#include <WiFi.h>
#include <time.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <DHTesp.h>

#define WFI_SSID "Wokwi-GUEST"
#define WFI_PASS ""

#define LED_1SEC 26

#define BTN_MENU 33
#define BTN_PLUS 32
#define BTN_MNUS 35
#define BTN_CNCL 34

#define DHT_DATA 25


// OLED Display COnfiguration
#define DSP_WDTH 128
#define DSP_HIGT 64
#define DSP_RSET -1
#define DSP_ADDR 0x3C

// NTP Configuration
#define NTP_SRVR "pool.ntp.org"

enum Button_state {
  off,
  potential_press,
  press,
  hold
};


hw_timer_t *TIM_1SEC = NULL;
Adafruit_SSD1306 DSP_object(DSP_WDTH, DSP_HIGT, &Wire, DSP_RSET);
DHTesp DHT_object;

String date_formatted_string;
String time_formatted_string;
int utc_offset = 0;
int p_utc_offset = 0;

unsigned int alarm_times[3];
unsigned int p_alarm_times[3];

time_t current_time;

int hours = 0;
int minutes = 0;
int seconds = 0;

int day = 0;
int month = 0;
int year = 0;

Button_state BTN_MENU_state;
Button_state BTN_PLUS_state;
Button_state BTN_MNUS_state;
Button_state BTN_CNCL_state;

unsigned int BTN_MENU_counter;
unsigned int BTN_PLUS_counter;
unsigned int BTN_MNUS_counter;
unsigned int BTN_CNCL_counter;


TempAndHumidity DHT_data;

int menu = 0;
int edit = false;
bool editing_mins = false;


void connectToWifi() {
  WiFi.begin(WFI_SSID, WFI_PASS);

  int retries = 0;

  while (WiFi.status() != WL_CONNECTED) {
    retries++;
    delay(1000);

    if(retries == 3) {
      show_splaash_screen("Check Wi-Fi AP");
    }
  }
}

void disconnectFromWifi() {
  WiFi.disconnect();
}

void getTime() {
  configTime(utc_offset, 0, NTP_SRVR);

  struct tm timeinfo;
  int retries = 0;

  while(!getLocalTime(&timeinfo)) {
    retries++;
    delay(1000);

    if(retries == 3) {
      show_splaash_screen("No Internet Connection");
    }
  }

  current_time = mktime(&timeinfo);
}

void IRAM_ATTR TIM_1SEC_ISR() {
  digitalWrite(LED_1SEC, !digitalRead(LED_1SEC));
  current_time++;
}

void IRAM_ATTR BTN_ISR() {
  menu++;
  detachInterrupt(digitalPinToInterrupt(BTN_MENU));
}

void DSP_print_text(String text, int col, int row, int size) { 
  DSP_object.setTextSize(size);
  DSP_object.setTextColor(WHITE);
  DSP_object.setCursor(col, row);
  DSP_object.println(text);
}

void show_splaash_screen(String status) {
  DSP_object.clearDisplay();

  DSP_print_text("SMART"   , 10,  5, 2);
  DSP_print_text("Medi Box", 10, 25, 2);
  DSP_print_text(status    , 10, 50, 1);

  DSP_object.display();  
}

void show_home_screen() {
  DSP_object.clearDisplay();

  char tempAndHumString[18]; 
  snprintf(tempAndHumString, sizeof(tempAndHumString), "%04.1f^C      %04.1f%%", DHT_data.temperature, DHT_data.humidity);

  DSP_print_text(date_formatted_string, 10,  4, 1);
  DSP_print_text(time_formatted_string, 10, 18, 2);
  DSP_print_text("Next Alarm: 13:30"  , 10, 43, 1);
  DSP_print_text(tempAndHumString     , 10, 55, 1);

  DSP_object.display(); 
}

void show_menu_timezone() {
  DSP_object.clearDisplay();

  char timeZoneString[6];

  char sn = utc_offset > 0 ? '+' : (utc_offset < 0 ? '-' : ' ' );
  int hr = (utc_offset / 2) * (utc_offset < 0 ? -1 : 1);
  int mn = utc_offset % 2;
  snprintf(timeZoneString, sizeof(timeZoneString), "%c%02d%02d",sn, hr, mn);

  DSP_print_text("Set time zone"        , 10,  4, 1);
  DSP_print_text(timeZoneString       , 10, 18, 2);
  DSP_print_text(time_formatted_string  , 10, 43, 1);
  DSP_print_text(date_formatted_string  , 10, 55, 1);

  DSP_object.display(); 
}

void show_menu_alarm(int alarm) {
  DSP_object.clearDisplay();

  char alarmTimeString[6];

  char sn = utc_offset > 0 ? '+' : (utc_offset < 0 ? '-' : ' ' );
  int hr = (utc_offset / 2) * (utc_offset < 0 ? -1 : 1);
  int mn = utc_offset % 2;
  snprintf(alarmTimeString, sizeof(alarmTimeString), "%c%02d%02d",sn, hr, mn);

  DSP_print_text("Set alarm zone"        , 10,  4, 1);
  DSP_print_text(alarmTimeString       , 10, 18, 2);
  DSP_print_text(time_formatted_string  , 10, 43, 1);
  DSP_print_text(date_formatted_string  , 10, 55, 1);

  DSP_object.display(); 
}

void hardCodeTime() {
  
  configTime(utc_offset, 0, NTP_SRVR);
  current_time = 1710073584l;
}

void setTimeString() {
  struct tm *timeinfo = localtime(&current_time);

  char timeHour[3];
  strftime(timeHour, 3, "%H", timeinfo);
  hours = atoi(timeHour);
  char timeMinute[3];
  strftime(timeMinute, 3, "%M", timeinfo);
  minutes = atoi(timeMinute);
  char timeSecond[3];
  strftime(timeSecond, 3, "%S", timeinfo);
  seconds = atoi(timeSecond);
  char timeDate[11];
  strftime(timeDate, 11, "%F", timeinfo);
  date_formatted_string = timeDate;
  char timeTime[25];
  strftime(timeTime, 25, "%H:%M:%S", timeinfo);
  time_formatted_string = timeTime;
}

void getTempetarureandHumidity() {
  DHT_data = DHT_object.getTempAndHumidity();
}


void setup() {  
  Serial.begin(115200);
  pinMode(LED_1SEC, OUTPUT);

  pinMode(BTN_MENU,  INPUT);
  pinMode(BTN_PLUS,  INPUT);
  pinMode(BTN_MNUS,  INPUT);
  pinMode(BTN_CNCL,  INPUT);

  BTN_MENU_state = off;  
  BTN_PLUS_state = off;
  BTN_MNUS_state = off;  
  BTN_CNCL_state = off;



  while(!DSP_object.begin(SSD1306_SWITCHCAPVCC, DSP_ADDR)) {
    delay(3000);
  }

  DHT_object.setup(DHT_DATA, DHTesp::DHT22);
  
  // show_splaash_screen("by Tharindu Perera");
  // delay(300);
  // connectToWifi();
  // show_splaash_screen("by Tharindu Perera");
  // delay(300);
  // getTime();
  // show_splaash_screen("by Tharindu Perera");
  // delay(300);
  // disconnectFromWifi();
  // show_splaash_screen("Initialized");
  // delay(300);

  hardCodeTime();

  attachInterrupt(BTN_MENU, BTN_ISR, FALLING);

  TIM_1SEC = timerBegin(0, 80, true);
  timerAttachInterrupt(TIM_1SEC, &TIM_1SEC_ISR, true);
  timerAlarmWrite(TIM_1SEC, 1000 * 1000, true);
  timerAlarmEnable(TIM_1SEC);

  getTempetarureandHumidity();
  show_home_screen();
}

void updateButtonStates() {
  updateButtonState(BTN_MENU, &BTN_MENU_state, &BTN_MENU_counter);
  updateButtonState(BTN_PLUS, &BTN_PLUS_state, &BTN_PLUS_counter);
  updateButtonState(BTN_MNUS, &BTN_MNUS_state, &BTN_MNUS_counter);
  updateButtonState(BTN_CNCL, &BTN_CNCL_state, &BTN_CNCL_counter);
}

void updateButtonState(int btn, Button_state *state, unsigned int *counter) {
  if(digitalRead(btn)) {
    if(*counter > 10) *state = hold;
    else if (*counter > 1) *state = potential_press;
    *counter++;
  } 
  else {
    if (*state == potential_press) *state = press;
    else *state == off;
    *counter = 0;
  }
}

int navigate () {
  if (BTN_PLUS_state == press) return menu++;
  if (BTN_MNUS_state == press) return menu++;
  if (BTN_CNCL_state == press) return menu = 0;
  if (BTN_MENU_state == press) return edit++;
}

int edit_values() {
  if(menu == 1) {
    if (BTN_PLUS_state == press || BTN_PLUS_state == hold) return utc_offset++;
    if (BTN_MNUS_state == press || BTN_MNUS_state == hold) return utc_offset--;
    if (BTN_CNCL_state == press || BTN_MENU_state ==  press) edit--;
    if (BTN_CNCL_state == press) return utc_offset = p_utc_offset;
    if (BTN_MENU_state ==  press) return p_utc_offset = utc_offset;
    return 0;
  }
  int alarm = menu - 2;
  if (BTN_PLUS_state == press || BTN_PLUS_state == hold) return alarm_times[alarm] += (60 - editing_mins *  59);
  if (BTN_MNUS_state == press || BTN_MNUS_state == hold) return alarm_times[alarm] -= (60 - editing_mins *  59);
  if (BTN_CNCL_state == press || BTN_MENU_state ==  press) edit--;
  if (BTN_CNCL_state == press) {
    edit--;
    return alarm_times[alarm] = p_alarm_times[alarm];
  }
  if (BTN_MENU_state ==  press) {
    if(editing_mins) edit--;
    else editing_mins = true;
    return p_alarm_times[alarm] = alarm_times[alarm];
  }
  return 0;
}

void loop() {
  // while(menu) {
  //   updateButtonStates();
  //   edit ? edit_values() : navigate();
  //   switch (menu) {
  //   case 1:
  //     show_menu_timezone();
  //     break;
  //   case 2 ... 4:
  //     show_menu_alarm(menu - 2);
  //     break;
  //   default:
  //     attachInterrupt(BTN_MENU, BTN_ISR, FALLING);
  //     menu = 0;
  //     break;
  //   }
  //   delay(50);
  // }
  getTempetarureandHumidity();
  setTimeString();
  show_home_screen();
  delay(200);
}