CCats/daemon/src/JsonCommander.cpp

#include "../include/JsonCommander.h"
#include "../include/UserManager.h"
#include "../include/base64.h"

JsonCommander::JsonCommander(FileManager &fileManager) : fileManager(fileManager) {
	commandsMap["status"] = &JsonCommander::executeStatus;
	commandsMap["close"] = &JsonCommander::executeClose;
	commandsMap["list"] = &JsonCommander::executeList;
	commandsMap["listdata"] = &JsonCommander::executeListData;
	commandsMap["put"] = &JsonCommander::executePut;
	commandsMap["putdata"] = &JsonCommander::executePutdata;
	commandsMap["get"] = &JsonCommander::executeGet;
	commandsMap["getdata"] = &JsonCommander::executeGetdata;
	commandsMap["head"] = &JsonCommander::executeHead;
	commandsMap["deleteme"] = &JsonCommander::executeDeleteMe;
	commandsMap["deletefile"] = &JsonCommander::executeDeleteFile;
}

JsonCommander::~JsonCommander() {}

JsonCommander::Response JsonCommander::execute(const Json::Value &message) {
	JsonCommander::Response response;

	Response (JsonCommander::*commandExecutor)(const Json::Value &) = commandsMap[message["command"].asString()];

	if (commandExecutor != nullptr) {
		response = (this->*commandExecutor)(message);
	} else {
		// command does not exist
		response.action = close;
	}

	return response;
}

JsonCommander::Response JsonCommander::executeStatus(const Json::Value &message) {
	JsonCommander::Response response;
	response.action = send;
	response.json["command"] = "status";

	// answer a real status message
	std::string status;
	if (this->fileManager.isUploading() && this->fileManager.isDownloading()) {
		status = "download and upload running";
	} else if (this->fileManager.isUploading()) {
		status = "upload running";
	} else if (this->fileManager.isDownloading()) {
		status = "download running";
	} else {
		status = "ok";
	}

	response.json["response"] = status;

	return response;
}

JsonCommander::Response JsonCommander::executeClose(const Json::Value &message) {
	JsonCommander::Response response;
	response.action = closeAndSend;
	response.json["command"] = "close";
	response.json["response"] = "bye";

	return response;
}

JsonCommander::Response JsonCommander::executeList(const Json::Value &message) {
	JsonCommander::Response response;
	response.action = send;
	response.json["command"] = "list";

	int chunks;
	if (fileManager.getRemainingListChunks() > 0) {
		response.json["accept"] = false;
		response.json["chunks"] = -1;
		response.json["items"] = -1;
		response.json["error"] = "there is already an open list command";
	} else if ((chunks = fileManager.openList()) == -1) { // TODO do we need to check? maybe. Think about it
		response.json["accept"] = false;
		response.json["chunks"] = -1;
		response.json["items"] = -1;
		response.json["error"] = "there is a filename which is too long";
	} else {
		response.json["accept"] = true;
		response.json["chunks"] = chunks;
		response.json["items"] = fileManager.getListSize();
		response.json["error"] = "";
	}

	return response;
}

JsonCommander::Response JsonCommander::executeListData(const Json::Value &message) {
	JsonCommander::Response response;
	response.action = send;
	response.json["command"] = "listdata";
	Json::Value array;

	const int remainingListchunks = fileManager.getRemainingListChunks();
	if (!message["chunk"].isInt() || !message["cancel"].isBool()) {
		response.action = closeAndSend;
		response.json["cancel"] = true;
		response.json["remaining"] = -1;
		response.json["names"] = Json::arrayValue;
		response.json["error"] = "incorrect listdata command request";
	} else if (remainingListchunks == 0) {
		response.json["cancel"] = true;
		response.json["remaining"] = -1;
		response.json["names"] = Json::arrayValue;
		response.json["error"] = "there are no chunks to send";
	} else if (message["cancel"].asBool()) {
		response.json["cancel"] = true;
		response.json["remaining"] = message["chunk"].asInt(); // so it can be associated to the request
		response.json["names"] = Json::arrayValue;
		response.json["error"] = "";
		fileManager.cancelList();
	} else if (remainingListchunks - 1 != message["chunk"].asInt()) {
		response.action = closeAndSend;
		response.json["cancel"] = true;
		response.json["remaining"] = -1;
		response.json["names"] = Json::arrayValue;
		response.json["error"] = "wrong chunk number";
	} else {
		std::vector<std::string> v = fileManager.getNextChunkFromList();
		for (int i = 0; i < v.size(); i++)
			array.append(v.at(i));
		response.json["remaining"] = message["chunk"].asInt();
		response.json["cancel"] = false;
		response.json["names"] = array;
		response.json["error"] = "";
	}

	return response;
}

JsonCommander::Response JsonCommander::executePut(const Json::Value &message) {
	JsonCommander::Response response;
	response.json["command"] = "put";
	response.json["file"] = message["file"].asString();

	if (!message["file"].isString() || !message["size"].isInt() || !message["chunks"].isInt()) {
		// if request is incomplete close connection
		response.action = closeAndSend;
		response.json["accept"] = false;
		response.json["error"] = "incorrect put command request";
	} else if (fileManager.isUploading()) {
		// if an upload is alread running deny request
		response.action = send;
		response.json["accept"] = false;
		response.json["error"] = "upload already running";
	} else if (message["chunks"].asInt() <= 0) {
		response.action = send;
		response.json["accept"] = false;
		response.json["error"] = "there must be at least one chunk";
	} else if (fileManager.checkFilename(message["file"].asString())) {
		// accept request
		response.action = send;

		bool opened = fileManager.openPutFile(message["file"].asString());
		if (opened) {
			response.json["accept"] = true;
			response.json["error"] = "";
			this->putFileReceived = message["chunks"].asInt();
		} else {
			response.json["accept"] = false;
			response.json["error"] = "file already exists";
		}

	} else {
		// deny request if file name is not valid
		response.action = send;
		response.json["accept"] = false;
		response.json["error"] = "invalid file name";
	}

	return response;
}

JsonCommander::Response JsonCommander::executePutdata(const Json::Value &message) {
	JsonCommander::Response response;
	response.json["command"] = "putdata";
	response.json["file"] = message["file"].asString();
	response.json["received"] = message["remaining"].asInt();

	if (!message["file"].isString() || !message["data"].isString() || !message["remaining"].isInt() || !message["cancel"].isBool()) {
		// if request is incomplete close connection
		response.action = closeAndSend;
		response.json["cancel"] = true;
		response.json["error"] = "incorrect putdata command request";

		this->fileManager.cancelPut();

	} else if (!fileManager.isUploading()) {
		// no upload running -> command
		response.action = send;
		response.json["cancel"] = true;
		response.json["error"] = "no upload running";
	} else if (message["cancel"].asBool()) {
		response.action = send;
		response.json["cancel"] = true;
		response.json["error"] = "";

		this->fileManager.cancelPut();

	} else if (message["file"].asString().compare(fileManager.getPutBaseFileName()) == 0) {

		if (--this->putFileReceived == message["remaining"].asInt()) {
			// accept request
			response.action = send;
			response.json["cancel"] = false;
			response.json["error"] = "";

			const std::vector<char> data = base64::decode<std::vector<char>>(message["data"].asString());

			fileManager.writePut(data);

			this->putFileReceived = message["remaining"].asInt();

			if (this->putFileReceived == 0) {
				// close file after last chunk was received
				this->fileManager.closePutFile();
			}

		} else {
			// wrong remaining number
			response.action = send;
			response.json["cancel"] = true;
			response.json["error"] = "wrong remaining number";

			this->fileManager.cancelPut();
		}
	} else {
		// wrong file name
		response.action = send;
		response.json["cancel"] = true;
		response.json["error"] = "another file was already being uploaded";

		this->fileManager.cancelPut();
	}

	return response;
}

JsonCommander::Response JsonCommander::executeGet(const Json::Value &message) {
	JsonCommander::Response response;
	response.json["command"] = "get";
	response.json["file"] = message["file"].asString();

	if (!message["file"].isString()) {
		// if request is incomplete close connection
		response.action = closeAndSend;
		response.json["accept"] = false;
		response.json["chunks"] = -1;
		response.json["error"] = "incorrect get command request";
	} else if (fileManager.isDownloading()) {
		// if an upload is alread running deny request
		response.action = send;
		response.json["accept"] = false;
		response.json["chunks"] = -1;
		response.json["error"] = "download already running";
	} else if (fileManager.checkFilename(message["file"].asString())) {
		// accept request
		response.action = send;

		std::pair<bool, int> opened = fileManager.openGetFile(message["file"].asString());

		if (opened.first) {
			this->getFileRemaining = opened.second;
			response.json["accept"] = true;
			response.json["chunks"] = this->getFileRemaining;
			response.json["error"] = "";
		} else {
			response.json["accept"] = false;
			response.json["chunks"] = -1;
			response.json["error"] = "file does not exist";
		}

	} else {
		// deny request if file name is not valid
		response.action = send;
		response.json["accept"] = false;
		response.json["chunks"] = -1;
		response.json["error"] = "invalid file name";
	}

	return response;
}

JsonCommander::Response JsonCommander::executeGetdata(const Json::Value &message) {
	JsonCommander::Response response;
	response.json["command"] = "getdata";
	response.json["file"] = message["file"].asString();
	response.json["remaining"] = message["chunk"].asInt();

	if (!message["file"].isString() || !message["chunk"].isInt() || !message["cancel"].isBool()) {
		// if request is incomplete close connection
		response.action = closeAndSend;
		response.json["cancel"] = true;
		response.json["data"] = "";
		response.json["error"] = "incorrect putdata command request";

		this->fileManager.closeGetFile();

	} else if (!fileManager.isDownloading()) {
		// no upload running -> command
		response.action = send;
		response.json["cancel"] = true;
		response.json["data"] = "";
		response.json["error"] = "no download running";
	} else if (message["cancel"].asBool()) {
		response.action = send;
		response.json["cancel"] = true;
		response.json["data"] = "";
		response.json["error"] = "";

		this->fileManager.closeGetFile();

	} else if (message["file"].asString().compare(fileManager.getGetBaseFileName()) == 0) {

		if (--this->getFileRemaining == message["chunk"].asInt()) {
			// accept request
			response.action = send;
			response.json["cancel"] = false;
			response.json["error"] = "";

			const std::vector<char> data = fileManager.readGet();
			response.json["data"] = base64::encode<std::vector<char>>(data);

			fileManager.writePut(data);

			if (this->getFileRemaining == 0) {
				// close file after last chunk was sent
				this->fileManager.closeGetFile();
			}

		} else {
			// wrong chunk number
			response.action = send;
			response.json["cancel"] = true;
			response.json["data"] = "";
			response.json["error"] = "wrong chunk number";

			this->fileManager.closeGetFile();
		}
	} else {
		// wrong file name
		response.action = send;
		response.json["cancel"] = true;
		response.json["data"] = "";
		response.json["error"] = "another file was already being downloaded";

		this->fileManager.closeGetFile();
	}

	return response;
}

JsonCommander::Response JsonCommander::executeHead(const Json::Value &message) {
	JsonCommander::Response response;
	response.action = send;
	response.json["command"] = "head";

	if (!message["file"].isString()) {
		response.json["accept"] = false;
		response.json["file"] = "";
		response.json["data"] = "";
		response.json["error"] = "incorrect head command request";
	} else {
		std::pair<std::vector<char>, FileManager::Error> res = fileManager.getBytesFromFile(message["file"].asString(), 4);
		switch (res.second) {
		case FileManager::Error::no_error:
			response.json["accept"] = true;
			response.json["file"] = message["file"].asString();
			response.json["data"] = base64::encode<std::vector<char>>(res.first);
			response.json["error"] = "";
			break;
		case FileManager::Error::no_such_file:
			response.json["accept"] = false;
			response.json["file"] = message["file"].asString();
			response.json["data"] = "";
			response.json["error"] = "no such file";
			break;
		case FileManager::Error::file_too_small:
			response.json["accept"] = false;
			response.json["file"] = message["file"].asString();
			response.json["data"] = "";
			response.json["error"] = "file is smaller than specified size";
			break;
		default:
			response.action = closeAndSend;
			response.json["accept"] = false;
			response.json["file"] = message["file"];
			response.json["data"] = "";
			response.json["error"] = "internal error. Please fix this!!!";
		}
	}

	return response;
}

JsonCommander::Response JsonCommander::executeDeleteMe(const Json::Value &message) {
	JsonCommander::Response response;
	response.json["command"] = "deleteme";

	if (!message["pass"].isString()) {
		response.action = closeAndSend;
		response.json["accept"] = false;
		response.json["error"] = "incorrect deleteme command request";
	} else if (UserManager::deleteUser(currentUser, message["pass"].asString())) {
		// success
		response.action = closeAndSend;
		response.json["accept"] = true;
		response.json["error"] = "";
	} else {
		response.action = send;
		response.json["accept"] = false;
		response.json["error"] = "wrong password";
	}

	return response;
}

JsonCommander::Response JsonCommander::testVersion(const Json::Value &message) {
	JsonCommander::Response response;
	response.json["major"] = this->protocolMajorVersion;
	response.json["minor"] = this->protocolMinorVersion;

	if (!message["major"].isInt() || !message["minor"].isInt()) {
		response.action = closeAndSend;
		response.json["accept"] = false;
	} else if (message["major"].asInt() == this->protocolMajorVersion && message["minor"].asInt() <= this->protocolMinorVersion) {
		response.action = send;
		response.json["accept"] = true;
	} else {
		response.action = closeAndSend;
		response.json["accept"] = false;
	}

	return response;
}

JsonCommander::Response JsonCommander::checkLogin(const Json::Value &message) {
	JsonCommander::Response response;

	if (!message["login"].isBool() || !message["user"].isString() || !message["pass"].isString() || !message["cancel"].isBool()) {
		// invalid login request
		response.action = closeAndSend;
		response.json["accept"] = false;
		response.json["error"] = "invalid login request";
	} else if (message["cancel"].asBool()) {
		response.action = close;

	} else if (message["login"].asBool() && UserManager::isAllowed(message["user"].asString(), message["pass"].asString())) {
		// credential check
		response.action = send;
		response.json["accept"] = true;
		response.json["error"] = "";
		currentUser = message["user"].asString();
	} else if (!message["login"].asBool()) {
		// add user. Check if already exists before
		if (!UserManager::addUser(message["user"].asString(), message["pass"].asString())) {
			response.action = closeAndSend;
			response.json["accept"] = false;
			response.json["error"] = "user does already exist";
		} else {
			response.action = send;
			response.json["accept"] = true;
			response.json["error"] = "";
			currentUser = message["user"].asString();
		}
	} else {
		// reject user
		response.action = closeAndSend;
		response.json["accept"] = false;
		response.json["error"] = "wrong username or password";
	}

	return response;
}

JsonCommander::Response JsonCommander::executeDeleteFile(const Json::Value &message) {
	JsonCommander::Response response;
	response.json["command"] = "deletefile";

	if (!message["file"].isString()) {
		response.action = closeAndSend;
		response.json["accept"] = false;
		response.json["error"] = "incorrect deletefile command request";
		response.json["file"] = "";
	} else {
		response.action = send;
		FileManager::Error err = fileManager.deleteFile(message["file"].asString());
		switch (err) {
		case FileManager::Error::no_error:
			response.json["accept"] = true;
			response.json["error"] = "";
			response.json["file"] = message["file"];
			break;
		case FileManager::Error::not_allowed:
			response.json["accept"] = false;
			response.json["error"] = "deleting files is disabled";
			response.json["file"] = message["file"];
			break;
		case FileManager::Error::no_such_file:
			response.json["accept"] = false;
			response.json["error"] = "no such file";
			response.json["file"] = message["file"];
			break;
		default:
			response.action = closeAndSend;
			response.json["accept"] = false;
			response.json["error"] = "internal error. Please fix this!!!";
			response.json["file"] = message["file"];
		}
	}

	return response;
}