// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _WIFIMGR_LOGLEVEL_  1
#define DEBUG               1

#include <WiFi.h>
#include <WiFiManager.h>
#include "debug.h"
#include <Arduino.h>
#include <ESPmDNS.h>
#include <LiquidCrystal_I2C.h>
#include <looper.h>
#include <RunningMedian.h>
#include <ESPDateTime.h>
#include <Time.h>

#define MDNS_NAME             "wlanthermometer"
#define AP_SSID_CONFIG_NAME   "WLANTHERMOMETER-Config"
#define AP_CONFIG_PASSWORD    "wlanthermometer"
#define AP_DATA_RESET_PIN     25
#define TEMP_SENS_PIN         34
#define LCD_I2C_ADDR          0x3f
#define LCD_COL               20
#define LCD_ROW               4
#define KRATE_TEMP            5000
#define KRATE_TIME            500
#define KRATE_RESET_AP_DATA   5000
#define MEDIAN_SAMPLES        60
#define ONBOARD_LED           2
#define NTP_TIMEOUT           15000
#define WIFI_CONNECT_TIMEOUT  30
#define CFG_PORTAL_TIMEOUT    90

LiquidCrystal_I2C lcd(LCD_I2C_ADDR, LCD_COL, LCD_ROW);
looper sched;
RunningMedian samples = RunningMedian(MEDIAN_SAMPLES);
float temp_min;
float temp_max;
float temp;
bool led_state;
String header;
WiFiServer server(80);
const uint8_t degree_sign[8] = { B00010, B00101, B00010, B00000, B00000, B00000, B00000, B00000 };
uint8_t add_summertime = 0;
bool last_config_check = false;

void setup()
{
  pinMode(AP_DATA_RESET_PIN, INPUT_PULLDOWN);
  pinMode(ONBOARD_LED, OUTPUT);

  Serial.begin(115200);
  Serial.println(F("WLANThermometer (c)2020 H. Wirtz <wirtz@parasitstudio.de>"));

  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.noCursor();
  lcd.setCursor(2, 0);
  lcd.print(F("WLAN THERMOMETER"));
  lcd.setCursor(2, 1);
  lcd.print(F("(c)parasiTstudio"));

  DEBUG_MSG("Mode Client\n");
  WiFi.mode(WIFI_STA); // explicitly set mode, esp defaults to STA+AP

  WiFiManager wm;

  lcd.setCursor(0, 2);
  lcd.print(F("Connecting WiFi...  "));
  lcd.setCursor(0, 3);
  lcd.print(F("CFG-AP: 192.168.4.1"));

  wm.setConnectTimeout(WIFI_CONNECT_TIMEOUT);
  wm.setConfigPortalTimeout(CFG_PORTAL_TIMEOUT);
  wm.setBreakAfterConfig(true);

  if (!wm.autoConnect(AP_SSID_CONFIG_NAME, AP_CONFIG_PASSWORD))
  {
    lcd.setCursor(0, 2);
    lcd.print(F("Failed              "));
    DEBUG_MSG("Failed to connect\n");
    delay(1000);
    lcd.setCursor(8, 2);
    lcd.print(F("- restart"));
    delay(1000);
    ESP.restart();
  }
  else
  {
    DEBUG_MSG("Connected\n");

    if (!MDNS.begin(MDNS_NAME))
    {
      DEBUG_MSG("Error setting up MDNS responder!\n");
    }
    else
    {
      DEBUG_MSG("mDNS started.\n");
    }

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print(F("Mode WiFi client"));
    lcd.setCursor(0, 1);
    lcd.print(WiFi.localIP());

    delay(500);
  }

  lcd.setCursor(0, 3);
  lcd.print("Getting time...");
  DateTime.setTimeZone(1);
  DateTime.begin(NTP_TIMEOUT);
  while (!DateTime.isTimeValid())
  {
    Serial.println("Failed to get time from server.");
    DateTime.forceUpdate();
  }
  if (is_wintertime(DateTime.getTime()) == false)
    add_summertime = 1;
  else
    add_summertime = 0;

  // create a degree sign
  lcd.createChar(0, (uint8_t*)degree_sign);

  server.begin();

  sched.addJob(show_temperature, KRATE_TEMP);
  sched.addJob(show_time, KRATE_TIME);
  sched.addJob(start_config_portal, KRATE_RESET_AP_DATA);

  temp_min = get_temp_sensor_data();
  temp_max = temp_min;
  temp = temp_min;

  lcd.clear();
  show_time();
  show_temperature();
}

void loop()
{
  sched.scheduler();

  WiFiClient client = server.available(); // Listen for incoming clients

  if (client) { // If a new client connects,
    Serial.println("New Client."); // print a message out in the serial port
    String currentLine = ""; // make a String to hold incoming data from the client
    while (client.connected())
    { // loop while the client's connected
      if (client.available()) { // if there's bytes to read from the client,
        char c = client.read(); // read a byte, then
        Serial.write(c); // print it out the serial monitor
        header += c;
        if (c == '\n') { // if the byte is a newline character
          // if the current line is blank, you got two newline characters in a row.
          // that's the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // checking if header is valid
            // YWRtaW46c3RhYWdhcg== (user:pass) admin:staagar
            if (header.indexOf("YWRtaW46c3RhYWdhcg==") >= 0) {
              client.println("HTTP/1.1 200 OK");
              client.println("Content-type:text/html");
              client.println("Connection: close");
              client.println();
              client.println("<!DOCTYPE html>\n");
              client.println("<html>\n");
              client.println("<meta http-equiv=\"refresh\" content=\"5\">\n");
              client.println("<body>\n");
              client.println("<center>\n");
              client.println("<h1 style=\"color:blue;\">Temperatur Kirche</h1>\n");
              client.print("<h2 style=\"color:green;\">Aktuell: ");
              client.print(temp);
              client.println(" &deg;C</h2>\n");
              client.print("<h2 style=\"color:green;\">Minimum: ");
              client.print(temp_min);
              client.println(" &deg;C</h2>\n");
              client.print("<h2 style=\"color:green;\">Maximum: ");
              client.print(temp_max);
              client.println(" &deg;C</h2>\n");
              client.println("</center>\n");
              client.println("</body>\n");
              client.println("</html>");

              break;
            }
            // Wrong user or password, so HTTP request fails...
            else {
              client.println("HTTP/1.1 401 Unauthorized");
              client.println("WWW-Authenticate: Basic realm=\"Secure\"");
              client.println("Content-Type: text/html");
              client.println();
              client.println("<html>Authentication failed</html>");
              break;
            }
          } else { // if you got a newline, then clear currentLine
            currentLine = "";
          }
        } else if (c != '\r') { // if you got anything else but a carriage return character,
          currentLine += c; // add it to the end of the currentLine
        }
      }
    }
    // Clear the header variable
    header = "";
    // Close the connection
    client.stop();
    Serial.println("Client disconnected.");
    Serial.println("");
  }
}

void start_config_portal(void)
{
  if (digitalRead(AP_DATA_RESET_PIN) == HIGH && last_config_check == true)
  {
    DEBUG_MSG("Reset AP data\n");

    WiFiManager wm;

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Resetting AP Data");
    delay(2000);
    wm.resetSettings();
    lcd.setCursor(0, 1);
    lcd.print("Done.");
    delay(1000);
    ESP.restart();
  }
  else if (digitalRead(AP_DATA_RESET_PIN) == HIGH)
  {
    if (digitalRead(AP_DATA_RESET_PIN) == HIGH)
      DEBUG_MSG("Reset AP data pressed\n");
    last_config_check = true;
  }
  else
    last_config_check = false;
}

void show_time(void)
{
  DateTimeParts p = DateTime.getParts();
  char dt[21];

  if (p.getHours() == 0 && p.getMinutes() == 0 && p.getSeconds() == 0)
    DateTime.forceUpdate();

  if ((p.getHours() == 2 || p.getHours() == 3) && p.getMinutes() == 0 && p.getSeconds() == 0)
  {
    if (is_wintertime(DateTime.getTime()) == false)
      add_summertime = 1;
    else
      add_summertime = 0;
  }

  sprintf(dt, "%02d.%02d.%4d  %02d:%02d:%02d", p.getMonthDay(), p.getMonth() + 1, p.getYear(), p.getHours() + add_summertime, p.getMinutes(), p.getSeconds());
  Serial.print(dt);
  if (add_summertime > 0)
    Serial.println(" Summertime");
  else
    Serial.println(" Wintertime");


  lcd.setCursor(0, 0);
  lcd.print(dt);

  digitalWrite(ONBOARD_LED, led_state);
  led_state = !led_state;
}

void show_temperature(void)
{
  float new_temp = get_temp_sensor_data();

  DEBUG_MSG("Temperature: %02.2f\n", new_temp);

  if (new_temp > temp)
  {
    if (new_temp - temp > 1.0)
      temp = temp + 1.0;
    else
      temp = new_temp;
  }
  else if (new_temp < temp)
  {
    if (new_temp - temp < -1.0)
      temp = temp - 1.0;
    else
      temp = new_temp;
  }

  samples.add(temp);

  if (samples.getLowest() < temp_min)
    temp_min = samples.getLowest();
  if (samples.getHighest() > temp_max)
    temp_max = samples.getHighest();

  lcd.setCursor(0, 1);
  lcd.print("Temperatur:  ");
  lcd.print(temp);
  lcd.write(0);
  lcd.print("C");
  lcd.setCursor(0, 2);
  lcd.print("Minimum:     ");
  lcd.print(temp_min);
  lcd.write(0);
  lcd.print("C");
  lcd.setCursor(0, 3);
  lcd.print("Maximum:     ");
  lcd.print(temp_max);
  lcd.write(0);
  lcd.print("C");
}

bool is_wintertime(time_t t)
{
  // Sommerzeit/Winterzeit http://manfred.wilzeck.de/Datum_berechnen.html#Jahreszahl
  // Tag = 31 – ( 4 + Jahr*5 / 4) MOD 7  ' Datum Tag für Beginn Sommerzeit (Jahr 4-stellig)
  // Tag = 31 – ( 1 + Jahr*5 / 4) MOD 7  ' Datum Tag für Ende Sommerzeit (Jahr 4-stellig)
  tmElements_t tm;
  byte day_of_switch[2];
  time_t switch_secs[2];
  byte i;

  day_of_switch[0] = 31 - (4 + year(t) * 5 / 4) % 7; // winter->summer
  day_of_switch[1] = 31 - (1 + year(t) * 5 / 4) % 7; // summer->winter

  for (i = 0; i < 2; i++)
  {
    tm.Second = 0;
    if (i == 0)
      tm.Hour = 2;
    else
      tm.Hour = 3;
    tm.Minute = 0;
    tm.Day = day_of_switch[i];
    if (i == 0)
      tm.Month = 3;
    else
      tm.Month = 10;
    tm.Year = year(t) - 1970;

    switch_secs[i] = makeTime(tm);
  }

  if (t >= switch_secs[0] && t < switch_secs[1])
    return (false);
  else
    return (true);
}

float get_temp_sensor_data(void)
{
  float t = constrain((analogRead(TEMP_SENS_PIN) / 2048.0) * 330.0, 0.0, 50.0);

  return (t);
}