midi_monitor.py

''' Asynchronous MIDI monitor based on the `log.Log` class

    Copyright (c) 2025 Harm Lammers
    
    MIT licence:

    Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the
    "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish,
    distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to
    the following conditions:

    The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
'''

import micropython
import builtins

from singleton import singleton
from log import Log

_NOTES            = b'C#D#EF#G#A#B' # used for translating MIDI note number to note string

_OUT_LEN_LONG     = const(34) # length of long MIDI monitor string
_OUT_LEN_SHORT    = const(25) # maximum length of short MIDI monitor string

# String indices of the different elements of a MIDI monitor string
_PRE_0_POS        = const(0)
_PRE_0_VAL_POS_0  = const(1)
_PRE_0_VAL_POS_1  = const(2)
_TXT_POS_1_PRE    = const(4)
_PRE_1_POS        = const(4)
_PRE_1_VAL_POS_0  = const(5)
_PRE_1_VAL_POS_1  = const(6)
_PRE_1_SP_POS     = const(7)
_TXT_POS_2_PRE    = const(8)
_BYTE_NOTE_POS    = const(17)
_BYTE_1_POS_0     = const(18)
_BYTE_1_POS_1     = const(19)
_BYTE_1_POS_2     = const(20)
_BYTE_2_POS_0     = const(22)
_BYTE_2_POS_1     = const(23)
_BYTE_2_POS_2     = const(24)
_WORD_POS_0       = const(20)
_WORD_POS_1       = const(21)
_WORD_POS_2       = const(22)
_WORD_POS_3       = const(23)
_WORD_POS_4       = const(24)
_WORD_POS_SIGN    = const(19) # position before sign
_HEX_OPEN_POS     = const(26)
_HEX_BYTE_0_POS_0 = const(27)
_HEX_BYTE_0_POS_1 = const(28)
_HEX_BYTE_1_POS_0 = const(29)
_HEX_BYTE_1_POS_1 = const(30)
_HEX_BYTE_2_POS_0 = const(31)
_HEX_BYTE_2_POS_1 = const(32)
_HEX_CLOSE_POS    = const(33)

# Constants needed to find the right slices of _TEXT_DEFS
_NUM_SHORT_ROWS   = const(7)
_SHORT_STR_LEN    = const(17)
_SHORT_ROW_LEN    = const(18)
_LONG_STR_LEN     = const(21)
_LONG_ROW_LEN     = const(22)

# Types of data byte(s) used by MIDI messages (the order of _TYP_* constant enumeration is critical!)
_TYP_NOTE_BYTE    = const(0)
_TYP_BYTE_BYTE    = const(1)
_TYP_BYTE         = const(2)
_TYP_WORD         = const(3)
_TYP_WORD_PB      = const(4)
# _TYP_NONE         = const(5)

# The following bytes object lists for each type of command the monitor base string followed by a byte indicating the type of data byte(s)
# Included types:
# 0x8n  Note Off             _TYP_NOTE_BYTE
# 0x9n  Note On              _TYP_NOTE_BYTE
# 0xAn  Polyphonic Pressure  _TYP_NOTE_BYTE
# 0xBn  Control Change       _TYP_BYTE_BYTE
# 0xCn  Program Change       _TYP_BYTE
# 0xDn  Channel Pressure     _TYP_BYTE
# 0xEn  Pitch Bend           _TYP_WORD_PB
# 0xF0  SysEx Start          _TYP_NONE
# 0xF1  MTC Quarter Frame    _TYP_BYTE      (not decoded)
# 0xF2  Song Pointer         _TYP_WORD
# 0xF3  Song Select          _TYP_BYTE
# 0xF6  Tune Request         _TYP_NONE
# 0xF7  End of SysEx         _TYP_NONE
# 0xF8  Timing Clock         _TYP_NONE
# 0xFA  Start                _TYP_NONE
# 0xFB  Continue             _TYP_NONE
# 0xFC  Stop                 _TYP_NONE
# 0xFE  Active Sensing       _TYP_NONE
# 0xFF  System Reset         _TYP_NONE
_TEXT_DEFS = b''\
b'Note Off         \x00'\
b'Note On          \x00'\
b'PolyPres         \x00'\
b'CtrlChnge        \x01'\
b'ProgChnge        \x02'\
b'ChanPres         \x02'\
b'PitchBend        \x04'\
b'SysEx Start          \x05'\
b'MTC Qtr Frme         \x02'\
b'Song Pos Ptr         \x03'\
b'Song Select          \x02'\
b'Tune Request         \x05'\
b'End of SysEx         \x05'\
b'Timing Clock         \x05'\
b'Start                \x05'\
b'Continue             \x05'\
b'Stop                 \x05'\
b'Active Sensng        \x05'\
b'System Reset         \x05'\

@singleton
class MidiMonitor:
    ''' Singleton MIDI monitor which uses the `log.Log` singleton class to log MIDI messages

    Args:
        long (bool): If `True` include HEX representation of the message; defaults to `True`
    '''
    def __init__(self, long: bool = True) -> None:
        self.long = long
        self.buf_len = (buf_len := _OUT_LEN_LONG if long else _OUT_LEN_SHORT)
        self._buf = (buf := bytearray(buf_len))
        buf[:] = b' ' * buf_len
        self._log = Log()

    @micropython.viper
    def write(self, port_id: int, byte_0: int, byte_1: int, byte_2: int):
        ''' Generate MIDI monitor string and send to logger; do not use for SysEx data bytes

        Args:
            port_id (int): Port number
            byte_0 (int): First byte of the MIDI message
            byte_1 (int): Second byte of the MIDI message
            byte_2 (int): Third byte of the MIDI message
        '''
        DEFS = ptr8(_TEXT_DEFS) # pyright: ignore[reportUndefinedVariable]
        buf_obj = self._buf
        buf = ptr8(buf_obj) # pyright: ignore[reportUndefinedVariable]
        # Port prefix
        buf[_PRE_0_POS] = 80 # ‘P’
        rem = port_id
        quot = rem // 10 if port_id >= 10 else 0
        buf[_PRE_0_VAL_POS_0] = 48 + quot
        rem -= quot * 10
        buf[_PRE_0_VAL_POS_1] = 48 + rem
        if byte_0 < 0xF0: # Channel Voice message or Channel Common message: abort (invalid SysEx data)
            # Channel prefix
            buf[_PRE_1_POS] = 67 # ‘C’
            byte = byte_0 & 0x0F
            rem = byte
            quot = rem // 10 if byte >= 10 else 0
            buf[_PRE_1_VAL_POS_0] = 48 + quot
            rem -= quot * 10
            buf[_PRE_1_VAL_POS_1] = 48 + rem
            buf[_PRE_1_SP_POS] = 32 # space
            # get definitions
            cmd = byte_0 & 0xF0
            txt_pos = (cmd >> 4) - 8
            if txt_pos < 0: return
            txt_pos *= _SHORT_ROW_LEN
            txt_len = _SHORT_STR_LEN
            type = DEFS[txt_pos + _SHORT_STR_LEN]
            pos = _TXT_POS_2_PRE
        else: # System Common message or System Real-Time message
            # Get definitions
            txt_pos = byte_0 & 0x0F
            if 4 <= txt_pos <= 5 or txt_pos == 9 or txt_pos == 0xD:
                return
            if txt_pos > 5:
                txt_pos -= 2
            if txt_pos > 7: # 9 - 2
                txt_pos -= 1
            if txt_pos > 0xA: # 0xD - 2 - 1
                txt_pos -= 1
            txt_pos *= _LONG_ROW_LEN
            txt_pos += _NUM_SHORT_ROWS * _SHORT_ROW_LEN
            txt_len = _LONG_STR_LEN
            type = DEFS[txt_pos + _LONG_STR_LEN]
            pos = _TXT_POS_1_PRE
        # Text label
        for i in range(txt_len):
            buf[pos + i] = DEFS[txt_pos + i]
        # First data value
        if type == _TYP_NOTE_BYTE:
            octave = byte_1 // 12
            octave -= 1
            pos = _BYTE_NOTE_POS + 1 if 0 <= octave <= 9 else _BYTE_NOTE_POS
            note_pos = byte_1 % 12
            notes = ptr8(_NOTES) # pyright: ignore[reportUndefinedVariable]
            if notes[note_pos] == 35: # ‘#’
                buf[pos] = notes[note_pos - 1]
                pos += 1
                buf[pos] = 35 # ‘#’
            else:
                pos += 1
                buf[pos] = notes[note_pos]
            pos += 1
            if octave < 0:
                buf[pos] = 45  # ‘-’
                pos += 1
                octave = -octave
            buf[pos] = 48 + octave
        elif type == _TYP_BYTE_BYTE:
            rem = byte_1
            if byte_1 >= 100:
                quot = rem // 100
                buf[_BYTE_1_POS_0] = 48 + quot
                rem -= quot * 100
            if byte_1 >= 10:
                quot = rem // 10
                buf[_BYTE_1_POS_1] = 48 + quot
                rem -= quot * 10
            buf[_BYTE_1_POS_2] = 48 + rem
        elif type == _TYP_BYTE:
            rem = byte_1
            if byte_1>= 100:
                quot = rem // 100
                buf[_BYTE_2_POS_0] = 48 + quot
                rem -= quot * 100
            if byte_1 >= 10:
                quot = rem // 10
                buf[_BYTE_2_POS_1] = 48 + quot
                rem -= quot * 10
            buf[_BYTE_2_POS_2] = 48 + rem
        # Second data value
        if type <= _TYP_BYTE_BYTE:
            rem = byte_2
            if byte_2 >= 100:
                quot = rem // 100
                buf[_BYTE_2_POS_0] = 48 + quot
                rem -= quot * 100
            if byte_2 >= 10:
                quot = rem // 10
                buf[_BYTE_2_POS_1] = 48 + quot
                rem -= quot * 10
            buf[_BYTE_2_POS_2] = 48 + rem
        elif type == _TYP_WORD:
            word = ((byte_2 << 7) | byte_1)
            rem = word
            if word >= 10000:
                quot = rem // 10000
                buf[_WORD_POS_0] = 48 + quot
                rem -= quot * 10000
            if word >= 1000:
                quot = rem // 1000
                buf[_WORD_POS_1] = 48 + quot
                rem -= quot * 1000
            if word >= 100:
                quot = rem // 100
                buf[_WORD_POS_2] = 48 + quot
                rem -= quot * 100
            if word >= 10:
                quot = rem // 10
                buf[_WORD_POS_3] = 48 + quot
                rem -= quot * 10
            buf[_WORD_POS_4] = 48 + rem
        elif type == _TYP_WORD_PB:
            word = ((byte_2 << 7) | byte_1) - 0x2000
            neg = word < 0
            if word < 0: word = -word
            rem = word
            first_pos = 0
            if word >= 1000:
                quot = rem // 1000
                buf[_WORD_POS_1] = 48 + quot
                rem -= quot * 1000
                first_pos = 1
            if word >= 100:
                quot = rem // 100
                buf[_WORD_POS_2] = 48 + quot
                rem -= quot * 100
                if not first_pos: first_pos = 2
            if word >= 10:
                quot = rem // 10
                buf[_WORD_POS_3] = 48 + quot
                rem -= quot * 10
                if not first_pos: first_pos = 3
            buf[_WORD_POS_4] = 48 + rem
            if not first_pos: first_pos = 4
            if neg:
                buf[_WORD_POS_SIGN + first_pos] = 45  # ‘-’
            elif word > 0:
                buf[_WORD_POS_SIGN + first_pos] = 43  # ‘+’
        _log = self._log
        if self.long:
        # HEX message
            buf[_HEX_OPEN_POS] = 0x5B # ‘[’
            quot = (byte_0 >> 4) & 0xF
            buf[_HEX_BYTE_0_POS_0] = 48 + quot if quot < 10 else 55 + quot
            quot = byte_0 & 0xF
            buf[_HEX_BYTE_0_POS_1] = 48 + quot if quot < 10 else 55 + quot
            quot = (byte_1 >> 4) & 0xF
            buf[_HEX_BYTE_1_POS_0] = 48 + quot if quot < 10 else 55 + quot
            quot = byte_1 & 0xF
            buf[_HEX_BYTE_1_POS_1] = 48 + quot if quot < 10 else 55 + quot
            quot = (byte_2 >> 4) & 0xF
            buf[_HEX_BYTE_2_POS_0] = 48 + quot if quot < 10 else 55 + quot
            quot = byte_2 & 0xF
            buf[_HEX_BYTE_2_POS_1] = 48 + quot if quot < 10 else 55 + quot
            buf[_HEX_CLOSE_POS] = 0x5D # ‘]’
            _log.write(buf_obj)
            return
        for i in range(_OUT_LEN_SHORT - 1, 0, -1):
            if buf[i] != 32: # space
                n = i + 1
                break
        _log.write(buf_obj[builtins.int(0):builtins.int(n)])