from machine import Pin, PWM
import time
from lcd import LCD

import apple
import mii

# lcd
lcd = LCD(rs=23, e=19, d4=26, d5=25, d6=33, d7=32)

# buzzer
buzzer = PWM(Pin(22))
buzzer.duty_u16(0)

# buttons
btn1 = Pin(12, Pin.IN, Pin.PULL_UP)
btn2 = Pin(14, Pin.IN, Pin.PULL_UP)

# state
song = 1
playing = False

note_index = 0
last_time = 0
in_gap = False

def get_song():
    if song == 1:
        return apple.melody, apple.notes, apple.wholenote
    else:
        return mii.melody, mii.notes, mii.wholenote

def play_note(freq):
    if freq == 0:
        buzzer.duty_u16(0)
    else:
        buzzer.freq(freq)
        buzzer.duty_u16(30000)

def stop():
    buzzer.duty_u16(0)

def show():
    lcd.clear()
    lcd.write("BAD APPLE" if song == 1 else "MII THEME")
    lcd._send(0xC0, 0)
    lcd.write("PLAYING" if playing else "PAUSED")


btn1_prev = 1
btn2_prev = 1

show()

while True:
    now = time.ticks_ms()

    b1 = btn1.value()
    b2 = btn2.value()

    # play > / pause II
    if btn1_prev == 1 and b1 == 0:
        playing = not playing
        show()

    # switch song
    if btn2_prev == 1 and b2 == 0:
        song = 2 if song == 1 else 1
        playing = False
        stop()
        note_index = 0
        show()

    btn1_prev = b1
    btn2_prev = b2

    # music engine
    if playing:
        melody, notes, wholenote = get_song()

        if note_index >= len(melody):
            note_index = 0

        note = melody[note_index]
        duration_type = notes[note_index]

        if duration_type > 0:
            note_duration = wholenote / duration_type
        else:
            note_duration = (wholenote / abs(duration_type)) * 1.5

        elapsed = time.ticks_diff(now, last_time)

        if not in_gap:
            if elapsed >= note_duration * 0.9:
                stop()
                in_gap = True
        else:
            if elapsed >= note_duration:
                note_index += 1
                last_time = now
                in_gap = False

                if note != 0:
                    play_note(note)
                else:
                    stop()

    else:
        last_time = now

    time.sleep_ms(5)