#ifndef WIFIRAW_H
#define WIFIRAW_H

#include "MAC.h"

#if IS_ESP8266
	extern "C" {
		#include "esp_wifi.h"
	}
#endif

// ifconfig wlp0s26u1u2u1 down && iw dev wlp0s26u1u2u1 set monitor none && ifconfig wlp0s26u1u2u1 up && iw dev wlp0s26u1u2u1 set channel 3
// ifconfig wlp0s26u1u2u1 down && iw dev wlp0s26u1u2u1 set monitor none && ifconfig wlp0s26u1u2u1 up iwconfig wlp0s26u1u2u1 channel 3

// https://supportforums.cisco.com/document/52391/80211-frames-starter-guide-learn-wireless-sniffer-traces

namespace WiFiRaw {

	/** frame type */
	enum Type {
		MANAGEMENT = 0b00,
		CONTROL = 0b01,
		DATA = 0b10,
		RESERVED = 0b11,
	};

	/** frame sub-type */
	enum SubType {

		DATA_DATA = 0b0000,
		DATA_DATA_CF_ACK = 0b0001,
		DATA_DATA_CF_POLL = 0b0010,
		DATA_DATA_CF_ACK_POLL = 0b0011,
		DATA_NULL = 0b0100,
		DATA_QOS = 0b1000,

		MGMT_ASSOC_REQUEST = 0b0000,
		MGMT_PROBE_REQUEST = 0b0100,
		MGMT_BEACON = 0b1000,
		MGMT_DISASSOCIATION = 0b1010,

	};

	/**
	 * 2 byte segment and fragment number.
	 * usually set by the ESP itself
	 */
	struct Fragment {

		uint8_t data[2];

		/** empty ctor */
		Fragment() : data() {;}

		/** ctor with values */
		Fragment(const uint8_t fragNr, const uint16_t seqNr) {
			data[1] = seqNr >> 4;
			data[0] = seqNr << 4 | fragNr;
		}
	};

//	/**
//	 * 4 byte checksum.
//	 * usually set by the ESP itself
//	 */
//	struct FCS {
//		uint8_t data[4];
//		FCS() : data() {;}
//	};

	struct Header {

		uint8_t version : 2;						// always 0
		uint8_t type : 2;							// see enum
		uint8_t subType : 4;						// see enum

		struct Flags {

			uint8_t toDS : 1;						// always 0
			uint8_t fromDS : 1;						// unencrypted: 0
			uint8_t moreFragments : 1;				// no more data: 0 , more data: 1
			uint8_t retransmission : 1;				// no retransmission: 0, retransmission: 1
			uint8_t powerManagement : 1;			// i am fully active: 0, tell AP that i safe power: 1,
			uint8_t moreData : 1;					// ?
			uint8_t protectedPkt : 1;				// 1 = encrypted, 0 = unencrypted
			uint8_t strictlyOrdered : 1;			// 0 = not strictly ordered

			Flags() :
				toDS(0), fromDS(0), moreFragments(0), retransmission(0), powerManagement(0),
				moreData(0), protectedPkt(0), strictlyOrdered(0) {;}

		} flags;

		uint16_t duration;							// ??

		Header(Type type, SubType subType) : version(0), type(type), subType(subType), duration(0) {
			;
		}

	};

	struct Timestamp {

		uint8_t data[8];

		Timestamp() : data() {;}

	};

	struct BeaconInterval {

		uint8_t data[2];

		BeaconInterval() {
			data[0] = 0x64;
			data[1] = 0x00;
		}

	};

	struct Capabilities {

		uint8_t isSTA : 1;
		uint16_t empty : 15;

		Capabilities() : isSTA(1), empty(0) {;}
	};

	/** base-struct for management frames */
	struct ManagementFrame {

		Timestamp ts;
		BeaconInterval interval;
		Capabilities capa;

		ManagementFrame() : ts(), interval(), capa() {;}

	};

	struct UnknownPkt {
		Header header;
		WiFiRaw::MACAddress destination;
		WiFiRaw::MACAddress transmitter;
		WiFiRaw::MACAddress bssid;
	};


	/** beacon packet */
	template <typename T> struct BeaconPkt {

		Header header;
		WiFiRaw::MACAddress destination;						// usually broadcast ff:ff:ff:ff:ff:ff
		WiFiRaw::MACAddress transmitter;						// usually the AP's MAC
		WiFiRaw::MACAddress bssid;								// the AP's MAC
		Fragment frag;

		ManagementFrame mgmt;

		T data;

		//FCS fcs;

		BeaconPkt(const WiFiRaw::MACAddress myMAC) :
			header(MANAGEMENT, MGMT_BEACON), destination(0xFF,0xFF,0xFF,0xFF,0xFF,0xFF), transmitter(myMAC), bssid(myMAC) {
			;
		}

	};

	/** data packet */
	template <int size> struct DataPkt {

		Header header;
		WiFiRaw::MACAddress bssid;								// the AP's mac
		WiFiRaw::MACAddress transmitter;							// my mac
		WiFiRaw::MACAddress destination;							// the receiver's mac

		Fragment frag;

		uint8_t data[size];

		//FCS fcs;

		DataPkt(const WiFiRaw::MACAddress& mine, const WiFiRaw::MACAddress& receiver, const WiFiRaw::MACAddress& bssid) :
			header(DATA, DATA_DATA_CF_ACK), bssid(bssid), transmitter(mine), destination(receiver) {
			header.flags.toDS = 1;
		}

	};


#if IS_ESP8266
	WiFiRaw::MACAddress getMyMAC() {
		WiFiRaw::MACAddress mine;
		esp_wifi_get_mac(ESP_IF_WIFI_STA, (uint8_t*)&mine);
		return mine;
	}
#endif

#if IS_ESP32
	WiFiRaw::MACAddress getMyMAC() {
		WiFiRaw::MACAddress mine;
		esp_wifi_get_mac(ESP_IF_WIFI_STA, (uint8_t*)&mine);
		return mine;
	}
#endif

};

#endif // WIFIRAW_H