/*
Copyright © 2009 Jim Porter

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "twitter.h"
//#include "tc2.h"

#include <windows.h>
#include <cstring>
#include <sstream>
#include <ctime>

#include "tinyjson.hpp"
#include <boost/lexical_cast.hpp>

//#include "boost/spirit/include/classic_core.hpp"
//#include "boost/spirit/include/classic_loops.hpp"

typedef json::grammar<char> js;

// utility functions

template <typename T>
static T cast_and_decode(boost::any &a,bool allow_null)
{
	if(allow_null && a.type() == typeid(void))
		return T();
	return boost::any_cast<T>(a);
}

template <>
static std::string cast_and_decode<std::string>(boost::any &a,bool allow_null)
{
	if(allow_null && a.type() == typeid(void))
		return std::string();
	std::string s = boost::any_cast<std::string>(a);

	// Twitter *only* encodes < and >, so decode them
	size_t off;
	while( (off = s.find("&lt;")) != std::string::npos)
		s.replace(off,4,"<");
	while( (off = s.find("&gt;")) != std::string::npos)
		s.replace(off,4,">");

	return s;
}

template <typename T>
static T retrieve(const js::object &o,const std::string &key,bool allow_null = false)
{
	using boost::any_cast;

	js::object::const_iterator i = o.find(key);
	if(i == o.end())
		throw std::exception( ("unable to retrieve key '"+key+"'").c_str());
	try
	{
		return cast_and_decode<T>(*i->second,allow_null);
	}
	catch(const boost::bad_any_cast &)
	{
		throw std::exception( ("unable to cast key '"+key+"' to target type").c_str());
	}
}



twitter::twitter() : base_url_("https://twitter.com/")
{}

bool twitter::set_credentials(const std::string &username, const std::wstring &consumerKey, const std::wstring &consumerSecret, 
	const std::wstring &oauthAccessToken, const std::wstring &oauthAccessTokenSecret, const std::wstring &pin, bool test)
{
	username_				= username;
	consumerKey_			= consumerKey;
	consumerSecret_			= consumerSecret;
	oauthAccessToken_		= oauthAccessToken;
	oauthAccessTokenSecret_ = oauthAccessTokenSecret;
	pin_ = pin;

	if(test)
		return slurp(base_url_+"account/verify_credentials.json",http::get).code == 200;
	else
		return true;
}

http::response twitter::request_token() {
	return slurp(base_url_+"oauth/request_token",http::get);
}

http::response twitter::request_access_tokens() {
	return slurp(base_url_+"oauth/access_token", http::get);
}

void twitter::set_base_url(const std::string &base_url)
{
	base_url_ = base_url;
}

const std::string & twitter::get_username() const
{
	return username_;
}

const std::string & twitter::get_base_url() const
{
	return base_url_;
}

std::vector<twitter_user> twitter::get_friends()
{
	std::vector<twitter_user> friends;
	http::response resp = slurp(base_url_+"statuses/friends.json",http::get);

	if(resp.code != 200)
		throw bad_response();

	const js::variant var = json::parse( resp.data.begin(),resp.data.end());
	if(var->type() != typeid(js::array))
		throw std::exception("unable to parse response");

	const js::array &list = boost::any_cast<js::array>(*var);
	for(js::array::const_iterator i=list.begin(); i!=list.end(); ++i)
	{
		if((*i)->type() == typeid(js::object))
		{
			const js::object &one = boost::any_cast<js::object>(**i);

			twitter_user user;
			user.username          = retrieve<std::string>(one,"screen_name");
			user.real_name         = retrieve<std::string>(one,"name",true);
			user.profile_image_url = retrieve<std::string>(one,"profile_image_url",true);

			if(one.find("status") != one.end())
			{
				js::object &status  = retrieve<js::object>(one,"status");
				user.status.text    = retrieve<std::string>(status,"text");

				user.status.id      = retrieve<long long>(status,"id");

				std::string timestr = retrieve<std::string>(status,"created_at");
				user.status.time    = parse_time(timestr);
			}

			friends.push_back(user);
		}
	}

	return friends;
}

bool twitter::get_info(const std::string &name,twitter_user *info)
{
	if(!info)
		return false;

	std::string url = base_url_+"users/show/"+http::url_encode(name)+".json";

	http::response resp = slurp(url,http::get);
	if(resp.code != 200)
		throw bad_response();

	const js::variant var = json::parse( resp.data.begin(),resp.data.end());
	if(var->type() == typeid(js::object))
	{
		const js::object &user_info = boost::any_cast<js::object>(*var);
		if(user_info.find("error") != user_info.end())
			return false;

		info->username          = retrieve<std::string>(user_info,"screen_name");
		info->real_name         = retrieve<std::string>(user_info,"name",true);
		info->profile_image_url = retrieve<std::string>(user_info,"profile_image_url",true);

		return true;
	}
	else
		return false;
}

bool twitter::get_info_by_email(const std::string &email,twitter_user *info)
{
	if(!info)
		return false;

	std::string url = base_url_+"users/show.json?email="+http::url_encode(email);

	http::response resp = slurp(url,http::get);
	if(resp.code != 200)
		throw bad_response();

	js::variant var = json::parse( resp.data.begin(),resp.data.end());
	if(var->type() == typeid(js::object))
	{
		const js::object &user_info = boost::any_cast<js::object>(*var);
		if(user_info.find("error") != user_info.end())
			return false;

		info->username          = retrieve<std::string>(user_info,"screen_name");
		info->real_name         = retrieve<std::string>(user_info,"name",true);
		info->profile_image_url = retrieve<std::string>(user_info,"profile_image_url",true);

		return true;
	}
	else
		return false;
}

twitter_user twitter::add_friend(const std::string &name)
{
	std::string url = base_url_+"friendships/create/"+http::url_encode(name)+".json";

	twitter_user ret;
	http::response resp = slurp(url,http::post);
	if(resp.code != 200)
		throw bad_response();

	js::variant var = json::parse( resp.data.begin(),resp.data.end());
	if(var->type() != typeid(js::object))
		throw std::exception("unable to parse response");

	const js::object &user_info = boost::any_cast<js::object>(*var);
	ret.username          = retrieve<std::string>(user_info,"screen_name");
	ret.real_name         = retrieve<std::string>(user_info,"name",true);
	ret.profile_image_url = retrieve<std::string>(user_info,"profile_image_url",true);

	if(user_info.find("status") != user_info.end())
	{
		// TODO: fill in more fields
		const js::object &status = retrieve<js::object>(user_info,"status");
		ret.status.text          = retrieve<std::string>(status,"text");
	}

	return ret;
}

void twitter::remove_friend(const std::string &name)
{
	std::string url = base_url_+"friendships/destroy/"+http::url_encode(name)+".json";

	slurp(url,http::post);
}

void twitter::set_status(const std::string &text)
{
	if(text.size())
	{
/*		slurp(base_url_+"statuses/update.json",http::post,
			"status="+http::url_encode(text)+
			"&source=mirandaim");*/

		//MessageBox(NULL, UTF8ToWide(text).c_str(), NULL, MB_OK);
		std::wstring wTweet = UTF8ToWide(text);
		OAuthParameters postParams;
		postParams[L"status"] = UrlEncode(wTweet);

		slurp(base_url_+"statuses/update.json",http::post, postParams);
	}
}

void twitter::send_direct(const std::string &name,const std::string &text)
{
	std::wstring temp = UTF8ToWide(text);
	OAuthParameters postParams;
	postParams[L"text"] = UrlEncode(temp);
	postParams[L"screen_name"] = UTF8ToWide(name);
	slurp(base_url_+"direct_messages/new.json", http::post,  postParams);
}

std::vector<twitter_user> twitter::get_statuses(int count,twitter_id id)
{
	using boost::lexical_cast;
	std::vector<twitter_user> statuses;

	std::string url = base_url_+"statuses/home_timeline.json?count="+
		lexical_cast<std::string>(count);
	if(id != 0)
		url += "&since_id="+boost::lexical_cast<std::string>(id);

	http::response resp = slurp(url,http::get);
	if(resp.code != 200)
		throw bad_response();

	js::variant var = json::parse( resp.data.begin(),resp.data.end());
	if(var->type() != typeid(js::array))
		throw std::exception("unable to parse response");

	const js::array &list = boost::any_cast<js::array>(*var);
	for(js::array::const_iterator i=list.begin(); i!=list.end(); ++i)
	{
		if((*i)->type() == typeid(js::object))
		{
			const js::object &one  = boost::any_cast<js::object>(**i);
			const js::object &user = retrieve<js::object>(one,"user");

			twitter_user u;
			u.username = retrieve<std::string>(user,"screen_name");
			bool isTruncated = retrieve<bool>(one,"truncated");

			if (isTruncated) { // the tweet will be truncated unless we take action.  i hate you twitter API

				// here we grab the "retweeted_status" um.. section?  it's in here that all the info we need is
				const js::object &Retweet = retrieve<js::object>(one,"retweeted_status");
				const js::object &RTUser = retrieve<js::object>(Retweet,"user");

				std::string retweeteesName = retrieve<std::string>(RTUser,"screen_name"); // the user that is being retweeted
				std::string retweetText = retrieve<std::string>(Retweet,"text"); // their tweet in all it's untruncated glory
				u.status.text = "RT @" + retweeteesName + " " + retweetText; // mash it together in some format people will understand
			}
			else { // if it's not truncated, then the twitter API returns the native RT correctly anyway,
				u.status.text = retrieve<std::string>(one,"text"); // so we can just pretend it doesn't happen
			}

			u.status.id         = retrieve<long long>(one,"id");
			std::string timestr = retrieve<std::string>(one,"created_at");
			u.status.time       = parse_time(timestr);

			statuses.push_back(u);
		}
	}


	return statuses;
}

std::vector<twitter_user> twitter::get_direct(twitter_id id)
{
	std::vector<twitter_user> messages;

	std::string url = base_url_+"direct_messages.json";
	if(id != 0)
		url += "?since_id="+boost::lexical_cast<std::string>(id);

	http::response resp = slurp(url,http::get);
	if(resp.code != 200)
		throw bad_response();

	js::variant var = json::parse( resp.data.begin(),resp.data.end());
	if(var->type() != typeid(js::array))
		throw std::exception("unable to parse response");

	const js::array &list = boost::any_cast<js::array>(*var);
	for(js::array::const_iterator i=list.begin(); i!=list.end(); ++i)
	{
		if((*i)->type() == typeid(js::object))
		{
			const js::object &one = boost::any_cast<js::object>(**i);

			twitter_user u;
			u.username = retrieve<std::string>(one,"sender_screen_name");

			u.status.text       = retrieve<std::string>(one,"text");
			u.status.id         = retrieve<long long>(one,"id");
			std::string timestr = retrieve<std::string>(one,"created_at");
			u.status.time       = parse_time(timestr);

			messages.push_back(u);
		}
	}


	return messages;
}

string twitter::urlencode(const string &c)
{

	string escaped;
	int max = c.length();
	for(int i=0; i<max; i++)
	{
		if ( (48 <= c[i] && c[i] <= 57) ||//0-9
			(65 <= c[i] && c[i] <= 90) ||//ABC...XYZ
			(97 <= c[i] && c[i] <= 122) || //abc...xyz
			(c[i]=='~' || c[i]=='-' || c[i]=='_' || c[i]=='.')
			)
		{
			escaped.append( &c[i], 1);
		}
		else
		{
			escaped.append("%");
			escaped.append( char2hex(c[i]));//converts char 255 to string "FF"
		}
	}
	return escaped;
}


wstring twitter::UrlEncode( const wstring& url ) 
{
	// multiple encodings r sux
	return UTF8ToWide(urlencode(WideToUTF8(url)));
}

// char2hex and urlencode from http://www.zedwood.com/article/111/cpp-urlencode-function
// modified according to http://oauth.net/core/1.0a/#encoding_parameters
//
//5.1.  Parameter Encoding
//
//All parameter names and values are escaped using the [RFC3986]  
//percent-encoding (%xx) mechanism. Characters not in the unreserved character set 
//MUST be encoded. Characters in the unreserved character set MUST NOT be encoded. 
//Hexadecimal characters in encodings MUST be upper case. 
//Text names and values MUST be encoded as UTF-8 
// octets before percent-encoding them per [RFC3629].
//
//  unreserved = ALPHA, DIGIT, '-', '.', '_', '~'

string twitter::char2hex( char dec )
{
	char dig1 = (dec&0xF0)>>4;
	char dig2 = (dec&0x0F);
	if ( 0<= dig1 && dig1<= 9) dig1+=48;    //0,48 in ascii
	if (10<= dig1 && dig1<=15) dig1+=65-10; //A,65 in ascii
	if ( 0<= dig2 && dig2<= 9) dig2+=48;
	if (10<= dig2 && dig2<=15) dig2+=65-10;

	string r;
	r.append( &dig1, 1);
	r.append( &dig2, 1);
	return r;
}

// Some Unices get this, now we do too!
time_t timegm(struct tm *t)
{
	_tzset();
	t->tm_sec -= _timezone;
	t->tm_isdst = 0;

	return mktime(t);
}

static char *month_names[] = { "Jan","Feb","Mar","Apr","May","Jun",
                               "Jul","Aug","Sep","Oct","Nov","Dec" };

int parse_month(const char *m)
{
	for(size_t i=0; i<12; i++)
	{
		if(strcmp(month_names[i],m) == 0)
			return i;
	}
	return -1;
}

time_t parse_time(const std::string &s)
{
	struct tm t;
	char day[4],month[4];
	char plus;
	int zone;
	if(sscanf(s.c_str(),"%3s %3s %d %d:%d:%d %c%d %d",
		day,month,&t.tm_mday,&t.tm_hour,&t.tm_min,&t.tm_sec,
		&plus,&zone,&t.tm_year) == 9)
	{
		t.tm_year -= 1900;
		t.tm_mon = parse_month(month);
		if(t.tm_mon == -1)
			return 0;
		return timegm(&t);
	}
	return 0;
}