/*
----
This file is part of SECONDO.

Copyright (C) 2007,
Faculty of Mathematics and Computer Science,
Database Systems for New Applications.

SECONDO is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

SECONDO 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with SECONDO; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
----


1 CollectFlobServer

A socket server accepting all collectFlob queries from the cluster on the current computer.

Requests are collected into a FIFO queue, being processed sequentially with
limited number of threads.

1.1 Includes

*/
#include <iostream>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <netinet/in.h>
#include <resolv.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <pthread.h>
#include <signal.h>
#include <algorithm>

#include "Profiles.h"
#include <map>
#include <queue>
#include <set>
#include <sys/time.h>
#include <assert.h>

#include "Profiles.h"

#define LOGFILE 1

using namespace std;

int string2int(const string& str){
  istringstream s(str);
  int res;
  s >> res;
  return res;
}

string int2string(const int& number)
{
  ostringstream oss;
  oss << number;
  return oss.str();
}

template<typename T1, typename T2>
struct classCompPair
{
  bool operator() (const pair<T1,T2>& pair_1,
      const pair<T1,T2>& pair_2) const
  {
    return (pair_1.first < pair_2.first)
        || (!(pair_1.first > pair_2.first && pair_1.first < pair_2.first)
          && (pair_1.second < pair_2.second));
  }
};

void* ReceiveRequest(void*);
void* ProcessRequest(void*);
bool collectFlob(string request);
void writeToFlobFile(char*, char*, size_t, ofstream*, size_t&);
void readFromFlobFile(char*, size_t, size_t, ifstream*, char*, size_t&);

const int MAX_COPYTIMES = 20;
const size_t bufferLen = 32 * 1024 * 1024;
const size_t wbLen = bufferLen / 2, rbLen = bufferLen / 2;
queue<pair<string, int*> > requests;
pthread_mutex_t CFBS_mutex;
const size_t PipeWidth = 1;
bool tokenPass[PipeWidth];
pthread_t threadId[PipeWidth];

#ifdef LOGFILE
ofstream logFile;
#endif

class Prcv_Thread{
public:
  Prcv_Thread(pair<string, int*> r, int t):
    token(t){
    request = r.first;
    csock = r.second;
  }

  string request;
  int* csock;
  int token;

};

int main(){
  pthread_mutex_init(&CFBS_mutex, NULL);

  //Read the port for collectFlobServer
  string config = string(getenv("SECONDO_CONFIG"));
  int host_port = string2int(SmiProfile::GetParameter(
      "Environment","SecondoPort", "", config)) + 1;


  struct sockaddr_in my_addr;
  int hsock;
  int* p_int;

  socklen_t addr_size = 0;
  int* csock;
  sockaddr_in sadr;

  pthread_t recvTID = 0;

  memset(threadId, 0, sizeof(pthread_t)*PipeWidth);

  hsock = socket(AF_INET, SOCK_STREAM, 0);
  if (hsock == -1){
    cerr << "Error!! Initializing socket fails: " << errno << endl;
    return -1;
  }

  p_int = (int*)malloc(sizeof(int));
  *p_int = 1;
  if ( (setsockopt(hsock, SOL_SOCKET, SO_REUSEADDR,
          (char*)p_int, sizeof(int)) == -1)
      || (setsockopt(hsock, SOL_SOCKET, SO_KEEPALIVE,
          (char*)p_int, sizeof(int)) == -1)){
    cerr << "Error!! Setting socket options fails: " << errno << endl;
    free(p_int);
    return -1;
  }
  free(p_int);

  my_addr.sin_family = AF_INET;
  my_addr.sin_port = htons(host_port);
  memset(&(my_addr.sin_zero), 0, 8);
  my_addr.sin_addr.s_addr = INADDR_ANY;

  if (bind(hsock, (sockaddr*)&my_addr, sizeof(my_addr)) == -1){
    cerr << "Error!! Binding socket on port " << host_port
        << " fails: " << errno << endl;
    cerr << "Make sure nothing else is listening on this port! " << endl;
    return -1;
  }
  if (listen(hsock, 10) == -1){
    cerr << "Error!! Listening fails: " << errno << endl;
    return -1;
  }

  addr_size = sizeof(sockaddr_in);

  while(true){
    csock = (int*)malloc(sizeof(int));
    if((*csock = accept(hsock, (sockaddr*)&sadr, &addr_size))!= -1){
      //Put it into the queue first
      pthread_create(&recvTID, 0, &ReceiveRequest, (void*)csock);
      pthread_detach(recvTID);
    }
    else {
      cerr << "Warning!! Accepting fails: " << errno << endl;
    }
  }
}


void* ReceiveRequest(void* lp)
{
  //Get one request and put it into the queue

  int* csock = (int*)lp;

  size_t buffer_len = 1024;
  char buffer[buffer_len];
  int byteCount;

  memset(buffer, 0, buffer_len);
  if ((byteCount = recv(*csock, buffer, buffer_len, 0)) == -1){
    cerr << "Error!! Receiving data fails: " << errno << endl;
    free(csock);
    return NULL;
  }
  string args(buffer, find(buffer, buffer + buffer_len, '\0'));

  pthread_mutex_lock(&CFBS_mutex);
  pair<string, int*> r = make_pair(args, csock);   
  size_t t = 0;
  tokenPass[t] = true;
  Prcv_Thread* pt = new Prcv_Thread(r, t);
  pthread_create(&threadId[t], 0, &ProcessRequest, (void*)pt);
  pthread_join(threadId[t], NULL); 
  pthread_mutex_unlock(&CFBS_mutex);
 
  return NULL;
}

void* ProcessRequest(void* ptr)
{
  //Process one request
  Prcv_Thread* pt = (Prcv_Thread*)ptr;
  int token = pt->token;
  int* csock = pt->csock;

  bool ok = collectFlob(pt->request);
  cerr << "The collect result is: " << (ok ? "true" : "false") << endl;

  int bytecount = 0;
  if ((bytecount = send(*csock, (char*)&ok, sizeof(bool), 0)) == -1){
    cerr << "Error!! Sending data fails: " << errno << endl;
    free(csock);
    return NULL;
  }
  close(*csock);
  free(csock);

//  pthread_mutex_lock(&CFBS_mutex);
  //Todo: use a different mutex, orelse it causes dead lock
  tokenPass[token] = false;
//  pthread_mutex_unlock(&CFBS_mutex);

  return NULL;
}

bool collectFlob(string request)
{
  timeval start,stop;
  gettimeofday(&start,NULL);

  istringstream ss(request);
  //The destPSFS contains the remote IP
  string sheetName, resultName, serverPSFS, clientPSFS;
  ss >> sheetName >> resultName >> serverPSFS >> clientPSFS;
cerr << "Process " << sheetName << ", then generate " << resultName << endl;
  //1. Fetch the sheet
  string command = "scp -q " + clientPSFS + "/" + sheetName
      + " " + serverPSFS;
  int atimes = MAX_COPYTIMES;
  while( atimes-- > 0 ){
    if (0 == system(command.c_str())){
      break;
    }
    else{
      sleep(1);
    }
  }
  if (atimes < 0){
    pthread_mutex_lock(&CFBS_mutex);
    cerr << "Error!! Fetching the sheet file "
        << clientPSFS << "/" << sheetName << " fails" << endl;
    pthread_mutex_unlock(&CFBS_mutex);
    return false;
  }

  //2. Prepare the result
  u_int32_t lastFileId = 0;
  ifstream* flobFile = 0;

  string sheetFilePath = serverPSFS + "/" + sheetName;
  string resultFilePath = serverPSFS + "/tmp_" + resultName;
  ifstream sheetFile(sheetFilePath.c_str());
  ofstream resultFile(resultFilePath.c_str(), ios::binary);

  //Cached Flob markers, avoid extract the same Flob
  set<pair<u_int32_t, size_t>, classCompPair<u_int32_t, size_t> > lobMarkers;
  //Empty lobs are prepared for Flobs that have been created in another sheet
  set<pair<u_int32_t, size_t>, classCompPair<u_int32_t, size_t> > emptyLobs;

  //Write buffer
  char* wbuffer = new char[wbLen];
  memset(wbuffer, 0, wbLen);
  size_t byteWritten = 0;

  //Read buffer
  char* rbuffer = new char[rbLen];
  //Number of read blocks
  size_t bcNum = 0;

  string flobOrder;
  while (getline(sheetFile, flobOrder))
  {
    stringstream ss(flobOrder);
    u_int32_t fileId;
    int sourceDS, mode;
    size_t offset, size;
    ss >> fileId >> sourceDS >> offset >> mode >> size;

    if ( mode != 3) {
      //This Flob may already have been fetched by another thread.
      size_t recId = sourceDS;
      pair<u_int32_t, size_t> mlob(fileId, recId);
      if (emptyLobs.find(mlob) != emptyLobs.end()){
        continue;
      } else {
        emptyLobs.insert(mlob);
      }

      char block[size];
      memset(block, 0, size);
      writeToFlobFile(wbuffer, block, size, &resultFile, byteWritten);
      continue;
    }

    //The flob is never mentioned in the current sheet
    pair<u_int32_t, size_t> mlob(fileId, offset);
    if (lobMarkers.find(mlob) != lobMarkers.end()){
      continue;
    } else {
      lobMarkers.insert(mlob);
    }

    if (lastFileId != fileId)
    {
      if (lastFileId > 0){
        //Close the last one
        assert(flobFile);
        flobFile->close();
      }
      
      string flobFileName = serverPSFS + "/flobFile_" + int2string(fileId);
      flobFile = new ifstream(flobFileName.c_str(), ios::binary);
      lastFileId = fileId;
      flobFile->read(rbuffer, rbLen);
      bcNum = 0;
    }

    char block[size];
    readFromFlobFile(block, offset, size, flobFile, rbuffer, bcNum);
    writeToFlobFile(wbuffer, block, size, &resultFile, byteWritten);
  }

  if (lastFileId > 0){
    assert(flobFile);
    flobFile->close();
  }

  if (byteWritten > 0){
    //Clean the buffer;
    resultFile.write(wbuffer, byteWritten);
  }
  resultFile.close();
  sheetFile.close();
  delete wbuffer;
  delete rbuffer;

  //3. Send the result
  command = "scp -q " + resultFilePath + " " + clientPSFS + "/" + resultName;
  atimes = MAX_COPYTIMES;
  while ( atimes-- > 0){
    if ( 0 == system(command.c_str())){

      if (::unlink(resultFilePath.c_str()) != 0){
        cerr << "Warning! Deleting the result file "
            << resultFilePath << " fails. " << endl;
      }

      if (::unlink(sheetFilePath.c_str()) != 0){
        cerr << "Warning! Deleting the sheet file "
            << sheetFilePath << " fails. " << endl;
      }

      break;
    }
    else {
      sleep(1);
    }
  }
  if (atimes < 0){
    cerr << "Error!! sending the result flob file fails" << endl;
    return false;
  }
  
  gettimeofday(&stop,NULL);
#ifdef LOGFILE
  double diffSec = (stop.tv_sec - start.tv_sec)*1.0;
  diffSec += (stop.tv_usec - start.tv_usec)*1.0 / 1000000;

    logFile.open("cfbServ.log", ios::app);
    logFile << "Cost: " << diffSec << endl;
    logFile.close();
#endif

  return true;
}

void writeToFlobFile(char* buffer, char* data, size_t size,
    ofstream* file, size_t& offset)
{
  if (offset + size >= wbLen){
    //the file is written only when the buffer cannot hold more
    file->write(buffer, offset);
    offset = 0;
    memset(buffer, 0, wbLen);
  }

  //Write to the buffer as the priority,
  memcpy(buffer + offset, data, size);
  offset += size;
}

void readFromFlobFile(char* block, size_t offset, size_t size,
    ifstream* file, char* buffer, size_t& bcNum)
{
/*
The Flob is read from the buffer as the priority,
if it is not completely cached within the buffer,
then read its partial data and load another buffer,
as last read the left part.

*/
//todo: leave the problem that one flob may cover several blocks
  bool contained = ((offset + size) < (bcNum + 1) * rbLen);
  size_t inOffset = offset - (bcNum * rbLen);

  if (contained){
    memcpy(block, buffer + inOffset, size);
  }
  else{
    size_t nb = bcNum;
    while ( (nb + 1)*rbLen < offset ){
      //Skip useless blocks
      nb++;
    }

    if (nb > bcNum){
      //Read the block completely in the new block 
      if (nb > (bcNum + 1)){
        file->seekg(nb*rbLen, ios::beg);
      }
      file->read(buffer, rbLen);
      inOffset = offset - (nb*rbLen);
      memcpy(block, buffer + inOffset, size);
      bcNum = nb;
    }
    else{
      //Read in two adjacent blocks
      size_t pSize1 = (bcNum + 1)* rbLen - offset;
      size_t pSize2 = size - pSize1;
      memcpy(block, buffer + inOffset, pSize1);

      file->read(buffer, rbLen);
      memcpy(block + pSize1, buffer, pSize2);
      bcNum++;
    }
  }
}