#include "U8glib.h"

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_DEV_0 | U8G_I2C_OPT_NO_ACK | U8G_I2C_OPT_FAST); // Fast I2C / TWI
// U8GLIB_SSD1306_128X64 u8g(13, 11, 8, 9, 10); // SPI connection
// for SPI connection, use this wiring:
// GND > GND
// VCC > 5V
// SCL > 13
// SDA > 11
// RES > 10
// DC > 9
// CS > 8

const int NUM_MAIN_ITEMS = 10; // number off main menu list
const int MAX_MAIN_ITEM_LENGTH = 20; // max char of main menu

char main_menu_items [NUM_MAIN_ITEMS] [MAX_MAIN_ITEM_LENGTH] = {
  { "GPS" },
  { "LORA" },
  { "Date & Time" },
  { "Battery" },
  { "Position Log" },
  { "Wifi & BT" },
  { "Tag Name & ID" },
  { "About Project" },
  { "dummy2" },
  { "dummy3" }
};

const int NUM_SUB_MENU1 = 3;
const int MAX_SUB_MENU1_LENGTH = 20;
char sub_menu1_items [NUM_SUB_MENU1] [MAX_SUB_MENU1_LENGTH] = {
  { "FIX LOACATION :" },
  { "dummy 1"},
  { "dummy 2"}
};

const int NUM_SUB_MENU2 = 3;
const int MAX_SUB_MENU2_LENGTH = 20;
char sub_menu2_items [NUM_SUB_MENU2] [MAX_SUB_MENU2_LENGTH] = {
  { "Connection Status :" },
  { "Signal Strength :" },
  { "dummy 2" }
};
char lora_status_text[2][10] = {
  { "Connected" },
  { "connecting" }
}

const int NUM_SUB_MENU3 = 3;
const int MAX_SUB_MENU3_LENGTH = 20;
char sub_menu3_items [NUM_SUB_MENU3] [MAX_SUB_MENU3_LENGTH] = {
  { "Date :" },
  { "Time :" },
  { "Sync Date & Time" }
};

const int NUM_SUB_MENU4 = 3;
const int MAX_SUB_MENU4_LENGTH = 20;
char sub_menu4_items [NUM_SUB_MENU4] [MAX_SUB_MENU4_LENGTH] = {
  { "Status :"},
  { "Percentage :" },
  { "Voltage :" }
};
char battery_status_text[3][10] = {
  { "Charging" },
  { "Charged" },
  { "On Battery" }
};

#define BUTTON_UP_PIN 12 // pin for UP button 
#define BUTTON_SELECT_PIN 11 // pin for SELECT button
#define BUTTON_DOWN_PIN 10 // pin for DOWN button

#define VOLTAGE_READ_PIN A0

//#define LED_PIN 13 // pin for demo mode, use switch or wire to enable or disable demo mode, see more details below

bool button_up_clicked = 0; // only perform action when button is clicked, and wait until another press
bool button_select_clicked = 0; // same as above
bool button_down_clicked = 0; // same as above

bool button_select_long_press = 0;

int item_selected = 0; // which item in the menu is selected

int item_sel_previous; // previous item - used in the menu screen to draw the item before the selected one
int item_sel_next; // next item - used in the menu screen to draw next item after the selected one

int current_screen = 0;   // 0 = main menu, 1 = submenu1
#define main_menu 0
#define sub_menu1 1
#define sub_menu2 2
#define sub_menu3 3
#define sub_menu4 4
#define sub_menu5 5
#define sub_menu6 6
#define sub_menu7 7
#define sub_menu8 8
int main_menu_item_selected = 0;
int main_menu_item_previous;
int main_menu_item_next;

int select_sampling_time = 2000;
uint32_t last_select_sampling_time;

uint32_t last_analog_read_time;
//int analog_read_sampling_time=200; //sampling each 200ms

//int time_elapsed = 0;
uint32_t last_millis;

// project global variable
int battery_level=99;
int battery_status=0;
float battery_voltage= 12.55;
int read_battery_voltage;
int current_draw;

int read_voltage;

bool wifi_status;
bool bluetooth_status;
int wifi_signal_strength;


void setup() {
  Serial.begin(115200);
  u8g.setColorIndex(1);  // set the color to white

  // define pins for buttons
  // INPUT_PULLUP means the button is HIGH when not pressed, and LOW when pressed
  // since it´s connected between some pin and GND
  pinMode(BUTTON_UP_PIN, INPUT_PULLUP); // up button
  pinMode(BUTTON_SELECT_PIN, INPUT_PULLUP); // select button
  pinMode(BUTTON_DOWN_PIN, INPUT_PULLUP); // down button

  //pinMode()

  pinMode(LED_BUILTIN, OUTPUT);

  //pinMode(DEMO_PIN, INPUT_PULLUP);
  u8g.firstPage();
  u8g.setFont(u8g_font_7x14);
  u8g.drawStr(25, 15, main_menu_items[1]);
}

void loop() {
  char s_battery_level[4];
  char s_battery_voltage[6];
  //scan for button pressed // in main menu
  //if(current_screen == main_menu) 
  //{
    if(digitalRead(BUTTON_UP_PIN) == LOW && button_up_clicked == false) //scan for click event
    {
      if(current_screen == main_menu)
      {
        main_menu_item_selected = main_menu_item_selected - 1;
        button_up_clicked = true; // 1 execution for 1 click // flag for click event
        if (main_menu_item_selected < 0) 
        {
          main_menu_item_selected = NUM_MAIN_ITEMS - 1;
        }
      }
    }
    else if(digitalRead(BUTTON_DOWN_PIN) == LOW && button_down_clicked == false)
    {
      if(current_screen == main_menu)
      {
        main_menu_item_selected = main_menu_item_selected + 1;
        button_down_clicked = true;
        if(main_menu_item_selected >= NUM_MAIN_ITEMS)
        {
          main_menu_item_selected = 0;
        }
      }
    }
    else if(digitalRead(BUTTON_SELECT_PIN) == LOW && button_select_clicked == false)
    {
      if(current_screen == main_menu)
      {
        if(main_menu_item_selected == 0)
        {
          current_screen = sub_menu1; //GPS menu
          Serial.println("sub_menu1");
        }
        else if (main_menu_item_selected == 1)
        {
          current_screen = sub_menu2; //lora menu
          Serial.println("sub_menu2");
        }
        else if (main_menu_item_selected == 2) //date & time
        {
          current_screen = sub_menu3;
          Serial.println("sub_menu3");
          //current_screen = sub_menu3; //test menu
        }
        else if (main_menu_item_selected == 3)
        {
          current_screen = sub_menu4;
          Serial.println("sub_menu4");
        }
        else if (main_menu_item_selected == 4)
        {
          current_screen = sub_menu5;
          Serial.println("sub_menu5");
        }

      }
      else if (current_screen == sub_menu1)
      {
        
      }
      else if (current_screen == sub_menu2)
      {
        
      }
      button_select_clicked = true;
      last_select_sampling_time = millis(); //for back to main menu command // hold select button for 2s
    }
    else if(digitalRead(BUTTON_SELECT_PIN) == LOW && button_select_clicked == true)
    {
      Serial.print(millis()); Serial.print("    "); Serial.println(millis()-last_select_sampling_time);
      if(current_screen == sub_menu1 || current_screen == sub_menu2 || current_screen == sub_menu3 || current_screen == sub_menu4 || current_screen == sub_menu5)
      {
        if((millis()-last_select_sampling_time)>select_sampling_time) // press select button for 2s for back to main menu
        {
          Serial.println("Back to main menu");
          current_screen = main_menu;
        }
      }
    } 
    
    if(digitalRead(BUTTON_UP_PIN) == HIGH && button_up_clicked == true) // clear of flag button up click event
    {
      button_up_clicked = false;
    }
    if(digitalRead(BUTTON_DOWN_PIN) == HIGH && button_down_clicked == true) // clear of flag button down click event
    {
      button_down_clicked = false;
    }
    if(digitalRead(BUTTON_SELECT_PIN) == HIGH && button_select_clicked == true)
    {
      button_select_clicked = false;
    }
  //}


  //display correction of next and previous value
  if (current_screen == main_menu) 
  {
    main_menu_item_previous = main_menu_item_selected - 1;
    main_menu_item_next = main_menu_item_selected + 1;
    if (main_menu_item_previous < 0) {main_menu_item_previous = NUM_MAIN_ITEMS - 1;}
    if (main_menu_item_next>=NUM_MAIN_ITEMS) {main_menu_item_next=0;}
  }
  // drawing procesure using u8glib // "picture loop" procedure from library
  u8g.firstPage();
  do {
    if (current_screen == main_menu)
    {
      u8g.setFont(u8g_font_7x14); // draw the first line text
      u8g.drawStr(25, 15, main_menu_items[main_menu_item_previous]);

      u8g.setFont(u8g_font_7x14B); // draw the middle line text
      u8g.drawStr(25, 15+20+2, main_menu_items[main_menu_item_selected]);

      u8g.setFont(u8g_font_7x14); // draw the last line text
      u8g.drawStr(25, 15+20+20+2+2, main_menu_items[main_menu_item_next]);
    }
    else if (current_screen == sub_menu1) //GPS MENU
    {
      u8g.setFont(u8g_font_7x14B); // draw the middle line text
      u8g.drawStr(5, 10, main_menu_items[main_menu_item_selected]);

      u8g.setFont(u8g_font_baby);
      u8g.drawStr(5, 20, sub_menu1_items[0]); 
    }
    else if (current_screen == sub_menu2) //lora menu
    {
      u8g.setFont(u8g_font_7x14B); // draw the middle line text
      u8g.drawStr(5, 10, main_menu_items[main_menu_item_selected]);

      u8g.setFont(u8g_font_baby);
      u8g.drawStr(5, 20, sub_menu2_items[0]);
    }
    else if (current_screen == sub_menu3)
    {

    }
    else if (current_screen == sub_menu4) //sub menu battery
    {
      u8g.setFont(u8g_font_7x14B); 
      u8g.drawStr(5, 10, main_menu_items[main_menu_item_selected]); //print title page

      u8g.setFont(u8g_font_baby);
      u8g.drawStr(10, 20, sub_menu4_items[0]); //print battery status label 
      u8g.drawStr(15, 28, battery_status_text[battery_status]); //print battery actual stat
      u8g.drawStr(10, 36, sub_menu4_items[1]); //print percentage label
      u8g.drawStr(15, 44, s_battery_level); u8g.drawStr(40, 44, "%"); // print actual percentage
      u8g.drawStr(10, 52, sub_menu4_items[2]); //print voltage label
      u8g.drawStr(15, 60, s_battery_voltage); u8g.drawStr(40, 60, "V");  //print actual voltage

    }
  }
  while ( u8g.nextPage() );
  // end of drawing procedure from u8glib

  itoa(battery_level, s_battery_level, 10);
  dtostrf(battery_voltage, 5, 2, s_battery_voltage);
  //Serial.println(s_battery_level);
  int read_analog_sampling_time = 1000; //read analog sampling time
  int time_elepased_analog_read = millis()-last_analog_read_time;
  if (time_elepased_analog_read > read_analog_sampling_time)
  {
    int analog_read = analogRead(VOLTAGE_READ_PIN);
    read_voltage = analog_read;
    last_analog_read_time = millis();
    //Serial.println(analog_read);
  }

  //test led toogle every blinktime (ms)
  int blinktime=500;
  int time_elapsed = millis() - last_millis;
  if(time_elapsed < blinktime){
    digitalWrite(LED_BUILTIN, HIGH);
  }
  else if(time_elapsed>=blinktime && time_elapsed<blinktime*2){
    digitalWrite(LED_BUILTIN, LOW);
  }
  else
  {
    last_millis = millis();
  }
}