franta-hg@18: /**
franta-hg@18:  * djm-fix
franta-hg@18:  * Copyright © 2025 František Kučera (Frantovo.cz, GlobalCode.info)
franta-hg@18:  *
franta-hg@18:  * This program is free software: you can redistribute it and/or modify
franta-hg@18:  * it under the terms of the GNU General Public License as published by
franta-hg@18:  * the Free Software Foundation, version 3 of the License.
franta-hg@18:  *
franta-hg@18:  * This program is distributed in the hope that it will be useful,
franta-hg@18:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
franta-hg@18:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
franta-hg@18:  * GNU General Public License for more details.
franta-hg@18:  *
franta-hg@18:  * You should have received a copy of the GNU General Public License
franta-hg@18:  * along with this program. If not, see <http://www.gnu.org/licenses/>.
franta-hg@18:  */
franta-hg@18: 
franta-hg@18: #include <iostream>
franta-hg@18: #include <iomanip>
franta-hg@18: 
franta-hg@18: #include "MessageCodec.h"
franta-hg@18: 
franta-hg@18: Message MessageCodec::decode(std::vector<uint8_t> data) {
franta-hg@18: 	using ERR = std::invalid_argument;
franta-hg@18: 
franta-hg@18: 	if (data.empty() || data.front() != 0xf0 || data.back() != 0xf7)
franta-hg@18: 		throw ERR("not a MIDI SysEx message");
franta-hg@18: 
franta-hg@18: 	// Manufacturer MIDI SysEx ID Numbers:
franta-hg@18: 	//   00H 40H 05H = AlphaTheta Corporation
franta-hg@18: 	//   00H 40H 06H = Pioneer Corporation
franta-hg@18: 	if (data.size() < 4
franta-hg@18: 			|| data[1] != 0x00
franta-hg@18: 			|| data[2] != 0x40
franta-hg@18: 			|| data[3] != 0x05)
franta-hg@18: 		throw ERR("wrong message Manufacturer MIDI SysEx ID");
franta-hg@18: 
franta-hg@19: 	if (data.size() < 8) throw ERR("missing model");
franta-hg@18: 
franta-hg@19: 	uint8_t model = data[7];
franta-hg@18: 
franta-hg@18: 	if (data.size() < 10) throw ERR("missing message type");
franta-hg@18: 
franta-hg@18: 	MessageType msgType;
franta-hg@18: 	if /**/ (data[9] == 0x11) msgType = MessageType::D11_GREETING;
franta-hg@18: 	else if (data[9] == 0x12) msgType = MessageType::H12_SEED1;
franta-hg@18: 	else if (data[9] == 0x13) msgType = MessageType::D13_HASH1_SEED2;
franta-hg@18: 	else if (data[9] == 0x14) msgType = MessageType::H14_HASH2;
franta-hg@18: 	else if (data[9] == 0x15) msgType = MessageType::D15_CONFIRMATION;
franta-hg@18: 	else throw ERR("unsupported message type");
franta-hg@18: 
franta-hg@18: 	if (data.size() < 11) throw ERR("missing message length");
franta-hg@18: 	if (data[10] != data.size() - 10) throw ERR("wrong message length");
franta-hg@18: 
franta-hg@18: 	std::vector<Field> fields;
franta-hg@18: 
franta-hg@18: 	for (size_t start = 11; data.size() > start + 1;) {
franta-hg@18: 		FieldType fieldType;
franta-hg@18: 		if /**/ (data[start] == 0x01) fieldType = FieldType::F01;
franta-hg@18: 		else if (data[start] == 0x02) fieldType = FieldType::F02;
franta-hg@18: 		else if (data[start] == 0x03) fieldType = FieldType::F03;
franta-hg@18: 		else if (data[start] == 0x04) fieldType = FieldType::F04;
franta-hg@18: 		else if (data[start] == 0x05) fieldType = FieldType::F05;
franta-hg@18: 		else throw ERR("unsupported field type");
franta-hg@18: 
franta-hg@18: 		size_t fieldSize = data[start + 1];
franta-hg@18: 
franta-hg@18: 		if (data.size() < start + fieldSize + 1) throw ERR("field overflow");
franta-hg@18: 		//                                    ^ 0xf7 messsage end
franta-hg@18: 
franta-hg@18: 		std::vector<uint8_t> fieldData(
franta-hg@18: 				data.begin() + start + 2,
franta-hg@18: 				data.begin() + start + fieldSize);
franta-hg@18: 
franta-hg@18: 		fields.push_back({fieldType, fieldData});
franta-hg@18: 
franta-hg@18: 		start += fieldSize;
franta-hg@18: 	}
franta-hg@18: 
franta-hg@19: 	return Message(msgType, model, fields);
franta-hg@18: }
franta-hg@18: 
franta-hg@18: std::vector<uint8_t> MessageCodec::encode(Message msg) {
franta-hg@18: 	using ERR = std::invalid_argument;
franta-hg@18: 
franta-hg@18: 	std::vector<uint8_t> data;
franta-hg@18: 
franta-hg@18: 	data.push_back(0xf0);
franta-hg@18: 
franta-hg@18: 	data.push_back(0x00);
franta-hg@18: 	data.push_back(0x40);
franta-hg@18: 	data.push_back(0x05);
franta-hg@18: 
franta-hg@18: 	data.push_back(0x00);
franta-hg@18: 	data.push_back(0x00);
franta-hg@18: 	data.push_back(0x00);
franta-hg@18: 
franta-hg@19: 	data.push_back(msg.model);
franta-hg@18: 	data.push_back(0x00);
franta-hg@18: 	data.push_back((uint8_t) msg.type);
franta-hg@18: 
franta-hg@18: 	uint8_t msgLength = 2; // 2 = type + lenght
franta-hg@18: 	for (const auto& field : msg.fields) msgLength += field.data.size() + 2;
franta-hg@18: 
franta-hg@18: 	data.push_back(msgLength);
franta-hg@18: 
franta-hg@18: 	for (const auto& field : msg.fields) {
franta-hg@18: 		size_t fieldSize = field.data.size() + 2;
franta-hg@18: 		if (fieldSize > 256) throw ERR("message field too long");
franta-hg@18: 		data.push_back((uint8_t) field.type);
franta-hg@18: 		data.push_back((uint8_t) (fieldSize));
franta-hg@18: 		data.insert(data.end(), field.data.begin(), field.data.end());
franta-hg@18: 	}
franta-hg@18: 
franta-hg@18: 	data.push_back(0xf7);
franta-hg@18: 
franta-hg@18: 	return data;
franta-hg@18: }