#include <Arduino.h>
#include <ArduinoJson.h>
#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>

const char* WIFI_SSID = "Protospace";
const char* WIFI_PASS = "yycmakers";
char wifiMACAddr[18];
const String API_ROUTE = String("http://tools-api.tannercollin.com/api/lockout/");

#define RELAY_PIN D1
#define ON_BUTTON_PIN D3
#define OFF_BUTTON_PIN D4
#define ARMED_LED_PIN D5
#define ON_LED_PIN D6
#define OFF_LED_PIN D7

#define RELAY_CLOSED HIGH
#define RELAY_OPEN !RELAY_CLOSED
#define BUTTON_CLOSED LOW
#define BUTTON_OPEN !BUTTON_CLOSED
#define LED_ON HIGH
#define LED_OFF !LED_ON

#define LOGGING true

#define DELAY_TIME 10
#define COMM_IDLE_TIME 500 / DELAY_TIME

enum wifiStates
{
	WIFI_DISCONNECTED,
	WIFI_CONNECTING,
	WIFI_CONNECTED,
} wifiState = WIFI_DISCONNECTED;

enum lockStates
{
	LOCK_OFF,
	LOCK_ARMED,
	LOCK_ON_PRESSED,
	LOCK_ON,
	LOCK_OFF_PRESSED,
} lockState = LOCK_OFF;

enum commStates
{
	COMM_INIT,
	COMM_IDLE,
	COMM_SEND,
} commState = COMM_INIT;

void setup()
{
	if (LOGGING) Serial.begin(115200);
	if (LOGGING) Serial.println("[INFO] Serial started.");

	pinMode(RELAY_PIN, OUTPUT);
	pinMode(ON_BUTTON_PIN, INPUT_PULLUP);
	pinMode(OFF_BUTTON_PIN, INPUT_PULLUP);
	pinMode(ARMED_LED_PIN, OUTPUT);
	pinMode(ON_LED_PIN, OUTPUT);
	pinMode(OFF_LED_PIN, OUTPUT);
}

void loop()
{
	processWifiState();
	processLockState();
	processCommState();

	delay(DELAY_TIME);
}

void processWifiState()
{
	switch(wifiState) {
		case WIFI_DISCONNECTED:
			lockState = LOCK_OFF;
			commState = COMM_INIT;

			if (LOGGING) Serial.println("[INFO] Wifi is disconnected. Attempting to connect...");
			WiFi.begin(WIFI_SSID, WIFI_PASS);

			wifiState = WIFI_CONNECTING;
			break;
		case WIFI_CONNECTING:
			lockState = LOCK_OFF;
			commState = COMM_INIT;

			if (WiFi.status() == WL_CONNECTED) {
				if (LOGGING) Serial.println("[INFO] Wifi is connected.");

				if (LOGGING) Serial.print("[INFO] Wifi IP Address: ");
				if (LOGGING) Serial.println(WiFi.localIP());
				byte ar[6];
				WiFi.macAddress(ar);
				sprintf(wifiMACAddr, "%02X%02X%02X%02X%02X%02X", ar[0], ar[1], ar[2], ar[3], ar[4], ar[5]);
				if (LOGGING) Serial.print("[INFO] Wifi MAC Address: ");
				if (LOGGING) Serial.println(wifiMACAddr);

				wifiState = WIFI_CONNECTED;
			}
			break;
		case WIFI_CONNECTED:
			if (WiFi.status() != WL_CONNECTED) {
				wifiState = WIFI_DISCONNECTED;
			}
			break;
		default:
			if (LOGGING) Serial.println("[ERROR] Invalid wifi state.");
			wifiState = WIFI_DISCONNECTED;
			break;
	}
}

void processLockState()
{
	switch (lockState) {
		case LOCK_OFF:
			digitalWrite(ARMED_LED_PIN, LED_OFF);
			digitalWrite(ON_LED_PIN, LED_OFF);
			digitalWrite(OFF_LED_PIN, LED_ON);

			digitalWrite(RELAY_PIN, RELAY_OPEN);
			break;
		case LOCK_ARMED:
			digitalWrite(ARMED_LED_PIN, LED_ON);
			digitalWrite(ON_LED_PIN, LED_OFF);
			digitalWrite(OFF_LED_PIN, LED_ON);

			digitalWrite(RELAY_PIN, RELAY_OPEN);

			if (digitalRead(OFF_BUTTON_PIN) == BUTTON_CLOSED) {
				if (LOGGING) Serial.println("[INFO] Unarming interlock.");
				lockState = LOCK_OFF_PRESSED;
			} else if (digitalRead(ON_BUTTON_PIN) == BUTTON_CLOSED) {
				if (LOGGING) Serial.println("[INFO] On button pressed.");
				lockState = LOCK_ON_PRESSED;
			}
			break;
		case LOCK_ON_PRESSED:
			if (digitalRead(OFF_BUTTON_PIN) == BUTTON_CLOSED) {
				if (LOGGING) Serial.println("[ERROR] Both buttons pressed, aborting.");
				lockState = LOCK_OFF_PRESSED;
			} else if (digitalRead(ON_BUTTON_PIN) == BUTTON_OPEN) {
				if (LOGGING) Serial.println("[INFO] Turning machine on.");
				lockState = LOCK_ON;
			}
			break;
		case LOCK_ON:
			digitalWrite(ARMED_LED_PIN, LED_ON);
			digitalWrite(ON_LED_PIN, LED_ON);
			digitalWrite(OFF_LED_PIN, LED_OFF);

			digitalWrite(RELAY_PIN, RELAY_CLOSED);

			if (digitalRead(OFF_BUTTON_PIN) == BUTTON_CLOSED) {
				if (LOGGING) Serial.println("[INFO] Off button pressed.");
				lockState = LOCK_OFF_PRESSED;
			}
			break;
		case LOCK_OFF_PRESSED:
			if (digitalRead(OFF_BUTTON_PIN) == BUTTON_OPEN) {
				if (LOGGING) Serial.println("[INFO] Turning machine off.");
				lockState = LOCK_OFF;
			}
			break;
		default:
			if (LOGGING) Serial.println("[ERROR] Invalid lock state.");
			lockState = LOCK_OFF;
			break;
	}
}

// JSON functions to prevent memory leaking
String serializeJson(int lockState) {
	// Generated with: https://arduinojson.org/assistant/
	const size_t bufferSize = JSON_OBJECT_SIZE(1) + 50;
	DynamicJsonBuffer jsonBuffer(bufferSize);

	JsonObject& root = jsonBuffer.createObject();
	root["lockState"] = (int) lockState;
	String postData = String();
	root.printTo(postData);

	return postData;
}

String deserializeJson(String input) {
	// Generated with: https://arduinojson.org/assistant/
	const size_t bufferSize = JSON_OBJECT_SIZE(1) + 50;
	DynamicJsonBuffer jsonBuffer(bufferSize);
	JsonObject& root = jsonBuffer.parseObject(input);

	String action = root["action"];

	return action;
}

void processCommState()
{
	static int commIdleCount = 0;

	switch (commState) {
		case COMM_INIT:
			commIdleCount = 0;
			commState = COMM_IDLE;
			break;
		case COMM_IDLE:
			commIdleCount++;
			if (commIdleCount >= COMM_IDLE_TIME) {
				commState = COMM_SEND;
			}
			break;
		case COMM_SEND:
			if (LOGGING) Serial.println("[INFO] HTTP begin.");
			HTTPClient http;
			//http.begin("https://url", "7a 9c f4 db 40 d3 62 5a 6e 21 bc 5c cc 66 c8 3e a1 45 59 38"); //HTTPS
			http.begin(API_ROUTE + wifiMACAddr);
			http.addHeader("Content-Type", "application/json");

			if (LOGGING) Serial.print("[INFO] HTTP POST: ");
			String postData = serializeJson(lockState);
			if (LOGGING) Serial.println(postData);
			int httpCode = http.POST(postData);

			if (httpCode > 0) {
				if (LOGGING) Serial.printf("[INFO] POST success, code: %d\n", httpCode);

				if (httpCode == HTTP_CODE_OK) {
					if (LOGGING) Serial.print("[INFO] Resource found, parsing response: ");
					String payload = http.getString();
					if (LOGGING) Serial.println(payload);
					String action = deserializeJson(payload);

					if (action == "arm"  && lockState == LOCK_OFF && digitalRead(ON_BUTTON_PIN) == BUTTON_OPEN) {
						lockState = LOCK_ARMED;
					} else if (action == "disarm" && lockState == LOCK_ARMED) {
						lockState = LOCK_OFF;
					} else if (action == "disarm" && lockState == LOCK_ON) {
						lockState = LOCK_OFF;
					}

					if (LOGGING) Serial.println("[INFO] action: " + action);
				} else {
					if (LOGGING) Serial.println("[ERROR] Resource not found.");
				}
			} else {
				if (LOGGING) Serial.printf("[ERROR] POST failed, error: %s\n", http.errorToString(httpCode).c_str());
			}

			commState = COMM_INIT;
			break;
	}
}