#include <PubSubClient.h>   //library for MQTT
#include <WiFi.h>   //library for WiFi
#include "cJSON.h"  //library for parsing json

const char *WIFI_SSID = "Wokwi-GUEST";

const char *WIFI_PWD = "";

const int ID = 4;         //Identifier of the device

const int TotalDevices = 4;



#define clientId "iot-polimi-actuator-4"
#define MQTT_TOPIC "polimi/project3/2023/10606435"

const char *MQTT_SERVER = "broker.hivemq.com";
const uint16_t MQTT_PORT = 1883;

WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);

#define LED 12
#define C_TIME 100

volatile int pmw_value = 0;       //variable used for set the luminosity

volatile int control = 0;         //variable used to esabilish if the payload is a message or a number

hw_timer_t *My_timer = NULL;

//FUnciton for the PMW 
void IRAM_ATTR onTimer(){
  bool led_status = digitalRead(LED);

  if (led_status && pmw_value != C_TIME){
    digitalWrite(LED, !led_status);
    timerWrite(My_timer, pmw_value);
  }
  else if(!led_status && pmw_value !=0){
    digitalWrite(LED, !led_status);
    timerWrite(My_timer, C_TIME-pmw_value);
  }

}

char msg[100];       // to store the payload 
char capmsg[100];   // to store the message for the response in the CAP.
char *endPtr;       // string to numeric value
int msgIndex = 0;
int  frameDuration_value = 0;



void CallbackPan(char* topic, byte* payload, unsigned int length)
{
  msgIndex = 0;
    
  //Store the paylaod

  for (int i = 0; i < length; i++)
  {
     msg[msgIndex] = payload[i];
        msgIndex++;
  }
  
  Serial.println(msg);
  const char* json_string = msg;

    // Parse the JSON string
    cJSON* root = cJSON_Parse(json_string);
   control = strtof(msg, &endPtr);   
    // Check if parsing was successful
  if (*endPtr != '\0' && root == NULL) {
        //It's not a json
        memset(msg, 0, sizeof(msg));
  }
  else if (*endPtr != '\0') {     

    //It's a json

    // Extract individual variables using cJSON_GetObjectItem
    cJSON* frameDuration = cJSON_GetObjectItem(root, "FrameDuration");
    cJSON* cap = cJSON_GetObjectItem(root, "CAP");
    cJSON* cfp = cJSON_GetObjectItem(root, "CFP");
    cJSON* info = cJSON_GetObjectItem(root, "Info");
    cJSON* bi = cJSON_GetObjectItem(root, "BI");
    memset(msg, 0, sizeof(msg));      //Erase the payload

    // Check if variables were extracted successfully
    if (frameDuration && cap && cfp && info && bi) {
        printf("FrameDuration: %s\n", frameDuration->valuestring);
        printf("CAP: %s\n", cap->valuestring);
        printf("CFP: %s\n", cfp->valuestring);
        printf("Info: %s\n", info->valuestring);
        printf("BI: %s\n", bi->valuestring);

        memset(msg, 0, sizeof(msg));    //Erase the payload
    
    int i ;   //Convert to int
    int cap_value = atoi(cap->valuestring);   //Convert to int
    int cfp_value = atoi(cfp->valuestring);   //Convert to int
    frameDuration_value = atoi( frameDuration->valuestring);    //Convert to int

    sprintf(capmsg, "%s connected in CAP!", clientId);
    mqttClient.publish(MQTT_TOPIC, capmsg);     // Send connection message
    Serial.println(capmsg);
    delay(cap_value);           // Wait for the CFP
    printf("CAP FINISHED.\n");}
    delay(frameDuration_value*(ID-1));      // Wait for the first assigned slot

  }else{

        // It's a numeric value
        pmw_value = strtof(msg, &endPtr);  //change the pmw value
        memset(msg, 0, sizeof(msg));        //Erase the payload 
        sprintf(msg, "Client ID: %s Led ON", clientId);
        Serial.println(msg);
        mqttClient.publish(MQTT_TOPIC, msg);    //Publish the status
        memset(msg, 0, sizeof(msg));          //Erase the msg
        delay(frameDuration_value*(TotalDevices-1));
        }
        
}

void SetupPan()
{
  mqttClient.setServer(MQTT_SERVER, MQTT_PORT);
  // set the callback function
  mqttClient.setCallback(CallbackPan);
}



void ConnectToPan()
{
  Serial.println("Connecting to MQTT Broker...");
  while (!mqttClient.connected())
  {
    
    Serial.println(clientId);

    if (mqttClient.connect(clientId))
    {
      Serial.println("Connected to MQTT broker.");
      // subscribe to topic
      mqttClient.subscribe(MQTT_TOPIC);
    }
  }
}




void ConnectToWiFi()
{
  Serial.print("Connecting to WiFi ");
  Serial.println(WIFI_SSID);

  WiFi.begin(WIFI_SSID, WIFI_PWD, 6);
  while (WiFi.status() != WL_CONNECTED)
  {
    Serial.print(".");
    delay(500);
  }
  Serial.print("\nConnected to ");
  Serial.println(WIFI_SSID);
}

void setup()
{
  Serial.begin(115200);
  Serial.println("Setup begin");
  pinMode(LED, OUTPUT);
  ConnectToWiFi();
  SetupPan();
  My_timer = timerBegin(0, 80, true);
  timerAttachInterrupt(My_timer, &onTimer, true);
  timerAlarmWrite(My_timer, C_TIME, true);
  timerAlarmEnable(My_timer);
  
  Serial.println("Setup end");
}


void loop()
{
  if (!mqttClient.connected())
  {
    ConnectToPan();
  }
  mqttClient.loop();

}