/** 
 * @file lllogchat.cpp
 * @brief LLLogChat class implementation
 *
 * $LicenseInfo:firstyear=2002&license=viewergpl$
 * 
 * Copyright (c) 2002-2009, Linden Research, Inc.
 * 
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 * 
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at
 * http://secondlifegrid.net/programs/open_source/licensing/flossexception
 * 
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 * 
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */

#include "llviewerprecompiledheaders.h"

#include "lllogchat.h"

// viewer includes
#include "llagent.h"
#include "llagentui.h"
#include "lltrans.h"
#include "llviewercontrol.h"

// library includes
#include "llchat.h"
#include "llinstantmessage.h"
#include "llsdserialize.h"
#include "llsingleton.h" // for LLSingleton

#include <boost/algorithm/string/trim.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <boost/regex.hpp>
#include <boost/regex/v4/match_results.hpp>

#if LL_MSVC
// disable warning about boost::lexical_cast unreachable code
// when it fails to parse the string
#pragma warning (disable:4702)
#endif

#include <boost/date_time/gregorian/gregorian.hpp>
#if LL_MSVC
#pragma warning(pop)   // Restore all warnings to the previous state
#endif

#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/date_time/local_time_adjustor.hpp>

const S32 LOG_RECALL_SIZE = 2048;

const std::string IM_TIME("time");
const std::string IM_TEXT("message");
const std::string IM_FROM("from");
const std::string IM_FROM_ID("from_id");
const std::string IM_SOURCE_TYPE("source_type");

const static std::string IM_SEPARATOR(": ");
const static std::string NEW_LINE("\n");
const static std::string NEW_LINE_SPACE_PREFIX("\n ");
const static std::string TWO_SPACES("  ");
const static std::string MULTI_LINE_PREFIX(" ");

/**
 *  Chat log lines - timestamp and name are optional but message text is mandatory.
 *
 *  Typical plain text chat log lines:
 *
 *  SuperCar: You aren't the owner
 *  [2:59]  SuperCar: You aren't the owner
 *  [2009/11/20 3:00]  SuperCar: You aren't the owner
 *  Katar Ivercourt is Offline
 *  [3:00]  Katar Ivercourt is Offline
 *  [2009/11/20 3:01]  Corba ProductEngine is Offline
 *
 * Note: "You" was used as an avatar names in viewers of previous versions
 */
const static boost::regex TIMESTAMP_AND_STUFF("^(\\[\\d{4}/\\d{1,2}/\\d{1,2}\\s+\\d{1,2}:\\d{2}\\]\\s+|\\[\\d{1,2}:\\d{2}\\]\\s+)?(.*)$");

/**
 *  Regular expression suitable to match names like
 *  "You", "Second Life", "Igor ProductEngine", "Object", "Mega House"
 */
const static boost::regex NAME_AND_TEXT("(You:|Second Life:|[^\\s:]+\\s*[:]{1}|\\S+\\s+[^\\s:]+[:]{1})?(\\s*)(.*)");

//is used to parse complex object names like "Xstreet SL Terminal v2.2.5 st"
const static std::string NAME_TEXT_DIVIDER(": ");

// is used for timestamps adjusting
const static char* DATE_FORMAT("%Y/%m/%d %H:%M");
const static char* TIME_FORMAT("%H:%M");

const static int IDX_TIMESTAMP = 1;
const static int IDX_STUFF = 2;
const static int IDX_NAME = 1;
const static int IDX_TEXT = 3;

using namespace boost::posix_time;
using namespace boost::gregorian;

class LLLogChatTimeScanner: public LLSingleton<LLLogChatTimeScanner>
{
public:
	LLLogChatTimeScanner()
	{
		// Note, date/time facets will be destroyed by string streams
		mDateStream.imbue(std::locale(mDateStream.getloc(), new date_input_facet(DATE_FORMAT)));
		mTimeStream.imbue(std::locale(mTimeStream.getloc(), new time_facet(TIME_FORMAT)));
		mTimeStream.imbue(std::locale(mTimeStream.getloc(), new time_input_facet(DATE_FORMAT)));
	}

	date getTodayPacificDate()
	{
		typedef	boost::date_time::local_adjustor<ptime, -8, no_dst> pst;
		typedef boost::date_time::local_adjustor<ptime, -7, no_dst> pdt;
		time_t t_time = time(NULL);
		ptime p_time = LLStringOps::getPacificDaylightTime()
			? pdt::utc_to_local(from_time_t(t_time))
			: pst::utc_to_local(from_time_t(t_time));
		struct tm s_tm = to_tm(p_time);
		return date_from_tm(s_tm);
	}

	void checkAndCutOffDate(std::string& time_str)
	{
		// Cuts off the "%Y/%m/%d" from string for todays timestamps.
		// Assume that passed string has at least "%H:%M" time format.
		date log_date(not_a_date_time);
		date today(getTodayPacificDate());

		// Parse the passed date
		mDateStream.str(LLStringUtil::null);
		mDateStream << time_str;
		mDateStream >> log_date;
		mDateStream.clear();

		days zero_days(0);
		days days_alive = today - log_date;

		if ( days_alive == zero_days )
		{
			// Yep, today's so strip "%Y/%m/%d" info
			ptime stripped_time(not_a_date_time);

			mTimeStream.str(LLStringUtil::null);
			mTimeStream << time_str;
			mTimeStream >> stripped_time;
			mTimeStream.clear();

			time_str.clear();

			mTimeStream.str(LLStringUtil::null);
			mTimeStream << stripped_time;
			mTimeStream >> time_str;
			mTimeStream.clear();
		}

		LL_DEBUGS("LLChatLogParser")
			<< " log_date: "
			<< log_date
			<< " today: "
			<< today
			<< " days alive: "
			<< days_alive
			<< " new time: "
			<< time_str
			<< LL_ENDL;
	}


private:
	std::stringstream mDateStream;
	std::stringstream mTimeStream;
};

//static
std::string LLLogChat::makeLogFileName(std::string filename)
{
	filename = cleanFileName(filename);
	filename = gDirUtilp->getExpandedFilename(LL_PATH_PER_ACCOUNT_CHAT_LOGS,filename);
	// new files are llsd notation format
	filename += ".llsd";
	return filename;
}

std::string LLLogChat::cleanFileName(std::string filename)
{
	std::string invalidChars = "\"\'\\/?*:<>|";
	std::string::size_type position = filename.find_first_of(invalidChars);
	while (position != filename.npos)
	{
		filename[position] = '_';
		position = filename.find_first_of(invalidChars, position);
	}
	return filename;
}

std::string LLLogChat::timestamp(bool withdate)
{
	time_t utc_time;
	utc_time = time_corrected();

	std::string timeStr;
	LLSD substitution;
	substitution["datetime"] = (S32) utc_time;

	if (withdate)
	{
		timeStr = "["+LLTrans::getString ("TimeYear")+"]/["
		          +LLTrans::getString ("TimeMonth")+"]/["
				  +LLTrans::getString ("TimeDay")+"] ["
				  +LLTrans::getString ("TimeHour")+"]:["
				  +LLTrans::getString ("TimeMin")+"]";
	}
	else
	{
		timeStr = "[" + LLTrans::getString("TimeHour") + "]:["
			      + LLTrans::getString ("TimeMin")+"]";
	}

	LLStringUtil::format (timeStr, substitution);
	return timeStr;
}


//static
void LLLogChat::saveHistory(const std::string& filename,
			    const std::string& from,
			    const LLUUID& from_id,
			    const std::string& line)
{
	LLChat chat;
	chat.mText = line;
	chat.mFromName = from;
	chat.mFromID = from_id;
	// default to being from an agent
	chat.mSourceType = CHAT_SOURCE_AGENT;
	saveHistory(filename, chat);
}

//static
void LLLogChat::saveHistory(const std::string& filename, const LLChat& chat)
{
	std::string tmp_filename = filename;
	LLStringUtil::trim(tmp_filename);
	if (tmp_filename.empty())
	{
		std::string warn = "Chat history filename [" + filename + "] is empty!";
		llwarning(warn, 666);
		llassert(tmp_filename.size());
		return;
	}
	
	llofstream file (LLLogChat::makeLogFileName(filename), std::ios_base::app);
	if (!file.is_open())
	{
		llwarns << "Couldn't open chat history log! - " + filename << llendl;
		return;
	}

	LLSD item;

	if (gSavedPerAccountSettings.getBOOL("LogTimestamp"))
		 item[IM_TIME] = LLLogChat::timestamp(gSavedPerAccountSettings.getBOOL("LogTimestampDate"));

	item[IM_FROM_ID] = chat.mFromID;
	item[IM_TEXT] = chat.mText;
	item[IM_SOURCE_TYPE] = chat.mSourceType;

	//adding "Second Life:" for all system messages to make chat log history parsing more reliable
	if (chat.mFromName.empty() && chat.mFromID.isNull())
	{
		item[IM_FROM] = SYSTEM_FROM; 
	}
	else
	{
		item[IM_FROM] = chat.mFromName;
	}

	file << LLSDOStreamer<LLSDNotationFormatter>(item) << std::endl;

	file.close();
}

void append_to_last_message(std::list<LLSD>& messages, const std::string& line)
{
	if (!messages.size()) return;

	std::string im_text = messages.back()[IM_TEXT].asString();
	im_text.append(line);
	messages.back()[IM_TEXT] = im_text;
}

// static
void LLLogChat::loadAllHistory(const std::string& file_name, std::list<LLSD>& messages)
{
	if (file_name.empty())
	{
		llwarns << "Session name is Empty!" << llendl;
		return ;
	}

	LLFILE* fptr = LLFile::fopen(makeLogFileName(file_name), "r");		/*Flawfinder: ignore*/
	if (!fptr) return;	//No previous conversation with this name.

	char buffer[LOG_RECALL_SIZE];		/*Flawfinder: ignore*/
	char *bptr;
	S32 len;
	bool firstline = TRUE;

	if (fseek(fptr, (LOG_RECALL_SIZE - 1) * -1  , SEEK_END))
	{	//File is smaller than recall size.  Get it all.
		firstline = FALSE;
		if (fseek(fptr, 0, SEEK_SET))
		{
			fclose(fptr);
			return;
		}
	}

	while (fgets(buffer, LOG_RECALL_SIZE, fptr)  && !feof(fptr)) 
	{
		len = strlen(buffer) - 1;		/*Flawfinder: ignore*/
		for (bptr = (buffer + len); (*bptr == '\n' || *bptr == '\r') && bptr>buffer; bptr--)	*bptr='\0';
		
		if (firstline)
		{
			firstline = FALSE;
			continue;
		}

		std::string line(buffer);

		//updated 1.23 plaint text log format requires a space added before subsequent lines in a multilined message
		if (' ' == line[0])
		{
			line.erase(0, MULTI_LINE_PREFIX.length());
			append_to_last_message(messages, '\n' + line);
		}
		else if (0 == len && ('\n' == line[0] || '\r' == line[0]))
		{
			//to support old format's multilined messages with new lines used to divide paragraphs
			append_to_last_message(messages, line);
		}
		else
		{
			LLSD item;
			if (!LLChatLogParser::parse(line, item))
			{
				item[IM_TEXT] = line;
			}
			messages.push_back(item);
		}
	}
	fclose(fptr);
}

// static
bool LLChatLogParser::parse(const std::string& raw, LLSD& im)
{
	if (!raw.length()) return false;
	
	im = LLSD::emptyMap();

	// In Viewer 2.1 we added UUID to chat/IM logging so we can look up
	// display names
	if (raw[0] == '{')
	{
		// ...this is a viewer 2.1, new-style LLSD notation format log
		std::istringstream raw_stream(raw);
		LLPointer<LLSDParser> parser = new LLSDNotationParser();
		S32 count = parser->parse(raw_stream, im, raw.length());
		// expect several map items per parsed line
		return (count != LLSDParser::PARSE_FAILURE);
	}

	//matching a timestamp
	boost::match_results<std::string::const_iterator> matches;
	if (!boost::regex_match(raw, matches, TIMESTAMP_AND_STUFF)) return false;
	
	bool has_timestamp = matches[IDX_TIMESTAMP].matched;
	if (has_timestamp)
	{
		//timestamp was successfully parsed
		std::string timestamp = matches[IDX_TIMESTAMP];
		boost::trim(timestamp);
		timestamp.erase(0, 1);
		timestamp.erase(timestamp.length()-1, 1);
		LLLogChatTimeScanner::instance().checkAndCutOffDate(timestamp);
		im[IM_TIME] = timestamp;
	}
	else
	{
		//timestamp is optional
		im[IM_TIME] = "";
	}

	bool has_stuff = matches[IDX_STUFF].matched;
	if (!has_stuff)
	{
		return false;  //*TODO should return false or not?
	}

	//matching a name and a text
	std::string stuff = matches[IDX_STUFF];
	boost::match_results<std::string::const_iterator> name_and_text;
	if (!boost::regex_match(stuff, name_and_text, NAME_AND_TEXT)) return false;
	
	bool has_name = name_and_text[IDX_NAME].matched;
	std::string name = name_and_text[IDX_NAME];

	//we don't need a name/text separator
	if (has_name && name.length() && name[name.length()-1] == ':')
	{
		name.erase(name.length()-1, 1);
	}

	if (!has_name || name == SYSTEM_FROM)
	{
		//name is optional too
		im[IM_FROM] = SYSTEM_FROM;
		im[IM_FROM_ID] = LLUUID::null;
	}

	//possibly a case of complex object names consisting of 3+ words
	if (!has_name)
	{
		U32 divider_pos = stuff.find(NAME_TEXT_DIVIDER);
		if (divider_pos != std::string::npos && divider_pos < (stuff.length() - NAME_TEXT_DIVIDER.length()))
		{
			im[IM_FROM] = stuff.substr(0, divider_pos);
			im[IM_TEXT] = stuff.substr(divider_pos + NAME_TEXT_DIVIDER.length());
			return true;
		}
	}

	if (!has_name)
	{
		//text is mandatory
		im[IM_TEXT] = stuff;
		return true; //parse as a message from Second Life
	}
	
	bool has_text = name_and_text[IDX_TEXT].matched;
	if (!has_text) return false;

	//for parsing logs created in very old versions of a viewer
	if (name == "You")
	{
		std::string agent_name;
		LLAgentUI::buildFullname(agent_name);
		im[IM_FROM] = agent_name;
		im[IM_FROM_ID] = gAgentID;
	}
	else
	{
		im[IM_FROM] = name;
	}
	

	im[IM_TEXT] = name_and_text[IDX_TEXT];
	return true;  //parsed name and message text, maybe have a timestamp too
}