# SPDX-License-Identifier: MIT
#
# Little christmas candle
#
# Author:    Nils Freydank <nils.freydank@datenschutz-ist-voll-doof.de>
# Year:      2022
# Copyright: MIT

import json
import machine
import time

pin_piezo = machine.Pin(12)


def _note_to_freq(note_name: str) -> int:
    """
    Translate note names from strings into frequency values.
    """
    freq: int = 0

    # frequencies, see e.g.
    # https://en.wikipedia.org/wiki/Piano_key_frequencies
    note_names: dict = {
        "c4": 262,
        "cis4": 277,
        "d4": 294,
        "e4": 330,
        "f4": 349,
        "fis4": 370,
        "g4": 392,
        "a4": 440,
        "b4": 466,
        "h4": 494,
        "c5": 523,
        "cis5": 554,
        "d5": 587,
        "e5": 659,
        "f5": 698,
        "fis5": 740,
        "g5": 784,
        "a5": 880,
        "b5": 923,
        "h5": 988,
        "c6": 1047,
    }

    try:
        freq = note_names[note_name]
    except KeyError:
        freq = -1
        print(f"exc in _note_to_freq() for {note_name}.")

    return freq


def _len_to_second(len_name: str, len_scaling: float = 0.6) -> float:
    time: float = 0.0

    len_names = {
        "_t": 0.125 * len_scaling,  # thirty-second note or pause
        "_s": 0.25 * len_scaling,  # sixteenth note or pause
        "_e": 0.5 * len_scaling,  # eight note or pause
        "_q": 1.0 * len_scaling,  # quarter note or pause
        "_h": 2.0 * len_scaling,  # half note or pause
        "_f": 4.0 * len_scaling,  # whole note or pause
    }
    try:
        for elem in len_name.split("+"):
            time += len_names[elem.replace(" ", "")]
    except KeyError:
        time = 0.0
        print(f"exc in _len_to_second() for {elem}.")
        print("Do you have a typo there, e.g. 'a' + 'b' instead of 'a + b'?")

    return time


def play_note(note_name: str, duration: str, loud: bool = False) -> int:
    if loud:
        duty_cycle: int = 16_000
    else:
        duty_cycle: int = 400
    real_pwm_freq: int = 0

    pwm_piezo = machine.PWM(pin_piezo)
    pwm_piezo.freq(_note_to_freq(note_name))
    real_pwm_freq = pwm_piezo.freq()

    pwm_piezo.duty_u16(duty_cycle)

    time.sleep(_len_to_second(duration))
    pwm_piezo.duty_u16(0)
    time.sleep(0.05)

    return real_pwm_freq


def pause(duration: str) -> None:
    time.sleep(_len_to_second(duration))
    time.sleep(0.05)


def play_music(file_name: str = "o-tannenbaum.json") -> None:
    data: dict = {}

    try:
        with open(file_name, "r") as f:
            data = json.load(f)

        try:
            if data["metadata"]["format"] == "json-0.1.0":
                for notes in data["music"]:
                    for note in notes.keys():
                        if note == "0":
                            pause(notes[note])
                        else:
                            play_note(note, notes[note])
            elif data["metadata"]["format"] == "json-0.2.0":
                pass

        except:
            print(f"play_oh_tannnebaum() failed to parse {data}.")

    except FileNotFoundError:
        print("Could not load the JSON file containing the song's details.")


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