# -*- coding: utf-8 -*-

from machine import Pin, PWM, Timer

import utime


class MorseCodeTransmitter:
    """摩斯码发送器"""

    # 摩斯码本
    MORSECODEBOOK = {
        "A": ".-",
        "B": "-...",
        "C": "-.-.",
        "D": "-..",
        "E": ".",
        "F": "..-.",
        "G": "--.",
        "H": "....",
        "I": "..",
        "J": ".---",
        "K": "-.-",
        "L": ".-..",
        "M": "--",
        "N": "-.",
        "O": "---",
        "P": ".--.",
        "Q": "--.-",
        "R": ".-.",
        "S": "...",
        "T": "-",
        "U": "..-",
        "V": "...-",
        "W": ".--",
        "X": "-..-",
        "Y": "-.--",
        "Z": "--..",
        "0": "-----",
        "1": ".----",
        "2": "..---",
        "3": "...--",
        "4": "....-",
        "5": ".....",
        "6": "-....",
        "7": "--...",
        "8": "---..",
        "9": "----.",
    }

    # 合法字符集
    CHARACTERSALLOWED = set("ABCDEFGHIJKLMNOPQRSTUVWXYZ 0123456789")

    def __init__(self):

        # 单位时距（单位为毫秒）
        self.unit_time_interval = 120

        # 初始化LED
        self.LED = Pin("LED", Pin.OUT, value=0)

    def emit(self, characters: str) -> bool:
        """发送摩斯码"""

        """
        :parma characters: 字符串，数据类型为字符

        """

        # 检查字符串
        if not all(
            character.upper() in self.CHARACTERSALLOWED for character in characters
        ):

            print("allowed: a-z, 0-9, space")

            return False

        # 转为大写
        characters = characters.upper()

        print(f"emitting {characters} ...", end="")

        for character in characters:

            # 单词间隔
            if character == " ":

                utime.sleep_ms(self.unit_time_interval * 7)

                continue

            for code in self.MORSECODEBOOK.get(character):

                # 点亮LED
                self.LED.value(1)

                if code == ".":

                    utime.sleep_ms(self.unit_time_interval * 1)

                else:

                    utime.sleep_ms(self.unit_time_interval * 3)

                # 熄灭LED
                self.LED.value(0)

                # 符号间隔
                utime.sleep_ms(self.unit_time_interval * 1)

            # 字母间隔
            utime.sleep_ms(self.unit_time_interval * 3)

        print("done")

        return True

    def __enter__(self):
        """支持上下文管理"""

        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        """退出"""

        self.LED.off()


if __name__ == "__main__":

    with MorseCodeTransmitter() as transmitter:

        result = transmitter.emit(characters="hello world")