import time
import digitalio
import board
import usb_midi
import adafruit_midi
 
from adafruit_midi.note_on import NoteOn
from adafruit_midi.note_off import NoteOff
 

# ============================================================
# KONFIGURATION
# ============================================================
 
# Anzahl der 74HC165 in der Kette
NUM_CHIPS = 6
 
# Anzahl der tatsächlich verwendeten Pedale
NUM_PEDALS = 30
 
# Pin-Belegung Raspberry Pi Pico
PIN_CLK = board.GP14
PIN_PL = board.GP15
PIN_DATA = board.GP16
 
# Entprellzeit
DEBOUNCE_TIME = 0.030
 
# MIDI-Kanal
# 0 = MIDI Kanal 1
# 1 = MIDI Kanal 2
# ...
MIDI_CHANNEL = 0
 
# Anschlagstärke
MIDI_VELOCITY = 100
 

# ============================================================
# MIDI-NOTEN
# ============================================================
#
# Hier wird jedem Pedal eine MIDI-Note zugeordnet.
#
# Beispiel:
# Pedal 0 -> MIDI 36 = C2
# Pedal 1 -> MIDI 37 = Cis2
# usw.
#
# Diese Liste kannst du frei verändern.
#
 
MIDI_NOTES = [
    36,  # Pedal 0
    37,  # Pedal 1
    38,  # Pedal 2
    39,  # Pedal 3
    40,  # Pedal 4
    41,  # Pedal 5
    42,  # Pedal 6
    43,  # Pedal 7
    44,  # Pedal 8
    45,  # Pedal 9
    46,  # Pedal 10
    47,  # Pedal 11
    48,  # Pedal 12
    49,  # Pedal 13
    50,  # Pedal 14
    51,  # Pedal 15
    52,  # Pedal 16
    53,  # Pedal 17
    54,  # Pedal 18
    55,  # Pedal 19
    56,  # Pedal 20
    57,  # Pedal 21
    58,  # Pedal 22
    59,  # Pedal 23
    60,  # Pedal 24
    61,  # Pedal 25
    62,  # Pedal 26
    63,  # Pedal 27
    64,  # Pedal 28
    65,  # Pedal 29
]
 

# ============================================================
# MIDI INITIALISIEREN
# ============================================================
 
midi = adafruit_midi.MIDI(
    midi_out=usb_midi.ports[1],
    out_channel=MIDI_CHANNEL
)
 

# ============================================================
# SCHIEBEREGISTER INITIALISIEREN
# ============================================================
 
clk = digitalio.DigitalInOut(PIN_CLK)
clk.direction = digitalio.Direction.OUTPUT
clk.value = True
 
pl = digitalio.DigitalInOut(PIN_PL)
pl.direction = digitalio.Direction.OUTPUT
pl.value = True
 
data_pin = digitalio.DigitalInOut(PIN_DATA)
data_pin.direction = digitalio.Direction.INPUT
 

# ============================================================
# ZUSTANDSSPEICHER
# ============================================================
 
# Zustand der Reedkontakte
#
# WICHTIG:
# 0 = geschlossen
# 1 = offen
#
# Beim Start wird alles als GESCHLOSSEN angenommen.
#
last_state = [0] * (NUM_CHIPS * 8)
 
last_change_time = [0] * (NUM_CHIPS * 8)
 

# ============================================================
# SCHIEBEREGISTER LESEN
# ============================================================
 
def read_shift_registers():
 
    input_values = []
 
    # Parallel Load
    pl.value = False
    time.sleep(0.000001)
    pl.value = True
 
    # Daten auslesen
    for _ in range(NUM_CHIPS * 8):
 
        bit = data_pin.value
 
        # Reedkontakt:
        #
        # geschlossen -> 0
        # offen       -> 1
        #
        input_values.append(1 if bit else 0)
 
        # Clock
        clk.value = False
        time.sleep(0.000001)
        clk.value = True
 
    return input_values
 

# ============================================================
# MIDI NOTE ON
# ============================================================
 
def midi_note_on(pedal_number):
 
    if pedal_number >= len(MIDI_NOTES):
        return
 
    note = MIDI_NOTES[pedal_number]
 
    midi.send(
        NoteOn(note, MIDI_VELOCITY)
    )
 
    print(
        "Pedal",
        pedal_number,
        "NOTE ON",
        note
    )
 

# ============================================================
# MIDI NOTE OFF
# ============================================================
 
def midi_note_off(pedal_number):
 
    if pedal_number >= len(MIDI_NOTES):
        return
 
    note = MIDI_NOTES[pedal_number]
 
    midi.send(
        NoteOff(note, 0)
    )
 
    print(
        "Pedal",
        pedal_number,
        "NOTE OFF",
        note
    )
 

# ============================================================
# ENTprellung
# ============================================================
 
def get_debounced_state(new_readings):
 
    stable_changes = []
 
    current_time = time.monotonic()
 
    for i in range(len(new_readings)):
 
        old_val = last_state[i]
        new_val = new_readings[i]
 
        # Zustand hat sich verändert
        if old_val != new_val:
 
            if current_time - last_change_time[i] > DEBOUNCE_TIME:
 
                # Neuer Zustand ist stabil
                last_state[i] = new_val
                last_change_time[i] = current_time
 
                stable_changes.append(
                    (i, new_val)
                )
 
        else:
 
            # Zustand unverändert
            last_change_time[i] = current_time
 
    return stable_changes
 

# ============================================================
# START
# ============================================================
 
print()
print("====================================")
print(" Orgelpedal MIDI Controller")
print("====================================")
print("Pedale:", NUM_PEDALS)
print("MIDI Kanal:", MIDI_CHANNEL + 1)
print("Startzustand: alle Reedkontakte geschlossen")
print()
 

# ============================================================
# HAUPTSCHLEIFE
# ============================================================
 
while True:
 
    # --------------------------------------------------------
    # 1. Schieberegister lesen
    # --------------------------------------------------------
 
    raw_data = read_shift_registers()
 

    # --------------------------------------------------------
    # 2. Entprellen
    # --------------------------------------------------------
 
    changes = get_debounced_state(raw_data)
 

    # --------------------------------------------------------
    # 3. Änderungen verarbeiten
    # --------------------------------------------------------
 
    for index, state in changes:
 
        # Nur die tatsächlich vorhandenen Pedale verwenden
        if index >= NUM_PEDALS:
            continue
 
        pedal_number = index
 

        # ----------------------------------------------------
        # Reedkontakt OFFEN
        # -> Pedal gedrückt
        # -> MIDI NOTE ON
        # ----------------------------------------------------
 
        if state == 1:
 
            print(
                "Pedal",
                pedal_number,
                "GEDRÜCKT / Reed OFFEN"
            )
 
            midi_note_on(pedal_number)
 

        # ----------------------------------------------------
        # Reedkontakt GESCHLOSSEN
        # -> Pedal losgelassen
        # -> MIDI NOTE OFF
        # ----------------------------------------------------
 
        else:
 
            print(
                "Pedal",
                pedal_number,
                "LOS GEGEBEN / Reed GESCHLOSSEN"
            )
 
            midi_note_off(pedal_number)
 

    # Kleine Pause
    time.sleep(0.005)