/* 7 rows LED bar firmware / main program for Arduino Nano 
 * Copyright (C) 2019 asdrea
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
#include "ledbar.h"

enum {
  CMD_NOSCROLL,
  CMD_HSCROLL,
  CMD_VSCROLL,
  CMD_SPACING
};

enum {
  ALIGN_LEFT,
  ALIGN_RIGHT,
  ALIGN_CENTER
};

static String text;
static int16_t text_pos = 0; // q11.5
static int8_t scroll_speed = 0, scroll_mode = CMD_NOSCROLL, text_align = ALIGN_LEFT;
static uint8_t text_spacing = 1;
static uint8_t cmd_mode = 0;

void setup()
{
  Serial.begin(9600);
  ledbar_init();
}

void loop()
{
int16_t p;

  while(Serial.available() > 0) {
    uint8_t c = Serial.read();

    if(cmd_mode) {
      switch(c >> 6) {
        case CMD_NOSCROLL:
          scroll_mode = CMD_NOSCROLL;
          text_align = c & 0x3f;
          text_pos = 0;
          break;
        case CMD_VSCROLL:
          scroll_mode = CMD_VSCROLL;
          scroll_speed = (c & 0x3f) << 2;
          break;
        case CMD_HSCROLL:
          scroll_mode = CMD_HSCROLL;
          scroll_speed = (c & 0x3f) << 2;
          break;
        case CMD_SPACING:
          text_spacing = c & 0x3f;
          break;
      }
      cmd_mode = 0;
      continue;      
    }
    
    if(c == '\0') {
      cmd_mode = 1;
      continue;
    }

    //Serial.write(c);

    if(c == '\n' || c == '\r') {
      text = "";
    }
    else if(c == 8 || c == 127) {
      if(text.length() > 0)
        text = text.substring(0, text.length() - 1);
    }
    else
      text += (char)c;
  }

  switch(scroll_mode) {
    default:
    case CMD_NOSCROLL:
      switch(text_align) {
        default:
        case ALIGN_LEFT:
          p = 0;
          break;
        case ALIGN_RIGHT:
          p = (5 + text_spacing) * (LEDBAR_COLS - (int16_t)text.length());
          break;
        case ALIGN_CENTER:
          p = LEDBAR_COLS / 2 - (5 + text_spacing) * ((int16_t)text.length() / 2);
          break;
      }
      break;

    case CMD_HSCROLL:
      text_pos += scroll_speed;
      p = text_pos / 32;

      if(scroll_speed < 0) {
        if(p < (-(5 + text_spacing) * (int16_t)text.length())) {
          p = LEDBAR_COLS;
          text_pos = p * 32;
        }
      }
      else {
        if(p > LEDBAR_COLS) {
          p = -(5 + text_spacing) * (int16_t)text.length();
          text_pos = p * 32;
        }        
      }
      break;

    case CMD_VSCROLL:
      // Implement me please :'(
      break;
  }

  ledbar_wait_vsync();
  ledbar_clear(LEDBAR_BACKBUF);
  ledbar_settext(LEDBAR_BACKBUF, p, text.c_str(), text_spacing);
  ledbar_swap_buf();
}