// Modified from original Python code from here: https://microbit-micropython.readthedocs.io/en/stable/tutorials/network.html

// To create a DOT you need to hold the button for less than 250ms.
const DOT_THRESHOLD = 250;

// To create a DASH you need to hold the button for less than 500ms.
const DASH_THRESHOLD = 500;

var kb = require("ble_hid_keyboard");

// bluetooth initialized marker
var bluettoothInited = false;

// set to true if Button A is currently pressed
var btnAPressed = false;

// contains the time when Button A was pressed
var btnAPressedTime = 0;

// The timeout for the currently entered morse input
var timeOutChar = null;

// A lookup table of morse codes and associated characters.
var morseDict = {
  ".-": "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",
  ".----": "1",
  "..---": "2",
  "...--": "3",
  "....-": "4",
  ".....": "5",
  "-....": "6",
  "--...": "7",
  "---..": "8",
  "----.": "9",
  "-----": "0"
};

// Holds the incoming Morse signals.
var buffer = "";

g = Graphics.createArrayBuffer(5, 5, 1);
g.flip = function() {
  show(this.buffer);
};

// for sound generation
b = [];
for (i = 0; i < 10; i++) {
  b.push(255);
  b.push(0);
}


// if Button A is pressed, plays a short tune repeatedly
function playTune() {
  if (btnAPressed) {
    Microbit.play(b, 4000, playTune);
  }
}

// initialize bluetooth 
function btnPressedInit() {

  // disconnect the BT console (if connected)
  E.setConsole("Serial1");

  if (!bluettoothInited) {
    // bluetooth not yet inited, do it now.
    NRF.setServices(undefined, {
      hid: kb.report
    });
    bluettoothInited = true;
    show("1   1\n" +
      "  1  \n" +
      "  1  \n" +
      "1   1\n" +
      " 111 \n");
  }
}

// Button A was pressesd
function btnPressed() {

  if (timeOutChar) {
    clearTimeout(timeOutChar);
  }

  btnAPressed = true;
  btnAPressedTime = new Date().getTime();
  playTune();
}

// Button A was released
function btnReleased() {
  btnAPressed = false;
  handleMorseReleased();
}

// Button was released.
function handleMorseReleased() {

  if (timeOutChar) {
    clearTimeout(timeOutChar);
  }
  if (!btnAPressedTime) {
    return;
  }

  // Get the current time
  var btnAReleasedTime = new Date().getTime();

  // work out for how long it was pressed.
  var duration = btnAReleasedTime - btnAPressedTime;

  if (duration < DOT_THRESHOLD) {
    // If the duration is less than the max length for a "dot" press...
    // ... then add a dot to the buffer containing incoming Morse codes
    // and display a dot on the display.
    buffer += '.';
    show("     \n" +
      "     \n" +
      "  1  \n" +
      "     \n" +
      "     \n");
  } else if (duration < DASH_THRESHOLD) {
    // Else, if the duration is less than the max length for a "dash"
    // ress... (but longer than that for a DOT ~ handled above)
    // then add a dash to the buffer and display a dash.
    buffer += '-';
    show("     \n" +
      "     \n" +
      " 111 \n" +
      "     \n" +
      "     \n");
  } else {
    //Otherwise, any other sort of keypress duration is ignored (this isn't
    // needed, but added for "understandability").
  }
  timeOutChar = setTimeout(handleCharEnd, DASH_THRESHOLD);
}

// called when a button was released longer than DASH_THRESHOLD ago. End current morse character
function handleCharEnd() {
  btnAPressedTime = 0;
  var character = morseDict[buffer];
  if (character) {
    // draw character
    g.clear();
    g.drawString(character, 0);
    g.flip();
    // send keycode via bluetooth
    var keycode = kb.KEY[character];
    if (keycode) {
      try {
        kb.tap(keycode, 0);
      } catch (eror) {
        show("1   1\n" +
          "  1  \n" +
          "  1  \n" +
          " 111 \n" +
          "1   1\n");
      }
    }
  } else {
    // draw a ?
    g.clear();
    g.drawString("?", 0);
    g.flip();
  }
  buffer = "";
}


// trigger btnPressed whenever the button 1 is pressed
setWatch(btnPressed, BTN1, {
  edge: "rising",
  repeat: true,
  debounce: 50
});
// trigger btnReleased whenever the button 1 is released
setWatch(btnReleased, BTN1, {
  edge: "falling",
  repeat: true,
  debounce: 10
});
// trigger btnPressedInit whenever the button 2 is pressed
setWatch(btnPressedInit, BTN2, {
  edge: "rising",
  repeat: true,
  debounce: 50
});