// Code to connect to the KA-WLAN and download UTF-8 file with API request

// Libraries used
#include <WiFi.h> // Library to connect to the internet via WiFi
#include <Arduino.h> // Library to work with the ESP32 as an arduino
#include <HTTPClient.h> // Library for API requests

// Constants
const char* ssid = "Wokwi-GUEST"; // Name of the network
const char* password = ""; // Password of the network
const char *apiEndpoint = "https://raumzeit.hka-iwi.de/api/v1/timetables/room/E-201?reload=t"; // API endpoint for room E-201
const char *authHeaderName = "X-API-Key";
const char *apiKey = "ghu438$Q#BJ!";

// Function to connect to the WiFi network that you want to use
void connectToWiFi(){
  Serial.print("Connecting to the WiFi network: ");
  Serial.print(ssid);
  WiFi.begin(ssid, password); // Used to connect to the network that you want to use

  // Prints a dot while the ESP32 is not connected to the network
  while(WiFi.status()!=WL_CONNECTED){
    Serial.print("."); 
    delay(500);
    }

  Serial.println("\nConnected to the WiFi network");
  Serial.print("IP Adress: ");
  Serial.println(WiFi.localIP());
}

// Login to the captive portal of KA -Wlan
void captiveLogin(){ 
  HTTPClient http;
  http.begin("https://cph.ka-wlan.de/login");
  http.addHeader("Content-Type", "application/x-www-form-urlencoded");
  Serial.println(WiFi.macAddress());
  int httpCode = http.POST("dst=&popup=false&username=" + WiFi.macAddress() + "&password=wSwb8w096");
  if (httpCode != 200){
    Serial.println("Failed");
  }
  else{
    Serial.println("Connected");
  }
  delay(3000);
}

void downloadSchedule(){
  HTTPClient http;
  http.begin(apiEndpoint);
  http.addHeader(authHeaderName, apiKey);
  int httpCode = http.GET();
  String payload = http.getString();
  Serial.println(payload);
  if (httpCode > 0) {
        Serial.printf("[HTTP] GET... code: %d\n", httpCode);
        if (httpCode == HTTP_CODE_OK) {
            String payload = http.getString();
            Serial.println(payload);
        }
    } else {
        Serial.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
    }
  delay(3000);
}

void setup(){
    Serial.begin(115200); // Baud rate used
    delay(3000);
    connectToWiFi(); // Setup to connect to WiFi network
    delay(5000);
    captiveLogin();
    delay(10000);
    if((WiFi.status() == WL_CONNECTED)){
      downloadSchedule();
    }
    else{
      Serial.println("Connection lost");
    }
    
}

void loop(){
    
}