#define WITH_HTTP
#define WITH_UDP
//#define WITH_MQTT
//#define WITH_OTA // flash size needs to be 2* sketch size :/
//#define WITH_SERIAL // not used yet
#define SILENT_STARTUP

#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>
#include <WiFiClient.h>
#include <ArduinoJson.h>

#ifdef WITH_OTA
#include <ArduinoOTA.h>
#endif
#ifdef WITH_HTTP
#include <ESP8266WebServer.h>
#endif
#ifdef WITH_UDP
#include <WiFiUdp.h>
#endif
#ifdef WITH_MQTT
#include <PubSubClient.h>
#endif

const char* ssid = "";
const char* password = "";
#define ME "esplamp-1"
#ifdef WITH_MQTT
const char* mqtt_server = "";
#endif
#ifdef WITH_UDP
const int udpPort = 2391;
IPAddress multicastAddr(239, 1, 0, 0);
#endif
#ifdef WITH_MQTT
const char* connectTopic = "api/" ME "/connected";
const char* outTopic = "api/" ME "/status/rgb";
const char* inTopic = "api/" ME "/set/rgb";
const char* updateTopic = "api/" ME "/get/rgb";
#endif

//                      R  G  B
const int leds[]     = {2, 0, 3}; // remember: TX is inverted, not used here
unsigned int state[] = {0, 0, 0};
unsigned char cstate[] = {0, 0, 0};

DynamicJsonBuffer jsonBuffer;
char cJson[50];

#ifdef WITH_HTTP
ESP8266WebServer server(80);
#endif
#ifdef WITH_UDP
WiFiUDP RAWudp;
#endif
#ifdef WITH_MQTT
WiFiClient espClient;
PubSubClient mqtt(espClient);
#endif

/* hardware access */
void writeJson() {
  JsonObject& root = jsonBuffer.createObject();
  root["red"] = state[0];
  root["green"] = state[1];
  root["blue"] = state[2];
  root.printTo(cJson, sizeof(cJson));
}

void updateLeds(bool fast) {
  for(int i=0; i<3; i++)
    analogWrite(leds[i], state[i]);
  if (!fast) {
    writeJson();
#ifdef WITH_MQTT
    if (mqtt.connected()) mqtt.publish(outTopic, cJson, true);
#endif
  }
}

#ifdef WITH_HTTP
/* http API */
void handleRoot() {
  if(server.hasArg("red"))
    state[0] = server.arg("red").toInt();
  if(server.hasArg("green")) 
    state[1] = server.arg("green").toInt();
  if(server.hasArg("blue"))
    state[2] = server.arg("blue").toInt();
    
  updateLeds(false);
  server.send(200, "application/json", cJson);
}
#endif

#ifdef WITH_MQTT
/* MQTT API */
void handleMqtt(char* topic, byte* payload, unsigned int length) {
  if (strcmp(topic, inTopic) == 0) {
    JsonObject& root = jsonBuffer.parseObject((char*)payload);
    if (!root.success()) return;
    state[0] = root["red"];
    state[1] = root["green"];
    state[2] = root["blue"];
    updateLeds(false);
  }
  if (strcmp(topic, updateTopic) == 0) {
    updateLeds(false); // force update /rgb information
  }
}

void connectMqtt() {
  // connect(id, willTopic, willQoS, willRetain, willMessage)
  if (mqtt.connect(ME, connectTopic, 2, true, "offline")) {
    // topic, msg, retain
    mqtt.publish(connectTopic, "online", true);
    mqtt.subscribe(inTopic);
    mqtt.subscribe(updateTopic);
  }
}
#endif

#ifdef WITH_UDP
/* UDP API */
// expected to be most time critical
void handleUdp() {
  if (!RAWudp)
    RAWudp.beginMulticast(WiFi.localIP(), multicastAddr, udpPort);
  if (!RAWudp)
    return;

  if (RAWudp.parsePacket()) {
    RAWudp.read(cstate, 3);
    for(int i=0; i<3; i++)
      state[i] = cstate[i] << 2;
    updateLeds(true); // skip publishing
  }
}
#endif

/* core code */
void setup() {
#ifdef WITH_SERIAL
  Serial.begin(115200);
#endif
  WiFi.begin(ssid, password);

  for(int i=0; i<3; i++)
    pinMode(leds[i], OUTPUT);

  while(WiFi.status() != WL_CONNECTED) {
#ifndef SILENT_STARTUP
    // blink three times
    for(int i=0; i<3; i++) {
      if(state[i] < 512)
        state[i] = 1023;
      else
        state[i] = 0;
    }
    updateLeds();
#endif
    delay(500);
  }

  WiFi.hostname(ME);
  MDNS.begin(ME, WiFi.localIP());

#ifdef WITH_OTA
  ArduinoOTA.setHostname(ME);
  ArduinoOTA.begin();
#endif
 
#ifdef WITH_HTTP
  server.on("/", handleRoot);
  server.begin();
  MDNS.addService("http", "tcp", 80);
#endif

#ifdef WITH_UDP
  MDNS.addService("udp", "udp", udpPort);
#endif

#ifdef WITH_MQTT
  mqtt.setServer(mqtt_server, 1883);
  mqtt.setCallback(handleMqtt);
#endif
}

void loop() {
#ifdef WITH_OTA
  ArduinoOTA.handle();
#endif
#ifdef WITH_HTTP
  server.handleClient();
#endif
#ifdef WITH_UDP
  handleUdp();
#endif
#ifdef WITH_MQTT
  if (!mqtt.connected())
    connectMqtt();
  mqtt.loop();
#endif
}