//===========================================
//  Lumina-DE source code
//  Copyright (c) 2016, Ken Moore
//  Available under the 3-clause BSD license
//  See the LICENSE file for full details
//===========================================
#include "TarBackend.h"
#include <QFile>
#include <QDir>
#include <QDebug>
#include <QDateTime>
#include <QCoreApplication>
#include <QTimer>

#ifdef Q_OS_LINUX
#define TAR_CMD "bsdtar"
#else
#define TAR_CMD "tar"
#endif

Backend::Backend(QObject *parent) : QObject(parent){
  //Setup the backend process
  PROC.setProcessChannelMode(QProcess::MergedChannels);
  PROC.setProgram(TAR_CMD);
  connect(&PROC, SIGNAL(finished(int, QProcess::ExitStatus)), this, SLOT(procFinished(int, QProcess::ExitStatus)) );
  connect(&PROC, SIGNAL(readyReadStandardOutput()), this, SLOT(processData()) );
  connect(&PROC, SIGNAL(started()), this, SIGNAL(ProcessStarting()) );
  LIST = STARTING = false;
}

Backend::~Backend(){

}

//===============
//        PUBLIC
//===============
void Backend::loadFile(QString path){
  qDebug() << "void Backend::loadFile(QString path) has started";
  qDebug() << "Loading Archive:" << path;
  filepath = path;
  tmpfilepath = filepath.section("/",0,-2)+"/"+".tmp_larchiver_"+filepath.section("/",-1);
  flags.clear();
  flags << "-f" << filepath; //add the actual archive path
  if(QFile::exists(path)){ startList(); qDebug () << "BACKEND LOAD startList has started";}
  else{ contents.clear(); emit FileLoaded(); emit ProcessFinished(true, ""); }
}

bool Backend::canModify(){
  static QStringList validEXT;
  if( validEXT.isEmpty() ){
    validEXT << ".zip" << ".tar.gz" << ".tgz" << ".tar.xz" << ".txz" << ".tar.bz" << ".tbz" << ".tar.bz2" << ".tbz2" << ".tar" \
      << ".tar.lzma" << ".tlz" << ".cpio" << ".pax" << ".ar" << ".shar" << ".7z";
  }
  for(int i=0; i<validEXT.length(); i++){
    if(filepath.endsWith(validEXT[i])){ return true; }
  }
  return false;
}

QString Backend::currentFile(){
  return filepath;
}

bool Backend::isWorking(){
  return (PROC.state() != QProcess::Running);
}

//Listing routines
QStringList Backend::heirarchy(){
  return contents.keys();
}

double Backend::size(QString file){
  if(!contents.contains(file)){ return -1; }
  return contents.value(file)[1].toDouble();
}

double Backend::csize(QString file){
  if(!contents.contains(file)){ return -1; }
  return contents.value(file)[1].toDouble();
}

bool Backend::isDir(QString file){
  if(!contents.contains(file)){ return false; }
  return contents.value(file)[0].startsWith("d");
}

bool Backend::isLink(QString file){
  if(!contents.contains(file)){ return false; }
  return contents.value(file)[0].startsWith("l");
}

QString Backend::linkTo(QString file){
  if(!contents.contains(file)){ return ""; }
  return contents.value(file)[2];
}

//Modification routines
void Backend::startAdd(QStringList paths,  bool absolutePaths){
  //if(paths.isEmpty() && !insertQueue.isEmpty()){ paths = insertQueue; } //load the queue
  if(paths.contains(filepath)){ paths.removeAll(filepath); }
  if(paths.isEmpty()){ return; }
  //NOTE: All the "paths" have to have the same parent directory
  //Go through and find all the files that contain the same parent dir, and put the rest into the insertQueue
  QString parent = paths[0].section("/",0,-2);
  insertQueue.clear();
  for(int i=1; i<paths.length(); i++){
    if(paths[i].section("/",0,-2)!=parent){
      insertQueue << paths.takeAt(i); i--; //push this back a bit for later
    }
  }
  //qDebug() << "Start Archive Insert:" << paths << "Queued:" << insertQueue;
  QStringList args;
  args << "-c" << "-a";
  args << flags;
  //Now setup the parent dir
  if(!absolutePaths) {
    for(int i=0; i<paths.length(); i++){
      paths[i] = paths[i].section(parent,1,-1);
      if(paths[i].startsWith("/")){ paths[i].remove(0,1); }
    }
    args << "-C" << parent;
  }else{
    args << "-C" << "/";
  }
  args << paths;
  if(QFile::exists(filepath)){ //append to existing
    args.replaceInStrings(filepath, tmpfilepath);
    args<< "@"+filepath;
  }
  STARTING=true;
  PROC.start(TAR_CMD, args);
}

void Backend::startRemove(QStringList paths){
  if(paths.contains(filepath)){ paths.removeAll(filepath); }
  if(contents.isEmpty() || paths.isEmpty() || !QFile::exists(filepath)){ return; } //invalid
  QStringList args;
  args << "-c" << "-a";
  args << flags;
  args.replaceInStrings(filepath, tmpfilepath);
  //Add the include rules for all the files we want to keep (no exclude option in "tar")
  for(int i=0; i<paths.length(); i++){
     args << "--exclude" << paths[i];
  }
  args<< "@"+filepath;
  STARTING=true;
  PROC.start(TAR_CMD, args);
}

void Backend::startExtract(QString path, bool overwrite, QString file){
  startExtract(path, overwrite, QStringList() << file); //overload for multi-file function

}

void Backend::startExtract(QString path, bool overwrite, QStringList files){
  QStringList args; //this is a new/empty list - no need for the check below (KPM)
  //remove --ax arg if its still lingering so its not passed to external process
  //for(int i=0; i<args.length(); i++){ if(args[i]=="--ax"){ args.removeAt(i);}}
  args << "-x" << "--no-same-owner";
  if(!overwrite){ args << "-k"; }
  args << flags;
  for(int i=0; i<files.length(); i++){
    if(files[i].simplified().isEmpty()){ continue; }
    args << "--include" << files[i] << "--strip-components" << QString::number(files[i].count("/"));
  }
  args << "-C" << path;
  STARTING=true;
  //qDebug() << "Starting command:" << "tar" << args;
  PROC.start(TAR_CMD, args);
}

void Backend::startViewFile(QString path){
  QStringList args;
  QString newfilename = QDateTime::currentDateTime().toString("yyyyMMddhhmmss")+"-"+path.section("/",-1);
  args << "-x";
  //args << flags <<"--include" << path <<"--strip-components" << QString::number(path.count("/")) << "-C" << QDir::tempPath();
  args << flags <<"--include" << path <<"--to-stdout";
  STARTING=true;
  //qDebug() << "Starting command:" << "tar" << args;
  emit ProcessStarting();
  QProcess tmpProc;
    tmpProc.setStandardOutputFile(newfilename);
    tmpProc.start("tar",args);
  while(!tmpProc.waitForFinished(500)){ QCoreApplication::processEvents(); }
  emit ProcessFinished(tmpProc.exitCode()==0, "");
  QProcess::startDetached("xdg-open", QStringList() << newfilename);
  //PROC.start(TAR_CMD, args);
}

//===============
//   PUBLIC SLOTS
//===============

//===============
//       PRIVATE
//===============
void Backend::parseLines(QStringList lines){
  for(int i=0; i<lines.length(); i++){
      QStringList info = lines[i].split(" ",QString::SkipEmptyParts);
      //Format: [perms, ?, user, group, size, month, day, time, file]
      if(info.startsWith("x ") && filepath.endsWith(".zip")){
        //ZIP archives do not have all the extra information - just filenames
        while(info.length()>2){ info[1]=info[1]+" "+info[2]; }
        QString file = info[1];
        QString perms = "";
         if(file.endsWith("/")){ perms = "d"; file.chop(1); }
        contents.insert(file, QStringList() << perms << "-1" <<""); //Save the [perms, size, linkto ]
      }
      else if(info.length()<9){ continue; } //invalid line
      //TAR Archive parsing
        while(info.length()>9){ info[8] = info[8]+" "+info[9]; info.removeAt(9); } //Filename has spaces in it
         QString file = info[8];
         if(file.endsWith("/")){ file.chop(1); }
         QString linkto;
         //See if this file has the "link to" or "->"  notation
         if(file.contains(" -> ")){ linkto = file.section(" -> ",1,-1); file = file.section(" -> ",0,0); }
         else if(file.contains(" link to ")){
            //Special case - alternate form of a link within a tar archive (not reflected in perms)
           linkto = file.section(" link to ",1,-1);
           file = file.section(" link to ",0,0);
           if(info[0].startsWith("-")){ info[0].replace(0,1,"l"); }
         }
        contents.insert(file, QStringList() << info[0] << info[4] << linkto); //Save the [perms, size, linkto ]
  }
}

void Backend::startList(){
  contents.clear();
  QStringList args;
  args << "-tv";
  LIST = STARTING=true;
  //qDebug() << "Starting List:" << "tar "+args.join(" ")+" "+flags.join(" ");
  PROC.start(TAR_CMD, QStringList() << args << flags);
}

//===============
//  PRIVATE SLOTS
//===============
void Backend::procFinished(int retcode, QProcess::ExitStatus){
  static QString result;
  //qDebug() << "Process Finished:" << PROC.arguments() << retcode;
  processData();
  LIST = STARTING = false;
  if(PROC.arguments().contains("-tv")){
    if(retcode!=0){  //could not read archive
      contents.clear();
      result = tr("Could not read archive");
    }else if(result.isEmpty()){
      result = tr("Archive Loaded");
      emit FileLoaded();
    }
    emit ProcessFinished((retcode==0), result);
    result.clear();
  }else{
    bool needupdate = true;
    QStringList args = PROC.arguments();
    if(args.contains("-x") && retcode==0){
       needupdate=false;
      if(args.count("--include")==1){
        //Need to find the full path to the (single) extracted file
        QString path = args.last() +"/"+ args[ args.indexOf("--include")+1].section("/",-1);
        QFile::setPermissions(path, QFileDevice::ReadOwner);
        QProcess::startDetached("xdg-open  \""+path+"\"");
      }else{
        //Multi-file extract - open the dir instead
        QString dir = args.last();
	//Check to see if tar extracted into a new subdir it just created
        if(QFile::exists(dir+"/"+filepath.section("/",-1).section(".",0,0) ) ){
          dir = dir+"/"+filepath.section("/",-1).section(".",0,0);
        }
        QProcess::startDetached("xdg-open \""+ dir+"\""); //just extracted to a dir - open it now
      }

    }else if(args.contains("-c") && QFile::exists(tmpfilepath)){
      if(retcode==0){
        QFile::remove(filepath);
        QFile::rename(tmpfilepath, filepath);
      }else{
        QFile::remove(tmpfilepath);
      }
    }
    if(args.contains("-x")){ result = tr("Extraction Finished"); emit ExtractSuccessful(); }
    else if(args.contains("-c")){
      result = tr("Modification Finished");
      if(insertQueue.isEmpty()){ emit ArchivalSuccessful(); }
      else{ needupdate = false; QTimer::singleShot(0, this, SLOT(startInsertFromQueue())); }
    }
    if(needupdate){ startList(); }
    else{ emit ProcessFinished(retcode==0, result); result.clear(); }
  }
}

void Backend::processData(){
  //Read the process
  static QString data;
  QString read = data+PROC.readAllStandardOutput();
  if(read.endsWith("\n")){ data.clear(); }
  else{ data = read.section("\n",-1); read = read.section("\n",0,-2); }
  QStringList lines =  read.split("\n",QString::SkipEmptyParts);
  QString info;
  if(LIST){ parseLines(lines); }
  else if(!lines.isEmpty()){ info = lines.last(); }
  //qDebug() << lines;
  emit ProgressUpdate(-1, info);
}