#include <boost/bind.hpp>
#include <boost/lexical_cast.hpp>

#include "base64.h"
#include "Log.h"
#include "Tunnel.h"
#include "TransitTunnel.h"
#include "Transports.h"
#include "NetDb.h"
#include "Streaming.h"
#include "HTTPProxy.h"

namespace i2p
{
namespace proxy
{
	namespace misc_strings 
	{

		const char name_value_separator[] = { ':', ' ' };
		const char crlf[] = { '\r', '\n' };

	} // namespace misc_strings

	std::vector<boost::asio::const_buffer> HTTPConnection::reply::to_buffers()
	{
		std::vector<boost::asio::const_buffer> buffers;
		if (headers.size () > 0)
		{	
			buffers.push_back (boost::asio::buffer ("HTTP/1.0 200 OK\r\n")); // always OK
			for (std::size_t i = 0; i < headers.size(); ++i)
			{
				header& h = headers[i];
				buffers.push_back(boost::asio::buffer(h.name));
				buffers.push_back(boost::asio::buffer(misc_strings::name_value_separator));
				buffers.push_back(boost::asio::buffer(h.value));
				buffers.push_back(boost::asio::buffer(misc_strings::crlf));
			}
			buffers.push_back(boost::asio::buffer(misc_strings::crlf));
		}	
		buffers.push_back(boost::asio::buffer(content));
		return buffers;
	}

	void HTTPConnection::Terminate ()
	{
		m_Socket->close ();
		delete this;
	}

	void HTTPConnection::Receive ()
	{
		m_Socket->async_read_some (boost::asio::buffer (m_Buffer, 8192),
			 boost::bind(&HTTPConnection::HandleReceive, this,
				 boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred));
	}

	void HTTPConnection::HandleReceive (const boost::system::error_code& ecode, std::size_t bytes_transferred)
	{
		if (!ecode)
  		{
			m_Buffer[bytes_transferred] = 0;
			
			std::pair<std::string,std::string> requestInfo = ExtractRequest ();
			request m_Request;
			parseHeaders(m_Buffer, m_Request.headers);
			
			LogPrint("Requesting ", requestInfo.first, " with path ", requestInfo.second);
			HandleDestinationRequest (requestInfo.first, requestInfo.second);
			
			boost::asio::async_write (*m_Socket, m_Reply.to_buffers(),
          		boost::bind (&HTTPConnection::HandleWrite, this,
           			boost::asio::placeholders::error));
			//Receive ();
		}
		else if (ecode != boost::asio::error::operation_aborted)
			Terminate ();
	}

void HTTPConnection::parseHeaders(const std::string& h, std::vector<header>& hm) {
	std::string str(h);
	std::string::size_type idx;
	std::string t;
	int i = 0;
	while((idx=str.find("\r\n")) != std::string::npos) {
		t=str.substr(0,idx);
		str.erase(0,idx+2);
		if(t == "")
			break;
		idx=t.find(": ");
		if(idx == std::string::npos) {
			std::cout << "Bad header line: " << t << std::endl;
			break;
		}
	 	LogPrint ("Name: ", t.substr (0,idx), " Value: ", t.substr (idx+2));
	 	hm[i].name = t.substr(0,idx);
	 	hm[i].value = t.substr(idx+2);
	 	i++;
	}
}

// TODO: Support other requests than GET.
std::pair<std::string, std::string> HTTPConnection::ExtractRequest ()
{
	char * get = strstr (m_Buffer, "GET");
	if (get)
	{
		char * http = strstr (get, "HTTP");
		if (http)
		{
			std::string url (get + 4, http - get - 5);
			size_t sp = url.find_first_of( '/', 7 /* skip http:// part */ );
			if ( sp != std::string::npos )
			{
				std::string base_url( url.begin()+7, url.begin()+sp );
				LogPrint("Base URL is: ", base_url);
				if ( sp != std::string::npos )
				{
					std::string query( url.begin()+sp+1, url.end() );
					LogPrint("Query is: ", "/" + query);

					return std::make_pair(base_url, "/" + query);
				}
				return std::make_pair(base_url, "/");
			}
		}
	}
	return std::make_pair("","");
}
	
	void HTTPConnection::HandleWrite (const boost::system::error_code& ecode)
	{
		Terminate ();
	}

	void HTTPConnection::HandleDestinationRequest (const std::string& address, const std::string& uri)
	{
		i2p::data::IdentHash destination;
		std::string fullAddress;
		if (address.find (".b32.i2p") != std::string::npos)
		{
			int li = address.find_first_of(".");
			std::string newaddress = address.substr(0, li);
			if (i2p::data::Base32ToByteStream (newaddress.c_str (), newaddress.length (), (uint8_t *)destination, 32) != 32)
			{
				LogPrint ("Invalid Base32 address ", newaddress);
				return;
			}
			fullAddress = newaddress + ".b32.i2p";
		}
		else
		{	
			auto addr = i2p::data::netdb.FindAddress(address);
			if (!addr) 
			{
				LogPrint ("Unknown address ", address);
				return;
			}	
			destination = *addr;
			fullAddress = address;
		}	
			
		auto leaseSet = i2p::data::netdb.FindLeaseSet (destination);
		if (!leaseSet || !leaseSet->HasNonExpiredLeases ())
		{
			i2p::data::netdb.Subscribe(destination);
			std::this_thread::sleep_for (std::chrono::seconds(10)); // wait for 10 seconds
			leaseSet = i2p::data::netdb.FindLeaseSet (destination);
			if (!leaseSet || !leaseSet->HasNonExpiredLeases ()) // still no LeaseSet
			{
				m_Reply.content = leaseSet ? "<html>Leases expired</html>" : "<html>LeaseSet not found</html>";
				m_Reply.headers.resize(2);
				m_Reply.headers[0].name = "Content-Length";
				m_Reply.headers[0].value = boost::lexical_cast<std::string>(m_Reply.content.size());
				m_Reply.headers[1].name = "Content-Type";
				m_Reply.headers[1].value = "text/html";
				return;
			}	
		}	
		auto s = i2p::stream::CreateStream (*leaseSet);
		if (s)
		{
			std::string request = "GET " + uri + " HTTP/1.1\n Host:" + fullAddress + "\n";
			s->Send ((uint8_t *)request.c_str (), request.length (), 10);			
			std::stringstream ss;
			uint8_t buf[8192];
			size_t r = s->Receive (buf, 8192, 30); // 30 seconds
			if (!r && s->IsEstablished ()) // nothing received but connection is established
				r = s->Receive (buf, 8192, 30); // wait for another 30 secondd
			if (r) // we recieved data
			{
				ss << std::string ((char *)buf, r);
				while (s->IsOpen () && (r = s->Receive (buf, 8192, 30)) > 0)
					ss << std::string ((char *)buf,r);	
				
				m_Reply.content = ss.str (); // send "as is"
				m_Reply.headers.resize(0); // no headers
				return;
			}	
			else // nothing received
				ss << "<html>Not responding</html>";
			s->Close ();
			DeleteStream (s);
			
			m_Reply.content = ss.str ();
			m_Reply.headers.resize(2);
			m_Reply.headers[0].name = "Content-Length";
			m_Reply.headers[0].value = boost::lexical_cast<std::string>(m_Reply.content.size());
			m_Reply.headers[1].name = "Content-Type";
			m_Reply.headers[1].value = "text/html";
		}	
	}	
	
	
	HTTPProxy::HTTPProxy (int port): 
		m_Thread (nullptr), m_Work (m_Service), 
		m_Acceptor (m_Service, boost::asio::ip::tcp::endpoint (boost::asio::ip::tcp::v4(), port)),
		m_NewSocket (nullptr)
	{
		
	}

	HTTPProxy::~HTTPProxy ()
	{
		Stop ();
	}

	void HTTPProxy::Start ()
	{
		m_Thread = new std::thread (std::bind (&HTTPProxy::Run, this));
		m_Acceptor.listen ();
		Accept ();
	}

	void HTTPProxy::Stop ()
	{
		m_Acceptor.close();
		m_Service.stop ();
		if (m_Thread)
        {       
            m_Thread->join (); 
            delete m_Thread;
            m_Thread = nullptr;
        }    
	}

	void HTTPProxy::Run ()
	{
		m_Service.run ();
	}	

	void HTTPProxy::Accept ()
	{
		m_NewSocket = new boost::asio::ip::tcp::socket (m_Service);
		m_Acceptor.async_accept (*m_NewSocket, boost::bind (&HTTPProxy::HandleAccept, this,
			boost::asio::placeholders::error));
	}

	void HTTPProxy::HandleAccept(const boost::system::error_code& ecode)
	{
		if (!ecode)
		{
			new HTTPConnection (m_NewSocket);
			Accept ();
		}
	}	
}
}