/**
 * ESP8266 ESP-01 Clock and Weather Firmware
 *
 * This firmware uses an SSD1306 128x64 OLED display to show alternating screens:
 * - Clock screen: shows day of week, current time (HH:MM), temperature & humidity, and date.
 * - Weather screen: shows city name, current temperature, weather condition, humidity, wind speed, and pressure.
 *
 * Wi-Fi Configuration:
 * If no configuration is found or if a button on GPIO3 is held at boot, the device
 * starts as an access point (SSID: ESP01-Setup) and serves a configuration page.
 * The page allows setting Wi-Fi SSID, password, city for weather, and timezone.
 * Settings are saved in EEPROM and the device reboots to normal mode.
 *
 * Normal Operation:
 * Connects to configured Wi-Fi and retrieves time via NTP (synchronized every 60s).
 * Retrieves weather from wttr.in for the specified city (HTTPS GET request).
 * Displays time and weather data on the OLED, switching screens every 15 seconds.
 *
 * Hardware:
 * - ESP8266 ESP-01 (GPIO0=SDA, GPIO2=SCL for I2C OLED; GPIO3 as input for config button).
 * - OLED display SSD1306 128x64 via I2C (address 0x3C).
 *
 * Note: Uses custom fonts (FreeMonoBold18pt7b for time, FreeMonoBold12pt7b for temperature).
 * All other text uses default font. Display is rotated 180 degrees (setRotation(2)).
 */


// Fast pragmas
// ----------------
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-O3")


#if defined(ESP8266) 
 whatever fwon;
 #include <ExxxSP8266WiFi.h> 
 #include <ExxSP8266WebServer.h>
#elif defined(ESP32) 
   #include <WiFi.h> 
   #include <WebServer.h>
#endif 


#include <EEPROM.h>
//#include <ESP8266WiFi.h>
//#include <ESP8266WebServer.h>
#include <WiFiClientSecure.h>
#include <NTPClient.h>
#include <WiFiUdp.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <Fonts/FreeMonoBold18pt7b.h>  // MM: FreeMonoBold24pt7b
#include <Fonts/FreeMonoBold12pt7b.h>
#include <time.h>


#if defined(ESP8266) 
  // Pin definitions (ESP-01):
  const uint8_t SDA_PIN = 0;           // I2C SDA connected to GPIO0
  const uint8_t SCL_PIN = 2;           // I2C SCL connected to GPIO2
  const uint8_t BUTTON_PIN = 3;        // Button on GPIO3 (RX pin)
#elif defined(ESP32) 
  //MM:
  const uint8_t SDA_PIN = 21;           // I2C SDA connected to GPIO0
  const uint8_t SCL_PIN = 22;           // I2C SCL connected to GPIO2
  const uint8_t BUTTON_PIN = 16;        // Button on GPIO3 (RX pin)
#endif 


// EEPROM addresses for configuration data:
const int EEPROM_SIZE = 512;
const int ADDR_SSID = 0;
const int ADDR_PASS = 70;
const int ADDR_CITY = 140;
const int ADDR_TZ   = 210;  // 4 bytes (int32) for timezone offset in seconds
const int ADDR_SIGNATURE = 500;  // 4-byte signature "CFG1" to indicate valid config

// Wi-Fi and server:

//MM: ESP8266WebServer server(80);
WebServer server(80);
const char *AP_SSID = "MM-ESP01-Setup";  // Access Point SSID for config mode

// Display:
Adafruit_SSD1306 display(128, 64, &Wire, -1);
bool displayInitialized = false;

// Time and weather:
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP);
unsigned long lastScreenSwitch = 0;
bool showWeatherScreen = false;
bool displayReady = false;
unsigned long lastWeatherFetch = 0;

// Configuration variables:
//String wifiSSID = "";
//String wifiPass = "";
//String city = "";
//int timezoneOffset = 0;  // in seconds
// MM...
String wifiSSID = "Wokwi-GUEST";
String wifiPass = "";
String city = "Oerlikon";
int timezoneOffset = 2*60*60;  // in seconds



// Weather data variables:
String weatherTemp = "N/A";
String weatherCond = "";
String weatherHum = "";
String weatherWind = "";
String weatherPress = "";
bool weatherValid = false;

// Function prototypes:
void loadSettings();
void saveSettings();
void startConfigPortal();
void handleConfigForm();
void drawTimeScreen();
void drawWeatherScreen();
bool getWeather();

void setup() {

  Serial.begin(115200);
  Serial.println();
  Serial.println(F("Booting..."));

    // Initialize display
    Wire.begin(SDA_PIN, SCL_PIN);
    if (display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
      displayInitialized = true;
      display.setRotation(2);
      display.clearDisplay();
      display.setTextColor(SSD1306_WHITE);
      display.print("Booting...");
      display.display();
      displayReady = true;
    } else {
      Serial.println(F("SSD1306 allocation failed"));
      // Leave displayInitialized as false
    }

  pinMode(BUTTON_PIN, INPUT_PULLUP);
  // Initialize EEPROM and load stored settings if available
  EEPROM.begin(EEPROM_SIZE);
  bool configMode = false;


//////////////////////////////////
//MM
/*
String wifiSSID = "Wokwi-GUEST";
String wifiPass = "";
String city = "Oerlikon";
int timezoneOffset = 2*60*60;  // in seconds
*/
 saveSettings();

///////////////////////////////

  // Check if config signature is present in EEPROM
  if (EEPROM.read(ADDR_SIGNATURE) == 'C' &&
      EEPROM.read(ADDR_SIGNATURE + 1) == 'F' &&
      EEPROM.read(ADDR_SIGNATURE + 2) == 'G' &&
      EEPROM.read(ADDR_SIGNATURE + 3) == '1') {
    Serial.println(F("Config signature found in EEPROM."));
  } else {
    Serial.println(F("No config signature found (EEPROM uninitialized)."));
  }

  // Check button press in first 300ms of boot
  bool buttonPressed = false;
  unsigned long startTime = millis();
  while (millis() - startTime < 300) {
    if (digitalRead(BUTTON_PIN) == LOW) {
      buttonPressed = true;
    }
    delay(10);
  }
  if (buttonPressed) {
    Serial.println(F("Config button held - entering AP configuration mode."));
  }

  // Determine if we should start config portal
  if (EEPROM.read(ADDR_SIGNATURE) != 'C' || EEPROM.read(ADDR_SIGNATURE+1) != 'F' ||
      EEPROM.read(ADDR_SIGNATURE+2) != 'G' || EEPROM.read(ADDR_SIGNATURE+3) != '1' ||
      buttonPressed) {
    configMode = true;
  }

  if (configMode) {
    // Load existing settings (if any) to pre-fill form
    if (EEPROM.read(ADDR_SIGNATURE) == 'C' && EEPROM.read(ADDR_SIGNATURE + 1) == 'F' &&
        EEPROM.read(ADDR_SIGNATURE + 2) == 'G' && EEPROM.read(ADDR_SIGNATURE + 3) == '1') {
      loadSettings();
    }
    // Start configuration portal (Access Point mode)
    startConfigPortal();
    // After configuration, ESP will reboot. If not rebooted (e.g. user didn't submit),
    // it will remain in AP mode and handleClient in loop.
  } else {
    // Load settings from EEPROM
    loadSettings();
    Serial.print(F("Connecting to WiFi: "));
    Serial.println(wifiSSID);
    WiFi.mode(WIFI_STA);
    WiFi.begin(wifiSSID.c_str(), wifiPass.c_str());
    // Wait up to 10 seconds for connection
    unsigned long wifiStart = millis();
    while (WiFi.status() != WL_CONNECTED && millis() - wifiStart < 10000) {
      delay(500);
      Serial.print('.');
    }
    Serial.println();
    if (WiFi.status() == WL_CONNECTED) {
      Serial.println(F("WiFi connected."));
      Serial.print(F("IP Address: "));
      Serial.println(WiFi.localIP());
    } else {
      Serial.println(F("WiFi connection failed. Starting AP mode instead."));
      startConfigPortal();
      return; // Exit setup to avoid running normal mode without WiFi
    }
    // Setup NTP client with stored timezone offset
    timeClient.setPoolServerName("pool.ntp.org");
    timeClient.setTimeOffset(timezoneOffset);
    timeClient.setUpdateInterval(900000);  // 15 mins interval
    timeClient.begin();
    // Perform initial NTP update
    timeClient.update();

    // Prepare first weather fetch
    lastWeatherFetch = 0; // force immediate fetch on first weather screen display
    weatherValid = false;
    Serial.println(F("Setup complete, entering loop."));
  }
Serial.println(F("Getting initial weather..."));
weatherValid = getWeather();
lastWeatherFetch = millis();
if (weatherValid) {
  Serial.println(F("Initial weather fetch successful."));
} else {
  Serial.println(F("Initial weather fetch failed."));
} 
}

void loop() {
  // If in config portal mode, handle web server
  if (WiFi.getMode() == WIFI_AP) {
    server.handleClient();
    // In AP mode, do not run normal display loop
    return;
  }

  // Regular mode: update time and handle display
  timeClient.update();
  unsigned long now = millis();

  // Switch screen every 15 seconds
  if (now - lastScreenSwitch > 15000) {
    showWeatherScreen = !showWeatherScreen;
    lastScreenSwitch = now;
    // If switching to weather screen, update weather data (limit fetch frequency)
    if (showWeatherScreen) {

// Update weather every 15 minutes
if (millis() - lastWeatherFetch > 900000UL || !weatherValid) {
  Serial.println(F("Updating weather data..."));
  weatherValid = getWeather();
  lastWeatherFetch = millis();
  if (weatherValid) {
    Serial.println(F("Weather update successful."));
  } else {
    Serial.println(F("Weather update failed or data invalid."));
  }
}
    }
  }

  // Draw the appropriate screen
  if (showWeatherScreen) {
    drawWeatherScreen();
  } else {
    drawTimeScreen();
  }

  // Small delay to yield to system
  delay(10);
}

void startConfigPortal() {
  // Stop any existing WiFi and start AP
  WiFi.disconnect();
  WiFi.mode(WIFI_AP);
  WiFi.softAP(AP_SSID);
  IPAddress apIP = WiFi.softAPIP();
  Serial.print(F("Started AP mode with SSID "));
  Serial.print(AP_SSID);
  Serial.print(F(". Connect and browse to http://"));
  Serial.println(apIP);

    if (displayReady) {
      display.clearDisplay();
      display.setTextColor(SSD1306_WHITE);
      display.setTextSize(1);
      display.setCursor(0, 0);
      display.println("AP mode");
      display.setCursor(0, 10);
      display.println("SSID: MM-ESP01-Setup");
      display.setCursor(0, 20);
      display.println("IP: 192.168.4.1");
      display.display();
    }
  // Setup web server routes
  server.on("/", HTTP_GET, []() {
    // HTML page for config
    String page = "<!DOCTYPE html><html><head><meta charset='UTF-8'>";
    page += String("<title>ESP8266 Setup</title><style>") +
            ".container{max-width:300px;margin:40px auto;padding:20px;background:#f7f7f7;border:1px solid #ccc;border-radius:5px;}" +
            "body{text-align:center;font-family:sans-serif;}h2{margin-bottom:15px;}label{display:block;text-align:left;margin-top:10px;}" +
            "input, select{width:100%;padding:8px;margin-top:5px;border:1px solid #ccc;border-radius:3px;}" +
            "input[type=submit]{margin-top:15px;background:#4caf50;color:white;border:none;cursor:pointer;border-radius:3px;font-size:16px;}" +
            "input[type=submit]:hover{background:#45a049;}" +
            "</style></head><body><div class='container'>";
    page += "<h2>Device Configuration</h2><form method='POST' action='/'>";
    // WiFi SSID field
    page += "<label>Wi-Fi SSID:</label><input type='text' name='ssid' value='" + wifiSSID + "' required>";
    // Password field
    page += "<label>Password:</label><input type='password' name='pass' value='" + wifiPass + "' placeholder=''>";
    // City field
    page += "<label>City:</label><input type='text' name='city' value='" + city + "' required>";
    // Timezone dropdown
    page += "<label>Timezone:</label><select name='tz'>";
    // Populate timezone options from UTC-12 to UTC+14
    for (int tzHour = -12; tzHour <= 14; ++tzHour) {
      long tzSeconds = tzHour * 3600;
      String option = "<option value='" + String(tzSeconds) + "'";
      if (tzSeconds == timezoneOffset) {
        option += " selected";
      }
      option += ">UTC";
      if (tzHour >= 0) option += "+" + String(tzHour);
      else option += String(tzHour);
      option += "</option>";
      page += option;
    }
    page += "</select>";
    // Submit button
    page += "<input type='submit' value='Save'></form></div></body></html>";
    server.send(200, "text/html", page);
  });

  server.on("/", HTTP_POST, handleConfigForm);
  server.begin();
  Serial.println(F("HTTP server started for config portal."));
}

void handleConfigForm() {
  // Get form values
  String ssid = server.arg("ssid");
  String pass = server.arg("pass");
  String newCity = server.arg("city");
  String tzStr = server.arg("tz");

  Serial.println(F("Received configuration:"));
  Serial.print(F("SSID: ")); Serial.println(ssid);
  Serial.print(F("Password: ")); Serial.println(pass);
  Serial.print(F("City: ")); Serial.println(newCity);
  Serial.print(F("Timezone (s): ")); Serial.println(tzStr);

  if (ssid.length() > 0 && newCity.length() > 0 && tzStr.length() > 0) {
    wifiSSID = ssid;
    wifiPass = pass;
    city = newCity;
    timezoneOffset = tzStr.toInt();
    // Save to EEPROM
    saveSettings();
    // Send response page
    server.send(200, "text/html", "<html><body><h3>Settings saved. Rebooting...</h3></body></html>");
    delay(1000);
    ESP.restart();
  } else {
    server.send(400, "text/html", "<html><body><h3>Invalid input, please fill all required fields.</h3></body></html>");
  }
}

void loadSettings() {
  // Read SSID
  uint8_t len = EEPROM.read(ADDR_SSID);
  if (len > 0 && len < 0xFF) {
    char buf[80];
    for (int i = 0; i < len; ++i) {
      buf[i] = char(EEPROM.read(ADDR_SSID + 1 + i));
    }
    buf[len] = '\0';
    wifiSSID = String(buf);
  } else {
    wifiSSID = "";
  }
  // Read Password
  len = EEPROM.read(ADDR_PASS);
  if (len > 0 && len < 0xFF) {
    char buf[80];
    for (int i = 0; i < len; ++i) {
      buf[i] = char(EEPROM.read(ADDR_PASS + 1 + i));
    }
    buf[len] = '\0';
    wifiPass = String(buf);
  } else {
    wifiPass = "";
  }
  // Read City
  len = EEPROM.read(ADDR_CITY);
  if (len > 0 && len < 0xFF) {
    char buf[80];
    for (int i = 0; i < len; ++i) {
      buf[i] = char(EEPROM.read(ADDR_CITY + 1 + i));
    }
    buf[len] = '\0';
    city = String(buf);
  } else {
    city = "";
  }
  // Read Timezone offset (int32)
  uint32_t b0 = EEPROM.read(ADDR_TZ);
  uint32_t b1 = EEPROM.read(ADDR_TZ + 1);
  uint32_t b2 = EEPROM.read(ADDR_TZ + 2);
  uint32_t b3 = EEPROM.read(ADDR_TZ + 3);
  uint32_t raw = (b0 & 0xFF) | ((b1 & 0xFF) << 8) | ((b2 & 0xFF) << 16) | ((b3 & 0xFF) << 24);
  timezoneOffset = (int) raw;
}

void saveSettings() {
  // Write SSID
  uint8_t len = wifiSSID.length();
  if (len > 0) {
    EEPROM.write(ADDR_SSID, len);
    for (int i = 0; i < len; ++i) {
      EEPROM.write(ADDR_SSID + 1 + i, wifiSSID[i]);
    }
  } else {
    EEPROM.write(ADDR_SSID, 0);
  }
  // Write Password
  len = wifiPass.length();
  if (len > 0) {
    EEPROM.write(ADDR_PASS, len);
    for (int i = 0; i < len; ++i) {
      EEPROM.write(ADDR_PASS + 1 + i, wifiPass[i]);
    }
  } else {
    EEPROM.write(ADDR_PASS, 0);
  }
  // Write City
  len = city.length();
  if (len > 0) {
    EEPROM.write(ADDR_CITY, len);
    for (int i = 0; i < len; ++i) {
      EEPROM.write(ADDR_CITY + 1 + i, city[i]);
    }
  } else {
    EEPROM.write(ADDR_CITY, 0);
  }
  // Write Timezone (int32)
  int tz = timezoneOffset;
  EEPROM.write(ADDR_TZ, tz & 0xFF);
  EEPROM.write(ADDR_TZ + 1, (tz >> 8) & 0xFF);
  EEPROM.write(ADDR_TZ + 2, (tz >> 16) & 0xFF);
  EEPROM.write(ADDR_TZ + 3, (tz >> 24) & 0xFF);
  // Write signature 'CFG1'
  EEPROM.write(ADDR_SIGNATURE, 'C');
  EEPROM.write(ADDR_SIGNATURE + 1, 'F');
  EEPROM.write(ADDR_SIGNATURE + 2, 'G');
  EEPROM.write(ADDR_SIGNATURE + 3, '1');
  // Commit changes to EEPROM
  EEPROM.commit();
  Serial.println(F("Configuration saved to EEPROM."));
}

void drawTimeScreen() {
  if (!displayInitialized) {
    return;
  }
  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
  // Day name at top center
  // Get current epoch time and derive day of week
  time_t epoch = timeClient.getEpochTime();
  // Calculate day of week (0=Sunday .. 6=Saturday)
  struct tm *tm = gmtime(&epoch);
  int wday = tm->tm_wday;  // tm_wday: days since Sunday (0-6)
  String dayName = "";
  switch(wday) {
    case 0: dayName = "Sunday"; break;
    case 1: dayName = "Monday"; break;
    case 2: dayName = "Tuesday"; break;
    case 3: dayName = "Wednesday"; break;
    case 4: dayName = "Thursday"; break;
    case 5: dayName = "Friday"; break;
    case 6: dayName = "Saturday"; break;
  }
  display.setFont(NULL); // default font
 // display.setFont(&FreeMonoBold12pt7b);
  int16_t x1, y1;
  uint16_t w, h;
  display.getTextBounds(dayName, 0, 0, &x1, &y1, &w, &h);
  // center horizontally
  int dayX = (128 - w) / 2;
  display.setCursor(dayX, 0); //MM: 16 statt 0 bei 12pt
  display.print(dayName);

  // Time HH:MM in large font, centered
  display.setFont(&FreeMonoBold18pt7b);
  // Format time as HH:MM
  char timeBuf[6];
  snprintf(timeBuf, sizeof(timeBuf), "%02d::%02d", timeClient.getHours(), timeClient.getMinutes());
  String timeStr = String(timeBuf);
  display.getTextBounds(timeStr, 0, 30, &x1, &y1, &w, &h);
  int timeX = (128 - w) / 2;
  // Vertically center the text around mid (y=32)
  int timeY = 32 + (h / 2);  // MM 38+ ...
  display.setCursor(timeX, timeY);
  display.print(timeStr);

  // Bottom left: temperature and humidity
  display.setFont(NULL);
  display.setCursor(0, 56);
  if (weatherValid && weatherTemp != "N/A" && weatherHum != "") {
    String tempDisplay = weatherTemp;
    tempDisplay.trim();
    display.print(tempDisplay);
    display.print((char)247); // degree symbol
    display.print("C ");
    display.print(weatherHum);
  } else {
    display.print("N/A");
  }

  // Bottom right: date dd.mm.yyyy
  tm = gmtime(&epoch);
  int day = tm->tm_mday;
  int month = tm->tm_mon + 1;
  int year = tm->tm_year + 1900;
  char dateBuf[12];
  snprintf(dateBuf, sizeof(dateBuf), "%02d.%02d.%04d", day, month, year);
  String dateStr = String(dateBuf);
  display.getTextBounds(dateStr, 0, 0, &x1, &y1, &w, &h);
  display.setCursor(128 - w, 56);
  display.print(dateStr);

  display.display();
}

void drawWeatherScreen() {
  if (!displayInitialized) {
    return;
  }
  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
  display.setFont(NULL);

  // Top center: city name
  String cityName = city;
  int16_t x1, y1; uint16_t w, h;
  display.getTextBounds(cityName, 0, 0, &x1, &y1, &w, &h);
  int cityX = (128 - w) / 2;
  display.setCursor(cityX, 0); 
  display.print(cityName);
  // Middle center: temperature (big font FreeMonoBold12pt7b)
  display.setFont(&FreeMonoBold12pt7b);
  if (weatherValid && weatherTemp != "N/A") {
    // weatherTemp is e.g. "+12" or "-3" as string (cleaned)
    String tempNum = weatherTemp;
    // Center the numeric part
    display.getTextBounds(tempNum, 0, 30, &x1, &y1, &w, &h);
    int tempX = (128 - (w + 12)) / 2; // leave space for degree and C (~12px)
    int tempY = 30; // baseline for 12pt font around mid screen
    display.setCursor(tempX, tempY);
    display.print(tempNum);
    // Now draw degree symbol and 'C' in default font after the number
    //display.setFont(NULL);
    // Place small degree symbol near top of big text and 'C' after it
    int degX = tempX + w + 3; // position degree just right of number
    int degY = tempY - 16;    // raise small text (approx half big font height)
    if (degY < 0) degY = 0;
    display.setCursor(degX, degY);
    //display.print((char)247);
    display.drawCircle(degX, degY, 2, SSD1306_WHITE);
    display.setCursor(degX + 3, tempY);
    display.setFont(&FreeMonoBold12pt7b);    
    display.print("C");
    display.setFont(NULL);
  } else {
    // If weather not available, show N/A in big font
    String na = "N/A";
    display.getTextBounds(na, 0, 30, &x1, &y1, &w, &h);
    int naX = (128 - w) / 2;
    display.setCursor(naX, 30);
    display.print(na);
    // No degree symbol or 'C' in this case
  }
  // Below temperature: condition string (centered)
  display.setFont(NULL);
  String cond = weatherValid ? weatherCond : "";
  cond.trim();
  display.getTextBounds(cond, 0, 40, &x1, &y1, &w, &h);
  int condX = (128 - w) / 2;
  display.setCursor(condX, 40);
  display.print(cond);
  // Bottom right: H:% W:m/s P:mm
  display.setFont(NULL);
  if (weatherValid && weatherTemp != "N/A") {
    String bottomStr = String("H:") + weatherHum;
    bottomStr += " W:" + weatherWind;
    if (weatherWind != "N/A") bottomStr += "m/s";
    bottomStr += " P:" + weatherPress + "mm";
    display.getTextBounds(bottomStr, 0, 56, &x1, &y1, &w, &h);
    display.setCursor(128 - w, 56);
    display.print(bottomStr);
  } else {
    String bottomStr = "H:N/A W:N/A P:N/A";
    display.getTextBounds(bottomStr, 0, 56, &x1, &y1, &w, &h);
    display.setCursor(128 - w, 56);
    display.print(bottomStr);
  }
  display.display();
}



bool getWeather() {

// www.howsmyssl.com root certificate authority, to verify the server
// change it to your server root CA
// SHA1 fingerprint is broken now!

const char* test_root_ca= \
  "-----BEGIN CERTIFICATE-----\n" \
  "MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw\n" \
  "TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh\n" \
  "cmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMTUwNjA0MTEwNDM4\n" \
  "WhcNMzUwNjA0MTEwNDM4WjBPMQswCQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJu\n" \
  "ZXQgU2VjdXJpdHkgUmVzZWFyY2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBY\n" \
  "MTCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIBAK3oJHP0FDfzm54rVygc\n" \
  "h77ct984kIxuPOZXoHj3dcKi/vVqbvYATyjb3miGbESTtrFj/RQSa78f0uoxmyF+\n" \
  "0TM8ukj13Xnfs7j/EvEhmkvBioZxaUpmZmyPfjxwv60pIgbz5MDmgK7iS4+3mX6U\n" \
  "A5/TR5d8mUgjU+g4rk8Kb4Mu0UlXjIB0ttov0DiNewNwIRt18jA8+o+u3dpjq+sW\n" \
  "T8KOEUt+zwvo/7V3LvSye0rgTBIlDHCNAymg4VMk7BPZ7hm/ELNKjD+Jo2FR3qyH\n" \
  "B5T0Y3HsLuJvW5iB4YlcNHlsdu87kGJ55tukmi8mxdAQ4Q7e2RCOFvu396j3x+UC\n" \
  "B5iPNgiV5+I3lg02dZ77DnKxHZu8A/lJBdiB3QW0KtZB6awBdpUKD9jf1b0SHzUv\n" \
  "KBds0pjBqAlkd25HN7rOrFleaJ1/ctaJxQZBKT5ZPt0m9STJEadao0xAH0ahmbWn\n" \
  "OlFuhjuefXKnEgV4We0+UXgVCwOPjdAvBbI+e0ocS3MFEvzG6uBQE3xDk3SzynTn\n" \
  "jh8BCNAw1FtxNrQHusEwMFxIt4I7mKZ9YIqioymCzLq9gwQbooMDQaHWBfEbwrbw\n" \
  "qHyGO0aoSCqI3Haadr8faqU9GY/rOPNk3sgrDQoo//fb4hVC1CLQJ13hef4Y53CI\n" \
  "rU7m2Ys6xt0nUW7/vGT1M0NPAgMBAAGjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNV\n" \
  "HRMBAf8EBTADAQH/MB0GA1UdDgQWBBR5tFnme7bl5AFzgAiIyBpY9umbbjANBgkq\n" \
  "hkiG9w0BAQsFAAOCAgEAVR9YqbyyqFDQDLHYGmkgJykIrGF1XIpu+ILlaS/V9lZL\n" \
  "ubhzEFnTIZd+50xx+7LSYK05qAvqFyFWhfFQDlnrzuBZ6brJFe+GnY+EgPbk6ZGQ\n" \
  "3BebYhtF8GaV0nxvwuo77x/Py9auJ/GpsMiu/X1+mvoiBOv/2X/qkSsisRcOj/KK\n" \
  "NFtY2PwByVS5uCbMiogziUwthDyC3+6WVwW6LLv3xLfHTjuCvjHIInNzktHCgKQ5\n" \
  "ORAzI4JMPJ+GslWYHb4phowim57iaztXOoJwTdwJx4nLCgdNbOhdjsnvzqvHu7Ur\n" \
  "TkXWStAmzOVyyghqpZXjFaH3pO3JLF+l+/+sKAIuvtd7u+Nxe5AW0wdeRlN8NwdC\n" \
  "jNPElpzVmbUq4JUagEiuTDkHzsxHpFKVK7q4+63SM1N95R1NbdWhscdCb+ZAJzVc\n" \
  "oyi3B43njTOQ5yOf+1CceWxG1bQVs5ZufpsMljq4Ui0/1lvh+wjChP4kqKOJ2qxq\n" \
  "4RgqsahDYVvTH9w7jXbyLeiNdd8XM2w9U/t7y0Ff/9yi0GE44Za4rF2LN9d11TPA\n" \
  "mRGunUHBcnWEvgJBQl9nJEiU0Zsnvgc/ubhPgXRR4Xq37Z0j4r7g1SgEEzwxA57d\n" \
  "emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc=\n" \
  "-----END CERTIFICATE-----\n"; 


  if (WiFi.status() != WL_CONNECTED) {
    Serial.println(F("WiFi not connected, cannot get weather."));
    return false;
  }

  WiFiClientSecure client;
    client.setCACert(test_root_ca);
  // client.setInsecure(); // Skip certificate validation for simplicity
  const char* host = "wttr.in";
  // MM: added https and explicit host
  //String url = "https://wttr.in/" + city + "?lang=de&format=%25t|%25C|%25h|%25w|%25P";
   String url = "/" + city + "?lang=de&format=%25t|%25C|%25h|%25w|%25P";


  Serial.print(F("Connecting to weather server: "));
  Serial.println(host);

  // MM: extra debugging  
  int conerr;
  conerr=client.connect(host, 443);
  if (!conerr) {
    Serial.println(F("Connection failed."));
    Serial.println(conerr);
    return false;
  }
  
  Serial.print(F("Sending Request for URL: "));
  Serial.println(url);

  // Send GET request
  client.print(String("GET ") + url + " HTTP/1.1\r\n" +
               "Host: " + host + "\r\n" +
               "User-Agent: MM-ESP8266\r\n" +
               "Connection: close\r\n\r\n");
 // Read full response as raw text
  String response = "";
  unsigned long timeout = millis() + 5000;
  while (millis() < timeout && client.connected()) {
    while (client.available()) {
      char c = client.read();
      response += c;
    }
  }
  client.stop();

  Serial.println(F("---- RAW RESPONSE ----"));
  Serial.println(response);
  Serial.println(F("----------------------"));

  // --- Extract line with weather data ---
  String result = "";
  int from = 0;
  while (from >= 0) {
    int to = response.indexOf('\n', from);
    if (to == -1) break;
    String line = response.substring(from, to);
    line.replace("\r", "");
    line.trim();

    Serial.print("DEBUG LINE: >");
    Serial.print(line);
    Serial.println("<");

    if (line.indexOf('|') != -1) {
      result = line;
      break;
    }

    from = to + 1;
  }

  // If no \n at the end — catch the remaining part
  if (result.length() == 0 && from < response.length()) {
    String line = response.substring(from);
    line.replace("\r", "");
    line.trim();
    Serial.print("FALLBACK LINE: >");
    Serial.print(line);
    Serial.println("<");
    if (line.indexOf('|') != -1) {
      result = line;
    }
  }

  Serial.print(F("Weather raw response: "));
  Serial.println(result);

  if (result.length() == 0) {
    Serial.println(F("No weather data found."));
    return false;
  }

  // Parse fields: temp|cond|hum|wind|press
  int idx1 = result.indexOf('|');
  int idx2 = result.indexOf('|', idx1 + 1);
  int idx3 = result.indexOf('|', idx2 + 1);
  int idx4 = result.indexOf('|', idx3 + 1);
  if (idx1 < 0 || idx2 < 0 || idx3 < 0 || idx4 < 0) return false;

  String tempStr   = result.substring(0, idx1);
  String condStr   = result.substring(idx1 + 1, idx2);
  String humStr    = result.substring(idx2 + 1, idx3);
  String windStr   = result.substring(idx3 + 1, idx4);
  String pressStr  = result.substring(idx4 + 1);

  // Clean Temperature: remove degree symbol and 'C'
  tempStr.replace("°C", "");
  tempStr.replace("°", "");
  tempStr.replace("C", "");
  tempStr.trim();
  weatherTemp = tempStr; // keep + or - sign if present

  // Clean Condition:
  condStr.trim();
  weatherCond = condStr;

  // Clean Humidity: ensure '%' present
  humStr.trim();
  if (!humStr.endsWith("%")) {
    weatherHum = humStr + "%";
  } else {
    weatherHum = humStr;
  }

  // Clean Wind: extract numeric part (km/h)
  String windNum = "";
  for (uint i = 0; i < windStr.length(); ++i) {
    char c = windStr.charAt(i);
    if ((c >= '0' && c <= '9') || c == '.') {
      windNum += c;
    } else if (c == ' ' && windNum.length() > 0) {
      break;
    }
  }
  if (windNum.length() == 0) {
    weatherWind = "N/A";
  } else {
    float windKmh = windNum.toFloat();
    float windMs = windKmh / 3.6;
    int windMsRounded = (int)round(windMs);
    weatherWind = String(windMsRounded);
  }

  // Clean Pressure: extract numeric part (hPa)
  String pressNum = "";
  for (uint i = 0; i < pressStr.length(); ++i) {
    char c = pressStr.charAt(i);
    if ((c >= '0' && c <= '9') || c == '.') {
      pressNum += c;
    } else if (!pressNum.isEmpty()) {
      break;
    }
  }
  if (pressNum.length() == 0) {
    weatherPress = "N/A";
  } else {
    float pressHpa = pressNum.toFloat();
    float pressMm = pressHpa * 0.75006;
    int pressRounded = (int) round(pressMm);
    weatherPress = String(pressRounded);
  }

  Serial.println(F("Parsed weather data:"));
  Serial.print(F("Temp=")); Serial.println(weatherTemp);
  Serial.print(F("Cond=")); Serial.println(weatherCond);
  Serial.print(F("Hum=")); Serial.println(weatherHum);
  Serial.print(F("Wind(m/s)=")); Serial.println(weatherWind);
  Serial.print(F("Pressure(mmHg)=")); Serial.println(weatherPress);

  // Validate critical fields
  if (weatherTemp == "" || weatherCond == "") {
    return false;
  }
  return true;
}