#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "base64.h"
#include <WiFi.h>
#include <PubSubClient.h>

#define PULSE_PIN 35 //le Pin qui correspond au pulse sensor sur la carte ESP 32
#define TEMP_PIN 25 // Temperature sensor
Adafruit_SSD1306 ecranOLED(128, 64, &Wire, -1);

// ThingSpeak channel and API key
const char* channel_id = "2596128"; 
const char* write_api_key = "PK1DCXEGFLFPS6VZ";

// WiFi credentials
const char* ssid = "Wokwi-GUEST"; // The SSID of the WiFi network
const char* password = ""; // WiFi password

// MQTT server details
const char* mqtt_server = "mqtt3.thingspeak.com"; // The MQTT server address
const int mqtt_port = 1883; // MQTT server port
const char* mqtt_client_id = "FSIUBRMSPCg5OTkRBDsOKRQ"; // MQTT client ID
const char* mqtt_username = "FSIUBRMSPCg5OTkRBDsOKRQ"; // MQTT username
const char* mqtt_password = "eSGLbSSVAI0rgr0kQDSvJRmS"; // MQTT password

WiFiClient espClient;
PubSubClient mqtt_client(espClient);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  ecranOLED.begin(SSD1306_SWITCHCAPVCC, 0x3c);

  Serial.println("Hello, ESP32!");

ecranOLED.clearDisplay();
ecranOLED.setTextSize(1);
ecranOLED.setTextColor(SSD1306_WHITE);

connectToWiFi(); // Connect to WiFi network
  mqtt_client.setServer(mqtt_server, mqtt_port); // Setup MQTT connection

}

void loop() {
  // put your main code here, to run repeatedly:
  // Read pulseValue from PULSE_PIN 

 
  ecranOLED.clearDisplay();
  ecranOLED.setCursor(20,0);
  int16_t pulseValue = analogRead(PULSE_PIN);
  int tempValue = analogRead(TEMP_PIN);
  // Convert pulseValue to voltage
  float voltage = (pulseValue * (5 / 4095.0));
  
  // calculate heartRate from voltage
  int heartRate = ((voltage / 3.3) * 67.5);

  ecranOLED.println("Signes Vitaux");
  ecranOLED.println("_____________________");
  ecranOLED.println("");
  ecranOLED.print("Coeur : ");
  ecranOLED.print(String(heartRate));
  ecranOLED.print (" BPM");
  ecranOLED.println("");
  ecranOLED.println("");
  ecranOLED.print("Temperature : ");
  ecranOLED.print((tempValue/100));
ecranOLED.display();
  delay(2000);

  // Ensure MQTT connection is maintained
  if (!mqtt_client.connected()) {
    reconnectMQTT();
  }
  mqtt_client.loop();

  // Read and publish sensor data every 2 seconds
  static unsigned long lastPublishTime = 0;
  if (millis() - lastPublishTime > 2000) {
    lastPublishTime = millis();
    readAndPublishSensorData(heartRate, tempValue);
}
}
// fonction connectToWifi

void connectToWiFi() {
  Serial.print("Connecting to Wi-Fi");
  WiFi.begin(ssid, password);

  // Wait until connected to WiFi
  while (WiFi.status() != WL_CONNECTED) { 
    delay(500);
    Serial.print(".");
  }
  Serial.println(" Connected!");
}

void reconnectMQTT() {
  // Reconnect to MQTT server if disconnected
  while (!mqtt_client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (mqtt_client.connect(mqtt_client_id, mqtt_username, mqtt_password)) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(mqtt_client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

// read and publih data

void readAndPublishSensorData(int heart,int temp) {
   

  // Prepare data string for ThingSpeak
  String data = String("Temperature=" + String(temp/100, 1) +
                "&Heartbeat=" + String(heart, 1)) ;
//String data = String("Temperature=") + String(temp/100, 1));
                
  char dataChar[100];
  data.toCharArray(dataChar, 100);

  // Publish the data to ThingSpeak
  if (mqtt_client.publish("channels/2596128/publish/PK1DCXEGFLFPS6VZ", dataChar)) {
    
    Serial.println("Publish successful");
  } else {
    Serial.println("Publish failed");
  }
}