monitor.hpp

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/**
 * @file monitor.hpp
 * @brief MIDI event monitor — tagged output formatter
 *
 * Formats MidiEvent structs as tagged output lines per the SBL tagged
 * output convention (#TAG key=value). Gated behind SBL_MIDI_MONITOR.
 *
 * Output examples:
 *   #MIDI ch=1 type=note_on num=60 vel=100
 *   #MIDI ch=1 type=cc num=74 val=127
 *   #MIDI ch=1 type=pb val=8192
 *   #MIDI type=clock
 *
 * Usage:
 *   void midi_callback(const sbl::midi::MidiEvent& event) {
 *       #ifdef SBL_MIDI_MONITOR
 *       char buf[64];
 *       sbl::midi::format_event(buf, sizeof(buf), event);
 *       log_write(buf);
 *       #endif
 *       // ... application handling ...
 *   }
 */
#pragma once
 
#ifdef SBL_MIDI_MONITOR
 
#include <cstddef>
#include <sbl/midi/types.hpp>
#include <sbl/log/format.hpp>
 
namespace sbl::midi {
 
/// Format a MidiEvent as a tagged output line.
/// Returns number of characters written (excluding null terminator).
inline int format_event(char* buf, size_t size, const MidiEvent& e) {
    uint8_t ch = e.channel + 1;  // Convention: 1-indexed
 
    switch (e.type) {
    case MessageType::NoteOn:
        return log::format(buf, size, "#MIDI ch=%u type=note_on num=%u vel=%u\r\n",
                           ch, e.note(), e.velocity());
    case MessageType::NoteOff:
        return log::format(buf, size, "#MIDI ch=%u type=note_off num=%u vel=%u\r\n",
                           ch, e.note(), e.velocity());
    case MessageType::ControlChange:
        return log::format(buf, size, "#MIDI ch=%u type=cc num=%u val=%u\r\n",
                           ch, e.cc_number(), e.cc_value());
    case MessageType::PitchBend:
        return log::format(buf, size, "#MIDI ch=%u type=pb val=%u\r\n",
                           ch, e.pitch_bend_raw());
    case MessageType::ProgramChange:
        return log::format(buf, size, "#MIDI ch=%u type=pc val=%u\r\n",
                           ch, e.data1);
    case MessageType::ChannelPressure:
        return log::format(buf, size, "#MIDI ch=%u type=cp val=%u\r\n",
                           ch, e.data1);
    case MessageType::PolyPressure:
        return log::format(buf, size, "#MIDI ch=%u type=pp num=%u val=%u\r\n",
                           ch, e.data1, e.data2);
 
    // System Real-Time (no channel)
    case MessageType::Clock:
        return log::format(buf, size, "#MIDI type=clock\r\n");
    case MessageType::Start:
        return log::format(buf, size, "#MIDI type=start\r\n");
    case MessageType::Continue:
        return log::format(buf, size, "#MIDI type=continue\r\n");
    case MessageType::Stop:
        return log::format(buf, size, "#MIDI type=stop\r\n");
    case MessageType::ActiveSensing:
        return log::format(buf, size, "#MIDI type=active_sensing\r\n");
    case MessageType::SystemReset:
        return log::format(buf, size, "#MIDI type=system_reset\r\n");
 
    // System Common
    case MessageType::SongPosition:
        return log::format(buf, size, "#MIDI type=song_pos val=%u\r\n",
                           (static_cast<uint16_t>(e.data2) << 7) | e.data1);
    case MessageType::SongSelect:
        return log::format(buf, size, "#MIDI type=song_sel val=%u\r\n", e.data1);
    case MessageType::TuneRequest:
        return log::format(buf, size, "#MIDI type=tune_req\r\n");
 
    default:
        return 0;
    }
}
 
} // namespace sbl::midi
 
#endif // SBL_MIDI_MONITOR