/// \file dtscfix.cpp
/// Contains the code that will attempt to fix the metadata contained in an DTSC file.

#include <string>
#include <mist/dtsc.h>
#include <mist/json.h>
#include <mist/config.h>

///\brief Holds everything unique to converters.
namespace Converters {
  class HeaderEntryDTSC {
    public:
      HeaderEntryDTSC() : totalSize(0), keyNum(0), packetID(0), firstms(-1), lastms(0), keynum(0) {}
      long long unsigned int totalSize;
      long long int keyNum;
      long long int packetID;
      long long int firstms;
      long long int lastms;
      long long int keynum;
      std::string type;
  };

  ///\brief Reads a DTSC file and attempts to fix the metadata in it.
  ///\param conf The current configuration of the program.
  ///\return The return code for the fixed program.
  int DTSCFix(Util::Config & conf){
    DTSC::File F(conf.getString("filename"));
    JSON::Value oriheader = F.getFirstMeta();
    JSON::Value meta = F.getMeta();
    JSON::Value pack;

    if ( !oriheader.isMember("moreheader")){
      std::cerr << "This file is too old to fix - please reconvert." << std::endl;
      return 1;
    }
    if (oriheader["moreheader"].asInt() > 0){
      if (meta.isMember("tracks") && meta.isMember("isFixed") && meta["isFixed"]){
        std::cerr << "This file was already fixed or doesn't need fixing - cancelling." << std::endl;
        return 0;
      }
    }
    meta.removeMember("isFixed");
    meta.removeMember("keytime");
    meta.removeMember("keybpos");
    meta.removeMember("moreheader");

    std::map<std::string,int> trackIDs;
    std::map<std::string,HeaderEntryDTSC> trackData;

    long long int nowpack = 0;
//    long long int lastaudio = 0;
//    long long int lastvideo = 0;
//    long long unsigned int totalvideo = 0;
//    long long unsigned int totalaudio = 0;
//    long long int keynum = 0;
    
    std::string currentID;
    int nextFreeID = 0;

    F.seekNext();
    while ( !F.getJSON().isNull()){
      if (F.getJSON()["packetid"].asInt() == 0){
        if (F.getJSON()["datatype"].asString() == "video"){
          currentID = "video0";
          trackData[currentID].packetID = 0;
          if (meta.isMember("video")){
            meta["tracks"][currentID] = meta["video"];
            meta.removeMember("video");
          }
          trackData[currentID].type = F.getJSON()["datatype"].asString();
        }else{
          if (F.getJSON()["datatype"].asString() == "audio"){
            currentID = "audio0";
            trackData[currentID].packetID = 0;
            if (meta.isMember("audio")){
              meta["tracks"][currentID] = meta["audio"];
              meta.removeMember("audio");
            }
            trackData[currentID].type = F.getJSON()["datatype"].asString();
          }else{
            F.seekNext();
            continue;
          }
        }
      }
      if (F.getJSON()["time"].asInt() >= nowpack){
        nowpack = F.getJSON()["time"].asInt();
      }
      if (trackData[currentID].firstms == -1){
        trackData[currentID].firstms = nowpack;
      }
      trackData[currentID].totalSize += F.getJSON()["data"].asString().size();
      trackData[currentID].lastms = nowpack;
      if (F.getJSON()["datatype"].asString() == "video"){
        if (F.getJSON()["keyframe"].asInt() != 0){
          meta["tracks"][currentID]["keytime"].append(F.getJSON()["time"]);
          meta["tracks"][currentID]["keybpos"].append(F.getLastReadPos());
          meta["tracks"][currentID]["keynum"].append( ++trackData[currentID].keynum);
          if (meta["tracks"][currentID]["keytime"].size() > 1){
            meta["tracks"][currentID]["keylen"].append(F.getJSON()["time"].asInt() - meta["tracks"][currentID]["keytime"][meta["tracks"][currentID]["keytime"].size() - 2].asInt());
          }
        }
      }
      F.seekNext();
    }

    long long int firstms = 9999999999;
    long long int lastms = -1;

    for (std::map<std::string,HeaderEntryDTSC>::iterator it = trackData.begin(); it != trackData.end(); it++){
      if (it->second.firstms < firstms){
        firstms = it->second.firstms;
      }
      if (it->second.lastms > lastms){
        lastms = it->second.lastms;
      }
      meta["tracks"][it->first]["firstms"] = it->second.firstms;
      meta["tracks"][it->first]["lastms"] = it->second.lastms;
      meta["tracks"][it->first]["length"] = (it->second.lastms - it->second.firstms) / 1000;
      if ( !meta["tracks"][it->first].isMember("bps")){
        meta["tracks"][it->first]["bps"] = (long long int)(it->second.lastms / ((it->second.lastms - it->second.firstms) / 1000));
      }
      meta["tracks"][it->first]["packetid"] = it->second.packetID;
      if (it->second.packetID != 0){
        meta["tracks"][it->first]["trackid"] = trackIDs[it->first];
      }else{
        meta["tracks"][it->first]["trackid"] = nextFreeID ++;
      }
      meta["tracks"][it->first]["type"] = it->second.type;
      if (it->second.type == "video"){
        int tmp = meta["tracks"][it->first]["keytime"].size();
        if (tmp > 0){
          meta["tracks"][it->first]["keylen"].append(it->second.lastms - meta["tracks"][it->first]["keytime"][tmp - 1].asInt());
        }else{
          meta["tracks"][it->first]["keylen"].append(it->second.lastms);
        }
        //calculate fragments
        meta["tracks"][it->first]["frags"].null();
        long long int currFrag = -1;
        for (unsigned int i = 0; i < meta["tracks"][it->first]["keytime"].size(); i++){
          if (meta["tracks"][it->first]["keytime"][i].asInt() / 10000 > currFrag){
            currFrag = meta["tracks"][it->first]["keytime"][i].asInt() / 10000;
            long long int fragLen = 1;
            long long int fragDur = meta["tracks"][it->first]["keylen"][i].asInt();
            for (unsigned int j = i; j < meta["tracks"][it->first]["keytime"].size(); j++){
              if (meta["tracks"][it->first]["keytime"][j].asInt() / 10000 > currFrag || j == meta["tracks"][it->first]["keytime"].size() - 1){
                JSON::Value thisFrag;
                thisFrag["num"] = meta["tracks"][it->first]["keynum"][i];
                thisFrag["len"] = fragLen;
                thisFrag["dur"] = fragDur;
                meta["tracks"][it->first]["frags"].append(thisFrag);
                break;
              }
              fragLen++;
              fragDur += meta["tracks"][it->first]["keylen"][j].asInt();
            }
          }
        }
      }
    }

    meta["firstms"] = firstms;
    meta["lastms"] = lastms;
    meta["length"] = (lastms - firstms) / 1000;

    //append the revised header
    std::string loader = meta.toPacked();
    long long int newHPos = F.addHeader(loader);
    if ( !newHPos){
      std::cerr << "Failure appending new header." << std::endl;
      return -1;
    }
    //re-write the original header with information about the location of the new one
    oriheader["moreheader"] = newHPos;
    loader = oriheader.toPacked();
    if (F.writeHeader(loader)){
      std::cerr << "Metadata is now: " << meta.toPrettyString(0) << std::endl;
      return 0;
    }else{
      std::cerr << "Failure rewriting header." << std::endl;
      return -1;
    }
  } //DTSCFix

}

/// Entry point for DTSCFix, simply calls Converters::DTSCFix().
int main(int argc, char ** argv){
  Util::Config conf = Util::Config(argv[0], PACKAGE_VERSION);
  conf.addOption("filename", JSON::fromString("{\"arg_num\":1, \"arg\":\"string\", \"help\":\"Filename of the file to attempt to fix.\"}"));
  conf.parseArgs(argc, argv);
  return Converters::DTSCFix(conf);
} //main