<?php
/**
 * @copyright Copyright (C) 2010-2021, the Friendica project
 *
 * @license GNU AGPL version 3 or any later version
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

namespace Friendica\Module;

use Friendica\BaseModule;
use Friendica\Core\Logger;
use Friendica\Core\System;
use Friendica\DI;
use Friendica\Model\Contact;
use Friendica\Model\Post;
use Friendica\Model\User;
use Friendica\Network\HTTPException;
use Friendica\Security\BasicAuth;
use Friendica\Security\OAuth;
use Friendica\Util\DateTimeFormat;
use Friendica\Util\HTTPInputData;

class BaseApi extends BaseModule
{
	const LOG_PREFIX = 'API {action} - ';

	const SCOPE_READ   = 'read';
	const SCOPE_WRITE  = 'write';
	const SCOPE_FOLLOW = 'follow';
	const SCOPE_PUSH   = 'push';

	/**
	 * @var array
	 */
	protected static $boundaries = [];

	/**
	 * @var array
	 */
	protected static $request = [];

	public function delete()
	{
		self::checkAllowedScope(self::SCOPE_WRITE);

		if (!DI::app()->isLoggedIn()) {
			throw new HTTPException\ForbiddenException(DI::l10n()->t('Permission denied.'));
		}
	}

	public function patch()
	{
		self::checkAllowedScope(self::SCOPE_WRITE);

		if (!DI::app()->isLoggedIn()) {
			throw new HTTPException\ForbiddenException(DI::l10n()->t('Permission denied.'));
		}
	}

	public function post()
	{
		self::checkAllowedScope(self::SCOPE_WRITE);

		if (!DI::app()->isLoggedIn()) {
			throw new HTTPException\ForbiddenException(DI::l10n()->t('Permission denied.'));
		}
	}

	public function put()
	{
		self::checkAllowedScope(self::SCOPE_WRITE);

		if (!DI::app()->isLoggedIn()) {
			throw new HTTPException\ForbiddenException(DI::l10n()->t('Permission denied.'));
		}
	}

	/**
	 * Processes data from GET requests and sets defaults
	 *
	 * @return array request data
	 */
	public static function getRequest(array $defaults)
	{
		$httpinput = HTTPInputData::process();
		$input = array_merge($httpinput['variables'], $httpinput['files'], $_REQUEST);

		self::$request    = $input;
		self::$boundaries = [];

		unset(self::$request['pagename']);

		$request = [];

		foreach ($defaults as $parameter => $defaultvalue) {
			if (is_string($defaultvalue)) {
				$request[$parameter] = $input[$parameter] ?? $defaultvalue;
			} elseif (is_int($defaultvalue)) {
				$request[$parameter] = (int)($input[$parameter] ?? $defaultvalue);
			} elseif (is_float($defaultvalue)) {
				$request[$parameter] = (float)($input[$parameter] ?? $defaultvalue);
			} elseif (is_array($defaultvalue)) {
				$request[$parameter] = $input[$parameter] ?? [];
			} elseif (is_bool($defaultvalue)) {
				$request[$parameter] = in_array(strtolower($input[$parameter] ?? ''), ['true', '1']);
			} else {
				Logger::notice('Unhandled default value type', ['parameter' => $parameter, 'type' => gettype($defaultvalue)]);
			}
		}

		foreach ($input ?? [] as $parameter => $value) {
			if ($parameter == 'pagename') {
				continue;
			}
			if (!in_array($parameter, array_keys($defaults))) {
				Logger::notice('Unhandled request field', ['parameter' => $parameter, 'value' => $value, 'command' => DI::args()->getCommand()]);
			}
		}

		Logger::debug('Got request parameters', ['request' => $request, 'command' => DI::args()->getCommand()]);
		return $request;
	}

	/**
	 * Set boundaries for the "link" header
	 * @param array $boundaries
	 * @param int $id
	 */
	protected static function setBoundaries(int $id)
	{
		if (!isset(self::$boundaries['min'])) {
			self::$boundaries['min'] = $id;
		}

		if (!isset(self::$boundaries['max'])) {
			self::$boundaries['max'] = $id;
		}

		self::$boundaries['min'] = min(self::$boundaries['min'], $id);
		self::$boundaries['max'] = max(self::$boundaries['max'], $id);
	}

	/**
	 * Set the "link" header with "next" and "prev" links
	 * @return void
	 */
	protected static function setLinkHeader()
	{
		if (empty(self::$boundaries)) {
			return;
		}

		$request = self::$request;

		unset($request['min_id']);
		unset($request['max_id']);
		unset($request['since_id']);

		$prev_request = $next_request = $request;

		$prev_request['min_id'] = self::$boundaries['max'];
		$next_request['max_id'] = self::$boundaries['min'];

		$command = DI::baseUrl() . '/' . DI::args()->getCommand();

		$prev = $command . '?' . http_build_query($prev_request);
		$next = $command . '?' . http_build_query($next_request);

		header('Link: <' . $next . '>; rel="next", <' . $prev . '>; rel="prev"');
	}

	/**
	 * Get current application token
	 *
	 * @return array token
	 */
	public static function getCurrentApplication()
	{
		$token = OAuth::getCurrentApplicationToken();

		if (empty($token)) {
			$token = BasicAuth::getCurrentApplicationToken();
		}

		return $token;
	}

	/**
	 * Get current user id, returns 0 if not logged in
	 *
	 * @return int User ID
	 */
	public static function getCurrentUserID()
	{
		$uid = OAuth::getCurrentUserID();

		if (empty($uid)) {
			$uid = BasicAuth::getCurrentUserID(false);
		}

		return (int)$uid;
	}

	/**
	 * Check if the provided scope does exist.
	 * halts execution on missing scope or when not logged in.
	 *
	 * @param string $scope the requested scope (read, write, follow, push)
	 */
	public static function checkAllowedScope(string $scope)
	{
		$token = self::getCurrentApplication();

		if (empty($token)) {
			Logger::notice('Empty application token');
			DI::mstdnError()->Forbidden();
		}

		if (!isset($token[$scope])) {
			Logger::warning('The requested scope does not exist', ['scope' => $scope, 'application' => $token]);
			DI::mstdnError()->Forbidden();
		}

		if (empty($token[$scope])) {
			Logger::warning('The requested scope is not allowed', ['scope' => $scope, 'application' => $token]);
			DI::mstdnError()->Forbidden();
		}
	}

	public static function checkThrottleLimit()
	{
		$uid = self::getCurrentUserID();

		// Check for throttling (maximum posts per day, week and month)
		$throttle_day = DI::config()->get('system', 'throttle_limit_day');
		if ($throttle_day > 0) {
			$datefrom = date(DateTimeFormat::MYSQL, time() - 24*60*60);

			$condition = ["`gravity` = ? AND `uid` = ? AND `wall` AND `received` > ?", GRAVITY_PARENT, $uid, $datefrom];
			$posts_day = Post::countThread($condition);

			if ($posts_day > $throttle_day) {
				Logger::info('Daily posting limit reached', ['uid' => $uid, 'posts' => $posts_day, 'limit' => $throttle_day]);
				$error = DI::l10n()->t('Too Many Requests');
				$error_description = DI::l10n()->tt("Daily posting limit of %d post reached. The post was rejected.", "Daily posting limit of %d posts reached. The post was rejected.", $throttle_day);
				$errorobj = new \Friendica\Object\Api\Mastodon\Error($error, $error_description);
				System::jsonError(429, $errorobj->toArray());
			}
		}

		$throttle_week = DI::config()->get('system', 'throttle_limit_week');
		if ($throttle_week > 0) {
			$datefrom = date(DateTimeFormat::MYSQL, time() - 24*60*60*7);

			$condition = ["`gravity` = ? AND `uid` = ? AND `wall` AND `received` > ?", GRAVITY_PARENT, $uid, $datefrom];
			$posts_week = Post::countThread($condition);

			if ($posts_week > $throttle_week) {
				Logger::info('Weekly posting limit reached', ['uid' => $uid, 'posts' => $posts_week, 'limit' => $throttle_week]);
				$error = DI::l10n()->t('Too Many Requests');
				$error_description = DI::l10n()->tt("Weekly posting limit of %d post reached. The post was rejected.", "Weekly posting limit of %d posts reached. The post was rejected.", $throttle_week);
				$errorobj = new \Friendica\Object\Api\Mastodon\Error($error, $error_description);
				System::jsonError(429, $errorobj->toArray());
			}
		}

		$throttle_month = DI::config()->get('system', 'throttle_limit_month');
		if ($throttle_month > 0) {
			$datefrom = date(DateTimeFormat::MYSQL, time() - 24*60*60*30);

			$condition = ["`gravity` = ? AND `uid` = ? AND `wall` AND `received` > ?", GRAVITY_PARENT, $uid, $datefrom];
			$posts_month = Post::countThread($condition);

			if ($posts_month > $throttle_month) {
				Logger::info('Monthly posting limit reached', ['uid' => $uid, 'posts' => $posts_month, 'limit' => $throttle_month]);
				$error = DI::l10n()->t('Too Many Requests');
				$error_description = DI::l10n()->t("Monthly posting limit of %d post reached. The post was rejected.", "Monthly posting limit of %d posts reached. The post was rejected.", $throttle_month);
				$errorobj = new \Friendica\Object\Api\Mastodon\Error($error, $error_description);
				System::jsonError(429, $errorobj->toArray());
			}
		}
	}

	public static function getContactIDForSearchterm(string $screen_name = null, string $profileurl = null, int $cid = null, int $uid)
	{
		if (!empty($cid)) {
			return $cid;
		}

		if (!empty($profileurl)) {
			return Contact::getIdForURL($profileurl);
		}

		if (empty($cid) && !empty($screen_name)) {
			if (strpos($screen_name, '@') !== false) {
				return Contact::getIdForURL($screen_name, 0, false);
			}

			$user = User::getByNickname($screen_name, ['uid']);
			if (!empty($user['uid'])) {
				return Contact::getPublicIdByUserId($user['uid']);
			}
		}

		if ($uid != 0) {
			return Contact::getPublicIdByUserId($uid);
		}

		return null;
	}
}