<?php
/**
 * @file include/diaspora.php
 * @brief The implementation of the diaspora protocol
 */

require_once("include/bb2diaspora.php");
require_once("include/Scrape.php");
require_once("include/Contact.php");

function array_to_xml($array, &$xml) {

	if (!is_object($xml)) {
		foreach($array as $key => $value) {
			$root = new SimpleXMLElement('<'.$key.'/>');
			array_to_xml($value, $root);

			$dom = dom_import_simplexml($root)->ownerDocument;
			$dom->formatOutput = true;
			return $dom->saveXML();
		}
	}

	foreach($array as $key => $value) {
		if (!is_array($value) AND !is_numeric($key))
			$xml->addChild($key, $value);
		elseif (is_array($value))
			array_to_xml($value, $xml->addChild($key));
	}
}

/**
 * @brief This class contain functions to create and send DFRN XML files
 *
 */
class diaspora {

	public static function dispatch_public($msg) {

		$enabled = intval(get_config("system", "diaspora_enabled"));
		if (!$enabled) {
			logger('diaspora is disabled');
			return false;
		}

		// Use a dummy importer to import the data for the public copy
		$importer = array("uid" => 0, "page-flags" => PAGE_FREELOVE);
		self::dispatch($importer,$msg);

		// Now distribute it to the followers
		$r = q("SELECT `user`.* FROM `user` WHERE `user`.`uid` IN
			(SELECT `contact`.`uid` FROM `contact` WHERE `contact`.`network` = '%s' AND `contact`.`addr` = '%s')
			AND NOT `account_expired` AND NOT `account_removed`",
			dbesc(NETWORK_DIASPORA),
			dbesc($msg["author"])
		);
		if(count($r)) {
			foreach($r as $rr) {
				logger("delivering to: ".$rr["username"]);
				self::dispatch($rr,$msg);
			}
		} else
			logger("No subscribers for ".$msg["author"]." ".print_r($msg, true));
	}

	public static function dispatch($importer, $msg) {

		// The sender is the handle of the contact that sent the message.
		// This will often be different with relayed messages (for example "like" and "comment")
		$sender = $msg["author"];

		if (!diaspora::valid_posting($msg, $fields)) {
			logger("Invalid posting");
			return false;
		}

		$type = $fields->getName();

		switch ($type) {
			case "account_deletion":
				return self::import_account_deletion($importer, $fields);

			case "comment":
				return true;
			//	return self::import_comment($importer, $sender, $fields);

			case "conversation":
				return self::import_conversation($importer, $fields);

			case "like":
			//	return true;
				return self::import_like($importer, $sender, $fields);

			case "message":
				return self::import_message($importer, $fields);

			case "participation":
				return self::import_participation($importer, $fields);

			case "photo":
				return self::import_photo($importer, $fields);

			case "poll_participation":
				return self::import_poll_participation($importer, $fields);

			case "profile":
				return self::import_profile($importer, $fields);

			case "request":
				return self::import_request($importer, $fields);

			case "reshare":
				return self::import_reshare($importer, $fields);

			case "retraction":
				return self::import_retraction($importer, $fields);

			case "status_message":
				return self::import_status_message($importer, $fields);

			default:
				logger("Unknown message type ".$type);
				return false;
		}

		return true;
	}

	/**
	 * @brief Checks if a posting is valid and fetches the data fields.
	 *
	 * This function does not only check the signature.
	 * It also does the conversion between the old and the new diaspora format.
	 *
	 * @param array $msg Array with the XML, the sender handle and the sender signature
	 * @param object $fields SimpleXML object that contains the posting
	 *
	 * @return bool Is the posting valid?
	 */
	private function valid_posting($msg, &$fields) {

		$data = parse_xml_string($msg["message"], false);

		$first_child = $data->getName();

		if ($data->getName() == "XML") {
			$oldXML = true;
			foreach ($data->post->children() as $child)
				$element = $child;
		} else {
			$oldXML = false;
			$element = $data;
		}

		$type = $element->getName();

		if (in_array($type, array("signed_retraction", "relayable_retraction")))
			$type = "retraction";

		$fields = new SimpleXMLElement("<".$type."/>");

		$signed_data = "";

		foreach ($element->children() AS $fieldname => $data) {

			if ($oldXML) {
				// Translation for the old XML structure
				if ($fieldname == "diaspora_handle")
					$fieldname = "author";

				if ($fieldname == "participant_handles")
					$fieldname = "participants";

				if (in_array($type, array("like", "participation"))) {
					if ($fieldname == "target_type")
						$fieldname = "parent_type";
				}

				if ($fieldname == "sender_handle")
					$fieldname = "author";

				if ($fieldname == "recipient_handle")
					$fieldname = "recipient";

				if ($fieldname == "root_diaspora_id")
					$fieldname = "root_author";

				if ($type == "retraction") {
					if ($fieldname == "post_guid")
						$fieldname = "target_guid";

					if ($fieldname == "type")
						$fieldname = "target_type";
				}
			}

			if ($fieldname == "author_signature")
				$author_signature = base64_decode($data);
			elseif ($fieldname == "parent_author_signature")
				$parent_author_signature = base64_decode($data);
			elseif ($fieldname != "target_author_signature") {
				if ($signed_data != "") {
					$signed_data .= ";";
					$signed_data_parent .= ";";
				}

				$signed_data .= $data;
			}
			if (!in_array($fieldname, array("parent_author_signature", "target_author_signature")))
				$fields->$fieldname = $data;
		}

		if (in_array($type, array("status_message", "reshare")))
			if ($msg["author"] != $fields->author) {
				logger("Message handle is not the same as envelope sender. Quitting this message.");
				return false;
			}

		if (!in_array($type, array("comment", "conversation", "message", "like")))
			return true;

		if (!isset($author_signature))
			return false;

		if (isset($parent_author_signature)) {
			$key = self::get_key($msg["author"]);

			if (!rsa_verify($signed_data, $parent_author_signature, $key, "sha256"))
				return false;
		}

		$key = self::get_key($fields->author);

		return rsa_verify($signed_data, $author_signature, $key, "sha256");
	}

	private function get_key($handle) {
		logger("Fetching diaspora key for: ".$handle);

		$r = self::get_person_by_handle($handle);
		if($r)
			return $r["pubkey"];

		return "";
	}

	private function get_person_by_handle($handle) {

		$r = q("SELECT * FROM `fcontact` WHERE `network` = '%s' AND `addr` = '%s' LIMIT 1",
			dbesc(NETWORK_DIASPORA),
			dbesc($handle)
		);
		if (count($r)) {
			$person = $r[0];
			logger("In cache ".print_r($r,true), LOGGER_DEBUG);

			// update record occasionally so it doesn't get stale
			$d = strtotime($person["updated"]." +00:00");
			if ($d < strtotime("now - 14 days"))
				$update = true;
		}

		if (!$person OR $update) {
			logger("create or refresh", LOGGER_DEBUG);
			$r = probe_url($handle, PROBE_DIASPORA);

			// Note that Friendica contacts will return a "Diaspora person"
			// if Diaspora connectivity is enabled on their server
			if (count($r) AND ($r["network"] === NETWORK_DIASPORA)) {
				self::add_fcontact($r, $update);
				$person = $r;
			}
		}
		return $person;
	}

	private function add_fcontact($arr, $update = false) {
		/// @todo Remove this function from include/network.php

		if($update) {
			$r = q("UPDATE `fcontact` SET
					`name` = '%s',
					`photo` = '%s',
					`request` = '%s',
					`nick` = '%s',
					`addr` = '%s',
					`batch` = '%s',
					`notify` = '%s',
					`poll` = '%s',
					`confirm` = '%s',
					`alias` = '%s',
					`pubkey` = '%s',
					`updated` = '%s'
				WHERE `url` = '%s' AND `network` = '%s'",
					dbesc($arr["name"]),
					dbesc($arr["photo"]),
					dbesc($arr["request"]),
					dbesc($arr["nick"]),
					dbesc($arr["addr"]),
					dbesc($arr["batch"]),
					dbesc($arr["notify"]),
					dbesc($arr["poll"]),
					dbesc($arr["confirm"]),
					dbesc($arr["alias"]),
					dbesc($arr["pubkey"]),
					dbesc(datetime_convert()),
					dbesc($arr["url"]),
					dbesc($arr["network"])
				);
		} else {
			$r = q("INSERT INTO `fcontact` (`url`,`name`,`photo`,`request`,`nick`,`addr`,
					`batch`, `notify`,`poll`,`confirm`,`network`,`alias`,`pubkey`,`updated`)
				VALUES ('%s','%s','%s','%s','%s','%s','%s','%s','%s','%s','%s','%s','%s','%s')",
					dbesc($arr["url"]),
					dbesc($arr["name"]),
					dbesc($arr["photo"]),
					dbesc($arr["request"]),
					dbesc($arr["nick"]),
					dbesc($arr["addr"]),
					dbesc($arr["batch"]),
					dbesc($arr["notify"]),
					dbesc($arr["poll"]),
					dbesc($arr["confirm"]),
					dbesc($arr["network"]),
					dbesc($arr["alias"]),
					dbesc($arr["pubkey"]),
					dbesc(datetime_convert())
				);
		}

		return $r;
	}

	private function get_contact_by_handle($uid, $handle) {
		$r = q("SELECT * FROM `contact` WHERE `uid` = %d AND `addr` = '%s' LIMIT 1",
			intval($uid),
			dbesc($handle)
		);

		if ($r AND count($r))
			return $r[0];

		$handle_parts = explode("@", $handle);
		$nurl_sql = '%%://' . $handle_parts[1] . '%%/profile/' . $handle_parts[0];
		$r = q("SELECT * FROM `contact` WHERE `network` = '%s' AND `uid` = %d AND `nurl` LIKE '%s' LIMIT 1",
			dbesc(NETWORK_DFRN),
			intval($uid),
			dbesc($nurl_sql)
		);
		if($r AND count($r))
			return $r[0];

		return false;
	}

	private function fetch_guid($item) {
		preg_replace_callback("&\[url=/posts/([^\[\]]*)\](.*)\[\/url\]&Usi",
			function ($match) use ($item){
				return(self::fetch_guid_sub($match, $item));
			},$item["body"]);
	}

	private function fetch_guid_sub($match, $item) {
		$a = get_app();

		if (!self::store_by_guid($match[1], $item["author-link"]))
			self::store_by_guid($match[1], $item["owner-link"]);
	}

	private function store_by_guid($guid, $server, $uid = 0) {
		$serverparts = parse_url($server);
		$server = $serverparts["scheme"]."://".$serverparts["host"];

		logger("Trying to fetch item ".$guid." from ".$server, LOGGER_DEBUG);

/// @todo		$item = self::fetch_message($guid, $server);

		if (!$item)
			return false;

		logger("Successfully fetched item ".$guid." from ".$server, LOGGER_DEBUG);

// @todo - neue Funktion import_status... nutzen
print_r($item);
die();
		return self::import_status_message($importer, $data);

/*
		$body = $item["body"];
		$str_tags = $item["tag"];
		$app = $item["app"];
		$created = $item["created"];
		$author = $item["author"];
		$guid = $item["guid"];
		$private = $item["private"];
		$object = $item["object"];
		$objecttype = $item["object-type"];

		$r = q("SELECT `id` FROM `item` WHERE `uid` = %d AND `guid` = '%s' LIMIT 1",
			intval($uid),
			dbesc($guid)
		);
		if(count($r))
			return $r[0]["id"];

		$person = self::get_person_by_handle($author);

		$contact_id = get_contact($person["url"], $uid);

		$contacts = q("SELECT * FROM `contact` WHERE `id` = %d", intval($contact_id));
		$importers = q("SELECT * FROM `user` WHERE `uid` = %d", intval($uid));

		if ($contacts AND $importers)
			if (!self::post_allow($importers[0],$contacts[0], false)) {
				logger("Ignoring author ".$person["url"]." for uid ".$uid);
				return false;
			} else
				logger("Author ".$person["url"]." is allowed for uid ".$uid);

		$datarray = array();
		$datarray["uid"] = $uid;
		$datarray["contact-id"] = $contact_id;
		$datarray["wall"] = 0;
		$datarray["network"] = NETWORK_DIASPORA;
		$datarray["guid"] = $guid;
		$datarray["uri"] = $datarray["parent-uri"] = $author.":".$guid;
		$datarray["changed"] = $datarray["created"] = $datarray["edited"] = datetime_convert('UTC','UTC',$created);
		$datarray["private"] = $private;
		$datarray["parent"] = 0;
		$datarray["plink"] = self::plink($author, $guid);
		$datarray["author-name"] = $person["name"];
		$datarray["author-link"] = $person["url"];
		$datarray["author-avatar"] = ((x($person,'thumb')) ? $person["thumb"] : $person["photo"]);
		$datarray["owner-name"] = $datarray["author-name"];
		$datarray["owner-link"] = $datarray["author-link"];
		$datarray["owner-avatar"] = $datarray["author-avatar"];
		$datarray["body"] = $body;
		$datarray["tag"] = $str_tags;
		$datarray["app"]  = $app;
		$datarray["visible"] = ((strlen($body)) ? 1 : 0);
		$datarray["object"] = $object;
		$datarray["object-type"] = $objecttype;

		if ($datarray["contact-id"] == 0)
			return false;

		self::fetch_guid($datarray);
		$message_id = item_store($datarray);

		/// @TODO
		/// Looking if there is some subscribe mechanism in Diaspora to get all comments for this post

		return $message_id;
*/
	}

	private function post_allow($importer, $contact, $is_comment = false) {

		// perhaps we were already sharing with this person. Now they're sharing with us.
		// That makes us friends.
		// Normally this should have handled by getting a request - but this could get lost
		if($contact["rel"] == CONTACT_IS_FOLLOWER && in_array($importer["page-flags"], array(PAGE_FREELOVE))) {
			q("UPDATE `contact` SET `rel` = %d, `writable` = 1 WHERE `id` = %d AND `uid` = %d",
				intval(CONTACT_IS_FRIEND),
				intval($contact["id"]),
				intval($importer["uid"])
			);
			$contact["rel"] = CONTACT_IS_FRIEND;
			logger("defining user ".$contact["nick"]." as friend");
		}

		if(($contact["blocked"]) || ($contact["readonly"]) || ($contact["archive"]))
			return false;
		if($contact["rel"] == CONTACT_IS_SHARING || $contact["rel"] == CONTACT_IS_FRIEND)
			return true;
		if($contact["rel"] == CONTACT_IS_FOLLOWER)
			if(($importer["page-flags"] == PAGE_COMMUNITY) OR $is_comment)
				return true;

		// Messages for the global users are always accepted
		if ($importer["uid"] == 0)
			return true;

		return false;
	}

	private function fetch_parent_item($uid, $guid, $author, $contact) {
		$r = q("SELECT `id`, `body`, `wall`, `uri`, `private`, `owner-name`, `owner-link`, `owner-avatar`, `origin`
			FROM `item` WHERE `uid` = %d AND `guid` = '%s' LIMIT 1",
			intval($uid), dbesc($guid));

		if(!count($r)) {
			$result = self::store_by_guid($guid, $contact["url"], $uid);

			if (!$result) {
				$person = self::get_person_by_handle($author);
				$result = self::store_by_guid($guid, $person["url"], $uid);
			}

			if ($result) {
				logger("Fetched missing item ".$guid." - result: ".$result, LOGGER_DEBUG);

				$r = q("SELECT `id`, `body`, `wall`, `uri`, `private`,
						`owner-name`, `owner-link`, `owner-avatar`, `origin`
					FROM `item` WHERE `uid` = %d AND `guid` = '%s' LIMIT 1",
					intval($uid), dbesc($guid));
			}
		}

		if (!count($r)) {
			logger("parent item not found: parent: ".$guid." item: ".$guid);
			return false;
		} else
			return $r[0];
	}

	private function import_account_deletion($importer, $data) {
		return true;
	}

	private function import_comment($importer, $sender, $data) {
		$guid = notags(unxmlify($data->guid));
		$parent_guid = notags(unxmlify($data->parent_guid));
		$text = unxmlify($data->text);
		$author = notags(unxmlify($data->author));

		$contact = self::get_contact_by_handle($importer["uid"], $sender);
		if (!$contact) {
			logger("cannot find contact for sender: ".$sender);
			return false;
		}

		if (!self::post_allow($importer,$contact, true)) {
			logger("Ignoring the author ".$sender);
			return false;
		}
/*
		$r = q("SELECT `id` FROM `item` WHERE `uid` = %d AND `guid` = '%s' LIMIT 1",
			intval($importer["uid"]),
			dbesc($guid)
		);
		if(count($r)) {
			logger("The comment already exists: ".$guid);
			return;
		}
*/
		$parent_item = self::fetch_parent_item($importer["uid"], $parent_guid, $author, $contact);
		if (!$parent_item)
			return false;

		$person = self::get_person_by_handle($author);
		if (!is_array($person)) {
			logger("unable to find author details");
			return false;
		}

		// Fetch the contact id - if we know this contact
		$r = q("SELECT `id`, `network` FROM `contact` WHERE `nurl` = '%s' AND `uid` = %d LIMIT 1",
			dbesc(normalise_link($person["url"])), intval($importer["uid"]));
		if ($r) {
			$cid = $r[0]["id"];
			$network = $r[0]["network"];
		} else {
			$cid = $contact["id"];
			$network = NETWORK_DIASPORA;
		}

		$body = diaspora2bb($text);

		$datarray = array();

		$datarray["uid"] = $importer["uid"];
		$datarray["contact-id"] = $cid;
		$datarray["type"] = 'remote-comment';
		$datarray["wall"] = $parent_item["wall"];
		$datarray["network"]  = $network;
		$datarray["verb"] = ACTIVITY_POST;
		$datarray["gravity"] = GRAVITY_COMMENT;
		$datarray["guid"] = $guid;
		$datarray["uri"] = $author.":".$guid;
		$datarray["parent-uri"] = $parent_item["uri"];

		// The old Diaspora protocol doesn't have a timestamp for comments
		$datarray["changed"] = $datarray["created"] = $datarray["edited"] = datetime_convert();
		$datarray["private"] = $parent_item["private"];

		$datarray["owner-name"] = $contact["name"];
		$datarray["owner-link"] = $contact["url"];
		$datarray["owner-avatar"] = ((x($contact,"thumb")) ? $contact["thumb"] : $contact["photo"]);

		$datarray["author-name"] = $person["name"];
		$datarray["author-link"] = $person["url"];
		$datarray["author-avatar"] = ((x($person,"thumb")) ? $person["thumb"] : $person["photo"]);
		$datarray["body"] = $body;
		$datarray["object"] = json_encode($data);
		$datarray["object-type"] = ACTIVITY_OBJ_COMMENT;

		self::fetch_guid($datarray);

//		$message_id = item_store($datarray);
print_r($datarray);
		$datarray["id"] = $message_id;

		// If we are the origin of the parent we store the original data and notify our followers
		if($message_id AND $parent_item["origin"]) {

			// Formerly we stored the signed text, the signature and the author in different fields.
			// The new Diaspora protocol can have variable fields. We now store the data in correct order in a single field.
			q("INSERT INTO `sign` (`iid`,`signed_text`) VALUES (%d,'%s')",
				intval($message_id),
				dbesc(json_encode($data))
			);

			// notify others
			proc_run("php", "include/notifier.php", "comment-import", $message_id);
		}

		return $message_id;
	}

	private function import_conversation($importer, $data) {
		return true;
	}

	private function import_like($importer, $sender, $data) {
		$positive = notags(unxmlify($data->positive));
		$guid = notags(unxmlify($data->guid));
		$parent_type = notags(unxmlify($data->parent_type));
		$parent_guid = notags(unxmlify($data->parent_guid));
		$author = notags(unxmlify($data->author));

		// likes on comments aren't supported by Diaspora - only on posts
		if ($parent_type !== "Post")
			return false;

		// "positive" = "false" doesn't seem to be supported by Diaspora
		if ($positive === "false") {
			logger("Received a like with positive set to 'false' - this shouldn't exist at all");
			return false;
		}

		$contact = self::get_contact_by_handle($importer["uid"], $sender);
		if (!$contact) {
			logger("cannot find contact for sender: ".$sender);
			return false;
		}

		if (!self::post_allow($importer,$contact, true)) {
			logger("Ignoring the author ".$sender);
			return false;
		}
/*
		$r = q("SELECT `id` FROM `item` WHERE `uid` = %d AND `guid` = '%s' LIMIT 1",
			intval($importer["uid"]),
			dbesc($guid)
		);
		if(count($r)) {
			logger("The like already exists: ".$guid);
			return false;
		}
*/
		$parent_item = self::fetch_parent_item($importer["uid"], $parent_guid, $author, $contact);
		if (!$parent_item)
			return false;

		$person = self::get_person_by_handle($author);
		if (!is_array($person)) {
			logger("unable to find author details");
			return false;
		}

		// Fetch the contact id - if we know this contact
		$r = q("SELECT `id`, `network` FROM `contact` WHERE `nurl` = '%s' AND `uid` = %d LIMIT 1",
			dbesc(normalise_link($person["url"])), intval($importer["uid"]));
		if ($r) {
			$cid = $r[0]["id"];
			$network = $r[0]["network"];
		} else {
			$cid = $contact["id"];
			$network = NETWORK_DIASPORA;
		}

// ------------------------------------------------
		$objtype = ACTIVITY_OBJ_NOTE;
		$link = xmlify('<link rel="alternate" type="text/html" href="'.App::get_baseurl()."/display/".$importer["nickname"]."/".$parent_item["id"].'" />'."\n") ;
		$parent_body = $parent_item["body"];

		$obj = <<< EOT

		<object>
			<type>$objtype</type>
			<local>1</local>
			<id>{$parent_item["uri"]}</id>
			<link>$link</link>
			<title></title>
			<content>$parent_body</content>
		</object>
EOT;
		$bodyverb = t('%1$s likes %2$s\'s %3$s');

		$ulink = "[url=".$contact["url"]."]".$contact["name"]."[/url]";
		$alink = "[url=".$parent_item["author-link"]."]".$parent_item["author-name"]."[/url]";
		$plink = "[url=".App::get_baseurl()."/display/".urlencode($guid)."]".t("status")."[/url]";
		$body = sprintf($bodyverb, $ulink, $alink, $plink);
// ------------------------------------------------

		$datarray = array();

		$datarray["uri"] = $author.":".$guid;
		$datarray["uid"] = $importer["uid"];
		$datarray["guid"] = $guid;
		$datarray["network"]  = $network;
		$datarray["contact-id"] = $cid;
		$datarray["type"] = "activity";
		$datarray["wall"] = $parent_item["wall"];
		$datarray["gravity"] = GRAVITY_LIKE;
		$datarray["parent"] = $parent_item["id"];
		$datarray["parent-uri"] = $parent_item["uri"];

		$datarray["owner-name"] = $contact["name"];
		$datarray["owner-link"] = $contact["url"];
		$datarray["owner-avatar"] = ((x($contact,"thumb")) ? $contact["thumb"] : $contact["photo"]);

		$datarray["author-name"] = $person["name"];
		$datarray["author-link"] = $person["url"];
		$datarray["author-avatar"] = ((x($person,"thumb")) ? $person["thumb"] : $person["photo"]);

		$datarray["body"] = $body;
		$datarray["private"] = $parent_item["private"];
		$datarray["verb"] = ACTIVITY_LIKE;
		$datarray["object-type"] = $objtype;
		$datarray["object"] = $obj;
		$datarray["visible"] = 1;
		$datarray["unseen"] = 1;
		$datarray["last-child"] = 0;

print_r($datarray);
//		$message_id = item_store($datarray);

		// If we are the origin of the parent we store the original data and notify our followers
		if($message_id AND $parent_item["origin"]) {

			// Formerly we stored the signed text, the signature and the author in different fields.
			// The new Diaspora protocol can have variable fields. We now store the data in correct order in a single field.
			q("INSERT INTO `sign` (`iid`,`signed_text`) VALUES (%d,'%s')",
				intval($message_id),
				dbesc(json_encode($data))
			);

			// notify others
			proc_run("php", "include/notifier.php", "comment-import", $message_id);
		}

		return true;
	}

	private function import_message($importer, $data) {
		return true;
	}

	private function import_participation($importer, $data) {
		return true;
	}

	private function import_photo($importer, $data) {
		return true;
	}

	private function import_poll_participation($importer, $data) {
		return true;
	}

	private function import_profile($importer, $data) {
		return true;
	}

	private function import_request($importer, $data) {
		return true;
	}

	private function import_reshare($importer, $data) {
		return true;
	}

	private function import_retraction($importer, $data) {
		return true;
	}

	private function import_status_message($importer, $data) {
		return true;
	}
}
?>