->writeln(sprintf('Could not write new %s file', $settingsPath));
            return 2;
        }

        return 0;
    }

}