/*
 * libdpkg - Debian packaging suite library routines
 * vercmp.c - comparison of version numbers
 *
 * Copyright (C) 1995 Ian Jackson <iwj10@cus.cam.ac.uk>
 *
 * This 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,
 * or (at your option) any later version.
 *
 * This 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 dpkg; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>

#include <qobject.h>

//# define _(Text) Text

class versionrevision
{
public:
    versionrevision()
    {
        version = 0;
    }

    ~versionrevision()
    {
        if ( version )
            delete [] version;
    }

    void setVersion( const char *str )
    {
        version = new char[(strlen(str)+1)];
        strcpy( version, str );
    }

  unsigned long epoch;
  char *version;
  const char *revision;
  const char *familiar_revision;
};

static int verrevcmp(const char *val, const char *ref)
{
  int vc, rc;
  long vl, rl;
  const char *vp, *rp;

  if (!val) val= "";
  if (!ref) ref= "";
  for (;;) {
    vp= val;  while (*vp && !isdigit(*vp)) vp++;
    rp= ref;  while (*rp && !isdigit(*rp)) rp++;
    for (;;) {
      vc= val == vp ? 0 : *val++;
      rc= ref == rp ? 0 : *ref++;
      if (!rc && !vc) break;
      if (vc && !isalpha(vc)) vc += 256; /* assumes ASCII character set */
      if (rc && !isalpha(rc)) rc += 256;
      if (vc != rc) return vc - rc;
    }
    val= vp;
    ref= rp;
    vl=0;  if (isdigit(*vp)) vl= strtol(val,(char**)&val,10);
    rl=0;  if (isdigit(*rp)) rl= strtol(ref,(char**)&ref,10);
    if (vl != rl) return vl - rl;
    if (!*val && !*ref) return 0;
    if (!*val) return -1;
    if (!*ref) return +1;
  }
}

int versioncompare(const struct versionrevision *version,
                   const struct versionrevision *refversion)
{
  int r;

  if (version->epoch > refversion->epoch) return 1;
  if (version->epoch < refversion->epoch) return -1;
  r= verrevcmp(version->version,refversion->version);  if (r) return r;
  r= verrevcmp(version->revision,refversion->revision); if (r) return r;
  return verrevcmp(version->familiar_revision,refversion->familiar_revision);
}

int versionsatisfied3(const struct versionrevision *it,
                      const struct versionrevision *ref,
                      const char *op)
{
  int r;
  r= versioncompare(it,ref);
  if (strcmp(op, "<=") == 0 || strcmp(op, "<") == 0)
    return r <= 0;
  if (strcmp(op, ">=") == 0 || strcmp(op, ">") == 0)
    return r >= 0;
  if (strcmp(op, "<<") == 0)
    return r < 0;
  if (strcmp(op, ">>") == 0)
    return r > 0;
  if (strcmp(op, "=") == 0)
    return r == 0;
//  fprintf(stderr, "unknown operator: %s", op);

  exit(1);
}

const char *parseversion(struct versionrevision *rversion, const char *string)
{
  char *hyphen, *colon, *eepochcolon;
  unsigned long epoch;

  if ( !*string )
    return QObject::tr( "Version string is empty." );

  colon= strchr(string,':');
  if (colon) {
    epoch= strtoul(string,&eepochcolon,10);
    if ( colon != eepochcolon )
        return QObject::tr( "Epoch in version is not number." );
    if ( !*++colon )
        return QObject::tr( "Nothing after colon in version number." );
    string= colon;
    rversion->epoch= epoch;
  } else {
    rversion->epoch= 0;
  }

  rversion->revision = "";
  rversion->familiar_revision = "";

  rversion->setVersion( string );
  hyphen= strrchr(rversion->version,'-');
  if (hyphen) {
    *hyphen++= 0;
    if (strncmp("fam", hyphen, 3) == 0) {
      rversion->familiar_revision=hyphen+3;
      hyphen= strrchr(rversion->version,'-');
      if (hyphen) {
	*hyphen++= 0;
	rversion->revision = hyphen;
      }
    } else {
      rversion->revision = hyphen;
    }
  }
/*
  fprintf(stderr,"Parsed version: %lu, %s, %s, %s\n",
	  rversion->epoch,
	  rversion->version,
	  rversion->revision,
	  rversion->familiar_revision);
*/
  return 0;
}

int compareVersions( const char *v1, const char *v2 )
{
  const char *err;
  versionrevision ver, ref;

  err = parseversion(&ref, v1);
  if (err) {
//    fprintf(stderr, "Invalid version `%s': %s\n", v2, err);
    return -2;
  }

  err = parseversion(&ver, v2);
  if (err) {
//    fprintf(stderr, "Invalid version `%s': %s\n", v1, err);
    return -2;
  }

  if ( versionsatisfied3( &ver, &ref, "=" ) )
    return 0;
  else if ( versionsatisfied3( &ver, &ref, "<" ) )
    return -1;
  else
    return 1;
}

/*
int main(int argc, char *argv[])
{
  const char *err;
  versionrevision ver, ref;

  if (argc < 4) {
    fprintf(stderr, "usage: %s: version op refversion\n", argv[0]);
    return 2;
  }

  err = parseversion(&ver, argv[1]);
  if (err) {
    fprintf(stderr, "Invalid version `%s': %s\n", argv[1], err);
    return 2;
  }

  err = parseversion(&ref, argv[3]);
  if (err) {
    fprintf(stderr, "Invalid version `%s': %s\n", argv[3], err);
    return 2;
  }

  printf( "Result: %d\n", versionsatisfied3(&ver, &ref, argv[2]) );
}

*/