#include <string>
#include <algorithm>
#include <cctype>
#include <functional>
#include <fstream>
#include <set>
#include <boost/asio.hpp>
#include <boost/filesystem.hpp>
#include <boost/filesystem/fstream.hpp>
#include <boost/foreach.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/program_options/detail/config_file.hpp>
#include <boost/program_options/parsers.hpp>
#include <boost/algorithm/string.hpp>
#include "util.h"
#include "Log.h"

#if defined(__linux__) || defined(__FreeBSD_kernel__)
#include <sys/types.h>
#include <ifaddrs.h>
#endif

#ifdef WIN32
#include <Windows.h>
#include <shlobj.h>
#endif

namespace i2p
{
namespace util
{

namespace config
{
	std::map<std::string, std::string> mapArgs;
	std::map<std::string, std::vector<std::string> > mapMultiArgs;

	void OptionParser(int argc, const char* const argv[])
	{
		mapArgs.clear();
		mapMultiArgs.clear();
		for (int i = 1; i < argc; i++)
		{
			std::string strKey (argv[i]);
			std::string strValue;
			size_t has_data = strKey.find('=');
			if (has_data != std::string::npos)
			{
				strValue = strKey.substr(has_data+1);
				strKey = strKey.substr(0, has_data);
			}

#ifdef WIN32
			boost::to_lower(strKey);
			if (boost::algorithm::starts_with(strKey, "/"))
				strKey = "-" + strKey.substr(1);
#endif
			if (strKey[0] != '-')
				break;

			mapArgs[strKey] = strValue;
			mapMultiArgs[strKey].push_back(strValue);
		}

		BOOST_FOREACH(PAIRTYPE(const std::string,std::string)& entry, mapArgs)
		{
			std::string name = entry.first;

			//  interpret --foo as -foo (as long as both are not set)
			if (name.find("--") == 0)
			{
				std::string singleDash(name.begin()+1, name.end());
				if (mapArgs.count(singleDash) == 0)
					mapArgs[singleDash] = entry.second;
				name = singleDash;
			}
		}
	}

	const char* GetCharArg(const std::string& strArg, const std::string& nDefault)
	{
		if (mapArgs.count(strArg))
			return mapArgs[strArg].c_str();
		return nDefault.c_str();
	}

	std::string GetArg(const std::string& strArg, const std::string& strDefault)
	{
		if (mapArgs.count(strArg))
			return mapArgs[strArg];
		return strDefault;
	}

	int GetArg(const std::string& strArg, int nDefault)
	{
		if (mapArgs.count(strArg))
			return atoi(mapArgs[strArg].c_str());
		return nDefault;
	}
}

namespace filesystem
{
	const boost::filesystem::path &GetDataDir()
	{
		static boost::filesystem::path path;

		// TODO: datadir parameter is useless because GetDataDir is called before OptionParser
		// and mapArgs is not initialized yet
		/*if (i2p::util::config::mapArgs.count("-datadir")) 
			path = boost::filesystem::system_complete(i2p::util::config::mapArgs["-datadir"]);
		else */
			path = GetDefaultDataDir();

		if (!boost::filesystem::exists( path ))
		{
			// Create data directory
			if (!boost::filesystem::create_directory( path ))
			{
				LogPrint("Failed to create data directory!");
				path = "";
				return path;
			}
		}
		if (!boost::filesystem::is_directory(path)) 
			path = GetDefaultDataDir();
		return path;
	}

	std::string GetFullPath (const std::string& filename)
	{
		std::string fullPath = GetDataDir ().string ();
#ifndef _WIN32
		fullPath.append ("/");
#else
		fullPath.append ("\\");
#endif
		fullPath.append (filename);
		return fullPath;
	}		

	boost::filesystem::path GetConfigFile()
	{
		boost::filesystem::path pathConfigFile(i2p::util::config::GetArg("-conf", "i2p.conf"));
		if (!pathConfigFile.is_complete()) pathConfigFile = GetDataDir() / pathConfigFile;
		return pathConfigFile;
	}

	void ReadConfigFile(std::map<std::string, std::string>& mapSettingsRet,
						std::map<std::string, std::vector<std::string> >& mapMultiSettingsRet)
	{
		boost::filesystem::ifstream streamConfig(GetConfigFile());
		if (!streamConfig.good())
			return; // No i2pd.conf file is OK

		std::set<std::string> setOptions;
		setOptions.insert("*");

		for (boost::program_options::detail::config_file_iterator it(streamConfig, setOptions), end; it != end; ++it)
		{
			// Don't overwrite existing settings so command line settings override i2pd.conf
			std::string strKey = std::string("-") + it->string_key;
			if (mapSettingsRet.count(strKey) == 0)
			{
				mapSettingsRet[strKey] = it->value[0];
			}
			mapMultiSettingsRet[strKey].push_back(it->value[0]);
		}
	}

	boost::filesystem::path GetDefaultDataDir()
	{
		// Windows < Vista: C:\Documents and Settings\Username\Application Data\i2pd
		// Windows >= Vista: C:\Users\Username\AppData\Roaming\i2pd
		// Mac: ~/Library/Application Support/i2pd
		// Unix: ~/.i2pd or /var/lib/i2pd is system=1
#ifdef WIN32
		// Windows
		char localAppData[MAX_PATH];
		SHGetFolderPath(NULL, CSIDL_APPDATA, 0, NULL, localAppData);
		return boost::filesystem::path(std::string(localAppData) + "\\i2pd");
#else
		if (i2p::util::config::GetArg("-service", 0)) // use system folder
			return boost::filesystem::path("/var/lib/i2pd");
		boost::filesystem::path pathRet;
		char* pszHome = getenv("HOME");
		if (pszHome == NULL || strlen(pszHome) == 0)
			pathRet = boost::filesystem::path("/");
		else
			pathRet = boost::filesystem::path(pszHome);
#ifdef MAC_OSX
		// Mac
		pathRet /= "Library/Application Support";
		boost::filesystem::create_directory(pathRet);
		return pathRet / "i2pd";
#else
		// Unix
		return pathRet / ".i2pd";
#endif
#endif
	}
}

namespace http
{
	std::string httpRequest(const std::string& address)
	{
		try
		{
			i2p::util::http::url u(address);
			boost::asio::ip::tcp::iostream site;
			// please don't uncomment following line because it's not compatible with boost 1.46
			// 1.46 is default boost for Ubuntu 12.04 LTS
			//site.expires_from_now (boost::posix_time::seconds(30));
			if (u.port_ == 80)
				site.connect(u.host_, "http");
			else
			{
				std::stringstream ss; ss << u.port_;
				site.connect(u.host_, ss.str());
			}
			if (site)
			{
				// User-Agent is needed to get the server list routerInfo files.
				site << "GET " << u.path_ << " HTTP/1.0\r\nHost: " << u.host_
				<< "\r\nAccept: */*\r\n" << "User-Agent: Wget/1.11.4\r\n" << "Connection: close\r\n\r\n";
				// read response
				std::string version, statusMessage;
				site >> version; // HTTP version
				int status;
				site >> status; // status
				std::getline (site, statusMessage);
				if (status == 200) // OK
				{
					std::string header;
					while (std::getline(site, header) && header != "\r"){}
					std::stringstream ss;
					ss << site.rdbuf();
					return ss.str();
				}
				else
				{
					LogPrint ("HTTP response ", status);
					return "";
				}
			}
			else
			{
				LogPrint ("Can't connect to ", address);
				return "";
			}
		}
		catch (std::exception& ex)
		{
			LogPrint ("Failed to download ", address, " : ", ex.what ());
			return "";
		}
	}

	int httpRequestViaI2pProxy(const std::string& address, std::string &content)
	{
		content = "";
		try
		{
			boost::asio::ip::tcp::iostream site;
			// please don't uncomment following line because it's not compatible with boost 1.46
			// 1.46 is default boost for Ubuntu 12.04 LTS
			//site.expires_from_now (boost::posix_time::seconds(30));
			{
				std::stringstream ss; ss << i2p::util::config::GetArg("-httpproxyport", 4446);
				site.connect("127.0.0.1", ss.str());
			}
			if (site)
			{
				i2p::util::http::url u(address);
				std::stringstream ss;
				ss << "GET " << address << " HTTP/1.0" << std::endl;
				ss << "Host: " << u.host_ << std::endl;
				ss << "Accept: */*" << std::endl;
				ss << "User - Agent: Wget / 1.11.4" << std::endl;
				ss << "Connection: close" << std::endl;
				ss << std::endl;
				site << ss.str();

				// read response
				std::string version, statusMessage;
				site >> version; // HTTP version
				int status;
				site >> status; // status
				std::getline(site, statusMessage);
				if (status == 200) // OK
				{
					std::string header;
					while (std::getline(site, header) && header != "\r"){}
					std::stringstream ss;
					ss << site.rdbuf();
					content = ss.str();
					return status;
				}
				else
				{
					LogPrint("HTTP response ", status);
					return status;
				}
			}
			else
			{
				LogPrint("Can't connect to proxy");
				return 408;
			}
		}
		catch (std::exception& ex)
		{
			LogPrint("Failed to download ", address, " : ", ex.what());
			return 408;
		}
	}
	
	url::url(const std::string& url_s)
	{
		portstr_ = "80";
		port_ = 80;
		user_ = "";
		pass_ = "";

		parse(url_s);
	}


	// code for parser tests
	//{
    //  i2p::util::http::url u_0("http://127.0.0.1:7070/asdasd?qqqqqqqqqqqq");
	//	i2p::util::http::url u_1("http://user:password@site.com:8080/asdasd?qqqqqqqqqqqqq");
	//	i2p::util::http::url u_2("http://user:password@site.com/asdasd?qqqqqqqqqqqqqq");
	//	i2p::util::http::url u_3("http://user:@site.com/asdasd?qqqqqqqqqqqqq");
	//	i2p::util::http::url u_4("http://user@site.com/asdasd?qqqqqqqqqqqq");
	//	i2p::util::http::url u_5("http://@site.com:800/asdasd?qqqqqqqqqqqq");
	//	i2p::util::http::url u_6("http://@site.com:err_port/asdasd?qqqqqqqqqqqq");
    //	i2p::util::http::url u_7("http://user:password@site.com:err_port/asdasd?qqqqqqqqqqqq");
	//}
	void url::parse(const std::string& url_s)
	{
		const std::string prot_end("://");
		std::string::const_iterator prot_i = search(url_s.begin(), url_s.end(),
										   prot_end.begin(), prot_end.end());
		protocol_.reserve(distance(url_s.begin(), prot_i));
		transform(url_s.begin(), prot_i,
			  back_inserter(protocol_),
			  std::ptr_fun<int,int>(tolower)); // protocol is icase
		if( prot_i == url_s.end() )
			return;
		advance(prot_i, prot_end.length());
		std::string::const_iterator path_i = find(prot_i, url_s.end(), '/');
		host_.reserve(distance(prot_i, path_i));
		transform(prot_i, path_i,
			  back_inserter(host_),
			  std::ptr_fun<int,int>(tolower)); // host is icase

		// parse user/password
		auto user_pass_i = find(host_.begin(), host_.end(), '@');
		if (user_pass_i != host_.end())
		{
			std::string user_pass = std::string(host_.begin(), user_pass_i);
			auto pass_i = find(user_pass.begin(), user_pass.end(), ':');
			if (pass_i != user_pass.end())
			{
				user_ = std::string(user_pass.begin(), pass_i);
				pass_ = std::string(pass_i + 1, user_pass.end());
			}
			else
				user_ = user_pass;

			host_.assign(user_pass_i + 1, host_.end());
		}

		// parse port
		auto port_i = find(host_.begin(), host_.end(), ':');
		if (port_i != host_.end())
		{
			portstr_ = std::string(port_i + 1, host_.end());
			host_.assign(host_.begin(), port_i);
			try{
				port_ = boost::lexical_cast<decltype(port_)>(portstr_);
			}
			catch (std::exception e) {
				port_ = 80;
			}
		}

		std::string::const_iterator query_i = find(path_i, url_s.end(), '?');
		path_.assign(path_i, query_i);
		if( query_i != url_s.end() )
			++query_i;
		query_.assign(query_i, url_s.end());
	}

} 

namespace net
{
	int GetMTU (const boost::asio::ip::address& localAddress)
	{
#if defined(__linux__) || defined(__FreeBSD_kernel__)	
		ifaddrs * ifaddr, * ifa = nullptr;
		if (getifaddrs(&ifaddr) == -1) 
		{
        	LogPrint (eLogError, "Can't excute getifaddrs");
            return 0;
        }
		int family = 0;
		// loook for interface matching local address	
		for (ifa = ifaddr; ifa != nullptr; ifa = ifa->ifa_next) 
		{
			if (!ifa->ifa_addr) continue;
        	family = ifa->ifa_addr->sa_family;
			if (family == AF_INET && localAddress.is_v4 ())
			{
				sockaddr_in * sa = (sockaddr_in *)ifa->ifa_addr;
				if (!memcmp (&sa->sin_addr, localAddress.to_v4 ().to_bytes ().data (), 4))
					break; // address matches
			}
			else if (family == AF_INET6 && localAddress.is_v6 ())
			{
				sockaddr_in6 * sa = (sockaddr_in6 *)ifa->ifa_addr;
				if (!memcmp (&sa->sin6_addr, localAddress.to_v6 ().to_bytes ().data (), 16))
					break; // address matches
			}
		}
		int mtu = 0;
		if (ifa && family) // interface found?
		{
			int fd = socket (family, SOCK_DGRAM, 0);
			if (fd > 0)
			{
				ifreq ifr;
				strncpy (ifr.ifr_name, ifa->ifa_name, IFNAMSIZ); // set interface for query
				if (ioctl (fd, SIOCGIFMTU, &ifr) >= 0)	
					mtu = ifr.ifr_mtu; // MTU
				else
					LogPrint (eLogError, "Failed to run ioctl");			
				close (fd);
			} 
			else
				LogPrint (eLogError, "Failed to create datagram socket");	
		}		
		else
			LogPrint (eLogWarning, "Interface for local address", localAddress.to_string (), " not found");

		freeifaddrs	(ifaddr);
		return mtu;
#else
		return 0;
#endif		
	}
} 

} // util
} // i2p