import ws281x from 'rpi-ws281x';
import * as fs from 'fs';
import Logger, { levels } from './logger.js';

const cfg = JSON.parse(fs.readFileSync('./config.json'));
const log = new Logger("lights", cfg.log_level ? levels[cfg.log_level] : levels.INFO);

const fade_ticks = cfg.fade_ticks || 20;
var pixels = new Uint32Array(cfg.leds);
var pixel_cache = new Uint32Array(cfg.leds);
var next_pattern = new Uint32Array(cfg.leds);
const targets = {}
var pattern = {}

function rgb_to_int(r, g, b) {
  let rgb = r;
  rgb = (rgb << 8) + g;
  rgb = (rgb << 8) + b;
  return rgb;
}
function int_to_rgb(int) {
  var r = (int >> 16) & 0xFF;
  var g = (int >> 8) & 0xFF;
  var b = (int) & 0xFF;
  return { r: r, g: g, b: b };
}

ws281x.configure({
  leds: cfg.leds || 300,
  brightness: cfg.brightness || 200,
  gpio: cfg.gpio || 18,
  stripType: cfg.type || 'grb'
});

export function set_pattern(pat) {
  log.debug("pattern set");
  pattern = pat;
}

export const functions = {
  random: (index, args, prev) => { return Math.floor(Math.random() * 256) },
  constant: (index, args, prev) => { return args; },
  modulo: (index, args, prev) => { return prev % args; },
  move: (index, args, prev) => { targets[args] = prev; return prev; },
  swap: (index, args, prev) => { let temp = targets[args]; targets[args] = prev; return temp; },
  add: (index, args, prev) => { return prev + args; },
  subtract: (index, args, prev) => { return prev - args; }
}

function tick_pattern() {
  // do the parsing stuff here
  log.debug("TICKING PATTERN")

  if (Object.keys(pattern).length > 0) {
    for (let i = 0; i < cfg.leds; i++) {
      for (let command of pattern) {
        if (command.valid) {
          let instruction = command.instruction;
          let name = instruction.name.toLowerCase();
          if (functions[name]) {
            for (let target of instruction.args) {
              let channel = target.channel;
              if (!targets[channel]) {
                targets[channel] = 0;
              }
              log.debug("targets " + name + " " + channel + " " + target.arg);
              targets[channel] =
                functions[name](i, target.arg, targets[channel]);
            }
          }
        }
      }

      log.debug(`next: ${targets["r"]}, ${targets["g"]}, ${targets["b"]}`);
      next_pattern[i] = rgb_to_int(targets["r"] || 0, targets["g"] || 0, targets["b"] || 0);
      targets["r"] = 0; targets["g"] = 0; targets["b"] = 0;
    }
  }
  else {
    getRandom()
  }
}

function getRandom() {
  for (let i = 0; i < cfg.leds; i++) {
    var r = Math.floor(Math.random() * 256)
    var g = Math.floor(Math.random() * 256);
    var b = Math.floor(Math.random() * 256);
    next_pattern[i] = rgb_to_int(r, g, b);
  }
}

export function tick() {
  var changed = false;
  for (let i = 0; i < cfg.leds; i++) {
    if (next_pattern[i] != pixels[i]) {
      if (next_pattern[i] == pixel_cache[i]) {
        log.debug("INCONGRUENCE WITH " + i);
        pixels[i] = next_pattern[i];
      }
      else {
        changed = true;
        fade(i);
      }
    }
    else if (pixel_cache[i] != pixels[i]) {
      log.debug("PATTERN NOT STORED " + i);
      pixel_cache[i] = pixels[i];
    }
  }
  if (!changed) {
    tick_pattern();
  }
  else {
    ws281x.render(pixels);
  }
  //ws281x.sleep(cfg.sleep_time || 500);
}

function fade(index) {
  var original = int_to_rgb(pixel_cache[index]);
  var current = int_to_rgb(pixels[index]);
  var final = int_to_rgb(next_pattern[index]);
  var diff_r = final.r - original.r;
  var diff_cr = current.r - original.r;
  var diff_g = final.g - original.g;
  var diff_cg = current.g - original.g;
  var diff_b = final.b - original.b;
  var diff_cb = current.b - original.b;
  var sign_r = diff_r === Math.abs(diff_r) ? 1 : -1;
  var sign_g = diff_g === Math.abs(diff_g) ? 1 : -1;
  var sign_b = diff_b === Math.abs(diff_b) ? 1 : -1;
  log.debug(`${diff_r} ${sign_r} ${diff_g} ${sign_g} ${diff_b} ${sign_b}`);
  var interval_r = sign_r * Math.ceil(Math.abs(diff_r) / fade_ticks);
  var interval_g = sign_g * Math.ceil(Math.abs(diff_g) / fade_ticks);
  var interval_b = sign_b * Math.ceil(Math.abs(diff_b) / fade_ticks);
  log.debug(`r${Math.abs(diff_r) / fade_ticks} ${Math.ceil(Math.abs(diff_r) / fade_ticks)}` +
    `g${Math.abs(diff_g) / fade_ticks} ${Math.ceil(Math.abs(diff_g) / fade_ticks)}` +
    `b${Math.abs(diff_b) / fade_ticks} ${Math.ceil(Math.abs(diff_b) / fade_ticks)}`);

  var current_tick_r = Math.floor(Math.abs(diff_cr / diff_r) * fade_ticks);
  var current_tick_g = Math.floor(Math.abs(diff_cg / diff_g) * fade_ticks);
  var current_tick_b = Math.floor(Math.abs(diff_cb / diff_b) * fade_ticks);
  if (diff_r == 0 ||
    (sign_r == 1 && current.r + interval_r >= final.r) ||
    (sign_r == -1 && current.r + interval_r <= final.r) ||
    current_tick_r + 1 >= fade_ticks) {
    current.r = final.r;
    interval_r = 0;
    current_tick_r = fade_ticks;
  }
  if (diff_g == 0 ||
    (sign_g == 1 && current.g + interval_g >= final.g) ||
    (sign_g == -1 && current.g + interval_g <= final.g) ||
    current_tick_g + 1 >= fade_ticks) {
    current.g = final.g;
    interval_g = 0;
    current_tick_g = fade_ticks;
  }
  if (diff_b == 0 ||
    (sign_b == 1 && current.b + interval_b >= final.b) ||
    (sign_b == -1 && current.b + interval_b <= final.b) ||
    current_tick_b + 1 >= fade_ticks) {
    current.b = final.b;
    interval_b = 0;
    current_tick_b = fade_ticks;
  }

  if (current_tick_r + 1 >= fade_ticks &&
    current_tick_g + 1 >= fade_ticks &&
    current_tick_b + 1 >= fade_ticks) {
    log.debug("FINISHED");
    pixel_cache[index] = next_pattern[index];
  }
  else {
    pixels[index] = rgb_to_int(current.r + interval_r,
      current.g + interval_g,
      current.b + interval_b);
    let prev = int_to_rgb(pixel_cache[index]);
    log.debug(`${current_tick_r} ${current_tick_g} ${current_tick_b}: `
      + `CURRENT COLOR: ${current.r} ${current.g} ${current.b} NEW COLOR: ${current.r + interval_r} ${current.g + interval_g} ${current.b + interval_b} ` +
      `FINAL: ${final.r} ${final.g} ${final.b} ` +
      `\nINTERVAL: ${interval_r} ${interval_g} ${interval_b} ` +
      `PREVIOUS: ${prev.r} ${prev.g} ${prev.b}`);
  }
}