<?php

declare(strict_types=1);

namespace Esun\MultiLocaleTranslation\Model\Google;

use Magento\Framework\App\Config\ScopeConfigInterface;
use Magento\Framework\App\Filesystem\DirectoryList;
use Magento\Framework\Exception\LocalizedException;
use Magento\Framework\Filesystem;

class Credentials
{
    private const XML_PATH_FILE = 'esun_multilocale_translation/google/credentials_file';

    private ?array $credentials = null;

    public function __construct(
        private readonly ScopeConfigInterface $scopeConfig,
        private readonly Filesystem $filesystem
    ) {
    }

    /**
     * @return array<string, string>
     */
    public function get(): array
    {
        if ($this->credentials !== null) {
            return $this->credentials;
        }

        $filename = basename((string)$this->scopeConfig->getValue(self::XML_PATH_FILE));
        if ($filename === '') {
            throw new LocalizedException(__('Google service account JSON is not configured.'));
        }

        $directory = $this->filesystem->getDirectoryRead(DirectoryList::VAR_DIR);
        $relativePath = 'esun/multilocale_translation/google/' . $filename;
        if (!$directory->isFile($relativePath)) {
            throw new LocalizedException(__('The configured Google service account JSON file was not found.'));
        }

        try {
            $data = json_decode($directory->readFile($relativePath), true, 32, JSON_THROW_ON_ERROR);
        } catch (\Throwable) {
            throw new LocalizedException(__('The configured Google service account JSON is invalid.'));
        }

        if (!is_array($data)
            || ($data['type'] ?? '') !== 'service_account'
            || empty($data['project_id'])
            || empty($data['client_email'])
            || empty($data['private_key'])
        ) {
            throw new LocalizedException(__('The configured JSON is not a valid Google service account key.'));
        }

        $this->credentials = array_map(
            static fn (mixed $value): string => is_scalar($value) ? (string)$value : '',
            $data
        );

        return $this->credentials;
    }
}