/*******************************************************************************
 * libretroshare/src/services: p3gxscommon.cc                                  *
 *                                                                             *
 * libretroshare: retroshare core library                                      *
 *                                                                             *
 * Copyright 2012-2013 Robert Fernie <retroshare@lunamutt.com>                 *
 *                                                                             *
 * This program is free software: you can redistribute it and/or modify        *
 * it under the terms of the GNU Lesser General Public License as              *
 * published by the Free Software Foundation, either version 3 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 Lesser General Public License for more details.                         *
 *                                                                             *
 * You should have received a copy of the GNU Lesser General Public License    *
 * along with this program. If not, see <https://www.gnu.org/licenses/>.       *
 *                                                                             *
 *******************************************************************************/
#include "retroshare/rsgxscommon.h"
#include "services/p3gxscommon.h"
#include "rsitems/rsgxscommentitems.h"
#include "util/rsstring.h"

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

//#define DEBUG_GXSCOMMON

RsGxsComment::RsGxsComment()
{
	mUpVotes = 0;
	mDownVotes = 0;
	mScore = 0;
	mOwnVote = 0;
}

/********************************************************************************/

RsGxsImage::RsGxsImage()
{
#ifdef DEBUG_GXSCOMMON
	std::cerr << "RsGxsImage(" << this << ")";
    std::cerr << std::endl;
#endif
	mData = NULL;
	mSize = 0;
}

RsGxsImage::RsGxsImage(const RsGxsImage& a)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "RsGxsImage(" << this << ") = RsGxsImage(" << (void *) &a << ")";
    std::cerr << std::endl;
#endif
	mData = NULL;
	mSize = 0;
	copy(a.mData, a.mSize);
}
	

RsGxsImage::~RsGxsImage()
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "~RsGxsImage(" << this << ")";
    std::cerr << std::endl;
#endif
	clear();
}


RsGxsImage &RsGxsImage::operator=(const RsGxsImage &a)
{
	copy(a.mData, a.mSize);
	return *this;
}


bool RsGxsImage::empty() const
{
	return ((mData == NULL) || (mSize == 0));
}

void RsGxsImage::take(uint8_t *data, uint32_t size)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "RsGxsImage(" << this << ")::take(" << (void *) data << "," << size << ")";
    std::cerr << std::endl;
#endif
	// Copies Pointer.
	clear();
	mData = data;
	mSize = size;
}

// NB Must make sure that we always use malloc/free for this data.
uint8_t *RsGxsImage::allocate(uint32_t size)
{
	uint8_t *val = (uint8_t *) rs_malloc(size);
    
#ifdef DEBUG_GXSCOMMON
    std::cerr << "RsGxsImage()::allocate(" << (void *) val << ")";
    std::cerr << std::endl;
#endif
	return val;
}

void RsGxsImage::release(void *data)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "RsGxsImage()::release(" << (void *) data << ")";
    std::cerr << std::endl;
#endif
	free(data);
}

void RsGxsImage::copy(uint8_t *data, uint32_t size)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "RsGxsImage(" << this << ")::copy(" << (void *) data << "," << size << ")";
    std::cerr << std::endl;
#endif
	// Allocates and Copies.
	clear(); 
	if (data && size)
	{
		mData = allocate(size);
		memcpy(mData, data, size);
		mSize = size;
	}
}

void RsGxsImage::clear()
{
	// Frees.
	if (mData)
	{
		release(mData);	       
	}
	mData = NULL;
	mSize = 0;
}

void RsGxsImage::shallowClear()
{
	// Clears Pointer.
	mData = NULL;
	mSize = 0;
}

/********************************************************************************/


RsGxsFile::RsGxsFile()
{
	mSize = 0;
}

RsGxsVote::RsGxsVote()
{
	mVoteType = 0;
}

/********************************************************************************/
/******************* Startup / Tick    ******************************************/
/********************************************************************************/

#define GXSCOMMENTS_VOTE_CHECK		0x0002
#define GXSCOMMENTS_VOTE_DONE		0x0003

p3GxsCommentService::p3GxsCommentService(RsGenExchange *exchange, uint16_t service_type)
    : GxsTokenQueue(exchange), mExchange(exchange), mServiceType(service_type)
{
	return;
}

static double calculateBestScore(int upVotes, int downVotes)
{

    float score;
    int n = upVotes + downVotes;

    if(n==0)
        score = 0.0;
    else
    {
        // See https://github.com/reddit/reddit/blob/master/r2/r2/lib/db/_sorts.pyx#L45 for the source of this nice formula.
        //     http://www.evanmiller.org/how-not-to-sort-by-average-rating.html for the mathematical explanation.

        float p = upVotes/n;
        float z = 1.281551565545 ;

        float left  = p + 1/(2*n)*z*z ;
        float right = z*sqrt(p*(1-p)/n + z*z/(4*n*n)) ;
        float under = 1+1/n*z*z ;

        score = (left - right)/under ;

        //static float z = 1.0;
        //score = sqrt(phat+z*z/(2*n)-z*((phat*(1-phat)+z*z/(4*n))/n))/(1+z*z/n);
    }
    return score;
}



// Turns message data into comments, counting other data that are votes as votes.
// Only the latest couple (authorId, parentId) are accounted for, for each vote.

static bool convertMsgDataToVotedComments(const std::vector<RsGxsMsgItem*>& msgItems, std::vector<RsGxsComment>& comments)
{
    std::map<std::pair<RsGxsId,RsGxsMessageId>,RsGxsVoteItem *> votes;

    std::multimap<RsGxsMessageId, RsGxsVoteItem *> voteMap;

        /* now split into Comments and Votes */

        for(auto vit = msgItems.begin(); vit != msgItems.end(); ++vit)
        {
            RsGxsCommentItem* item = dynamic_cast<RsGxsCommentItem*>(*vit);

            if(item)
            {
                RsGxsComment comment = item->mMsg;
                comment.mMeta = item->meta;
                comments.push_back(comment);
                delete item;
            }
            else
            {
                RsGxsVoteItem* vote = dynamic_cast<RsGxsVoteItem*>(*vit);
                if (vote)
                {
                    voteMap.insert(std::make_pair(vote->meta.mParentId, vote));
                }
                else
                {
                    std::cerr << "Not a Comment or Vote, deleting!" << std::endl;
                    delete *vit;
                }
            }
        }

    /* now iterate through comments - and set the vote counts */
    std::vector<RsGxsComment>::iterator cit;
    std::multimap<RsGxsMessageId, RsGxsVoteItem *>::iterator it;
    for(cit = comments.begin(); cit != comments.end(); ++cit)
    {
        for (it = voteMap.lower_bound(cit->mMeta.mMsgId); it != voteMap.upper_bound(cit->mMeta.mMsgId); ++it)
        {
            if (it->second->mMsg.mVoteType == GXS_VOTE_UP)
            {
                cit->mUpVotes++;
            }
            else
            {
                cit->mDownVotes++;
            }
        }
        cit->mScore = calculateBestScore(cit->mUpVotes, cit->mDownVotes);

        /* convert Status -> mHaveVoted */
        if (cit->mMeta.mMsgStatus & GXS_SERV::GXS_MSG_STATUS_VOTE_MASK)
        {
            if (cit->mMeta.mMsgStatus & GXS_SERV::GXS_MSG_STATUS_VOTE_UP)
            {
                cit->mOwnVote = GXS_VOTE_UP;
            }
            else
            {
                cit->mOwnVote = GXS_VOTE_DOWN;
            }
        }
        else
        {
            cit->mOwnVote = GXS_VOTE_NONE;
        }
    }

#ifdef DEBUG_GXSCOMMON
    std::cerr << "p3GxsCommentService::getGxsCommentData() Found " << comments.size() << " Comments";
    std::cerr << std::endl;
    std::cerr << "p3GxsCommentService::getGxsCommentData() Found " << voteMap.size() << " Votes";
    std::cerr << std::endl;
#endif

    /* delete the votes */
    for (it = voteMap.begin(); it != voteMap.end(); ++it)
        delete it->second;

    return true;
}



void p3GxsCommentService::comment_tick()
{
        GxsTokenQueue::checkRequests();
}

bool p3GxsCommentService::getGxsCommentData(const uint32_t &token, std::vector<RsGxsComment> &comments)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "p3GxsCommentService::getGxsCommentData()";
    std::cerr << std::endl;
#endif

	GxsMsgDataMap msgData;
	bool ok = mExchange->getMsgData(token, msgData);
		
    if(msgData.empty())
        return true;

    if(msgData.size() > 1)
        return false;

    return ok && convertMsgDataToVotedComments( msgData.begin()->second,comments);
}


bool p3GxsCommentService::getGxsRelatedComments(const uint32_t &token, std::vector<RsGxsComment> &comments)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "p3GxsCommentService::getGxsRelatedComments()";
    std::cerr << std::endl;
#endif

	GxsMsgRelatedDataMap msgData;
	bool ok = mExchange->getMsgRelatedData(token, msgData);

    if(msgData.empty())
        return true;

    if(msgData.size() > 1)
        return false;

    return ok && convertMsgDataToVotedComments(msgData.begin()->second,comments);
}



/********************************************************************************************/

bool p3GxsCommentService::createGxsComment(uint32_t &token, const RsGxsComment &msg)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "p3GxsCommentService::createGxsComment() GroupId: " << msg.mMeta.mGroupId;
    std::cerr << std::endl;
#endif

	RsGxsCommentItem* msgItem = new RsGxsCommentItem(mServiceType);
	msgItem->mMsg = msg;
	msgItem->meta = msg.mMeta;
	
	mExchange->publishMsg(token, msgItem);
	return true;
}



bool p3GxsCommentService::createGxsVote(uint32_t &token, RsGxsVote &vote)
{
	// NOTE Because we cannot do this operation immediately, we create a token, 
	// and monitor acknowledgeTokenMsg ... to return correct answer.

#ifdef DEBUG_GXSCOMMON
    std::cerr << "p3GxsCommentService::createGxsVote() GroupId: " << vote.mMeta.mGroupId;
    std::cerr << std::endl;
#endif

	/* vote must be associated with another item */
	if (vote.mMeta.mThreadId.isNull())
    {
		std::cerr << "p3GxsCommentService::createGxsVote() ERROR Missing Required ThreadId";
		std::cerr << std::endl;
		return false;
	}

	if (vote.mMeta.mParentId.isNull())
	{
		std::cerr << "p3GxsCommentService::createGxsVote() ERROR Missing Required ParentId";
		std::cerr << std::endl;
		return false;
	}

	if (vote.mMeta.mGroupId.isNull())
	{
		std::cerr << "p3GxsCommentService::createGxsVote() ERROR Missing Required GroupId";
		std::cerr << std::endl;
		return false;
	}

	if (vote.mMeta.mAuthorId.isNull())
	{
		std::cerr << "p3GxsCommentService::createGxsVote() ERROR Missing Required AuthorId";
		std::cerr << std::endl;
		return false;
	}


	/* now queue */

	RsGxsGrpMsgIdPair parentId(vote.mMeta.mGroupId, vote.mMeta.mParentId);

	std::map<RsGxsGrpMsgIdPair, VoteHolder>::iterator it;
	it = mPendingVotes.find(parentId);
	if (it != mPendingVotes.end())
	{
		std::cerr << "p3GxsCommentService::createGxsVote() ERROR Already a pending vote!";
		std::cerr << std::endl;
		return false;
	}

	token = mExchange->generatePublicToken();
	mPendingVotes[parentId] = VoteHolder(vote, token);

	// request parent, and queue for response.
	RsTokReqOptions opts;
	opts.mReqType = GXS_REQUEST_TYPE_MSG_META;

	GxsMsgReq msgIds;
	std::set<RsGxsMessageId> &vect_msgIds = msgIds[parentId.first];
	vect_msgIds.insert(parentId.second);

	uint32_t int_token;
	mExchange->getTokenService()->requestMsgInfo(int_token, RS_TOKREQ_ANSTYPE_SUMMARY, opts, msgIds);
	GxsTokenQueue::queueRequest(int_token, GXSCOMMENTS_VOTE_CHECK);

	return true;
}







void p3GxsCommentService::load_PendingVoteParent(const uint32_t &token)
{
#ifdef DEBUG_GXSCOMMON
        std::cerr << "p3GxsCommentService::load_PendingVoteParent()";
    std::cerr << std::endl;
#endif
	GxsMsgMetaMap msginfo;
        if (!mExchange->getMsgMeta(token, msginfo))
	{
                std::cerr << "p3GxsCommentService::load_PendingVoteParent() ERROR Fetching Data";
		std::cerr << std::endl;
                std::cerr << "p3GxsCommentService::load_PendingVoteParent() Warning - this means LOST QUEUE ENTRY";
		std::cerr << std::endl;
                std::cerr << "p3GxsCommentService::load_PendingVoteParent() Need to track tokens - if this happens";
		std::cerr << std::endl;
                return;
        }

	GxsMsgMetaMap::iterator it;
	for(it = msginfo.begin(); it != msginfo.end(); ++it)
	{
		std::vector<RsMsgMetaData>::iterator mit;
		for(mit = it->second.begin(); mit != it->second.end(); ++mit)
		{
			/* find the matching Pending Vote */
			RsMsgMetaData &meta = *mit;

#ifdef DEBUG_GXSCOMMON
                    std::cerr << "p3GxsCommentService::load_PendingVoteParent() recv (groupId: " << meta.mGroupId;
            std::cerr << ", msgId: " << meta.mMsgId << ")";
            std::cerr << std::endl;
#endif

			RsGxsGrpMsgIdPair parentId(meta.mGroupId, meta.mMsgId);
			std::map<RsGxsGrpMsgIdPair, VoteHolder>::iterator pit;
			pit = mPendingVotes.find(parentId);
			if (pit == mPendingVotes.end())
			{
				std::cerr << __PRETTY_FUNCTION__
				          << " ERROR Finding Pending Vote" << std::endl;
				continue;
			}

			RsGxsVote vote = pit->second.mVote;
			if (meta.mMsgStatus & GXS_SERV::GXS_MSG_STATUS_VOTE_MASK)
			{
				std::cerr << __PRETTY_FUNCTION__ << " ERROR Already Voted"
				          << std::endl
				          << "mGroupId: " << meta.mGroupId << std::endl
				          << "mMsgId: " << meta.mMsgId << std::endl;

				pit->second.mStatus = VoteHolder::VOTE_ERROR;
				mExchange->updatePublicRequestStatus(
				            pit->second.mReqToken, RsTokenService::FAILED );
				continue;
			}

#ifdef DEBUG_GXSCOMMON
                    std::cerr << "p3GxsCommentService::load_PendingVoteParent() submitting Vote";
            std::cerr << std::endl;
#endif

			uint32_t status_token;
			if (vote.mVoteType == GXS_VOTE_UP)
			{
				mExchange->setMsgStatusFlags(status_token, parentId, 
						GXS_SERV::GXS_MSG_STATUS_VOTE_UP, GXS_SERV::GXS_MSG_STATUS_VOTE_MASK);
			}
			else
			{
				mExchange->setMsgStatusFlags(status_token, parentId, 
						GXS_SERV::GXS_MSG_STATUS_VOTE_DOWN, GXS_SERV::GXS_MSG_STATUS_VOTE_MASK);
			}

			uint32_t vote_token;
			castVote(vote_token, vote);
			GxsTokenQueue::queueRequest(vote_token, GXSCOMMENTS_VOTE_DONE);

			pit->second.mVoteToken = vote_token;
			pit->second.mStatus = VoteHolder::VOTE_SUBMITTED;
		}
	}
}



void p3GxsCommentService::completeInternalVote(uint32_t &token)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "p3GxsCommentService::completeInternalVote() token: " << token;
    std::cerr << std::endl;
#endif
	std::map<RsGxsGrpMsgIdPair, VoteHolder>::iterator it;
	for (it = mPendingVotes.begin(); it != mPendingVotes.end(); ++it)
	{
		if (it->second.mVoteToken == token)
		{
			RsTokenService::GxsRequestStatus status =
			        mExchange->getTokenService()->requestStatus(token);
			mExchange->updatePublicRequestStatus(it->second.mReqToken, status);

#ifdef DEBUG_GXSCOMMON
            std::cerr << "p3GxsCommentService::completeInternalVote() Matched to PendingVote. status: " << status;
            std::cerr << std::endl;
#endif

			it->second.mStatus = VoteHolder::VOTE_READY;
			return;
		}
	}

	std::cerr << "p3GxsCommentService::completeInternalVote() ERROR Failed to match PendingVote";
	std::cerr << std::endl;

	return;
}


bool p3GxsCommentService::acknowledgeVote(const uint32_t& token, RsGxsGrpMsgIdPair& msgId)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "p3GxsCommentService::acknowledgeVote() token: " << token;
    std::cerr << std::endl;
#endif

	std::map<RsGxsGrpMsgIdPair, VoteHolder>::iterator it;
	for (it = mPendingVotes.begin(); it != mPendingVotes.end(); ++it)
	{
		if (it->second.mReqToken == token)
		{
#ifdef DEBUG_GXSCOMMON
            std::cerr << "p3GxsCommentService::acknowledgeVote() Matched to PendingVote";
            std::cerr << std::endl;
#endif

			bool ans = false;
			if (it->second.mStatus == VoteHolder::VOTE_READY)
			{
#ifdef DEBUG_GXSCOMMON
                std::cerr << "p3GxsCommentService::acknowledgeVote() PendingVote = READY";
                std::cerr << std::endl;
#endif

				// Finally finish this Vote off.
				ans = mExchange->acknowledgeTokenMsg(it->second.mVoteToken, msgId);
			}
			else if (it->second.mStatus == VoteHolder::VOTE_ERROR)
            {
				std::cerr << "p3GxsCommentService::acknowledgeVote() PendingVote = ERROR ???";
				std::cerr << std::endl;
			}
#ifdef DEBUG_GXSCOMMON
            else
			{
				std::cerr << "p3GxsCommentService::acknowledgeVote() PendingVote = OTHER STATUS";
				std::cerr << std::endl;
            }

			std::cerr << "p3GxsCommentService::acknowledgeVote() cleanup token & PendingVote";
			std::cerr << std::endl;
#endif
            mExchange->disposeOfPublicToken(it->second.mReqToken);
			mPendingVotes.erase(it);

			return ans;
		}
	}

#ifdef DEBUG_GXSCOMMON
    std::cerr << "p3GxsCommentService::acknowledgeVote() Failed to match PendingVote";
    std::cerr << std::endl;
#endif

	return false;
}


        // Overloaded from GxsTokenQueue for Request callbacks.
void p3GxsCommentService::handleResponse(uint32_t token, uint32_t req_type
                                         , RsTokenService::GxsRequestStatus status)
{
#ifdef DEBUG_GXSCOMMON
	std::cerr << "p3GxsCommentService::handleResponse(" << token << "," << req_type << "," << status << ")" << std::endl;
#endif
	if (status != RsTokenService::COMPLETE)
		return; //For now, only manage Complete request


        // stuff.
        switch(req_type)
        {
		case GXSCOMMENTS_VOTE_CHECK:
			load_PendingVoteParent(token);
			break;

		case GXSCOMMENTS_VOTE_DONE:
			completeInternalVote(token);
			break;

                default:
                        /* error */
                        std::cerr << "p3GxsCommentService::handleResponse() Unknown Request Type: " << req_type;
                        std::cerr << std::endl;
                        break;
        }
}

bool p3GxsCommentService::castVote(uint32_t &token, RsGxsVote &msg)
{
#ifdef DEBUG_GXSCOMMON
    std::cerr << "p3GxsCommentService::castVote() GroupId: " << msg.mMeta.mGroupId;
    std::cerr << std::endl;
#endif

	RsGxsVoteItem* msgItem = new RsGxsVoteItem(mServiceType);
	msgItem->mMsg = msg;
	msgItem->meta = msg.mMeta;
	
	mExchange->publishMsg(token, msgItem);
	return true;
}

