#include <bitset>
#include <string>

// #include <ArduinoJson.h>

#include <WiFi.h>

#include "settings.h"

#ifdef WIFI_ENTERPRISE_ENABLED
// Ref https://github.com/martinius96/ESP32-WPA2-enterprise/blob/master/ESP32_WPA2enterprise.ino
#include "esp_wpa2.h"
#include "esp_wifi.h"
#endif


#ifdef MQTT_NO_TLS
#include <WiFiClient.h>
#else
#include <WiFiClientSecure.h>
#endif

#include <PubSubClient.h>

// These libraries need installing in the Arduino IDE Library Manager (if you install the BME280 one it should prompt for the unified sensor library automatically)
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>


// WAS D5 D6 D7

#define MULTIPLEX_PINA	17
#define MULTIPLEX_PINB	16
#define MULTIPLEX_PINC	4

// WAS A0
#define ANALOG_PIN		34

/*
000	0
001	1
010	2
011	3
100	4
101	5
110	6
111	7
*/

#define SOIL_A			0
#define SOIL_B			6
#define WATER_LEVEL_A	2
#define WATER_LEVEL_B	4

#define REFERENCE_VOLTAGE	3.3

// Ref https://stackoverflow.com/a/523737/1460422
#define CHECK_BIT(var,pos) ((var) & (1<<(pos)))

#ifdef MQTT_NO_TLS
WiFiClient transport;
#else
WiFiClientSecure transport;
#endif
PubSubClient mqtt;

Adafruit_BME280 bme;	// I2C

void connect_wifi() {
#ifndef WIFI_ENTERPRISE_ENABLED
	Serial.print("personal");
	WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
#else
	Serial.print("enterprise");
	
	// Ref https://github.com/martinius96/ESP32-WPA2-enterprise/blob/master/ESP32_WPA2enterprise.ino
	// For ESP32 ONLY! For esp8266, see the code with the esp8266-last tag, which is the last commit that supports the esp8266.
	WiFi.disconnect(true);
	WiFi.mode(WIFI_STA);
	
	const char* user = WIFI_ENTERPRISE_USERNAME;
	const char* pass = WIFI_ENTERPRISE_PASSWORD;
	
	// 'esp_wifi_sta_wpa2_ent_set_identity' was not declared in this scope :-(
	esp_wpa2_config_t config = WPA2_CONFIG_INIT_DEFAULT();
    esp_wifi_sta_wpa2_ent_set_identity((uint8_t *)user, strlen(user));
    esp_wifi_sta_wpa2_ent_set_username((uint8_t *)user, strlen(user));
    esp_wifi_sta_wpa2_ent_set_password((uint8_t *)pass, strlen(pass));
	esp_wifi_sta_wpa2_ent_enable(&config);
	// esp_wpa2_config_t config = WPA2_CONFIG_INIT_DEFAULT();
	// esp_wifi_sta_wpa2_ent_enable(&config);
	
	WiFi.begin(WIFI_SSID);
#endif
}


float read_analog(int channel) {
	
	const char* bin = std::bitset<8>(channel).to_string().c_str();
	
	bool b0 = bin[7] == u'1';
	bool b1 = bin[6] == u'1';
	bool b2 = bin[5] == u'1';
	
	digitalWrite(MULTIPLEX_PINA, b2);
	digitalWrite(MULTIPLEX_PINB, b1);
	digitalWrite(MULTIPLEX_PINC, b0);
	
	int rawValue = analogRead(ANALOG_PIN);
	float parsedValue = ((float)rawValue) / 1024.0 * REFERENCE_VOLTAGE;
		
	return parsedValue;
}

void connect_mqtt() {
	if(!mqtt.connect(
		("autoplant_" + String(random(0, 999999))).c_str(),
		MQTT_USERNAME, MQTT_PASSWORD)
	) {
		/* Ref https://pubsubclient.knolleary.net/api#state
		-4 : MQTT_CONNECTION_TIMEOUT - the server didn't respond within the keepalive time
		-3 : MQTT_CONNECTION_LOST - the network connection was broken
		-2 : MQTT_CONNECT_FAILED - the network connection failed
		-1 : MQTT_DISCONNECTED - the client is disconnected cleanly
		0 : MQTT_CONNECTED - the client is connected
		1 : MQTT_CONNECT_BAD_PROTOCOL - the server doesn't support the requested version of MQTT
		2 : MQTT_CONNECT_BAD_CLIENT_ID - the server rejected the client identifier
		3 : MQTT_CONNECT_UNAVAILABLE - the server was unable to accept the connection
		4 : MQTT_CONNECT_BAD_CREDENTIALS - the username/password were rejected
		5 : MQTT_CONNECT_UNAUTHORIZED - the client was not authorized to connect
		*/
		int error_code = mqtt.state();
		Serial.println("failed, error code "+String(error_code));
		while(true) delay(10000);
	}
	Serial.println("ok");
}

void check_mqtt(bool reset = false) {
	if(mqtt.connected() == 0) {
		if(reset) {
			Serial.print("MQTT reconnect: ");
			connect_mqtt();
			delay(2000);
			if(mqtt.connected() == 0) {
				Serial.println("failed! rebooting.\n\n");
				ESP.restart();
			}
		}
		else {
			Serial.print("MQTT reconnect: ");
			connect_mqtt();
		}
	}
	else {
		Serial.println("MQTT: connection ok");
	}
}

bool send_mqtt(String id, String sensor, float value) {
	// StaticJsonDocument<96> data;
	// 
	// data["id"] = id;
	// data["sensor"] = sensor;
	// data["value"] = value;
	
	String payload = "{\"id\": \""+id+"\",\"sensor\": \""+sensor+"\",\"value\": "+String(value)+"}";
	// int length = measureJson(&data);
	// char* payload = new char[length]();
	// serializeJson(data, payload, length);
	
	check_mqtt(false);
	check_mqtt(true);
	bool result = mqtt.publish("sensors/data", payload.c_str());
	// delete[] payload;
	
	return result;
}

void setup() {
	Serial.begin(9600);
	delay(1000);
	Serial.println("\nAnalogue Soil Sensor Test");
	Serial.println("=========================");
	Serial.print("PIN MODES: ");
	pinMode(MULTIPLEX_PINA, OUTPUT);
	pinMode(MULTIPLEX_PINB, OUTPUT);
	pinMode(MULTIPLEX_PINC, OUTPUT);
	Serial.println("ok");
	
	// Enterprise WiFi example:
	// https://gist.github.com/Matheus-Garbelini/2cd780aed2eddbe17eb4adb5eca42bd6
	// TODO Add support for enterprise WiFi here so we can connect to eduroam
	Serial.print("WIFI: ");
	
	connect_wifi();
	
	int attempts = 0;
	while (WiFi.status() != WL_CONNECTED) {
		delay(500);
		Serial.print(".");
		attempts++;
		if(attempts > 25)
			break;
	}
	if(WiFi.status() == WL_CONNECTED) {
		Serial.print("ok, IP: ");
		Serial.println(WiFi.localIP());
	}
	else {
		// Ref https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/readme.html#check-return-codes
		Serial.print("failed, error code ");
		Serial.println(WiFi.status());
	}
	
	Serial.print("MQTT: ");
#ifdef MQTT_NO_TLS
	Serial.print("notls");
#else
	Serial.print("tls");
	transport.setInsecure(); Serial.print(".");
#endif
	// mqtt.setBufferSize(1000);
	mqtt.setClient(transport); Serial.print(".");
	mqtt.setServer(MQTT_SERVER, MQTT_PORT); Serial.print(".");
	mqtt.setKeepAlive(INTERVAL / 2);
	// Serial.print(MQTT_SERVER);
	// Serial.print(":");
	// Serial.print(MQTT_PORT);
	// Serial.print(".");
	
	connect_mqtt();
	
	Serial.print("BME280: ");
	
    if(!bme.begin(0x76)) {
		Serial.println("failed!");
	}
	else {
		Serial.println("ok");
	}
}

void loop() {
	float soil_a = read_analog(SOIL_A);
	float soil_b = read_analog(SOIL_B);
	float water_level_a = read_analog(WATER_LEVEL_A);
	float water_level_b = read_analog(WATER_LEVEL_B);
	float temp = bme.readTemperature();
	float humidity = bme.readHumidity();
	float pressure = bme.readPressure() / 100.0F;
	
	// StaticJsonDocument<96> data;
	
	if(!send_mqtt(
		"autoplant-a",
		"soil",
		soil_a
	)) Serial.println("[mqtt] Failed to send message");
	if(!send_mqtt(
		"autoplant-a",
		"water-level",
		water_level_a
	)) Serial.println("[mqtt] Failed to send message");
	if(!send_mqtt(
		"autoplant-b",
		"soil",
		soil_b
	)) Serial.println("[mqtt] Failed to send message");
	if(!send_mqtt(
		"autoplant-b",
		"water-level",
		water_level_b
	)) Serial.println("[mqtt] Failed to send message");
	
	if(!send_mqtt(
		"autoplant-a",
		"temperature",
		temp
	)) Serial.println("[mqtt] Failed to send message");
	if(!send_mqtt(
		"autoplant-a",
		"humidity",
		humidity
	)) Serial.println("[mqtt] Failed to send message");
	if(!send_mqtt(
		"autoplant-a",
		"pressure",
		pressure
	)) Serial.println("[mqtt] Failed to send message");
	
	// data["id"] = "autoplant-a";
	// data["sensor"] = "soil";
	// data["value"] = soil_a;
	// if(!send_mqtt(&data)) Serial.println("[mqtt] Failed to send message");
	// 
	// data["sensor"] = "water-level";
	// data["value"] = water_level_a;
	// if(!send_mqtt(&data)) Serial.println("[mqtt] Failed to send message");
	// 
	// data["id"] = "autoplant-b";
	// data["value"] = water_level_a;
	// if(!send_mqtt(&data)) Serial.println("[mqtt] Failed to send message");
	// 
	// data["sensor"] = "soil";
	// data["value"] = soil_a;
	// if(!send_mqtt(&data)) Serial.println("[mqtt] Failed to send message");
	
	Serial.print("SOIL_A\t");
	Serial.println(soil_a);
	Serial.print("SOIL_B\t");
	Serial.println(soil_b);
	Serial.print("WATER_LEVEL_A\t");
	Serial.println(water_level_a);
	Serial.print("WATER_LEVEL_B\t");
	Serial.println(water_level_b);
	
	Serial.println("\n\n\n\n\n");
	
	delay(INTERVAL);
}