/*
 * httppoll.cpp - HTTP polling proxy
 * Copyright (C) 2003  Justin Karneges
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include "httppoll.h"

#include <tqstringlist.h>
#include <tqurl.h>
#include <tqtimer.h>
#include <tqguardedptr.h>
#include <tqca.h>
#include <stdlib.h>
#include "bsocket.h"
#include "base64.h"

#ifdef PROX_DEBUG
#include <stdio.h>
#endif

#define POLL_KEYS 64

// CS_NAMESPACE_BEGIN

static TQByteArray randomArray(int size)
{
	TQByteArray a(size);
	for(int n = 0; n < size; ++n)
		a[n] = (char)(256.0*rand()/(RAND_MAX+1.0));
	return a;
}

//----------------------------------------------------------------------------
// HttpPoll
//----------------------------------------------------------------------------
static TQString hpk(int n, const TQString &s)
{
	if(n == 0)
		return s;
	else
		return Base64::arrayToString( TQCA::SHA1::hash( TQCString(hpk(n - 1, s).latin1()) ) );
}

class HttpPoll::Private
{
public:
	Private() {}

	HttpProxyPost http;
	TQString host;
	int port;
	TQString user, pass;
	TQString url;
	bool use_proxy;

	TQByteArray out;

	int state;
	bool closing;
	TQString ident;

	TQTimer *t;

	TQString key[POLL_KEYS];
	int key_n;

	int polltime;
};

HttpPoll::HttpPoll(TQObject *parent)
:ByteStream(parent)
{
	d = new Private;

	d->polltime = 30;
	d->t = new TQTimer;
	connect(d->t, TQT_SIGNAL(timeout()), TQT_SLOT(do_sync()));

	connect(&d->http, TQT_SIGNAL(result()), TQT_SLOT(http_result()));
	connect(&d->http, TQT_SIGNAL(error(int)), TQT_SLOT(http_error(int)));

	reset(true);
}

HttpPoll::~HttpPoll()
{
	reset(true);
	delete d->t;
	delete d;
}

void HttpPoll::reset(bool clear)
{
	if(d->http.isActive())
		d->http.stop();
	if(clear)
		clearReadBuffer();
	clearWriteBuffer();
	d->out.resize(0);
	d->state = 0;
	d->closing = false;
	d->t->stop();
}

void HttpPoll::setAuth(const TQString &user, const TQString &pass)
{
	d->user = user;
	d->pass = pass;
}

void HttpPoll::connectToUrl(const TQString &url)
{
	connectToHost("", 0, url);
}

void HttpPoll::connectToHost(const TQString &proxyHost, int proxyPort, const TQString &url)
{
	reset(true);

	// using proxy?
	if(!proxyHost.isEmpty()) {
		d->host = proxyHost;
		d->port = proxyPort;
		d->url = url;
		d->use_proxy = true;
	}
	else {
		TQUrl u = url;
		d->host = u.host();
		if(u.hasPort())
			d->port = u.port();
		else
			d->port = 80;
		d->url = u.encodedPathAndQuery();
		d->use_proxy = false;
	}

	resetKey();
	bool last;
	TQString key = getKey(&last);

#ifdef PROX_DEBUG
	fprintf(stderr, "HttpPoll: Connecting to %s:%d [%s]", d->host.latin1(), d->port, d->url.latin1());
	if(d->user.isEmpty())
		fprintf(stderr, "\n");
	else
		fprintf(stderr, ", auth {%s,%s}\n", d->user.latin1(), d->pass.latin1());
#endif
	TQGuardedPtr<TQObject> self = this;
	syncStarted();
	if(!self)
		return;

	d->state = 1;
	d->http.setAuth(d->user, d->pass);
	d->http.post(d->host, d->port, d->url, makePacket("0", key, "", TQByteArray()), d->use_proxy);
}

TQByteArray HttpPoll::makePacket(const TQString &ident, const TQString &key, const TQString &newkey, const TQByteArray &block)
{
	TQString str = ident;
	if(!key.isEmpty()) {
		str += ';';
		str += key;
	}
	if(!newkey.isEmpty()) {
		str += ';';
		str += newkey;
	}
	str += ',';
	TQCString cs = str.latin1();
	int len = cs.length();

	TQByteArray a(len + block.size());
	memcpy(a.data(), cs.data(), len);
	memcpy(a.data() + len, block.data(), block.size());
	return a;
}

int HttpPoll::pollInterval() const
{
	return d->polltime;
}

void HttpPoll::setPollInterval(int seconds)
{
	d->polltime = seconds;
}

bool HttpPoll::isOpen() const
{
	return (d->state == 2 ? true: false);
}

void HttpPoll::close()
{
	if(d->state == 0 || d->closing)
		return;

	if(bytesToWrite() == 0)
		reset();
	else
		d->closing = true;
}

void HttpPoll::http_result()
{
	// check for death :)
	TQGuardedPtr<TQObject> self = this;
	syncFinished();
	if(!self)
		return;

	// get id and packet
	TQString id;
	TQString cookie = d->http.getHeader("Set-Cookie");
	int n = cookie.find("ID=");
	if(n == -1) {
		reset();
		error(ErrRead);
		return;
	}
	n += 3;
	int n2 = cookie.find(';', n);
	if(n2 != -1)
		id = cookie.mid(n, n2-n);
	else
		id = cookie.mid(n);
	TQByteArray block = d->http.body();

	// session error?
	if(id.right(2) == ":0") {
		if(id == "0:0" && d->state == 2) {
			reset();
			connectionClosed();
			return;
		}
		else {
			reset();
			error(ErrRead);
			return;
		}
	}

	d->ident = id;
	bool justNowConnected = false;
	if(d->state == 1) {
		d->state = 2;
		justNowConnected = true;
	}

	// sync up again soon
	if(bytesToWrite() > 0 || !d->closing)
		d->t->start(d->polltime * 1000, true);

	// connecting
	if(justNowConnected) {
		connected();
	}
	else {
		if(!d->out.isEmpty()) {
			int x = d->out.size();
			d->out.resize(0);
			takeWrite(x);
			bytesWritten(x);
		}
	}

	if(!self)
		return;

	if(!block.isEmpty()) {
		appendRead(block);
		readyRead();
	}

	if(!self)
		return;

	if(bytesToWrite() > 0) {
		do_sync();
	}
	else {
		if(d->closing) {
			reset();
			delayedCloseFinished();
			return;
		}
	}
}

void HttpPoll::http_error(int x)
{
	reset();
	if(x == HttpProxyPost::ErrConnectionRefused)
		error(ErrConnectionRefused);
	else if(x == HttpProxyPost::ErrHostNotFound)
		error(ErrHostNotFound);
	else if(x == HttpProxyPost::ErrSocket)
		error(ErrRead);
	else if(x == HttpProxyPost::ErrProxyConnect)
		error(ErrProxyConnect);
	else if(x == HttpProxyPost::ErrProxyNeg)
		error(ErrProxyNeg);
	else if(x == HttpProxyPost::ErrProxyAuth)
		error(ErrProxyAuth);
}

int HttpPoll::tryWrite()
{
	if(!d->http.isActive())
		do_sync();
	return 0;
}

void HttpPoll::do_sync()
{
	if(d->http.isActive())
		return;

	d->t->stop();
	d->out = takeWrite(0, false);

	bool last;
	TQString key = getKey(&last);
	TQString newkey;
	if(last) {
		resetKey();
		newkey = getKey(&last);
	}

	TQGuardedPtr<TQObject> self = this;
	syncStarted();
	if(!self)
		return;

	d->http.post(d->host, d->port, d->url, makePacket(d->ident, key, newkey, d->out), d->use_proxy);
}

void HttpPoll::resetKey()
{
#ifdef PROX_DEBUG
	fprintf(stderr, "HttpPoll: reset key!\n");
#endif
	TQByteArray a = randomArray(64);
	TQString str = TQString::fromLatin1(a.data(), a.size());

	d->key_n = POLL_KEYS;
	for(int n = 0; n < POLL_KEYS; ++n)
		d->key[n] = hpk(n+1, str);
}

const TQString & HttpPoll::getKey(bool *last)
{
	*last = false;
	--(d->key_n);
	if(d->key_n == 0)
		*last = true;
	return d->key[d->key_n];
}


//----------------------------------------------------------------------------
// HttpProxyPost
//----------------------------------------------------------------------------
static TQString extractLine(TQByteArray *buf, bool *found)
{
	// scan for newline
	int n;
	for(n = 0; n < (int)buf->size()-1; ++n) {
		if(buf->at(n) == '\r' && buf->at(n+1) == '\n') {
			TQCString cstr;
			cstr.resize(n+1);
			memcpy(cstr.data(), buf->data(), n);
			n += 2; // hack off CR/LF

			memmove(buf->data(), buf->data() + n, buf->size() - n);
			buf->resize(buf->size() - n);
			TQString s = TQString::fromUtf8(cstr);

			if(found)
				*found = true;
			return s;
		}
	}

	if(found)
		*found = false;
	return "";
}

static bool extractMainHeader(const TQString &line, TQString *proto, int *code, TQString *msg)
{
	int n = line.find(' ');
	if(n == -1)
		return false;
	if(proto)
		*proto = line.mid(0, n);
	++n;
	int n2 = line.find(' ', n);
	if(n2 == -1)
		return false;
	if(code)
		*code = line.mid(n, n2-n).toInt();
	n = n2+1;
	if(msg)
		*msg = line.mid(n);
	return true;
}

class HttpProxyPost::Private
{
public:
	Private() {}

	BSocket sock;
	TQByteArray postdata, recvBuf, body;
	TQString url;
	TQString user, pass;
	bool inHeader;
	TQStringList headerLines;
	bool asProxy;
	TQString host;
};

HttpProxyPost::HttpProxyPost(TQObject *parent)
:TQObject(parent)
{
	d = new Private;
	connect(&d->sock, TQT_SIGNAL(connected()), TQT_SLOT(sock_connected()));
	connect(&d->sock, TQT_SIGNAL(connectionClosed()), TQT_SLOT(sock_connectionClosed()));
	connect(&d->sock, TQT_SIGNAL(readyRead()), TQT_SLOT(sock_readyRead()));
	connect(&d->sock, TQT_SIGNAL(error(int)), TQT_SLOT(sock_error(int)));
	reset(true);
}

HttpProxyPost::~HttpProxyPost()
{
	reset(true);
	delete d;
}

void HttpProxyPost::reset(bool clear)
{
	if(d->sock.state() != BSocket::Idle)
		d->sock.close();
	d->recvBuf.resize(0);
	if(clear)
		d->body.resize(0);
}

void HttpProxyPost::setAuth(const TQString &user, const TQString &pass)
{
	d->user = user;
	d->pass = pass;
}

bool HttpProxyPost::isActive() const
{
	return (d->sock.state() == BSocket::Idle ? false: true);
}

void HttpProxyPost::post(const TQString &proxyHost, int proxyPort, const TQString &url, const TQByteArray &data, bool asProxy)
{
	reset(true);

	d->host = proxyHost;
	d->url = url;
	d->postdata = data;
	d->asProxy = asProxy;

#ifdef PROX_DEBUG
	fprintf(stderr, "HttpProxyPost: Connecting to %s:%d", proxyHost.latin1(), proxyPort);
	if(d->user.isEmpty())
		fprintf(stderr, "\n");
	else
		fprintf(stderr, ", auth {%s,%s}\n", d->user.latin1(), d->pass.latin1());
#endif
	d->sock.connectToHost(proxyHost, proxyPort);
}

void HttpProxyPost::stop()
{
	reset();
}

TQByteArray HttpProxyPost::body() const
{
	return d->body;
}

TQString HttpProxyPost::getHeader(const TQString &var) const
{
	for(TQStringList::ConstIterator it = d->headerLines.begin(); it != d->headerLines.end(); ++it) {
		const TQString &s = *it;
		int n = s.find(": ");
		if(n == -1)
			continue;
		TQString v = s.mid(0, n);
		if(v == var)
			return s.mid(n+2);
	}
	return "";
}

void HttpProxyPost::sock_connected()
{
#ifdef PROX_DEBUG
	fprintf(stderr, "HttpProxyPost: Connected\n");
#endif
	d->inHeader = true;
	d->headerLines.clear();

	TQUrl u = d->url;

	// connected, now send the request
	TQString s;
	s += TQString("POST ") + d->url + " HTTP/1.0\r\n";
	if(d->asProxy) {
		if(!d->user.isEmpty()) {
			TQString str = d->user + ':' + d->pass;
			s += TQString("Proxy-Authorization: Basic ") + Base64::encodeString(str) + "\r\n";
		}
		s += "Proxy-Connection: Keep-Alive\r\n";
		s += "Pragma: no-cache\r\n";
		s += TQString("Host: ") + u.host() + "\r\n";
	}
	else {
		s += TQString("Host: ") + d->host + "\r\n";
	}
	s += "Content-Type: application/x-www-form-urlencoded\r\n";
	s += TQString("Content-Length: ") + TQString::number(d->postdata.size()) + "\r\n";
	s += "\r\n";

	// write request
	TQCString cs = s.utf8();
	TQByteArray block(cs.length());
	memcpy(block.data(), cs.data(), block.size());
	d->sock.write(block);

	// write postdata
	d->sock.write(d->postdata);
}

void HttpProxyPost::sock_connectionClosed()
{
	d->body = d->recvBuf.copy();
	reset();
	result();
}

void HttpProxyPost::sock_readyRead()
{
	TQByteArray block = d->sock.read();
	ByteStream::appendArray(&d->recvBuf, block);

	if(d->inHeader) {
		// grab available lines
		while(1) {
			bool found;
			TQString line = extractLine(&d->recvBuf, &found);
			if(!found)
				break;
			if(line.isEmpty()) {
				d->inHeader = false;
				break;
			}
			d->headerLines += line;
		}

		// done with grabbing the header?
		if(!d->inHeader) {
			TQString str = d->headerLines.first();
			d->headerLines.remove(d->headerLines.begin());

			TQString proto;
			int code;
			TQString msg;
			if(!extractMainHeader(str, &proto, &code, &msg)) {
#ifdef PROX_DEBUG
				fprintf(stderr, "HttpProxyPost: invalid header!\n");
#endif
				reset(true);
				error(ErrProxyNeg);
				return;
			}
			else {
#ifdef PROX_DEBUG
				fprintf(stderr, "HttpProxyPost: header proto=[%s] code=[%d] msg=[%s]\n", proto.latin1(), code, msg.latin1());
				for(TQStringList::ConstIterator it = d->headerLines.begin(); it != d->headerLines.end(); ++it)
					fprintf(stderr, "HttpProxyPost: * [%s]\n", (*it).latin1());
#endif
			}

			if(code == 200) { // OK
#ifdef PROX_DEBUG
				fprintf(stderr, "HttpProxyPost: << Success >>\n");
#endif
			}
			else {
				int err;
				TQString errStr;
				if(code == 407) { // Authentication failed
					err = ErrProxyAuth;
					errStr = tr("Authentication failed");
				}
				else if(code == 404) { // Host not found
					err = ErrHostNotFound;
					errStr = tr("Host not found");
				}
				else if(code == 403) { // Access denied
					err = ErrProxyNeg;
					errStr = tr("Access denied");
				}
				else if(code == 503) { // Connection refused
					err = ErrConnectionRefused;
					errStr = tr("Connection refused");
				}
				else { // invalid reply
					err = ErrProxyNeg;
					errStr = tr("Invalid reply");
				}

#ifdef PROX_DEBUG
				fprintf(stderr, "HttpProxyPost: << Error >> [%s]\n", errStr.latin1());
#endif
				reset(true);
				error(err);
				return;
			}
		}
	}
}

void HttpProxyPost::sock_error(int x)
{
#ifdef PROX_DEBUG
	fprintf(stderr, "HttpProxyPost: socket error: %d\n", x);
#endif
	reset(true);
	if(x == BSocket::ErrHostNotFound)
		error(ErrProxyConnect);
	else if(x == BSocket::ErrConnectionRefused)
		error(ErrProxyConnect);
	else if(x == BSocket::ErrRead)
		error(ErrProxyNeg);
}

// CS_NAMESPACE_END

#include "httppoll.moc"