// src/render/loop.cpp
#include "loop.h"
#include "../background_dark_inverted.h"
#include "background.h"
#include "mbed.h"
#include "player.h"
#include <cstring>

extern BufferedSerial serial_port;
extern DigitalOut led;

#define BUFFER_SIZE 64

static char rx_buffer[BUFFER_SIZE];
static char message[BUFFER_SIZE];
static bool message_active = false;

void draw_mask(const char *unused_filename, int shift, const char *text);

static bool read_uart() {
  bool changed = false;

  // cita spravu z uartu
  if (serial_port.readable()) {
    memset(rx_buffer, 0, sizeof(rx_buffer));
    ssize_t num = serial_port.read(rx_buffer, sizeof(rx_buffer) - 1);
    if (num > 0) {
      // toogle ledky
      led = !led;
      strncpy(message, rx_buffer, sizeof(message) - 1);
      message_active = true;
      changed = true;
    }
  }

  // casovac na 1s zobrazenia spravy
  static Timer msg_timer;
  static bool timer_started = false;
  if (!timer_started) {
    msg_timer.start();
    timer_started = true;
  }

  // po jednu sekundu sa sprava zobrazi
  if (message_active && msg_timer.elapsed_time() > 1s) {
    message_active = false;
    memset(message, 0, sizeof(message));
    msg_timer.reset();
    changed = true;
  }

  return changed;
}

static bool update_animation(Timer &anim_timer, int &shift, int speed) {
  if (anim_timer.elapsed_time() >= 200ms) {
    // speed determines scroll steps per tick
    shift += speed;
    anim_timer.reset();
    return true;
  }
  return false;
}

void render_loop(int speed) {
  Timer msg_timer;
  Timer anim_timer;
  msg_timer.start();
  anim_timer.start();

  int shift = 0;
  const char *bg_file = "background_dark_inverted.txt";
  bool need_redraw = false;

  while (true) {
    need_redraw = false;

    if (read_uart()) {
      need_redraw = true;
    }

    if (update_animation(anim_timer, shift, speed))
      need_redraw = true;

    if (need_redraw) {
      draw_mask(bg_file, shift, message_active ? message : nullptr);
      draw_player(18, 16);
      ThisThread::sleep_for(50ms);
    }

    ThisThread::sleep_for(25ms);
  }
}