#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <unistd.h>
#include <semaphore.h>
#include <iterator> //std::distance

#include <mist/stream.h>
#include <mist/defines.h>
#include <mist/http_parser.h>
#include <mist/timing.h>
#include "output.h"

namespace Mist {
  Util::Config * Output::config = NULL;
  JSON::Value Output::capa = JSON::Value();

  int getDTSCLen(char * mapped, long long int offset){
    return ntohl(((int*)(mapped + offset))[1]);
  }

  long long int getDTSCTime(char * mapped, long long int offset){
    char * timePoint = mapped + offset + 12;
    return ((long long int)timePoint[0] << 56) | ((long long int)timePoint[1] << 48) | ((long long int)timePoint[2] << 40) | ((long long int)timePoint[3] << 32) | ((long long int)timePoint[4] << 24) | ((long long int)timePoint[5] << 16) | ((long long int)timePoint[6] << 8) | timePoint[7];
  }

   void Output::init(Util::Config * cfg){
    capa["optional"]["debug"]["name"] = "debug";
    capa["optional"]["debug"]["help"] = "The debug level at which messages need to be printed.";
    capa["optional"]["debug"]["option"] = "--debug";
    capa["optional"]["debug"]["type"] = "uint";
  }
  
  Output::Output(Socket::Connection & conn) : myConn(conn) {
    firstTime = 0;
    parseData = false;
    wantRequest = true;
    isInitialized = false;
    isBlocking = false;
    lastStats = 0;
    maxSkipAhead = 7500;
    minSkipAhead = 5000;
    realTime = 1000;
    if (myConn){
      setBlocking(true);
    }else{
      DEBUG_MSG(DLVL_WARN, "Warning: MistOut created with closed socket!");
    }
    sentHeader = false;
  }
  
  void Output::setBlocking(bool blocking){
    isBlocking = blocking;
    myConn.setBlocking(isBlocking);
  }
  
  Output::~Output(){
    statsPage.finish();
    playerConn.finish();
  }

  void Output::updateMeta(){
    //read metadata from page to myMeta variable
    if (streamIndex.mapped){
      DTSC::Packet tmpMeta(streamIndex.mapped, streamIndex.len, true);
      if (tmpMeta.getVersion()){
        /// \todo Make sure this doesn't go wrong when overwritten by MistInBuffer during parse
        myMeta.reinit(tmpMeta);
      }
    }
  }
  
  /// Called when stream initialization has failed.
  /// The standard implementation will set isInitialized to false and close the client connection,
  /// thus causing the process to exit cleanly.
  void Output::onFail(){
    isInitialized = false;
    myConn.close();
  }
  
  void Output::initialize(){
    if (isInitialized){
      return;
    }
    if (streamIndex.mapped){
      return;
    }
    if (!Util::Stream::getStream(streamName)){
      DEBUG_MSG(DLVL_FAIL, "Opening stream disallowed - aborting initalization");
      onFail();
      return;
    }
    isInitialized = true;
    streamIndex.init(streamName,8 * 1024 * 1024);
    if (!streamIndex.mapped){
      DEBUG_MSG(DLVL_FAIL, "Could not connect to server for %s\n", streamName.c_str());
      onFail();
      return;
    }
    statsPage = IPC::sharedClient("statistics", 88, true);
    playerConn = IPC::sharedClient(streamName + "_users", 30, true);
    
    updateMeta();
    
    //check which tracks don't actually exist
    std::set<long unsigned int> toRemove;
    for (std::set<long unsigned int>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); it++){
      if (!myMeta.tracks.count(*it)){
        toRemove.insert(*it);
      }
    }
    //remove those from selectedtracks
    for (std::set<long unsigned int>::iterator it = toRemove.begin(); it != toRemove.end(); it++){
      selectedTracks.erase(*it);
    }
    
    //loop through all codec combinations, count max simultaneous active
    unsigned int bestSoFar = 0;
    unsigned int bestSoFarCount = 0;
    unsigned int index = 0;
    for (JSON::ArrIter it = capa["codecs"].ArrBegin(); it != capa["codecs"].ArrEnd(); it++){
      unsigned int genCounter = 0;
      unsigned int selCounter = 0;
      if ((*it).size() > 0){
        for (JSON::ArrIter itb = (*it).ArrBegin(); itb != (*it).ArrEnd(); itb++){
          if ((*itb).size() > 0){
            bool found = false;
            for (JSON::ArrIter itc = (*itb).ArrBegin(); itc != (*itb).ArrEnd() && !found; itc++){
              for (std::set<long unsigned int>::iterator itd = selectedTracks.begin(); itd != selectedTracks.end(); itd++){
                if (myMeta.tracks[*itd].codec == (*itc).asStringRef()){
                  selCounter++;
                  found = true;
                  break;
                }
              }
              if (!found){
                for (std::map<int,DTSC::Track>::iterator trit = myMeta.tracks.begin(); trit != myMeta.tracks.end(); trit++){
                  if (trit->second.codec == (*itc).asStringRef()){
                    genCounter++;
                    found = true;
                    break;
                  }
                }
              }
            }
          }
        }
        if (selCounter == selectedTracks.size()){
          if (selCounter + genCounter > bestSoFarCount){
            bestSoFarCount = selCounter + genCounter;
            bestSoFar = index;
            DEBUG_MSG(DLVL_HIGH, "Match (%u/%u): %s", selCounter, selCounter+genCounter, (*it).toString().c_str());
          }
        }else{
          DEBUG_MSG(DLVL_VERYHIGH, "Not a match for currently selected tracks: %s", (*it).toString().c_str());
        }
      }
      index++;
    }
    
    DEBUG_MSG(DLVL_MEDIUM, "Trying to fill: %s", capa["codecs"][bestSoFar].toString().c_str());
    //try to fill as many codecs simultaneously as possible
    if (capa["codecs"][bestSoFar].size() > 0){
      for (JSON::ArrIter itb = capa["codecs"][bestSoFar].ArrBegin(); itb != capa["codecs"][bestSoFar].ArrEnd(); itb++){
        if ((*itb).size() > 0){
          bool found = false;
          for (JSON::ArrIter itc = (*itb).ArrBegin(); itc != (*itb).ArrEnd() && !found; itc++){
            for (std::set<long unsigned int>::iterator itd = selectedTracks.begin(); itd != selectedTracks.end(); itd++){
              if (myMeta.tracks[*itd].codec == (*itc).asStringRef()){
                found = true;
                break;
              }
            }
            if (!found){
              for (std::map<int,DTSC::Track>::iterator trit = myMeta.tracks.begin(); trit != myMeta.tracks.end(); trit++){
                if (trit->second.codec == (*itc).asStringRef()){
                  selectedTracks.insert(trit->first);
                  found = true;
                  break;
                }
              }
            }
          }
        }
      }
    }
    
    #if DEBUG >= DLVL_MEDIUM
    //print the selected tracks
    std::stringstream selected;
    for (std::set<long unsigned int>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); it++){
      if (it != selectedTracks.begin()){
        selected << ", ";
      }
      selected << (*it);
    }
    DEBUG_MSG(DLVL_MEDIUM, "Selected tracks: %s", selected.str().c_str());    
    #endif
    
    unsigned int firstms = 0x0;
    for (std::set<long unsigned int>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); it++){
      lastKeyTime[*it] = 0xFFFFFFFF;
      if (myMeta.tracks[*it].firstms > firstms){
        firstms = myMeta.tracks[*it].firstms;
      }
    }
    if (myMeta.live){
      if (firstms < 5000){
        firstms = 0;
      }
      seek(firstms);
    }else{
      seek(0);
    }
    capa.null();
  }
  
  /// Clears the buffer, sets parseData to false, and generally makes not very much happen at all.
  void Output::stop(){
    buffer.clear();
    parseData = false;
  }
  
  unsigned int Output::getKeyForTime(long unsigned int trackId, long long timeStamp){
    DTSC::Track & trk = myMeta.tracks[trackId];
    if (!trk.keys.size()){
      return 0;
    }
    unsigned int keyNo = trk.keys.begin()->getNumber();
    for (std::deque<DTSC::Key>::iterator it = trk.keys.begin(); it != trk.keys.end() && it->getTime() <= timeStamp; it++){
      keyNo = it->getNumber();
    }
    return keyNo;
  }
  
  void Output::loadPageForKey(long unsigned int trackId, long long int keyNum){
    if (myMeta.vod && keyNum > myMeta.tracks[trackId].keys.rbegin()->getNumber()){
      curPages.erase(trackId);
      currKeyOpen.erase(trackId);
      return;
    }
    DEBUG_MSG(DLVL_HIGH, "Loading track %lu, containing key %lld", trackId, keyNum);
    int pageNum = -1;
    int keyAmount = -1;
    unsigned int timeout = 0;
    if (!indexPages.count(trackId)){
      char id[100];
      sprintf(id, "%s%lu", streamName.c_str(), trackId);
      indexPages[trackId].init(id, 8 * 1024);
    }
    while (pageNum == -1 || keyAmount == -1){
      for (int i = 0; i < indexPages[trackId].len / 8; i++){
        long amountKey = ntohl((((long long int*)indexPages[trackId].mapped)[i]) & 0xFFFFFFFF);
        if (amountKey == 0){continue;}
        long tmpKey = ntohl(((((long long int*)indexPages[trackId].mapped)[i]) >> 32) & 0xFFFFFFFF);
        if (tmpKey <= keyNum && (tmpKey + amountKey) > keyNum){
          pageNum = tmpKey;
          keyAmount = amountKey;
          break;
        }
      }
      if (pageNum == -1 || keyAmount == -1){
        if (!timeout){
          DEBUG_MSG(DLVL_DEVEL, "Requesting/waiting for page that has key %lu:%lld...", trackId, keyNum);
        }
        if (timeout++ > 100){
          DEBUG_MSG(DLVL_FAIL, "Timeout while waiting for requested page. Aborting.");
          curPages.erase(trackId);
          currKeyOpen.erase(trackId);
          return;
        }
        if (keyNum){
          nxtKeyNum[trackId] = keyNum-1;
        }else{
          nxtKeyNum[trackId] = 0;
        }
        stats();
        Util::sleep(100);
      }
    }
    
    if (keyNum){
      nxtKeyNum[trackId] = keyNum-1;
    }else{
      nxtKeyNum[trackId] = 0;
    }
    stats();
    nxtKeyNum[trackId] = pageNum;
    
    if (currKeyOpen.count(trackId) && currKeyOpen[trackId] == pageNum){
      return;
    }
    char id[100];
    sprintf(id, "%s%lu_%d", streamName.c_str(), trackId, pageNum);
    curPages[trackId].init(std::string(id),26 * 1024 * 1024);
    if (!(curPages[trackId].mapped)){
      DEBUG_MSG(DLVL_FAIL, "Initializing page %s failed", curPages[trackId].name.c_str());
      return;
    }
    currKeyOpen[trackId] = pageNum;
  }
  
  /// Prepares all tracks from selectedTracks for seeking to the specified ms position.
  /// \todo Make this actually seek, instead of always loading position zero.
  void Output::seek(long long pos){
    firstTime = Util::getMS() - pos;
    if (!isInitialized){
      initialize();
    }
    buffer.clear();
    currentPacket.null();
    updateMeta();
    DEBUG_MSG(DLVL_MEDIUM, "Seeking to %llims", pos);
    for (std::set<long unsigned int>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); it++){
      seek(*it, pos);
    }
  }

  bool Output::seek(int tid, long long pos, bool getNextKey){
    loadPageForKey(tid, getKeyForTime(tid, pos) + (getNextKey?1:0));
    if (!curPages.count(tid) || !curPages[tid].mapped){
      DEBUG_MSG(DLVL_DEVEL, "Aborting seek to %llims in track %d, not available.", pos, tid);
      return false;
    }
    sortedPageInfo tmp;
    tmp.tid = tid;
    tmp.offset = 0;
    DTSC::Packet tmpPack;
    tmpPack.reInit(curPages[tid].mapped + tmp.offset, 0, true);
    tmp.time = tmpPack.getTime();
    while ((long long)tmp.time < pos && tmpPack){
      tmp.offset += tmpPack.getDataLen();
      tmpPack.reInit(curPages[tid].mapped + tmp.offset, 0, true);
      tmp.time = tmpPack.getTime();
    }
    if (tmpPack){
      buffer.insert(tmp);
      return true;
    }else{
      //don't print anything for empty packets - not sign of corruption, just unfinished stream.
      if (curPages[tid].mapped[tmp.offset] != 0){
        DEBUG_MSG(DLVL_FAIL, "Noes! Couldn't find packet on track %d because of some kind of corruption error or somesuch.", tid);
      }else{
        DEBUG_MSG(DLVL_FAIL, "Track %d no data (key %u) - waiting...", tid, getKeyForTime(tid, pos) + (getNextKey?1:0));
        unsigned int i = 0;
        while (curPages[tid].mapped[tmp.offset] == 0 && ++i < 10){
          Util::sleep(100);
        }
        if (curPages[tid].mapped[tmp.offset] == 0){
          DEBUG_MSG(DLVL_FAIL, "Track %d no data (key %u) - timeout", tid, getKeyForTime(tid, pos) + (getNextKey?1:0));
        }else{
          return seek(tid, pos, getNextKey);
        }
      }
      return false;
    }
  }
 
  int Output::run() {
    bool firstData = true;//only the first time, we call OnRequest if there's data buffered already.
    DEBUG_MSG(DLVL_MEDIUM, "MistOut client handler started");
    while (myConn.connected() && (wantRequest || parseData)){
      stats();
      if (wantRequest){
        if ((firstData && myConn.Received().size()) || myConn.spool()){
          firstData = false;
          DEBUG_MSG(DLVL_VERYHIGH, "OnRequest");
          onRequest();
        }else{
          if (!isBlocking && !parseData){
            Util::sleep(500);
          }
        }
      }
      if (parseData){
        if (!isInitialized){
          initialize();
        }
        if ( !sentHeader){
          DEBUG_MSG(DLVL_VERYHIGH, "SendHeader");
          sendHeader();
        }
        prepareNext();
        if (currentPacket){
          sendNext();
        }else{
          if (!onFinish()){
            break;
          }
        }
      }
    }
    DEBUG_MSG(DLVL_MEDIUM, "MistOut client handler shutting down: %s, %s, %s", myConn.connected() ? "conn_active" : "conn_closed", wantRequest ? "want_request" : "no_want_request", parseData ? "parsing_data" : "not_parsing_data");
    myConn.close();
    return 0;
  }
  
  void Output::prepareNext(){
    static unsigned int emptyCount = 0;
    if (!buffer.size()){
      currentPacket.null();
      DEBUG_MSG(DLVL_DEVEL, "Buffer completely played out");
      return;
    }
    sortedPageInfo nxt = *(buffer.begin());
    buffer.erase(buffer.begin());

    DEBUG_MSG(DLVL_DONTEVEN, "Loading track %u (next=%lu), %llu ms", nxt.tid, nxtKeyNum[nxt.tid], nxt.time);
    
    if (nxt.offset >= curPages[nxt.tid].len){
      loadPageForKey(nxt.tid, ++nxtKeyNum[nxt.tid]);
      nxt.offset = 0;
      if (curPages.count(nxt.tid) && curPages[nxt.tid].mapped){
        if (getDTSCTime(curPages[nxt.tid].mapped, nxt.offset) < nxt.time){
          DEBUG_MSG(DLVL_DEVEL, "Time going backwards in track %u - dropping track.", nxt.tid);
        }else{
          nxt.time = getDTSCTime(curPages[nxt.tid].mapped, nxt.offset);
          buffer.insert(nxt);
        }
        prepareNext();
        return;
      }
    }
    
    if (!curPages.count(nxt.tid) || !curPages[nxt.tid].mapped){
      //mapping failure? Drop this track and go to next.
      //not an error - usually means end of stream.
      DEBUG_MSG(DLVL_DEVEL, "Track %u no page - dropping track.", nxt.tid);
      prepareNext();
      return;
    }
    
    if (!memcmp(curPages[nxt.tid].mapped + nxt.offset, "\000\000\000\000", 4)){
      if (!currentPacket.getTime()){
        DEBUG_MSG(DLVL_DEVEL, "Timeless empty packet on track %u - dropping track.", nxt.tid);
        prepareNext();
        return;
      }
      if (myMeta.live){
        Util::sleep(500);
        updateMeta();
        if (myMeta && ++emptyCount < 20){
          if (!seek(nxt.tid, currentPacket.getTime(), true)){
            buffer.insert(nxt);
          }
        }else{
          DEBUG_MSG(DLVL_DEVEL, "Empty packet on track %u - could not reload, dropping track.", nxt.tid);
        }
      }else{
        DEBUG_MSG(DLVL_DEVEL, "Empty packet on track %u - dropping track.", nxt.tid);
      }
      prepareNext();
      return;
    }
    currentPacket.reInit(curPages[nxt.tid].mapped + nxt.offset, 0, true);
    if (currentPacket){
      if (currentPacket.getTime() != nxt.time){
        DEBUG_MSG(DLVL_DEVEL, "ACTUALLY Loaded track %ld (next=%lu), %llu ms", currentPacket.getTrackId(), nxtKeyNum[nxt.tid], currentPacket.getTime());
      }
      nxtKeyNum[nxt.tid] = getKeyForTime(nxt.tid, currentPacket.getTime());
      emptyCount = 0;
    }
    nxt.offset += currentPacket.getDataLen();
    if (realTime){
      while (nxt.time > (Util::getMS() - firstTime + maxSkipAhead)*1000/realTime) {
        Util::sleep(nxt.time - (Util::getMS() - firstTime + minSkipAhead)*1000/realTime);
      }
    }
    if (curPages[nxt.tid]){
      if (nxt.offset < curPages[nxt.tid].len){
        nxt.time = getDTSCTime(curPages[nxt.tid].mapped, nxt.offset);
      }
      buffer.insert(nxt);
    }
    playerConn.keepAlive();
  }

  void Output::stats(){
    if (!statsPage.getData()){
      return;
    }
    unsigned long long int now = Util::epoch();
    if (now != lastStats){
      lastStats = now;
      IPC::statExchange tmpEx(statsPage.getData());
      tmpEx.now(now);
      tmpEx.host(myConn.getHost());
      tmpEx.streamName(streamName);
      tmpEx.connector(capa["name"].asString());
      tmpEx.up(myConn.dataUp());
      tmpEx.down(myConn.dataDown());
      tmpEx.time(now - myConn.connTime());
      statsPage.keepAlive();
    }
    int tNum = 0;
    if (!playerConn.getData()){
      playerConn = IPC::sharedClient(streamName + "_users", 30, true);
      if (!playerConn.getData()){
        DEBUG_MSG(DLVL_WARN, "Player connection failure - aborting output");
        myConn.close();
        return;
      }
    }
    for (std::set<unsigned long>::iterator it = selectedTracks.begin(); it != selectedTracks.end() && tNum < 5; it++){
      char thisData[6];
      thisData[0] = ((*it >> 24) & 0xFF);
      thisData[1] = ((*it >> 16) & 0xFF);
      thisData[2] = ((*it >> 8) & 0xFF);
      thisData[3] = ((*it) & 0xFF);
      thisData[4] = ((nxtKeyNum[*it] >> 8) & 0xFF);
      thisData[5] = ((nxtKeyNum[*it]) & 0xFF);
      memcpy(playerConn.getData() + (6 * tNum), thisData, 6);
      tNum ++;
      playerConn.keepAlive();
    }
    if (tNum >= 5){
      DEBUG_MSG(DLVL_WARN, "Too many tracks selected, using only first 5");
    }
  }
  
  void Output::onRequest(){
    //simply clear the buffer, we don't support any kind of input by default
    myConn.Received().clear();
    wantRequest = false;
  }

  void Output::sendHeader(){
    //just set the sentHeader bool to true, by default
    sentHeader = true;
  }
  
}