#include <fstream>
#include <sstream>
#include <boost/regex.hpp>
#include <boost/filesystem.hpp>
#include <cryptopp/osrng.h>
#include <cryptopp/zinflate.h>
#include "I2PEndian.h"
#include "Reseed.h"
#include "Log.h"
#include "Identity.h"
#include "NetDb.h"
#include "util.h"


namespace i2p
{
namespace data
{

	static std::vector<std::string> httpReseedHostList = {
				"http://193.150.121.66/netDb/",
				"http://netdb.i2p2.no/",
				"http://reseed.i2p-projekt.de/",
				"http://cowpuncher.drollette.com/netdb/",
				"http://i2p.mooo.com/netDb/",
				"http://reseed.info/",
				"http://uk.reseed.i2p2.no/",
				"http://us.reseed.i2p2.no/",
				"http://jp.reseed.i2p2.no/",
				"http://i2p-netdb.innovatio.no/",
				"http://ieb9oopo.mooo.com"
			};

	//TODO: Remember to add custom port support. Not all serves on 443
	static std::vector<std::string> httpsReseedHostList = {
				"https://193.150.121.66/netDb/",
				"https://netdb.i2p2.no/",
				"https://reseed.i2p-projekt.de/",
				"https://cowpuncher.drollette.com/netdb/",
				"https://i2p.mooo.com/netDb/",
				"https://reseed.info/",
				"https://i2p-netdb.innovatio.no/",
				"https://ieb9oopo.mooo.com/",
				"https://ssl.webpack.de/ivae2he9.sg4.e-plaza.de/" // Only HTTPS and SU3 (v2) support
			};
	
	//TODO: Implement v2 reseeding. Lightweight zip library is needed.
	//TODO: Implement SU3, utils.
	Reseeder::Reseeder()
	{
	}

	Reseeder::~Reseeder()
	{
	}

	bool Reseeder::reseedNow()
	{
		try
		{
			// Seems like the best place to try to intercept with SSL
			/*ssl_server = true;
			try {
				// SSL
			}
			catch (std::exception& e)
			{
				LogPrint("Exception in SSL: ", e.what());
			}*/
			std::string reseedHost = httpReseedHostList[(rand() % httpReseedHostList.size())];
			LogPrint("Reseeding from ", reseedHost);
			std::string content = i2p::util::http::httpRequest(reseedHost);
			if (content == "")
			{
				LogPrint("Reseed failed");
				return false;
			}
			boost::regex e("<\\s*A\\s+[^>]*href\\s*=\\s*\"([^\"]*)\"", boost::regex::normal | boost::regbase::icase);
			boost::sregex_token_iterator i(content.begin(), content.end(), e, 1);
			boost::sregex_token_iterator j;
			//TODO: Ugly code, try to clean up.
			//TODO: Try to reduce N number of variables
			std::string name;
			std::string routerInfo;
			std::string tmpUrl;
			std::string filename;
			std::string ignoreFileSuffix = ".su3";
			boost::filesystem::path root = i2p::util::filesystem::GetDataDir();
			while (i != j)
			{
				name = *i++;
				if (name.find(ignoreFileSuffix)!=std::string::npos)
					continue;
				LogPrint("Downloading ", name);
				tmpUrl = reseedHost;
				tmpUrl.append(name);
				routerInfo = i2p::util::http::httpRequest(tmpUrl);
				if (routerInfo.size()==0)
					continue;
				filename = root.string();
#ifndef _WIN32
				filename += "/netDb/r";
#else
				filename += "\\netDb\\r";
#endif
				filename += name.at(11); // first char in id
#ifndef _WIN32
				filename.append("/");
#else
				filename.append("\\");
#endif
				filename.append(name.c_str());
				std::ofstream outfile (filename, std::ios::binary);
				outfile << routerInfo;
				outfile.close();
			}
			return true;
		}
		catch (std::exception& ex)
		{
			//TODO: error reporting
			return false;
		}
		return false;
	}	

	int Reseeder::ReseedNowSU3 ()
	{
		CryptoPP::AutoSeededRandomPool rnd;
		auto ind = rnd.GenerateWord32 (0, httpReseedHostList.size() - 1);
		std::string reseedHost = httpReseedHostList[ind];
		return ReseedFromSU3 (reseedHost);
	}

	int Reseeder::ReseedFromSU3 (const std::string& host)
	{
		std::string url = host + "i2pseeds.su3";
		LogPrint (eLogInfo, "Dowloading SU3 from ", host);
		std::string su3 = i2p::util::http::httpRequest (url);
		if (su3.length () > 0)
		{
			std::stringstream s(su3);
			return ProcessSU3Stream (s);
		}
		else
		{
			LogPrint (eLogWarning, "SU3 download failed");
			return 0;
		}
	}
	
	int ProcessSU3File (const char * filename)
	{
		std::ifstream s(filename, std::ifstream::binary);
		if (s.is_open ())	
			return ProcessSU3Stream (s);
		else
		{
			LogPrint (eLogError, "Can't open file ", filename);
			return 0;
		}
	}

	const char SU3_MAGIC_NUMBER[]="I2Psu3";	
	int ProcessSU3Stream (std::istream& s)
	{
		static uint32_t headerSignature = htole32 (0x04034B50);

		char magicNumber[7];
		s.read (magicNumber, 7); // magic number and zero byte 6
		if (strcmp (magicNumber, SU3_MAGIC_NUMBER))
		{
			LogPrint (eLogError, "Unexpected SU3 magic number");	
			return 0;
		}			
		s.seekg (1, std::ios::cur); // su3 file format version
		SigningKeyType signatureType;
		s.read ((char *)&signatureType, 2);  // signature type
		signatureType = be16toh (signatureType);
		uint16_t signatureLength;
		s.read ((char *)&signatureLength, 2);  // signature length
		signatureLength = be16toh (signatureLength);
		s.seekg (1, std::ios::cur); // unused
		uint8_t versionLength;
		s.read ((char *)&versionLength, 1);  // version length	
		s.seekg (1, std::ios::cur); // unused
		uint8_t signerIDLength;
		s.read ((char *)&signerIDLength, 1);  // signer ID length	
		uint64_t contentLength;
		s.read ((char *)&contentLength, 8);  // content length	
		contentLength = be64toh (contentLength);
		s.seekg (1, std::ios::cur); // unused
		uint8_t fileType;
		s.read ((char *)&fileType, 1);  // file type	
		if (fileType != 0x00) //  zip file
		{
			LogPrint (eLogError, "Can't handle file type ", (int)fileType);	
			return 0;
		}
		s.seekg (1, std::ios::cur); // unused
		uint8_t contentType;
		s.read ((char *)&contentType, 1);  // content type	
		if (contentType != 0x03) // reseed data
		{
			LogPrint (eLogError, "Unexpected content type ", (int)contentType);	
			return 0;
		}
		s.seekg (12, std::ios::cur); // unused

		s.seekg (versionLength, std::ios::cur); // skip version
		s.seekg (signerIDLength, std::ios::cur); // skip signer ID

		// handle content
		int numFiles = 0;
		size_t contentPos = s.tellg ();
		while (!s.eof ())
		{	
			uint32_t signature;
			s.read ((char *)&signature, 4);
			if (signature == headerSignature)
			{
				// next local file
				s.seekg (4, std::ios::cur); // skip fields we don't care about
				uint16_t compressionMethod;
				s.read ((char *)&compressionMethod, 2);	
				compressionMethod = le16toh (compressionMethod);
				s.seekg (8, std::ios::cur); // skip fields we don't care about
				uint32_t compressedSize, uncompressedSize; 
				s.read ((char *)&compressedSize, 4);	
				compressedSize = le32toh (compressedSize);	
				s.read ((char *)&uncompressedSize, 4);
				uncompressedSize = le32toh (uncompressedSize);	
				uint16_t fileNameLength, extraFieldLength; 
				s.read ((char *)&fileNameLength, 2);	
				fileNameLength = le16toh (fileNameLength);
				s.read ((char *)&extraFieldLength, 2);
				extraFieldLength = le16toh (extraFieldLength);
				char localFileName[255];
				s.read (localFileName, fileNameLength);
				localFileName[fileNameLength] = 0;
				s.seekg (extraFieldLength, std::ios::cur);
				LogPrint (eLogDebug, "Proccessing file ", localFileName, " ", compressedSize, " bytes");
				if (!compressedSize)
				{
					LogPrint (eLogWarning, "Unexpected size 0. Skipped");
					continue;
				}	
				
				uint8_t * compressed = new uint8_t[compressedSize];
				s.read ((char *)compressed, compressedSize);
				if (compressionMethod) // we assume Deflate
				{
					CryptoPP::Inflator decompressor;
					decompressor.Put (compressed, compressedSize);	
					size_t len = decompressor.MaxRetrievable (); 
					if (len <= uncompressedSize)
					{
						uint8_t * uncompressed = new uint8_t[uncompressedSize];	
						decompressor.Get (uncompressed, len);	
						i2p::data::netdb.AddRouterInfo (uncompressed, len);
						numFiles++;
						delete[] uncompressed;
					}
					else
						LogPrint (eLogError, "Actual uncompressed size ", decompressor.MaxRetrievable (), " exceed ", uncompressedSize, " from header");
				}	
				else // no compression
				{
					i2p::data::netdb.AddRouterInfo (compressed, compressedSize);
					numFiles++;
				}	
				delete[] compressed;
			}
			else
				break; // no more files
			size_t end = s.tellg ();
			if (end - contentPos >= contentLength)
				break; // we are beyond contentLength
		}
		return numFiles;
	}
}
}