/**

 * 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;

}