#include <tox/tox.h>

#include "ngc_ext_common.h"
#include "ngc_hs1.h"
#include "ngc_ft1.h"

//#include <cstdint>
//#include <cassert>
//#include <new>
//#include <map>
//#include <list>
//#include <set>
//#include <optional>
//#include <algorithm>
#include <array>

struct _GroupKey {
	std::array<uint8_t, TOX_GROUP_CHAT_ID_SIZE> data;

	_GroupKey(void) = default;
	_GroupKey(const _GroupKey& other) : data(other.data) {}
	_GroupKey(_GroupKey&&) = delete;

	bool operator<(const _GroupKey& rhs) const {
		for (size_t i = 0; i < data.size(); i++) {
			if (data[i] < rhs.data[i]) {
				return true;
			} else if (data[i] > rhs.data[i]) {
				return false;
			}
		}
		return false; // equal
	}

	bool operator==(const _GroupKey& rhs) const {
		for (size_t i = 0; i < data.size(); i++) {
			if (data[i] != rhs.data[i]) {
				return false;
			}
		}
		return true;
	}
};

struct _PeerKey {
	std::array<uint8_t, TOX_GROUP_PEER_PUBLIC_KEY_SIZE> data;

	_PeerKey(void) = default;
	_PeerKey(const _PeerKey& other) : data(other.data) {}
	_PeerKey(_PeerKey&&) = delete;

	bool operator<(const _PeerKey& rhs) const {
		for (size_t i = 0; i < data.size(); i++) {
			if (data[i] < rhs.data[i]) {
				return true;
			} else if (data[i] > rhs.data[i]) {
				return false;
			}
		}
		return false; // equal
	}

	bool operator==(const _PeerKey& rhs) const {
		for (size_t i = 0; i < data.size(); i++) {
			if (data[i] != rhs.data[i]) {
				return false;
			}
		}
		return true;
	}
};

enum _PacketType : uint8_t {
	// TODO: why?
	INVALID = 0u,

	//TODO: make it possible to go further back
	// request last (few) message_ids for a peer
	// - peer_key bytes (peer key we want to know ids for)
	// - 1 byte (uint8_t count ids, atleast 1)
	HS1_REQUEST_LAST_IDS,

	// respond to a request with 0 or more message ids, sorted by newest first
	// - peer_key bytes (the msg_ids are from)
	// - 1 byte (uint8_t count ids, can be 0)
	// - array [
	//   - msg_id bytes (the message id
	// - ]
	HS1_RESPONSE_LAST_IDS,

	// request the other side to initiate a FT
	// - 1 byte (file_kind)
	// - X bytes (file_kind dependent id, differnt sizes)
	FT1_REQUEST,

	// tell the other side you want to start a FT
	// TODO: might use id layer instead. with it, it would look similar to friends_ft
	// - 1 byte (file_kind)
	// - X bytes (file_kind dependent id, differnt sizes)
	// - 8 bytes (data size) // TODO: do all file kinds have a size at init?
	// - 1 byte (temporary_file_tf_id, for this peer only, technically just a prefix to distinguish between simultainious fts)
	FT1_INIT,

	// acknowlage init (like an accept)
	// - 1 byte (temporary_file_tf_id)
	FT1_INIT_ACK,

	// data fragment
	// - 1 byte (temporary_file_tf_id)
	// - 2 bytes (sequece id)
	// - X bytes (the data fragment)
	// (size is implicit)
	FT1_DATA,

	// acknowlage data fragments
	// TODO: last 3 should be sufficient, 5 should be generous, would eleminate the byte for size
	// - 1 byte (temporary_file_tf_id)
	// - 1 byte (number of sequence ids to ack, this kind of depends on window size)
	// - array [ (of sequece ids)
	//   - 2 bytes (sequece id)
	// - ]
	FT1_DATA_ACK,

	// sender has gotten every data fragment acked, so we signal finish
	// - 1 byte (temporary_file_tf_id)
	FT1_DATA_FIN,

	// and we ack that, we need this, so file_id is not reused earlier
	// - 1 byte (temporary_file_tf_id)
	FT1_DATA_FIN_ACK,
};

static const char* _pkgid2str(_PacketType type) {
#define _EXT_CASE(x) case (x): return #x;
	switch (type) {
		_EXT_CASE(INVALID)

		_EXT_CASE(HS1_REQUEST_LAST_IDS)
		_EXT_CASE(HS1_RESPONSE_LAST_IDS)

		_EXT_CASE(FT1_REQUEST)
		_EXT_CASE(FT1_INIT)
		_EXT_CASE(FT1_INIT_ACK)
		_EXT_CASE(FT1_DATA)
		_EXT_CASE(FT1_DATA_ACK)
		_EXT_CASE(FT1_DATA_FIN)
		_EXT_CASE(FT1_DATA_FIN_ACK)

		default: return "<unk>";
	}
#undef _EXT_CASE
}

using handle_group_custom_packet_cb = void(*)(
	Tox* tox,
	NGC_EXT_CTX* ngc_ext_ctx,

	uint32_t group_number,
	uint32_t peer_number,

	const uint8_t *data,
	size_t length
);


struct NGC_EXT_CTX {
	std::array<handle_group_custom_packet_cb, 256> callbacks;
	NGC_HS1* ngc_hs1_ctx = nullptr;
	NGC_FT1* ngc_ft1_ctx = nullptr;
};