<?php
	$op = $_REQUEST['op'] ?? '';
	$method = !empty($_REQUEST['subop']) ?
		$_REQUEST['subop'] :
		$_REQUEST["method"] ?? false;

	if (!$method)
		$method = 'index';
	else
		$method = strtolower($method);

	// Public calls compatibility shim
	if (in_array($op, ['rss', 'getUnread', 'getProfiles', 'share'])) {
		header('Location: public.php?' . $_SERVER['QUERY_STRING']);
		return;
	}

	$csrf_token = $_POST['csrf_token'] ?? "";

	require_once __DIR__ . '/include/autoload.php';
	require_once __DIR__ . '/include/sessions.php';

	$op = (string)clean($op);
	$method = (string)clean($method);

	startup_gettext();

	if (!init_plugins()) {
		return;
	}

	header("Content-Type: application/json; charset=utf-8");

	if (Config::get(Config::SINGLE_USER_MODE)) {
		UserHelper::authenticate("admin", null);
	}

	if (!empty($_SESSION["uid"])) {
		if (!Sessions::validate_session()) {
			header("Content-Type: application/json");
			print Errors::to_json(Errors::E_UNAUTHORIZED);

			return;
		}
		UserHelper::load_user_plugins($_SESSION["uid"]);
	}

	if (Config::is_migration_needed()) {
		print Errors::to_json(Errors::E_SCHEMA_MISMATCH);

		return;
	}

	$purge_intervals = [
		0  => __("Use default"),
		-1 => __("Never purge"),
		7  => __("1 week old"),
		14 => __("2 weeks old"),
		31 => __("1 month old"),
		60 => __("2 months old"),
		90 => __("3 months old")];

	$update_intervals = [
		0   => __("Default interval"),
		-1  => __("Disable updates"),
		15  => __("15 minutes"),
		30  => __("30 minutes"),
		60  => __("Hourly"),
		240 => __("4 hours"),
		720 => __("12 hours"),
		1440 => __("Daily"),
		10080 => __("Weekly")];

	$update_intervals_nodefault = [
		-1  => __("Disable updates"),
		15  => __("15 minutes"),
		30  => __("30 minutes"),
		60  => __("Hourly"),
		240 => __("4 hours"),
		720 => __("12 hours"),
		1440 => __("Daily"),
		10080 => __("Weekly")];

	$access_level_names = [
		UserHelper::ACCESS_LEVEL_DISABLED 	=> __("Disabled"),
		UserHelper::ACCESS_LEVEL_READONLY 	=> __("Read Only"),
		UserHelper::ACCESS_LEVEL_USER			=> __("User"),
		UserHelper::ACCESS_LEVEL_POWERUSER	=> __("Power User"),
		UserHelper::ACCESS_LEVEL_ADMIN		=> __("Administrator")
	];

	// shortcut syntax for plugin methods (?op=plugin--pmethod&...params)
	/* if (str_contains($op, PluginHost::PUBLIC_METHOD_DELIMITER)) {
		list ($plugin, $pmethod) = explode(PluginHost::PUBLIC_METHOD_DELIMITER, $op, 2);

		// TODO: better implementation that won't modify $_REQUEST
		$_REQUEST["plugin"] = $plugin;
		$method = $pmethod;
		$op = "pluginhandler";
	} */

	// $op = str_replace(, "_", $op);

	$override = PluginHost::getInstance()->lookup_handler($op, $method);

	if (class_exists($op) || $override) {

		if (str_starts_with($method, "_")) {
			user_error("Refusing to invoke method $method of handler $op which starts with underscore.", E_USER_WARNING);
			header("Content-Type: application/json");
			print Errors::to_json(Errors::E_UNAUTHORIZED);

			return;
		}

		if ($override) {
			$handler = $override;
		} else {
			$reflection = new ReflectionClass($op);
			$handler = $reflection->newInstanceWithoutConstructor();
		}

		if (implements_interface($handler, 'IHandler')) {

			$handler->__construct($_REQUEST);

			if (validate_csrf($csrf_token) || $handler->csrf_ignore($method)) {

				$before = $handler->before($method);

				if ($before) {
					if ($method && method_exists($handler, $method)) {
						$reflection = new ReflectionMethod($handler, $method);

						if ($reflection->getNumberOfRequiredParameters() == 0) {
							$handler->$method();
						} else {
							user_error("Refusing to invoke method $method of handler $op which has required parameters.", E_USER_WARNING);
							header("Content-Type: application/json");

							print Errors::to_json(Errors::E_UNAUTHORIZED);
						}
					} else {
						if (method_exists($handler, "catchall")) {
							$handler->catchall($method);
						} else {
							header("Content-Type: application/json");

							print Errors::to_json(Errors::E_UNKNOWN_METHOD, ["info" => $handler::class . "->$method"]);
						}
					}

					$handler->after();
					return;
				} else {
					header("Content-Type: application/json");
					print Errors::to_json(Errors::E_UNAUTHORIZED);

					return;
				}
			} else {
				user_error("Refusing to invoke method $method of handler $op with invalid CSRF token.", E_USER_WARNING);
				header("Content-Type: application/json");
				print Errors::to_json(Errors::E_UNAUTHORIZED);

				return;
			}
		}
	}

	header("Content-Type: application/json");
	print Errors::to_json(Errors::E_UNKNOWN_METHOD, [ "info" => (isset($handler) ? $handler::class : "UNKNOWN:".$op) . "->$method"]);

