#include "zfstream.h"

gzfilebuf::gzfilebuf() : file(NULL), mode(0), own_file_descriptor(0) {}

gzfilebuf::~gzfilebuf() {

  sync();
  if (own_file_descriptor)
    close();
}

gzfilebuf *gzfilebuf::open(const char *name, int io_mode) {

  if (is_open())
    return NULL;

  char char_mode[10];
  char *p = char_mode;

  if (io_mode & ios::in) {
    mode = ios::in;
    *p++ = 'r';
  } else if (io_mode & ios::app) {
    mode = ios::app;
    *p++ = 'a';
  } else {
    mode = ios::out;
    *p++ = 'w';
  }

  if (io_mode & ios::binary) {
    mode |= ios::binary;
    *p++ = 'b';
  }

  // Hard code the compression level
  if (io_mode & (ios::out | ios::app)) {
    *p++ = '9';
  }

  // Put the end-of-string indicator
  *p = '\0';

  if ((file = gzopen(name, char_mode)) == NULL)
    return NULL;

  own_file_descriptor = 1;

  return this;
}

gzfilebuf *gzfilebuf::attach(int file_descriptor, int io_mode) {

  if (is_open())
    return NULL;

  char char_mode[10];
  char *p = char_mode;

  if (io_mode & ios::in) {
    mode = ios::in;
    *p++ = 'r';
  } else if (io_mode & ios::app) {
    mode = ios::app;
    *p++ = 'a';
  } else {
    mode = ios::out;
    *p++ = 'w';
  }

  if (io_mode & ios::binary) {
    mode |= ios::binary;
    *p++ = 'b';
  }

  // Hard code the compression level
  if (io_mode & (ios::out | ios::app)) {
    *p++ = '9';
  }

  // Put the end-of-string indicator
  *p = '\0';

  if ((file = gzdopen(file_descriptor, char_mode)) == NULL)
    return NULL;

  own_file_descriptor = 0;

  return this;
}

gzfilebuf *gzfilebuf::close() {

  if (is_open()) {

    sync();
    gzclose(file);
    file = NULL;
  }

  return this;
}

int gzfilebuf::setcompressionlevel(int comp_level) {

  return gzsetparams(file, comp_level, -2);
}

int gzfilebuf::setcompressionstrategy(int comp_strategy) {

  return gzsetparams(file, -2, comp_strategy);
}

streampos gzfilebuf::seekoff(streamoff off, ios::seek_dir dir, int which) {

  return streampos(EOF);
}

int gzfilebuf::underflow() {

  // If the file hasn't been opened for reading, error.
  if (!is_open() || !(mode & ios::in))
    return EOF;

  // if a buffer doesn't exists, allocate one.
  if (!base()) {

    if ((allocate()) == EOF)
      return EOF;
    setp(0, 0);

  } else {

    if (in_avail())
      return (unsigned char)*gptr();

    if (out_waiting()) {
      if (flushbuf() == EOF)
        return EOF;
    }
  }

  // Attempt to fill the buffer.

  int result = fillbuf();
  if (result == EOF) {
    // disable get area
    setg(0, 0, 0);
    return EOF;
  }

  return (unsigned char)*gptr();
}

int gzfilebuf::overflow(int c) {

  if (!is_open() || !(mode & ios::out))
    return EOF;

  if (!base()) {
    if (allocate() == EOF)
      return EOF;
    setg(0, 0, 0);
  } else {
    if (in_avail()) {
      return EOF;
    }
    if (out_waiting()) {
      if (flushbuf() == EOF)
        return EOF;
    }
  }

  int bl = blen();
  setp(base(), base() + bl);

  if (c != EOF) {

    *pptr() = c;
    pbump(1);
  }

  return 0;
}

int gzfilebuf::sync() {

  if (!is_open())
    return EOF;

  if (out_waiting())
    return flushbuf();

  return 0;
}

int gzfilebuf::flushbuf() {

  int n;
  char *q;

  q = pbase();
  n = pptr() - q;

  if (gzwrite(file, q, n) < n)
    return EOF;

  setp(0, 0);

  return 0;
}

int gzfilebuf::fillbuf() {

  int required;
  char *p;

  p = base();

  required = blen();

  int t = gzread(file, p, required);

  if (t <= 0)
    return EOF;

  setg(base(), base(), base() + t);

  return t;
}

gzfilestream_common::gzfilestream_common()
    : ios(gzfilestream_common::rdbuf()) {}

gzfilestream_common::~gzfilestream_common() {}

void gzfilestream_common::attach(int fd, int io_mode) {

  if (!buffer.attach(fd, io_mode))
    clear(ios::failbit | ios::badbit);
  else
    clear();
}

void gzfilestream_common::open(const char *name, int io_mode) {

  if (!buffer.open(name, io_mode))
    clear(ios::failbit | ios::badbit);
  else
    clear();
}

void gzfilestream_common::close() {

  if (!buffer.close())
    clear(ios::failbit | ios::badbit);
}

gzfilebuf *gzfilestream_common::rdbuf() { return &buffer; }

gzifstream::gzifstream() : ios(gzfilestream_common::rdbuf()) {
  clear(ios::badbit);
}

gzifstream::gzifstream(const char *name, int io_mode)
    : ios(gzfilestream_common::rdbuf()) {
  gzfilestream_common::open(name, io_mode);
}

gzifstream::gzifstream(int fd, int io_mode)
    : ios(gzfilestream_common::rdbuf()) {
  gzfilestream_common::attach(fd, io_mode);
}

gzifstream::~gzifstream() {}

gzofstream::gzofstream() : ios(gzfilestream_common::rdbuf()) {
  clear(ios::badbit);
}

gzofstream::gzofstream(const char *name, int io_mode)
    : ios(gzfilestream_common::rdbuf()) {
  gzfilestream_common::open(name, io_mode);
}

gzofstream::gzofstream(int fd, int io_mode)
    : ios(gzfilestream_common::rdbuf()) {
  gzfilestream_common::attach(fd, io_mode);
}

gzofstream::~gzofstream() {}