/**

  * SysEx message encoder for Roland MT-32

  * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 3 of the License.

  *

  * 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 General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. If not, see <http://www.gnu.org/licenses/>.

  */

 #include <iostream>

 #include <iomanip>

 /**

  * Translates text from standard input to a hex-formatted System Exclusive (SysEx) message for Roland MT-32,

  * which instructs the unit to show given text on the display.

  * 

  * Roland MT-32 is capable to display 20 characters.

  * Longer messages are silently truncated by the MT-32 unit (this software does not check the length).

  * 

  * The SysEx message contains a checksum.

  * If the checksum is wrong, the MT-32 unit shows the "Exc. Checksum error" message for few seconds

  * and then returns back to the default screen.

  * 

  * Only printable ASCII characters are supported. Other characters (bytes) are replaced by "."

  * 

  * Some characters are displayed differently:

  *   ASCII   MT-32

  *       ~   →

  *       \   ¥

  * 

  * Usage examples:

  *     amidi --port="hw:2,0,0" --send-hex="$(echo -n '   Run GNU/Linux    ' | ./mt-32-display )"

  *     while read message; do amidi --port="hw:2,0,0" --send-hex="$(echo -n "$message" | ./mt-32-display )"; done

  * 

  * @param argc

  * @param argv

  * @return 

  */

 int main(int argc, char**argv) {

 	std::cout << "f0 41 10 16 12 20 00 00 ";

 	// f0 = start of SysEx message

 	// 41 = Roland manufacturer ID, see https://www.midi.org/specifications-old/item/manufacturer-id-numbers

 	// 10 = device ID

 	// 16 = model ID

 	// 12 = command ID

 	// 20 00 00 = show message on the display

 	// The start and end of the SysEx message and the manufacturer ID are part of the MIDI standard.

 	// The rest of the bytes is Roland specific.

 	// TODO: allow changing device ID to support controlling multiple devices in daisy-chain

 	// TODO: allow custom replacement character ('.')

 	std::cout << std::hex << std::setfill('0');

 	int sum = 0;

 	// 20 00 00 = display message

 	sum += 0x20;

 	sum += 0x00;

 	sum += 0x00;

 	for (char ch; std::cin.read(&ch, 1).good();) {

 		if (ch < 32 || ch > 126) ch = '.';

 		std::cout << std::setw(2) << ((int) ch) << " ";

 		sum += ch;

 	}

 	sum %= 128;

 	sum = 128 - sum;

 	std::cout << std::setw(2) << sum;

 	std::cout << " f7";

 	// f7 = end of SysEx message

 	std::cout << std::endl;

 	return 0;

 }