#include "IOPool/Streamer/interface/MsgTools.h"
#include "IOPool/Streamer/interface/StreamerInputFile.h"
#include "CalibCalorimetry/EcalLaserSorting/interface/WatcherStreamFileReader.h"
#include "FWCore/Utilities/interface/Exception.h"

#include <cerrno>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fcntl.h>
#include <fstream>
#include <libgen.h>
#include <memory>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

//using namespace edm;
using namespace std;
using namespace edm::streamer;

//std::string WatcherStreamFileReader::fileName_;

#if !defined(__linux__) && !(defined(__APPLE__) && __DARWIN_C_LEVEL >= 200809L)
/* getline implementation is copied from glibc. */

#ifndef SIZE_MAX
#define SIZE_MAX ((size_t) - 1)
#endif
#ifndef SSIZE_MAX
#define SSIZE_MAX ((ssize_t)(SIZE_MAX / 2))
#endif
namespace {
  ssize_t getline(char** lineptr, size_t* n, FILE* fp) {
    ssize_t result = -1;
    size_t cur_len = 0;

    if (lineptr == NULL || n == NULL || fp == NULL) {
      errno = EINVAL;
      return -1;
    }

    if (*lineptr == NULL || *n == 0) {
      *n = 120;
      *lineptr = (char*)malloc(*n);
      if (*lineptr == NULL) {
        result = -1;
        goto end;
      }
    }

    for (;;) {
      int i;

      i = getc(fp);
      if (i == EOF) {
        result = -1;
        break;
      }

      /* Make enough space for len+1 (for final NUL) bytes.  */
      if (cur_len + 1 >= *n) {
        size_t needed_max = SSIZE_MAX < SIZE_MAX ? (size_t)SSIZE_MAX + 1 : SIZE_MAX;
        size_t needed = 2 * *n + 1; /* Be generous. */
        char* new_lineptr;

        if (needed_max < needed)
          needed = needed_max;
        if (cur_len + 1 >= needed) {
          result = -1;
          goto end;
        }

        new_lineptr = (char*)realloc(*lineptr, needed);
        if (new_lineptr == NULL) {
          result = -1;
          goto end;
        }

        *lineptr = new_lineptr;
        *n = needed;
      }

      (*lineptr)[cur_len] = i;
      cur_len++;

      if (i == '\n')
        break;
    }
    (*lineptr)[cur_len] = '\0';
    result = cur_len ? (ssize_t)cur_len : result;

  end:
    return result;
  }
}  // namespace
#endif

static std::string now() {
  struct timeval t;
  gettimeofday(&t, nullptr);

  char buf[256];
  strftime(buf, sizeof(buf), "%F %R %S s", localtime(&t.tv_sec));
  buf[sizeof(buf) - 1] = 0;

  stringstream buf2;
  buf2 << buf << " " << ((t.tv_usec + 500) / 1000) << " ms";

  return buf2.str();
}

WatcherStreamFileReader::WatcherStreamFileReader(edm::ParameterSet const& pset)
    : inputDir_(pset.getParameter<std::string>("inputDir")),
      filePatterns_(pset.getParameter<std::vector<std::string> >("filePatterns")),
      inprocessDir_(pset.getParameter<std::string>("inprocessDir")),
      processedDir_(pset.getParameter<std::string>("processedDir")),
      corruptedDir_(pset.getParameter<std::string>("corruptedDir")),
      tokenFile_(pset.getUntrackedParameter<std::string>("tokenFile", "watcherSourceToken")),
      timeOut_(pset.getParameter<int>("timeOutInSec")),
      end_(false),
      verbosity_(pset.getUntrackedParameter<int>("verbosity", 0)) {
  struct stat buf;
  if (stat(tokenFile_.c_str(), &buf)) {
    FILE* f = fopen(tokenFile_.c_str(), "w");
    if (f) {
      fclose(f);
    } else {
      throw cms::Exception("WatcherSource") << "Failed to create token file.";
    }
  }
  vector<string> dirs;
  dirs.push_back(inprocessDir_);
  dirs.push_back(processedDir_);
  dirs.push_back(corruptedDir_);

  for (unsigned i = 0; i < dirs.size(); ++i) {
    const string& dir = dirs[i];
    struct stat fileStat;
    if (0 == stat(dir.c_str(), &fileStat)) {
      if (!S_ISDIR(fileStat.st_mode)) {
        throw cms::Exception("[WatcherSource]") << "File " << dir << " exists but is not a directory "
                                                << " as expected.";
      }
    } else {  //directory does not exists, let's try to create it
      if (0 != mkdir(dir.c_str(), 0755)) {
        throw cms::Exception("[WatcherSource]") << "Failed to create directory " << dir << " for writing data.";
      }
    }
  }
}

WatcherStreamFileReader::~WatcherStreamFileReader() {}

const bool WatcherStreamFileReader::newHeader() { return getInputFile() != nullptr; }

const InitMsgView* WatcherStreamFileReader::getHeader() {
  StreamerInputFile* inputFile = getInputFile();

  //TODO: shall better send an exception...
  if (inputFile == nullptr) {
    throw cms::Exception("WatcherSource") << "No input file found.";
  }

  const InitMsgView* header = inputFile->startMessage();

  if (header->code() != Header::INIT)  //INIT Msg
    throw cms::Exception("readHeader", "WatcherStreamFileReader")
        << "received wrong message type: expected INIT, got " << header->code() << "\n";

  return header;
}

const EventMsgView* WatcherStreamFileReader::getNextEvent() {
  if (end_) {
    moveJustReadFile();
    return nullptr;
  }

  StreamerInputFile* inputFile;
  if ((inputFile = getInputFile()) != nullptr and inputFile->next() == StreamerInputFile::Next::kStop) {
    moveJustReadFile();
    return nullptr;
  }

  return inputFile == nullptr ? nullptr : inputFile->currentRecord();
}

StreamerInputFile* WatcherStreamFileReader::getInputFile() {
  char* lineptr = nullptr;
  size_t n = 0;
  static stringstream cmd;
  static bool cmdSet = false;
  static char curDir[PATH_MAX > 0 ? PATH_MAX : 4096];

  if (!cmdSet) {
    cmd.str("");
    //    cmd << "/bin/ls -rt " << inputDir_ << " | egrep '(";
    //by default ls will sort the file alphabetically which will results
    //in ordering the files in increasing LB number, which is the desired
    //order.
    //    cmd << "/bin/ls " << inputDir_ << " | egrep '(";
    cmd << "/bin/find " << inputDir_ << " -maxdepth 2 -print | egrep '(";
    //TODO: validate patternDir (see ;, &&, ||) and escape special character
    if (filePatterns_.empty())
      return nullptr;
    if (getcwd(curDir, sizeof(curDir)) == nullptr) {
      throw cms::Exception("WatcherSource") << "Failed to retreived working directory path: " << strerror(errno);
    }

    for (unsigned i = 0; i < filePatterns_.size(); ++i) {
      if (i > 0)
        cmd << "|";
      //     if(filePatterns_[i].size()>0 && filePatterns_[0] != "/"){//relative path
      //       cmd << curDir << "/";
      //     }
      cmd << filePatterns_[i];
    }
    cmd << ")' | sort";

    cout << "[WatcherSource " << now() << "]"
         << " Command to retrieve input files: " << cmd.str() << "\n";
    cmdSet = true;
  }

  struct stat buf;

  if (stat(tokenFile_.c_str(), &buf) != 0) {
    end_ = true;
  }

  bool waiting = false;
  static bool firstWait = true;
  timeval waitStart;
  //if no cached input file, look for new files until one is found:
  if (!end_ && streamerInputFile_.get() == nullptr) {
    fileName_.assign("");

    //check if we have file in the queue, if not look for new files:
    while (filesInQueue_.empty()) {
      if (stat(tokenFile_.c_str(), &buf) != 0) {
        end_ = true;
        break;
      }
      FILE* s = popen(cmd.str().c_str(), "r");
      if (s == nullptr) {
        throw cms::Exception("WatcherSource") << "Failed to retrieve list of input file: " << strerror(errno);
      }

      ssize_t len;
      while (!feof(s)) {
        if ((len = getline(&lineptr, &n, s)) > 0) {
          //remove end-of-line character:
          lineptr[len - 1] = 0;
          string fileName;
          if (lineptr[0] != '/') {
            if (!inputDir_.empty() && inputDir_[0] != '/') {  //relative path
              fileName.assign(curDir);
              fileName.append("/");
              fileName.append(inputDir_);
            } else {
              fileName.assign(inputDir_);
            }
            fileName.append("/");
          }
          fileName.append(lineptr);
          filesInQueue_.push_back(fileName);
          if (verbosity_)
            cout << "[WatcherSource " << now() << "]"
                 << " File to process: '" << fileName << "'\n";
        }
      }
      while (!feof(s))
        fgetc(s);
      pclose(s);
      if (filesInQueue_.empty()) {
        if (!waiting) {
          cout << "[WatcherSource " << now() << "]"
               << " No file found. Waiting for new file...\n";
          cout << flush;
          waiting = true;
          gettimeofday(&waitStart, nullptr);
        } else if (!firstWait) {
          timeval t;
          gettimeofday(&t, nullptr);
          float dt = (t.tv_sec - waitStart.tv_sec) * 1. + (t.tv_usec - waitStart.tv_usec) * 1.e-6;
          if ((timeOut_ >= 0) && (dt > timeOut_)) {
            cout << "[WatcherSource " << now() << "]"
                 << " Having waited for new file for " << (int)dt << " sec. "
                 << "Timeout exceeded. Exits.\n";
            //remove(tokenFile_.c_str()); //we do not delete the token, otherwise sorting process on the monitoring farm will not be restarted by the runloop.sh script.
            end_ = true;
            break;
          }
        }
      }
      sleep(1);
    }  //end of file queue update
    firstWait = false;
    free(lineptr);
    lineptr = nullptr;

    while (streamerInputFile_.get() == nullptr && !filesInQueue_.empty()) {
      fileName_ = filesInQueue_.front();
      filesInQueue_.pop_front();
      int fd = open(fileName_.c_str(), 0);
      if (fd != 0) {
        struct stat buf;
        off_t size = -1;
        //check that file transfer is finished, by monitoring its size:
        time_t t = time(nullptr);
        for (;;) {
          fstat(fd, &buf);
          if (verbosity_)
            cout << "file size: " << buf.st_size << ", prev size: " << size << "\n";
          if (buf.st_size == size)
            break;
          else
            size = buf.st_size;
          if (difftime(t, buf.st_mtime) > 60)
            break;  //file older then 1 min=> tansfer must be finished
          sleep(1);
        }

        if (fd != 0 && buf.st_size == 0) {  //file is empty. streamer reader
          //                   does not like empty file=> skip it
          stringstream c;
          c << "/bin/mv -f \"" << fileName_ << "\" \"" << corruptedDir_ << "/.\"";
          if (verbosity_)
            cout << "[WatcherSource " << now() << "]"
                 << " Executing " << c.str() << "\n";
          int i = system(c.str().c_str());
          if (i != 0) {
            //throw cms::Exception("WatcherSource")
            cout << "[WatcherSource " << now() << "] "
                 << "Failed to move empty file '" << fileName_ << "'"
                 << " to corrupted directory '" << corruptedDir_ << "'\n";
          }
          continue;
        }

        close(fd);

        vector<char> buf1(fileName_.size() + 1);
        copy(fileName_.begin(), fileName_.end(), buf1.begin());
        buf1[buf1.size() - 1] = 0;

        vector<char> buf2(fileName_.size() + 1);
        copy(fileName_.begin(), fileName_.end(), buf2.begin());
        buf2[buf2.size() - 1] = 0;

        string dirnam(dirname(&buf1[0]));
        string filenam(basename(&buf2[0]));

        string dest = inprocessDir_ + "/" + filenam;

        if (verbosity_)
          cout << "[WatcherSource " << now() << "]"
               << " Moving file " << fileName_ << " to " << dest << "\n";

        //	stringstream c;
        //c << "/bin/mv -f \"" << fileName_ << "\" \"" << dest
        // << "/.\"";

        if (0 != rename(fileName_.c_str(), dest.c_str())) {
          //if(0!=system(c.str().c_str())){
          throw cms::Exception("WatcherSource") << "Failed to move file '" << fileName_ << "' "
                                                << "to processing directory " << inprocessDir_ << ": "
                                                << strerror(errno) << " (Error no " << errno << ")";
        }

        fileName_ = dest;

        cout << "[WatcherSource " << now() << "]"
             << " Opening file " << fileName_ << "\n"
             << flush;
        streamerInputFile_ = std::make_unique<StreamerInputFile>(fileName_);

        ofstream f(".watcherfile");
        f << fileName_;
      } else {
        cout << "[WatcherSource " << now() << "]"
             << " Failed to open file " << fileName_ << endl;
      }
    }  //loop on file queue to find one file which opening succeeded
  }
  return streamerInputFile_.get();
}

void WatcherStreamFileReader::closeFile() {}

void WatcherStreamFileReader::moveJustReadFile() {
  if (streamerInputFile_.get() == nullptr)
    return;
  //delete the streamer input file:
  streamerInputFile_.reset();
  stringstream cmd;
  //TODO: validation of processDir
  //cmd << "/bin/mv -f \"" << fileName_ << "\" \"" << processedDir_ << "/.\"";
  //if(verbosity_) cout << "[WatcherSource " << now() << "]"
  //<< " Executing (in closeFile())" << cmd.str() << "\n";
  //int i = system(cmd.str().c_str());
  //cout << "move command done at " << now() << "\n";
  vector<char> buf(fileName_.size() + 1);
  copy(fileName_.begin(), fileName_.end(), buf.begin());
  buf[buf.size() - 1] = 0;
  string dest = processedDir_ + "/" + basename(&buf[0]);
  if (verbosity_)
    cout << "[WatcherSource " << now() << "]"
         << " Moving " << fileName_ << " to " << dest << "... ";
  int i = rename(fileName_.c_str(), dest.c_str());
  if (i != 0) {
    throw cms::Exception("WatcherSource")
        << "Failed to move processed file '" << fileName_ << "'"
        << " to processed directory '" << processedDir_ << ": " << strerror(errno) << " (Error no " << errno << ")";

    //Stop further processing to prevent endless loop:
    end_ = true;
  }
  if (verbosity_)
    cout << "Done at " << now() << "\n";

  //  cout << flush;
}