#include <string.h>
#include <stdbool.h>
#include <WiFi.h>
#include "PubSubClient.h"
#include "ArduinoJson.h"
#include "Stepper.h"
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"





// Wifi settings and variables
String stMac;
char mac[50];
char clientId[50];
WiFiClient espClient;

// MQTT settings and variables
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqttServer = "broker.emqx.io";
int port = 1883;
PubSubClient client(espClient);

// JSON parser
DynamicJsonDocument recv_doc(256);
DynamicJsonDocument send_doc(512);
uint8_t tx_message[128] = {0};
uint8_t rx_message[128] = {0};

// Temperature variables
double temperature = 22;

// Stepper motor
uint8_t step_pin = 12, dir_pin = 13;
const uint8_t steps_per_rev = 200;
uint16_t rpm = 1; //default speed = 60 rotations per minute
Stepper stepper(steps_per_rev, dir_pin, step_pin);

// Display
#define TFT_DC 2
#define TFT_CS 15
#define BLACK   0x0000
#define WHITE   0xFFFF
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);

// Function declarations
uint16_t temp_to_speed(double);
uint32_t calc_steps(uint16_t, uint16_t);






void wifiConnect(){
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
}

void mqttReconnect(){
  while(!client.connected()){
    Serial.print("Attempting MQTT connection...");
    sprintf(clientId, "system-led");

    if(client.connect(clientId)){
      Serial.print(clientId);
      Serial.println(" connected");
      client.subscribe("vasil-kolev/cooling-system/to-cooler");
    }else{
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void callback(char* topic, byte* message, unsigned int length){
  recv_doc.clear();
  deserializeJson(recv_doc, message);

  if(strstr(topic, "vasil-kolev/cooling-system/to-cooler")){
    if(!strcmp(recv_doc["cmd"], "set-temp")){
      if(rpm != temp_to_speed((double)recv_doc["temp"])){
        char display_text[20] = {0};

        sprintf(display_text, "RPM: %d", temp_to_speed((double)recv_doc["temp"]));

        tft.fillScreen(BLACK);
        tft.setCursor(0, 0);
        tft.print(display_text);
      }

      temperature = (double)recv_doc["temp"];
    }
  }
}

void setup(){
  // Begin UART debug port
  Serial.begin(115200);
  // Don't know what that line of code does...
  randomSeed(analogRead(0));

  // Connect to WIFI network
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  wifiConnect();
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println(WiFi.macAddress());
  stMac = WiFi.macAddress();
  stMac.replace(":", "_");
  Serial.println(stMac);

  // Establish a connection to mqtt broker
  client.setServer(mqttServer, port);
  client.setCallback(callback);

  // Setup stepper motor
  stepper.setSpeed(rpm);
  stepper.step(-8);

  // Setup and clear TFT screen
  tft.begin();
  tft.setRotation(0);
  tft.setCursor(0, 0);
  tft.setTextSize(2);
  tft.setTextColor(WHITE);
  tft.fillScreen(BLACK);

  // Write on screen
  tft.print("Hello, world!");
  tft.setTextSize(5);
}





uint16_t temp_to_speed(double temp){
  uint16_t speed = 1;

  if(temp >= 22 && temp <= 24){
    speed = 60;
  }else if(temp > 24){
    speed = 120;
  }

  return speed;
}

uint32_t calc_steps(uint16_t rpm, uint16_t dur_ms){
  uint32_t steps;

  steps = (rpm * steps_per_rev * dur_ms) / 60000;

  return steps;
}





void loop(){
  static int8_t cnt = -1;
  delay(10);

  // Implement something like a wait() procedure
  // In this if statement the stepper motor is
  // being controlled around every second
  if(++cnt >= 10){
    cnt = 0;

    // control stepper motor
    rpm = temp_to_speed(temperature);
    uint32_t steps = calc_steps(rpm, 1000);

    stepper.setSpeed(rpm);
    stepper.step(steps * 4);
  }

  // Check connection
  if(!client.connected()){
    mqttReconnect();
  }

  // Check for messages
  client.loop();
}