/*
 * Simple program to publish and subscribe to a topic
 * from an MQTT server using the PubSub.
 * Use as a base for more interesting code.
 */
#include <ESP8266WiFi.h>
#include <PubSubClient.h>

// Override the maximum message size
// Client and Topic setups
#define MQTT_CLIENT_ID "Development_Strip"
#define MQTT_COLOR_TOPIC "smartthings/Development Strip/color/state"
#define MQTT_BRIGHTNESS_TOPIC "smartthings/Development Strip/level/state"
#define MQTT_SWITCH_TOPIC "smartthings/Development Strip/switch/state"
#define MQTT_MODE_TOPIC "smartthings/Development Strip/button/state"
#define MQTT_STATUS_TOPIC "smartthings/Development Strip/status/cmd"

// LED setups
#define LED_PIN 2 // On-board LED
#define RED_PIN D6 // Pin for controlling the RED channel.
#define GREEN_PIN D5 //  Pin for controlling the GREEN channel.
#define BLUE_PIN D8 // Pin for controlling the BLUE channel.

// Network setup
#define WIFI_SSID "Green Bowser"
#define WIFI_PASSWORD "SpandexSkank"
#define MQTT_SERVER "192.168.1.45"
#define MQTT_PORT 1883
#define MQTT_USERNAME "Epidurality"
#define MQTT_PASSWORD "mqttPass"

// MQTT client
WiFiClient wifi_client;
PubSubClient mqtt_client(wifi_client);

// Holders for last events
char* state_switch = "off";
char* state_brightness = "100";
char* state_color = "#ffffff";
char* state_mode = "err";
bool mqtt_resp_new = false;

// Uses the preset parameters to setup a wifi connection.
void wifiConnect() {
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" Connected!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());
}

// Attempts connection to MQTT server passed to it.
void mqttConnect(PubSubClient &c) {
  while (!c.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (c.connect(MQTT_CLIENT_ID, MQTT_USERNAME, MQTT_PASSWORD)) {
      Serial.println(" Connected!");
    } else {
      Serial.print(" Failed, rc=");
      Serial.print(c.state());
      Serial.println(". Trying again in 5 seconds...");
      delay(5000);
    }
  }
}

void mqttCallback(char* topic, byte* payload, unsigned int length) {
  char* message = (char*)payload;
  message[length] = '\0';
  Serial.print("Message received on topic ");
  Serial.println(topic);
  Serial.print("Payload:");
  Serial.println(message);
  if (strcmp(topic, MQTT_SWITCH_TOPIC)==0) {
    strcpy(state_switch, message);
    mqtt_resp_new = true;
  } else if (strcmp(topic, MQTT_BRIGHTNESS_TOPIC)==0) {
    strcpy(state_brightness,message);
    mqtt_resp_new = true;
  } else if (strcmp(topic, MQTT_COLOR_TOPIC)==0) {
    char* excerpt = strstr(message, "#");
    for (int i=0; i<7; i++) {
      state_color[i] = excerpt[i];
    }
    mqtt_resp_new = true;
  } else if (strcmp(topic, MQTT_MODE_TOPIC)==0) {
    strcpy(state_mode,message);
    mqtt_resp_new = true;
  } else {
    mqtt_client.publish(MQTT_STATUS_TOPIC, payload, true);
  }
}

void mqttSubscribeAll() {
  mqtt_client.subscribe(MQTT_SWITCH_TOPIC);
  mqtt_client.subscribe(MQTT_BRIGHTNESS_TOPIC);
  mqtt_client.subscribe(MQTT_COLOR_TOPIC);
  mqtt_client.subscribe(MQTT_MODE_TOPIC);
}

void setLights(int r, int g, int b) {
  analogWrite(RED_PIN, r*4);
  analogWrite(GREEN_PIN, g*4);
  analogWrite(BLUE_PIN, b*4);
}

void setLights(char* hex_col) {
  Serial.println(hex_col);
  long hex_as_long = strtol(&hex_col[1], NULL, 16);
  long r = hex_as_long >> 16;
  long g = hex_as_long >> 8 & 0xFF;
  long b = hex_as_long & 0xFF;
  setLights(r, g, b);
}

void logStates() {
  char state_log[256];
  sprintf(state_log, "Switch: %s | Brightness: %s | Color: %s | Mode: %s", state_switch, state_brightness, state_color, state_mode);
  Serial.println(state_log);
}

void setup() {
  Serial.begin(9600);
  Serial.println();
  pinMode(LED_PIN, OUTPUT);
  pinMode(RED_PIN, OUTPUT);
  pinMode(GREEN_PIN, OUTPUT);
  pinMode(BLUE_PIN, OUTPUT);
  analogWrite(RED_PIN, 0);
  analogWrite(GREEN_PIN, 0);
  analogWrite(BLUE_PIN, 0);
  wifiConnect();
  mqtt_client.setServer(MQTT_SERVER, MQTT_PORT);
  mqtt_client.setCallback(mqttCallback);
  mqttConnect(mqtt_client);
  mqttSubscribeAll();
}

void loop() {
  // Check connection to WiFi
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("WiFi connection lost.");
    wifiConnect();
  }

  // Check connection to MQTT
  if (!mqtt_client.connected()) {
    Serial.println("MQTT connection lost.");
    mqttConnect(mqtt_client);
    mqttSubscribeAll();
  }

  // Listen to our subscriptions
  mqtt_client.loop();

  if (mqtt_resp_new) {
    if (strcmp(state_switch, "off")==0) {
      setLights(0,0,0);
    }
    else if (strcmp(state_switch, "on")==0) {
      setLights(state_color);
    }
    mqtt_resp_new = false;
    logStates();
  }
}