/*
 * archive.c -- enfle transparent archive file handler
 * (C)Copyright 1998, 99 by Hiroshi Takekawa
 * This file if part of Enfle.
 *
 * Last Modified: Mon Mar  6 04:00:45 2000.
 * $Id: archive.c,v 1.8 2000/03/22 18:09:13 sian Exp $
 *
 * Enfle 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.
 *
 * Enfle 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include <unistd.h>

#include "archive.h"
#include "plugin.h"

static Dlist *plugin_list = NULL;

static Archive *
archive_open_core(Dlist *p, Archive *ar)
{
  Dlist_data *t;
  PluginInfo *pinfo, *gz_pinfo = NULL, *bz2_pinfo = NULL;
  int if_stdin = !strcmp(ar->filename, "-");

  if (!if_stdin) {
    for (t = dlist_gettop(p); t != NULL; t = t->next) {
      pinfo = t->data;
      ar->fp = NULL;
      if (pinfo->type == _Archiver) {
	if (!strcmp(pinfo->pluginshortname, "GZ")) {
	  gz_pinfo = pinfo;
	  continue;
	} else if (!strcmp(pinfo->pluginshortname, "BZ2")) {
	  bz2_pinfo = pinfo;
	  continue;
	} else if ((*pinfo->functions.archiver.open)(ar))
	  return ar;
      }
    }
    if (gz_pinfo && (*gz_pinfo->functions.archiver.open)(ar))
      return ar;
    if (bz2_pinfo && (*bz2_pinfo->functions.archiver.open)(ar))
      return ar;
  }

  /* normal file */
  if (!if_stdin) {
    if ((ar->fp = fopen(ar->filename, "rb")) == NULL) {
      free(ar);
      return NULL;
    }
  } else {
    int size;
    unsigned char buf[1024];

#if HAVE_MKSTEMP
    int fd;
    char *tmpfilename;

    if ((tmpfilename = calloc(strlen("/tmp/.enfle.XXXXXX") + 1, sizeof(char))) == NULL) {
      fprintf(stderr, "archive_open_core: no enough memory.\n");
      exit(1);
    }
    strcpy(tmpfilename, "/tmp/.enfle.XXXXXX");

    if ((fd = mkstemp(tmpfilename)) == -1) {
      perror("enfle: mkstemp:");
      fprintf(stderr, "archive_open_core: cannot create tmp file.\n");
      exit(1);
    }

    if (unlink(tmpfilename)) {
      perror("archive_open_core: unlink: ");
      exit(1);
    }
    free(tmpfilename);

    if ((ar->fp = fdopen(fd, "w+b")) == NULL) {
      fprintf(stderr, "archive_open_core: cannot open created tmp file.\n");
      exit(1);
    }
#else
    if ((ar->fp = tmpfile()) == NULL) {
      fprintf(stderr, "archive_open_core: cannot open tmp file.\n");
      exit(1);
    }
#endif

    while ((size = fread(buf, 1, 1024, stdin)))
      fwrite(buf, 1, size, ar->fp);
  }

  fseek(ar->fp, 0L, SEEK_END);
  ar->asize = ar->size = ftell(ar->fp);
  fseek(ar->fp, 0L, SEEK_SET);
  ar->offset = 0;

#ifdef DEBUG
  fprintf(stderr, "opening as normal file: size = %d\n", ar->size);
#endif
  ar->format = "NOR";
  ar->nfiles = 1;
  ar->select = NULL;
  ar->seek = NULL;
  ar->tell = NULL;
  ar->read = NULL;
  ar->close = NULL;
  return ar;
}

Archive *
archive_open(Dlist *p, char *filename)
{
  Archive *ar;

  plugin_list = p;

  if ((ar = calloc(1, sizeof(Archive))) == NULL)
    return NULL;

  ar->filename = filename;
  return archive_open_core(p, ar);
}

Archive *
archive_open_from_plugin(char *filename, char *format)
{
  Archive *ar;

  if ((ar = calloc(1, sizeof(Archive))) == NULL)
    return NULL;

  ar->filename = filename;
  ar->format = format;
  return archive_open_core(plugin_list, ar);
}

int
archive_select(Archive *ar, int index)
{
  if (ar->select != NULL)
    return (ar->select)(ar, index);
  ar->index = index;
  return 1;
}

int
archive_seek(Archive *ar, long pos, int whence)
{
  if (ar->seek != NULL)
    return (ar->seek)(ar, pos, whence);
  switch (whence) {
  case SEEK_SET:
    return fseek(ar->fp, ar->offset + pos, SEEK_SET);
  case SEEK_CUR:
    return fseek(ar->fp, pos, SEEK_CUR);
  case SEEK_END:
    return fseek(ar->fp, ar->offset + ar->size - 1 + pos, SEEK_SET);
  default:
    fprintf(stderr, "archive_seek: FATAL: Invalid whence specified: %d\n", whence);
    exit(-1);
  }
}

int
archive_tell(Archive *ar)
{
  if (ar->tell != NULL)
    return (ar->tell)(ar);
  return ftell(ar->fp) - ar->offset;
}

int
archive_read(Archive *ar, unsigned char *buf, int size)
{
  if (ar->read != NULL)
    return (ar->read)(ar, buf, size);
  return fread(buf, 1, size, ar->fp);
}

int
archive_getc(Archive *ar)
{
  unsigned char d;

  if (archive_read(ar, &d, 1) == 1)
    return (int)d;
  return -1;
}

unsigned char *
archive_gets(Archive *ar, unsigned char *buf, int size)
{
  unsigned char *p = buf;
  int r;

  for (; size > 1; size--) {
    if ((r = archive_read(ar, p, 1)) < 0)
      return NULL;
    if (r != 1)
      break;
    if (*p == '\n' || *p == '\0') {
      p++;
      break;
    }
    p++;
  }
  *p = '\0';

  return buf;
}

int
archive_close(Archive *ar)
{
  int f;

  if (ar->close != NULL)
    f = (ar->close)(ar);
  else
    f = fclose(ar->fp);

  free(ar);

  return f;
}