/*
  #ifdef ESP32
  #include <WiFi.h>
  #include <ESPAsyncWebServer.h>
  #include <SPIFFS.h>
#else
  #include <Arduino.h>
  #include <ESP8266WiFi.h>
  #include <Hash.h>
  #include <ESPAsyncTCP.h>
  #include <ESPAsyncWebServer.h>
  #include "FS.h"
#endif
*/

// WLAN
#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>

// WLAN-Zugangsdaten
const char* ssid = "MYSSID";
const char* password = "MYPASSWORD";

IPAddress ip(192,168,0,1);
IPAddress gateway(192,168,0,1);
IPAddress subnet(255,255,255,0);

// Hostname of the ESPs -> http://esp8266.local/
const char* espHostname = "adventskranz";

// Webserver 
#include <ESPAsyncTCP.h>
#include <ESPAsyncWebServer.h>
#define PORT 80     // Standard HTTP-Port 80
AsyncWebServer server(PORT);

// Filesystem
#include <FS.h>
// Date and time functions using a DS1307 RTC connected via I2C and Wire lib
#include "RTClib.h"

RTC_DS1307 rtc;
char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

DateTime now, ChristmasDay, ThreeKingsDayThisYear, ThreeKingsDayNextYear, AdventDay[4], last_day;

#define MAX_CANDLES 4
#define DEBUG true
#define SER_DEBUG_OUTPUT_INTERVALL 1000  // in milliseconds
#define LED_TEST_INTERVALL 5000  // in milliseconds

const int CandlePin[] = {          // define each candle control gpi/o pin to use
 14,    // 1. LED Candle @ Pin D5
 12,    // 2. LED Candle @ Pin D6
 13,    // 3. LED Candle @ Pin D7
 15,    // 4. LED Candle @ Pin D8
};

int num_of_candles = 0;
int counter = 0;
int CandleToUse[] = {0, 0, 0, 0}; // Init CandlesToUse with zeros
unsigned long time_start = 0;     // Start time periode in milliseconds
unsigned long time_stop = 0;      // Stop time periode in milliseconds
bool maintenance = false;         // Set maintenance mode [true|false]

void setupServerRoutes();
void setupFilePaths();

// What should happen when page isn't found:
void notFound(AsyncWebServerRequest *request) {
    request->send(404, "text/html", "<center><h1>404 error - Page not found!</h1></center>");
}
 
void setup() {
  Serial.begin(115200);
  #ifndef ESP8266
    while (!Serial); // wait for serial port to connect. Needed for native USB
  #endif
  //Serial.println();
  Serial.println("Entering setup ...");
  // delay(500);

  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    Serial.flush();
    while (1) delay(10);
  }

  // Init all candle pins as "output" and switch off relay
  Serial.println("Init candle control pins ...");
  for (int counter = 0; counter < MAX_CANDLES; counter++){
    pinMode(CandlePin[counter], OUTPUT);
    digitalWrite(CandlePin[counter], HIGH);
  }

//  Usefull suff for handling the RTC:
//  if (! rtc.isrunning()) {
//    Serial.println("RTC is NOT running, let's set the time!");
    // When time needs to be set on a new device, or after a power loss, the
    // following line sets the RTC to the date & time this sketch was compiled
//    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
    // This line sets the RTC with an explicit date & time, for example to set
    // January 21, 2014 at 3am you would call:
    // rtc.adjust(DateTime(2014, 1, 21, 3, 0, 0));
//  }

  // When time needs to be re-set on a previously configured device, the
  // following line sets the RTC to the date & time this sketch was compiled
  // rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  // This line sets the RTC with an explicit date & time, for example to set
  // January 21, 2014 at 3am you would call:
  // rtc.adjust(DateTime(2022, 10, 9, 14, 20, 0));

  if(SPIFFS.begin()){
    Serial.println("File system initialized.");
    }
  else{
    Serial.println("Error initializing file system");
  }

/* when ESP8266 should act as a WiFi client:
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  if (WiFi.waitForConnectResult() != WL_CONNECTED) {
    Serial.println("WLAN Verbindung fehlgeschlagen");
    return;
  }
    Serial.print("Verbunden! IP-Adresse: "); Serial.println(WiFi.localIP());
*/
  Serial.println("Configuring network parameters ...");
  WiFi.softAPConfig(ip, gateway, subnet); 
  Serial.println("Configuring WiFi parameters ... ");
  WiFi.softAP(ssid, password);

  // Starting mDNS-Servers
  if (!MDNS.begin(espHostname)) {             
    Serial.println("Error starting mDNS-Server");
  }

  // Define Server routes in separate function
  setupServerRoutes();

  // Define file routes in separate function
  setupFilePaths();

  // Start HTTP server function:
  Serial.println("Starting HTTP server ...");
  server.begin();

  random_candles();                // random all candles
  Serial.println("Switch OFF all candles...");
  set_all_candles(HIGH);  // switch all candles off
  Serial.println("Switch ON all candles...");
  set_all_candles(LOW);   // switch all candles on
  delay(LED_TEST_INTERVALL);       // wait for LED_TEST_INTERVALL seconds
  Serial.println("Switch OFF all candles...");
  set_all_candles(HIGH);  // switch all candles off
 
  get_current_timestamp();        // get current timestamp
  DateTime last_day ((now.year()), (now.month()), (now.day()), 00, 00, 00);  // save actual day for later use
  
} // END OF SETUP()

void loop() {
  MDNS.update();

  time_stop = millis();  // get current ticks counter
  // execute every SER_DEBUG_OUTPUT_INTERVALL milliseconds
  if (((time_stop - time_start) > SER_DEBUG_OUTPUT_INTERVALL) && (maintenance == false)) {
    time_start = time_stop;

    get_current_timestamp();        // get current timestamp    
    //Serial.println("Actual time and date: ");
    printDate(now);
    //Serial.print(".");

    if ( last_day.day() != now.day() ) {     // check if we have a new day to scramble the candles again
      //Serial.print("new day!");
      set_all_candles(HIGH);                 // switch all candles off
      random_candles();                      // random all candles
    }

    //Serial.println("Calculate celebration dates ...");
    DateTime ChristmasDay (now.year(), 12, 24, 00, 00, 00);
    //Serial.print("Christmas: ");
    //printDate(ChristmasDay);
    DateTime ThreeKingsDayThisYear ((now.year()), 01, 06, 23, 59, 59);
    //Serial.print("Three Kings this year: ");
    //printDate(ThreeKingsDayThisYear);
    DateTime ThreeKingsDayNextYear ((now.year()+1), 01, 06, 23, 59, 59);
    //Serial.print("Three Kings next year: ");
    //printDate(ThreeKingsDayNextYear);

    get_advent_days(ChristmasDay);

    //Serial.println("Check calendar week ...");
    if (now.unixtime() <= ThreeKingsDayThisYear.unixtime()) {
      //Serial.println("we are past New Year's Eve but before Three Kings Day  -> all candles on");
      num_of_candles = 4;
    }
    else if ((now.unixtime() > ThreeKingsDayThisYear.unixtime()) && (now.unixtime() < AdventDay[0].unixtime()))  {
      //Serial.println("we are between Three Kings Day and 1st. advent! -> all candles off");
      num_of_candles = 0;
    }
    else if ((now.unixtime() >= AdventDay[0].unixtime()) && (now.unixtime() < AdventDay[1].unixtime())) {
      //Serial.println("we are in 1st. advent week! -> turn 1 candles on");
      num_of_candles = 1;
    }
    else if ((now.unixtime() >= AdventDay[1].unixtime()) && (now.unixtime() < AdventDay[2].unixtime())) {
        //Serial.println("we are in 2nd. advent week! -> turn 2 candles on");
      num_of_candles = 2;
    }
    else if ((now.unixtime() >= AdventDay[2].unixtime()) && (now.unixtime() < AdventDay[3].unixtime())) {
      //Serial.println("we are in 3rd. advent week! -> turn 3 candles on");
      num_of_candles = 3;
    }
    else if ((now.unixtime() >= AdventDay[3].unixtime()) && (now.unixtime() <= ChristmasDay.unixtime())) {
      //Serial.println("we are in 4th. advent week! -> turn all 4 candles on");
      num_of_candles = 4;
    }
    else if ((now.unixtime() >= ChristmasDay.unixtime())&& (ThreeKingsDayNextYear.unixtime())) {
      //Serial.println("we are bast Christmas day but before Three Kings day! -> turn all 4 candles on");
      num_of_candles = 4;
    }
    else {
      //Serial.println("We should not go here, what's wrong?");
    }

    if (num_of_candles >= 1){
      for (int counter = 0; counter < num_of_candles; counter++){
        digitalWrite(CandleToUse[counter], LOW);                   // switch CandleToUse[counter] ON (yes LOW means ON because the relay logic is low active)
      } 
    }
    else{
      set_all_candles(HIGH);    // otherwise switch all candles off
    }
    //Serial.println();
  }
  last_day = now;
} // END OF LOOP()

void setupServerRoutes(){
  // Document-Root --> folder "data"
  // All file path must be defines relative to "data"
  // Deliver file "index.html"
  server.on("/", HTTP_GET, [](AsyncWebServerRequest *request){
  request->send(SPIFFS, "/index.html", String(), false, processor);
  //request->send(SPIFFS, "/index.html");
  });

  server.onNotFound(notFound);
}

void setupFilePaths(){
  server.on("/jquery.mobile-1.4.5.css", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send(SPIFFS, "/jquery.mobile-1.4.5.css", "text/css");
  });

  server.on("/jqm-datebox-1.4.5.all.js", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send(SPIFFS, "/jqm-datebox-1.4.5.all.js", "text/javascript");
  });

  server.on("/jquery.mobile-1.4.5.js", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send(SPIFFS, "/jquery.mobile-1.4.5.js", "text/javascript");
  });

  server.on("/jquery-1.12.4.min.js", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send(SPIFFS, "/jquery-1.12.4.min.js", "text/javascript");
  });

  server.on("/images/ajax-loader.gif", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send(SPIFFS, "/ajax-loader.gif", "image/gif");
  });

  server.on("/favicon.ico", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send(SPIFFS, "/favicon.ico", "text/html");
  });
  
  server.on("/get", HTTP_GET, [] (AsyncWebServerRequest *request) {
    String message;
    String state;
    if (request->hasParam("pinstate")) {
      message = request->getParam("pinstate")->value();
      state = get_PinState(message.toInt());
      //Serial.print("GET Pinstate: ");
      //Serial.print(message);
      //Serial.print(" -> ");
      //Serial.println(state);
      //request->send(200, "text/plain", "Hello, GET: " + message);
      //request->send(200, "text/plain", "ON");
      request->send(200, "text/plain", state.c_str());
    }
    else if (request->hasParam("maintenance")) {
      if (maintenance == true){
        message = "ON";
      }
      else {
         message = "OFF";
      }
      //Serial.print("GET Mainenance: ");
      //Serial.println(message);
      //request->send(200, "text/plain", "Hello, GET: " + message);
      //request->send(200, "text/plain", "ON");
      request->send(200, "text/plain", message.c_str());
    }
    else if (request->hasParam("time")) {
      //Serial.print("GET Time: ");
      //Serial.println(message);
      //request->send(200, "text/plain", "Hello, GET: " + message);
      //request->send(200, "text/plain", "ON");
      request->send_P(200, "text/plain", getTime().c_str());
    }
    else if (request->hasParam("date")) {
      //Serial.print("GET Date: ");
      //Serial.println(message);
      //request->send(200, "text/plain", "Hello, GET: " + message);
      //request->send(200, "text/plain", "ON");
      request->send_P(200, "text/plain", getDate().c_str());
    }
    else {
      message = "No message sent";
      Serial.print("GET: ");
      Serial.println(message);
    }
  });

  server.on("/set", HTTP_GET, [] (AsyncWebServerRequest *request) {
    String message;
    if (request->hasParam("pinstate")) {
      message = request->getParam("pinstate")->value();
      //Serial.print("SET Pinstate: ");
      //Serial.println(message);
      int candle_number = message.substring(0,message.indexOf(':')).toInt();
      String state = message.substring(message.indexOf(':')+1, message.length());
      if (state == "ON") {
        set_candle(candle_number, LOW);
      }
      else {
        set_candle(candle_number, HIGH);
      }
      //request->send(200, "text/plain", "Hello, GET: " + message);
      //request->send(200, "text/plain", "ON");
      //request->send(200, "text/plain", get_PinState(message.toInt()).c_str());
      request->send(200);
    }
    
    else if (request->hasParam("maintenance")) {
      message = request->getParam("maintenance")->value();
      if (message == "true"){
        maintenance = true;       // enable maintenance mote 
        set_all_candles(HIGH);    // switch all candles off
      }
      else {
        set_all_candles(HIGH);    // switch all candles off
        maintenance = false;      // disable maintenance mode
      }
      //Serial.print("SET Maintenance: ");
      //Serial.println(message);
      //Serial.print(":");
      //Serial.println(value);
      request->send(200);
    }

    else if (request->hasParam("reorder_candles")) {
      //message = request->getParam("reorder_candles")->value();
      //Serial.print("SET Reorder Candles: ");
      //Serial.println(message);
      reorder_candles();
      request->send(200);
    }

    else if (request->hasParam("time")) {
      message = request->getParam("time")->value();
      //Serial.print("SET Time to: ");
      //Serial.println(message);
      int set_hour = message.substring(0,message.indexOf(':')).toInt();
      int set_minute = message.substring(message.indexOf(':')+1, message.length()).toInt();
      now = rtc.now();                  // get current time and date
      rtc.adjust(DateTime(now.year(), now.month(), now.day(), set_hour, set_minute, 0));
      request->send(200);
    }

    else if (request->hasParam("date")) {
      message = request->getParam("date")->value();
      //Serial.print("SET Date to: ");
      //Serial.println(message);
      int first = message.indexOf('-');
      int second = message.indexOf('-', first + 1 );
      int set_year = message.substring(0,first).toInt();
      int set_month = message.substring(first+1,second).toInt();
      int set_day = message.substring(second+1, message.length()).toInt();
      now = rtc.now();                  // get current time and date
      rtc.adjust(DateTime(set_year, set_month, set_day, now.hour(), now.minute(), now.second()));
      set_all_candles(HIGH);    // switch all candles off
      request->send(200);
    }

    else {
      message = "No message sent";
      //Serial.print("SET: ");
      //Serial.println(message);
      request->send(200);
    }
  });
}

String processor(const String& var){
  Serial.println(var);
/* this function to replace "placeholders (%PLACEHOLDER%) is not used anymore but we keep this strukture maybe for later use ...

  if (var == "SWITCHSTATE1"){
    return get_PinState(0);
  }
  else if (var == "SWITCHSTATE2"){
    return get_PinState(1);
  }
  else if (var == "SWITCHSTATE3"){
    return get_PinState(2);
  }
  else if (var == "SWITCHSTATE4"){
    return get_PinState(3);
  }

  else if (var == "MAINTENACESTATE"){
    if (maintenance == false){
      return "";
    }
    else{
    return "checked";
    }
  }
*/
return "";   // returns nothing ;-)
}

String getTime() {
  char actual_time[8];
  now = rtc.now();                  // get current time and date
  sprintf(actual_time,"%02u:%02u:%02u", now.hour(), now.minute(), now.second());
  //Serial.print("Send system time: ");
  //Serial.println(actual_time); 
  return String(actual_time);
}

String getDate() {
  char actual_date[10];
  now = rtc.now();                  // get current time and date
  sprintf(actual_date,"%02u:%02u:%02u", now.day(), now.month(), now.year());
  //Serial.print("Send system date: ");
  //Serial.println(actual_date); 
  return String(actual_date);
}

void random_candles (){
  for (int counter = 0; counter < MAX_CANDLES; counter++){
    CandleToUse[counter] = 0;
  }
  int buff = 0;
  if (DEBUG == true) {
    //Serial.println("Debug: Entering \"random_candles\"");  
  }
  counter = 0;
  do {
   buff = random(0, MAX_CANDLES);
   if (CandleToUse[buff] == 0 ){
     CandleToUse[buff] = CandlePin[counter];
     counter+=1;
   }
  } while (counter < MAX_CANDLES);

/*  if (DEBUG == true) {
    Serial.print("Debug: Candle order today: ");
    Serial.print(CandleToUse[0], DEC);
    Serial.print(", ");
    Serial.print(CandleToUse[1], DEC);
    Serial.print(", ");
    Serial.print(CandleToUse[2], DEC);
    Serial.print(", ");
    Serial.println(CandleToUse[3], DEC);
  }
*/
}

void reorder_candles(){
  if (maintenance == false){
    maintenance = true;       // enable maintenance mote 
    set_all_candles(HIGH);    // switch all candles off
    random_candles();                // random all candles
    maintenance = false;      // disable maintenance mode
  }
  else {
    set_all_candles(HIGH);    // switch all candles off
    random_candles();                // random all candles
  }
}

void set_candle (int candle_number, bool switch_state){  // switch_state == LOW --> candle on; switch_state == HIGH --> candle off  
  //for (int counter = 0; counter < numberofcandles; counter++){
    if(digitalRead(CandlePin[candle_number]) == switch_state){
      //Serial.println("no candle state change");
    }
    else {
/*      if (DEBUG == true) {
        Serial.print("Debug: Switching candle ");
        Serial.print(counter, DEC);
        Serial.print(" to ");
        Serial.println(switch_state ? "OFF" : "ON");
      } */
      digitalWrite(CandlePin[candle_number], switch_state);
    }  
  //}
}

void set_all_candles(bool switch_state){  // switch_state == LOW --> candle on; switch_state == HIGH --> candle off  
  for (int counter = 0; counter < MAX_CANDLES; counter++){
    set_candle(counter, switch_state);
/*      if (DEBUG == true) {
        Serial.print("Debug: Switching candle ");
        Serial.print(counter, DEC);
        Serial.print(" to ");
        Serial.println(switch_state ? "OFF" : "ON");
      } */
  }
}

String get_PinState(int output){
  //Serial.print("Candle ");
  //Serial.print(output);
  if(digitalRead(CandlePin[output]) == HIGH){
    //Serial.println(" is OFF");
    return "OFF";
  }
  else {
    //Serial.println(" is ON");
    return "ON";
  }
}

void get_advent_days (const DateTime& dt){
  AdventDay[3] = (dt - TimeSpan(dt.dayOfTheWeek(),0,0,0));
  for (int counter = 0; counter <= 2 ; counter++){
    AdventDay[counter] = AdventDay[3] - TimeSpan(((3 - counter) * 7), 0, 0, 0);
  }  
  // print advent days
/*  if (DEBUG == true) {
    Serial.print("1st. advent day: ");
    printDate(AdventDay[0]);
    //Serial.println(dateToUnix(AdventDay[0]));
    Serial.print("2nd. advent day: ");
    printDate(AdventDay[1]);
    //Serial.println(dateToUnix(AdventDay[1]));
    Serial.print("3rd. advent day: ");
    printDate(AdventDay[2]);
    Serial.print("4th. advent day: ");
    printDate(AdventDay[3]);
  }
*/
}

void get_current_timestamp(){
  now = (00, 00, 00, 00, 00, 00);
  now = rtc.now();                  // get current time and date
  delay(50);
/*  if (DEBUG == true) {
  printDate(now);
  } */
}

void printDate(const DateTime& dt)
{
  char s[80];
  sprintf(s,"Time: %02u:%02u:%02u - Date: %02u.%02u.%04u - Day of Week: %1u",dt.hour(), dt.minute(), dt.second(), dt.day(), dt.month(), dt.year(), dt.dayOfTheWeek());
  Serial.println(s);
}