// ========================================================
// POP3  Protocol Handler
//
// Design and Implementation by Floris van den Berg
// ========================================================

#pragma warning (disable : 4275)
#pragma warning (disable : 4786)

#include <string>
#include "..\OpenNet.h"
#include "Cabinet.h"

// --------------------------------------------------------

class CPop3Protocol : public IProtocol {
public :
	CPop3Protocol();
	virtual unsigned long DLL_CALLCONV AddRef();
	virtual unsigned long DLL_CALLCONV Release();
	virtual HRESULT DLL_CALLCONV QueryInterface(REFIID guid, void **iif);
	virtual void DLL_CALLCONV Initialize(TRANSPORT_HANDLE transport);
	virtual void DLL_CALLCONV Receive(unsigned char *data, int size);
	virtual void DLL_CALLCONV Send(EpAction *action);
	virtual void DLL_CALLCONV Reset();
	virtual int DLL_CALLCONV GetName(char *name, int size);
	virtual int DLL_CALLCONV GetMessageName(int msg, char *name, int size);

private :
	int m_ref_count;
	TRANSPORT_HANDLE m_transport;
	char data[8192];
	int data_size;
	int data_pos;
};

// --------------------------------------------------------

CPop3Protocol::CPop3Protocol() :
m_ref_count(0),
m_transport(NULL),
data(),
data_size(0),
data_pos(0) {
	memset(&data, 0, sizeof(data));
}

unsigned long DLL_CALLCONV
CPop3Protocol::AddRef() {
	return ++m_ref_count;
}

unsigned long DLL_CALLCONV
CPop3Protocol::Release() {
	int ref_count = --m_ref_count;

	if (ref_count == 0) 
		delete this;

	return ref_count;
}

HRESULT DLL_CALLCONV
CPop3Protocol::QueryInterface(REFIID guid, void **iif) {
	if (IsEqualGUID(guid, CLSID_POP3_PROTOCOL)) {
		AddRef();
		*iif = this;
		return S_OK;
	} else if (IsEqualGUID(guid, GUID_OBJECT)) {
		AddRef();
		*iif = this;
		return S_OK;
	}

	return E_NOINTERFACE;
}
	
void DLL_CALLCONV
CPop3Protocol::Initialize(TRANSPORT_HANDLE transport) {
	m_transport = transport;
}

void DLL_CALLCONV
CPop3Protocol::Receive(unsigned char *data, int size) {
	// copy the data into the buffer

	memcpy(data + data_size, data, size);	
	data_size += size;

	// search for 0x0D's. if found we found a valid SMTP reply

	int i = 0;
	int pos = 0;

	// strip any pending 0x0A and 0x0D chars

	while (pos < data_size) {
		if ((data[pos] != 0x0A) && (data[pos] != 0x0D))
			break;

		++pos;
	}

	// search for the next 0x0A or 0x0D

	while (pos + i < data_size) {
		if ((data[pos + i] == 0x0A) || (data[pos + i] == 0x0D)) {
			int char_before_delimiter = (pos + i);

			// search a bit further for more 0x0As or 0x0Ds

			while (pos + i < data_size) {
				if ((data[pos + i] != 0x0A) && (data[pos + i] != 0x0D))
					break;

				++i;
			}

			// allocate memory for reply data

			char temp[8192];

			// allocate an ePlug event

			EpEvent pm_event;
			pm_event.reference_id = 0;
			pm_event.protocol = CLSID_POP3_PROTOCOL;
			pm_event.data = (unsigned char *)temp;

			// grab the message data			

			char *dat = (char *)(data + pos);

			if ((char_before_delimiter >= 3) && (dat[0] == '+') && (dat[1] == 'O') && (dat[2] == 'K')) {
				if (char_before_delimiter - 4 > 0)
					memcpy(temp, data + pos + 4, char_before_delimiter - 4);

				pm_event.msg = POP3_REPLY_OK;
				pm_event.size = char_before_delimiter - 3;
			} else if ((char_before_delimiter >= 4) && (dat[0] == '-') && (dat[1] == 'E') && (dat[2] == 'R') && (dat[3] == 'R')) {
				if (char_before_delimiter - 5 > 0)
					memcpy(temp, data + pos + 5, char_before_delimiter - 5);

				pm_event.msg = POP3_REPLY_ERROR;
				pm_event.size = char_before_delimiter - 4;
			} else if ((char_before_delimiter >= 1) && (dat[0] == '.')) {
				pm_event.msg = POP3_REPLY_ENDLIST;
				pm_event.data = NULL;
				pm_event.size = 0;
			} else {
				memcpy(temp, data + pos, char_before_delimiter);

				pm_event.msg = POP3_REPLY_LISTING;
				pm_event.size = char_before_delimiter + 1;
			}

			// add one extra 0 byte to terminate the string

			temp[pm_event.size - 1] = '\0';

			// post event

			EpDispatchEvent(m_transport, &pm_event);

			// move message from queue

			memcpy(data, data + i, data_size - i);

			data_size -= i;

			i = 0;
		} else {
			++i;
		}
	}
}

void DLL_CALLCONV
CPop3Protocol::Send(EpAction *action) {
	switch(action->msg) {
		case POP3_USER :
		{
			_STL::string s = _STL::string("USER ") + _STL::string((char *)action->data) + _STL::string("\r\n");
			EpCompleteAction(m_transport, (unsigned char *)s.c_str(), s.length());
			break;
		}

		case POP3_PASS :
		{
			_STL::string s = _STL::string("PASS ") + _STL::string((char *)action->data) + _STL::string("\r\n");
			EpCompleteAction(m_transport, (unsigned char *)s.c_str(), s.length());
			break;
		}

		case POP3_LIST :
			if (action->data) {
				char tmp[64];
				_STL::string s = _STL::string("LIST ") + _STL::string(itoa(*(DWORD *)action->data, tmp, 10)) + _STL::string("\r\n");
				EpCompleteAction(m_transport, (unsigned char *)s.c_str(), s.length());
			} else {
				EpCompleteAction(m_transport, (unsigned char *)"LIST\r\n", 6);
			}

			break;

		case POP3_RETR :
		{
			char tmp[64];
			_STL::string s = _STL::string("RETR ") + _STL::string(itoa(*(DWORD *)action->data, tmp, 10)) + _STL::string("\r\n");
			EpCompleteAction(m_transport, (unsigned char *)s.c_str(), s.length());
			break;
		}

		case POP3_DELE :
		{
			char tmp[64];
			_STL::string s = _STL::string("DELE ") + _STL::string(itoa(*(DWORD *)action->data, tmp, 10)) + _STL::string("\r\n");
			EpCompleteAction(m_transport, (unsigned char *)s.c_str(), s.length());
			break;
		}

		case POP3_UIDL :
			if (action->data) {
				char tmp[64];
				_STL::string s = _STL::string("UIDL ") + _STL::string(itoa(*(DWORD *)action->data, tmp, 10)) + _STL::string("\r\n");
				EpCompleteAction(m_transport, (unsigned char *)s.c_str(), s.length());
			} else {
				EpCompleteAction(m_transport, (unsigned char *)"UIDL\r\n", 6);
			}

			break;

		case POP3_NOOP :
			EpCompleteAction(m_transport, (unsigned char *)"NOOP\r\n", 6);
			break;

		case POP3_STAT :
			EpCompleteAction(m_transport, (unsigned char *)"STAT\r\n", 6);
			break;

		case POP3_RSET :
			EpCompleteAction(m_transport, (unsigned char *)"RSET\r\n", 6);
			break;

		case POP3_TOP :
		{
			Pop3Top *top = (Pop3Top *)action->data;

			char tmp1[64];
			char tmp2[64];

			_STL::string s = _STL::string("TOP ") + _STL::string(itoa(top->message_id, tmp1, 10)) + _STL::string(" ") + _STL::string(itoa(top->max_lines, tmp2, 10)) + _STL::string("\r\n");

			EpCompleteAction(m_transport, (unsigned char *)s.c_str(), s.length());
			break;
		}

		case POP3_QUIT :
			EpCompleteAction(m_transport, (unsigned char *)"QUIT\r\n", 6);
			break;
	};
}

void DLL_CALLCONV
CPop3Protocol::Reset() {
	data_size = 0;
	data_pos = 0;
	memset(&data, 0, sizeof(data));
}

int DLL_CALLCONV
CPop3Protocol::GetName(char *name, int size) {
	if (size >= 5)
		strcpy(name, "POP3");

	return 5;
}

int DLL_CALLCONV
CPop3Protocol::GetMessageName(int msg, char *name, int size) {
	return 0;
}

// --------------------------------------------------------
// Instantation function
// --------------------------------------------------------

static HRESULT DLL_CALLCONV
Pop3ProtocolCreate(void **iif) {
	CPop3Protocol *object = new CPop3Protocol;

	if (object) {
		object->AddRef();
		*iif = object;
		return S_OK;
	}

	return E_FAIL;
}

// --------------------------------------------------------
// Discover function
// --------------------------------------------------------

void DLL_CALLCONV
Pop3ProtocolInitialize() {
	EpRegisterProtocol(CLSID_POP3_PROTOCOL, Pop3ProtocolCreate);
}