/*****************************************************************
 ESP32 MASTER PROJECT (WOKWI)

 HOW TO USE:
 - Set ONLY ONE assignment to #if 1
 - Keep others as #if 0
 - Follow wiring steps inside each block

 PIN PLAN (DO NOT RANDOMLY CHANGE):
 LED (basic)     -> GPIO 2
 SERVO           -> GPIO 18
 DHT11           -> GPIO 4
 HOME LEDS       -> 16, 17, 19
 BUTTON (mock)   -> GPIO 5
*****************************************************************/


// ================== ASSIGNMENT 3 ==================
#if 1
// assignment - 3
// LED control using web interface

/*
WOKWI STEPS:
1. LED → GPIO 2 via resistor
2. Open Serial Monitor → copy IP
3. Open browser → control LED
*/

#include <WiFi.h>
#include <WebServer.h>

const char* ssid = "Wokwi-GUEST";
const char* password = "";

WebServer server(80);
const int LED = 2;

void root() {
  server.send(200, "text/html",
    "<h1>LED Control</h1>"
    "<a href='/on'>ON</a><br>"
    "<a href='/off'>OFF</a>");
}

void ledOn() {
  digitalWrite(LED, HIGH);
  server.send(200, "text/html", "LED ON");
}

void ledOff() {
  digitalWrite(LED, LOW);
  server.send(200, "text/html", "LED OFF");
}

void setup() {
  Serial.begin(115200);
  pinMode(LED, OUTPUT);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) delay(500);

  Serial.println(WiFi.localIP());

  server.on("/", root);
  server.on("/on", ledOn);
  server.on("/off", ledOff);
  server.begin();
}

void loop() {
  server.handleClient();
}
#endif



// ================== ASSIGNMENT 4 ==================
#if 0
// assignment - 4
// LED toggle web UI

#include <WiFi.h>
#include <WebServer.h>

const char* ssid = "Wokwi-GUEST";
const char* password = "";

WebServer server(80);
const int LED = 2;
bool state = false;

String page() {
  return "<h2>Status: " + String(state ? "ON" : "OFF") +
         "</h2><a href='/toggle'>Toggle</a>";
}

void toggle() {
  state = !state;
  digitalWrite(LED, state);
  server.send(200, "text/html", page());
}

void setup() {
  Serial.begin(115200);
  pinMode(LED, OUTPUT);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) delay(500);

  Serial.println(WiFi.localIP());

  server.on("/", [](){ server.send(200,"text/html",page()); });
  server.on("/toggle", toggle);
  server.begin();
}

void loop() {
  server.handleClient();
}
#endif



// ================== ASSIGNMENT 5 ==================
#if 0
// assignment - 5
// Servo control via web

/*
WOKWI:
Servo → GPIO 18
*/

#include <WiFi.h>
#include <WebServer.h>
#include <ESP32Servo.h>

const char* ssid = "Wokwi-GUEST";
const char* password = "";

WebServer server(80);
Servo s;

int angle = 90;

String page() {
  return "<form action='/set'>"
         "<input type='range' name='a' min='0' max='180' value='" + String(angle) + "'>"
         "<input type='submit'></form>";
}

void setAngle() {
  angle = server.arg("a").toInt();
  s.write(angle);
  server.send(200,"text/html",page());
}

void setup() {
  Serial.begin(115200);
  s.attach(18);

  WiFi.begin(ssid,password);
  while (WiFi.status()!=WL_CONNECTED) delay(500);

  Serial.println(WiFi.localIP());

  server.on("/", [](){ server.send(200,"text/html",page()); });
  server.on("/set", setAngle);
  server.begin();
}

void loop() {
  server.handleClient();
}
#endif



// ================== ASSIGNMENT 6 ==================
#if 0
// assignment - 6
// Basic web server

#include <WiFi.h>
#include <WebServer.h>

const char* ssid = "Wokwi-GUEST";
const char* password = "";

WebServer server(80);

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid,password);
  while (WiFi.status()!=WL_CONNECTED) delay(500);

  Serial.println(WiFi.localIP());

  server.on("/", [](){
    server.send(200,"text/html","ESP32 Web Server Running");
  });

  server.begin();
}

void loop() {
  server.handleClient();
}
#endif



// ================== ASSIGNMENT 7 ==================
#if 0
// assignment - 7
// ThingSpeak

/*
PUT YOUR API KEY
*/

#include <WiFi.h>
#include <HTTPClient.h>
#include <DHT.h>

#define DHTPIN 4
#define DHTTYPE DHT11

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* apiKey = "YOUR_API_KEY";

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(115200);
  dht.begin();

  WiFi.begin(ssid,password);
  while (WiFi.status()!=WL_CONNECTED) delay(500);
}

void loop() {
  float t = dht.readTemperature();

  if (WiFi.status()==WL_CONNECTED) {
    HTTPClient http;
    String url = "http://api.thingspeak.com/update?api_key=" + String(apiKey) + "&field1=" + String(t);
    http.begin(url);
    http.GET();
    http.end();
  }

  delay(20000);
}
#endif



// ================== ASSIGNMENT 9 ==================
#if 0
// assignment - 9
// MQTT

#include <WiFi.h>
#include <PubSubClient.h>

WiFiClient espClient;
PubSubClient client(espClient);

const char* ssid="Wokwi-GUEST";
const char* password="";
const char* server="broker.hivemq.com";

void callback(char* topic, byte* payload, unsigned int length) {
  String msg;
  for(int i=0;i<length;i++) msg+=(char)payload[i];

  if(msg=="ON") digitalWrite(2,HIGH);
  else digitalWrite(2,LOW);
}

void reconnect() {
  while(!client.connected()) {
    if(client.connect("esp32")) {
      client.subscribe("wokwi/led");
    } else delay(1000);
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(2,OUTPUT);

  WiFi.begin(ssid,password);
  while (WiFi.status()!=WL_CONNECTED) delay(500);

  client.setServer(server,1883);
  client.setCallback(callback);
}

void loop() {
  if(!client.connected()) reconnect();
  client.loop();
}
#endif



// ================== ASSIGNMENT 10 ==================
#if 0
// assignment - 10
// Home Automation

#include <WiFi.h>
#include <WebServer.h>

WebServer server(80);

void setup() {
  Serial.begin(115200);

  pinMode(16,OUTPUT);
  pinMode(17,OUTPUT);
  pinMode(19,OUTPUT);

  WiFi.begin("Wokwi-GUEST","");
  while(WiFi.status()!=WL_CONNECTED) delay(500);

  Serial.println(WiFi.localIP());

  server.on("/l1", [](){ digitalWrite(16,HIGH); server.send(200); });
  server.on("/l2", [](){ digitalWrite(17,HIGH); server.send(200); });
  server.on("/l3", [](){ digitalWrite(19,HIGH); server.send(200); });

  server.begin();
}

void loop() {
  server.handleClient();
}
#endif



// ================== ASSIGNMENT 13 ==================
#if 0
// assignment - 13
// Voice control (mock)

/*
Type ON / OFF in Serial Monitor
*/

const int LED = 2;

void setup() {
  Serial.begin(115200);
  pinMode(LED,OUTPUT);
}

void loop() {
  if(Serial.available()) {
    String cmd = Serial.readStringUntil('\n');
    cmd.trim();

    if(cmd=="ON") digitalWrite(LED,HIGH);
    else if(cmd=="OFF") digitalWrite(LED,LOW);
  }
}
#endif