<?php
/**
 * @package     MokoSuite
 * @subpackage  com_mokosuite
 * @copyright   Copyright (C) 2026 Moko Consulting. All rights reserved.
 * @license     GNU General Public License version 3 or later; see LICENSE
 */

namespace Moko\Component\MokoSuite\Api\Controller;

defined('_JEXEC') or die;

use Joomla\CMS\Factory;
use Joomla\CMS\MVC\Controller\BaseController;
use Joomla\CMS\Plugin\PluginHelper;
use Joomla\CMS\Uri\Uri;
use Joomla\Registry\Registry;

/**
 * Remote login API controller.
 *
 * POST /api/index.php/v1/mokosuite/remote-login
 * Body: {"token": "health_api_token", "user": "requesting_username", "origin": "MokoSuiteHQ"}
 *
 * Validates the health API token, generates a one-time login token
 * for the master user, and returns a URL that auto-authenticates.
 *
 * @since  02.35.00
 */
class RemoteLoginController extends BaseController
{
	/**
	 * One-time token validity in seconds.
	 */
	private const OTL_TTL = 60;

	/**
	 * Generate a one-time login URL for the master user.
	 *
	 * @return  void
	 */
	public function execute($task = 'remoteLogin'): void
	{
		$app   = Factory::getApplication();
		$input = $app->getInput()->json;

		$token  = $input->get('token', '', 'RAW');
		$origin = $input->get('origin', '', 'STRING');

		if (empty($token))
		{
			$this->sendJson(401, ['error' => 'Missing token']);

			return;
		}

		// Validate against the core plugin's health_api_token
		$plugin = PluginHelper::getPlugin('system', 'mokosuite');

		if (!$plugin)
		{
			$this->sendJson(503, ['error' => 'MokoSuite core plugin not found']);

			return;
		}

		$params      = new Registry($plugin->params);
		$healthToken = $params->get('health_api_token', '');

		if (empty($healthToken) || !hash_equals($healthToken, $token))
		{
			$this->sendJson(401, ['error' => 'Invalid token']);

			return;
		}

		// Find the master user
		$masterUsernames = $this->getMasterUsernames($params);

		if (empty($masterUsernames))
		{
			$this->sendJson(403, ['error' => 'No master user configured']);

			return;
		}

		// Use the first master username
		$masterUsername = $masterUsernames[0];

		// Look up the user
		$db = Factory::getDbo();
		$db->setQuery(
			$db->getQuery(true)
				->select([$db->quoteName('id'), $db->quoteName('username')])
				->from($db->quoteName('#__users'))
				->where($db->quoteName('username') . ' = ' . $db->quote($masterUsername))
				->where($db->quoteName('block') . ' = 0')
		);
		$user = $db->loadObject();

		if (!$user)
		{
			$this->sendJson(403, ['error' => 'Master user not found or blocked']);

			return;
		}

		// Generate one-time login token
		$otlToken = bin2hex(random_bytes(32));
		$expires  = time() + self::OTL_TTL;

		// Store in a temp file (avoids DB schema changes)
		$otlFile = JPATH_ADMINISTRATOR . '/cache/mokosuite_otl_' . md5($otlToken) . '.json';
		file_put_contents($otlFile, json_encode([
			'token'    => $otlToken,
			'user_id'  => (int) $user->id,
			'username' => $user->username,
			'expires'  => $expires,
			'origin'   => substr($origin, 0, 100),
		]));

		// Build login URL
		$loginUrl = rtrim(Uri::root(), '/') . '/administrator/index.php?mokosuite_otl=' . $otlToken;

		$this->sendJson(200, [
			'status'    => 'ok',
			'login_url' => $loginUrl,
			'expires'   => $expires,
			'user'      => $user->username,
		]);
	}

	/**
	 * Decode master usernames from plugin params.
	 *
	 * @param   Registry  $params  Plugin params.
	 *
	 * @return  array
	 */
	private function getMasterUsernames(Registry $params): array
	{
		// Use MokoSuiteHelper if available
		$helperFile = JPATH_PLUGINS . '/system/mokosuite/Helper/MokoSuiteHelper.php';

		if (file_exists($helperFile))
		{
			require_once $helperFile;

			if (method_exists(\Moko\Plugin\System\MokoSuite\Helper\MokoSuiteHelper::class, 'getMasterUsernames'))
			{
				return \Moko\Plugin\System\MokoSuite\Helper\MokoSuiteHelper::getMasterUsernames();
			}
		}

		return [];
	}

	/**
	 * Send JSON response and terminate.
	 *
	 * @param   int    $code  HTTP status code.
	 * @param   array  $data  Response data.
	 *
	 * @return  void
	 */
	private function sendJson(int $code, array $data): void
	{
		http_response_code($code);
		header('Content-Type: application/json; charset=utf-8');
		echo json_encode($data, JSON_UNESCAPED_SLASHES);
		Factory::getApplication()->close();
	}
}