/**
Program to create a car monitor display using:
    - Arduino Due
    - a TFT display (https://www.tinytronics.nl/shop/en/displays/tft/3.5-inch-tft-display-320*480-pixels-mega-compatible-ili9486)
    - ELM327 Bluetooth OBD2 scanner
    - FSC-DB004 (BT 836B) bluetooth module
*/

#include "Arduino.h"
/* include UTFT library */
#include <UTFT.h>
#include <DueTimer.h>
// #include "obd2_timer.h"
#include "obd2_display.h"
#include "statemachine.h"

#define DEBUG 1
// #define RTT_MR 0x400E1A30U

/* pins */
#define PIN_BT_RX 19
#define PIN_BT_TX 18
#define PIN_BT_STATE 3 /* connected/disconnected state of BT */

#define MS(x) x * 1000
#define S(x) MS(x) * 1000

#define INIT_TEXT_WIDTH 15
#define FLAG_INIT_UPDATE_TEXT_POS 0x01
#define FLAG_INIT_CLEAR_POS 0x02
#define FLAG_INIT_UPDATE_PERCENT_POS 0x03

extern uint8_t BigFont[];
extern uint8_t SmallFont[];
extern uint8_t OCR_A_Extended_M[];

char should_clear = 1;
char led_state = LOW;
char init_flag = 0;
char init_text_i = -1;
int init_text_x = 100;
char init_text[] PROGMEM = "Initialising...";
char text_temp[2] = {'a', '\0'};
int init_percent = 0;

void on_init_enter();
void on_init_run();
void on_init_exit();
void on_main_enter();
void on_main_run();
void __state_none()
{ /* do nothing */
}

state_t init_state =
    {
        .id = STATE_INIT,
        .next = STATE_INIT,
        .on_enter = &on_init_enter,
        .on_run = &on_init_run,
        .on_exit = &on_init_exit};

state_t main_state =
    {
        .id = STATE_CAR_INFO,
        .next = STATE_CAR_INFO,
        .on_enter = &on_main_enter,
        .on_run = &on_main_run,
        .on_exit = &__state_none};

/* Set the pins for the display and dev board                                */
/* Standard Arduino Mega/Due shield            : <display model>,38,39,40,41 */
UTFT display(ILI9486, 38, 39, 40, 41);

/****************************/
/*INIT STATE*/
/****************************/

void on_init_enter()
{
  display.clrScr();

  Timer0.attachInterrupt(update_init_text);
  Timer0.start(MS(200));

  // TODO change to update when initializing bluetooth..
  Timer1.attachInterrupt(update_percent_test);
  Timer1.start(MS(60));

  Serial.println("Entering init state!");
}

void on_init_run()
{
  if (init_flag & (1 << FLAG_INIT_CLEAR_POS))
  {
    init_flag &= ~(1 << FLAG_INIT_CLEAR_POS);
    display.setColor(VGA_BLACK);
    /*clear only initializing text*/
    display.print("               ",(display.getDisplayXSize() / 2) - (INIT_TEXT_WIDTH * display.getFontXsize() / 2),display.getDisplayYSize() / 2 + 50);
  }
  if (init_flag & (1 << FLAG_INIT_UPDATE_TEXT_POS))
  {
    init_flag &= ~(1 << FLAG_INIT_UPDATE_TEXT_POS);
    display.setColor(VGA_AQUA);
    int x_position = (display.getDisplayXSize() / 2 - (INIT_TEXT_WIDTH * display.getFontXsize() / 2)) + (init_text_i * display.getFontXsize());
    Serial.println(x_position);
    text_temp[0] = init_text[init_text_i];
    display.print(text_temp, x_position, display.getDisplayYSize() / 2 + 50); // print as string with one character
  }
  if (init_flag & (1 << FLAG_INIT_UPDATE_PERCENT_POS))
  {
    init_flag &= ~(1 << FLAG_INIT_UPDATE_PERCENT_POS);
    int percent_x_pos = (display.getDisplayXSize() / 2 - (INIT_TEXT_WIDTH * display.getFontXsize() / 2)) + (INIT_TEXT_WIDTH * display.getFontXsize());
    display.setColor(VGA_BLACK);
    /*clear text region for percent*/
    display.print("   ", percent_x_pos, display.getDisplayYSize() / 2 + 50);

    display.setColor(VGA_FUCHSIA);
    char *percent_text = (char *)malloc(3 * sizeof(char));
    sprintf(percent_text, "%d", init_percent);
    display.print(percent_text, percent_x_pos, display.getDisplayYSize() / 2 + 50);
    display.print("%", percent_x_pos + 3 * display.getFontXsize(), display.getDisplayYSize() / 2 + 50);
    free(percent_text);
  }
}

void on_init_exit()
{
  Serial.println("Exiting init state!");
  display.clrScr();
  Timer0.stop();
}

/****************************/
/*MAIN STATE*/
/****************************/

void on_main_enter()
{
  Serial.println("Entering main loop");
}

void on_main_run()
{
  delay(500);
  Serial.println("main!");
}

void update_init_text()
{
  init_text_i++;
  if (init_text_i == 15)
  {
    init_text_i = 0;
    init_flag |= (1 << FLAG_INIT_CLEAR_POS);
  }
  init_flag |= (1 << FLAG_INIT_UPDATE_TEXT_POS);
}

void update_percent_test()
{
  init_percent++;
  if (init_percent > 100)
  {
    init_percent = 0;
  }
  init_flag |= (1 << FLAG_INIT_UPDATE_PERCENT_POS);
}

void setup()
{

  /* TODO change for TRNG (section 42 of datasheet)*/
  randomSeed(analogRead(0));

#if (DEBUG == 1)
  Serial.begin(9600);
#endif
  /* Serial1 is bluetooth module, pin 18 and 19. */
  Serial1.begin(115200);

  /* Init display */
  display.InitLCD();
  display.setFont(OCR_A_Extended_M);

#if (DEBUG == 1)
  Serial.println("Starting");
#endif

  pinMode(LED_BUILTIN, OUTPUT);

  statemachine_register_state(&init_state, STATE_INIT);
  statemachine_register_state(&main_state, STATE_CAR_INFO);
  statemachine_init();
}

void loop()
{

  statemachine_loop();
  // Serial.println("Running");
  // delay(10);
  //   while (Serial1.available())
  //   {
  //     char rec = Serial1.read();
  // #if (DEBUG == 1)
  //     Serial.println(rec);
  // #endif
  //   }

  //   if (should_clear)
  //   {
  //     display.clrScr();
  //     display.setColor(255, 0, 166);
  //     display.fillRect(LCD_W / 2 - 200, LCD_H / 2 - 100, LCD_W / 2 + 200, LCD_H / 2 + 100);
  //     display.setColor(0, 247, 255);
  //     display.print("OBD2 display yeet", CENTER, LCD_H / 2);
  //     delay(10);
  //     should_clear = 0;
  //   }
}