/* pkginfo.c - Retrieve information about packages for deborphan.
   Copyright (C) 2000, 2001, 2002, 2003 Cris van Pelt
   Copyright (C) 2003, 2004, 2006 Peter Palfrader
   Copyright (C) 2008, 2009 Carsten Hey

   $Id: pkginfo.c 904 2012-04-26 00:19:03Z carsten $

   Distributed under the terms of the Artistic License.
*/

/* This code is not nearly as advanced as dpkg's. It assumes a
   "perfect" statusfile. If the status-file is corrupted it may
   result in deborphan giving the wrong packages, or even crashing. */

#include <stdlib.h>
#include <string.h>
#include <regex.h>

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <deborphan.h>
#include <set.h>

#ifdef USE_XALLOC
#  include <xalloc.h>
#endif

extern int options[];

static regex_t re_statusinst, re_statusnotinst, re_statushold, re_namedev,
               re_gnugrepv, re_descdummy, re_desctransit, re_statusconfig,
               re_status;

void
init_pkg_regex()
{
    regcomp(&re_statusinst,
	    "^Status:.*[^-]installed$", REG_EXTENDED | REG_FLAGS);
    regcomp(&re_statusnotinst,
	    "^Status:.*not\\-installed$", REG_EXTENDED | REG_FLAGS);
    regcomp(&re_statushold,
	    "^Status:hold.*[^-]installed$", REG_EXTENDED | REG_FLAGS);
    regcomp(&re_statusconfig,
	    "^Status:.*config\\-files$", REG_EXTENDED | REG_FLAGS);
    regcomp(&re_status,
	    "^Status:", REG_EXTENDED | REG_FLAGS);

    if (options[GUESS]) {
	char guess[256];
	guess[0] = '\0';

	if (guess_chk(GUESS_PERL))
	    strcat(guess, "^lib.*-perl$|");
	if (guess_chk(GUESS_PYTHON))
	    strcat(guess, "^python[[:digit:].]*-|");
	if (guess_chk(GUESS_PIKE))
	    strcat(guess, "^pike[[:digit:].]*-|");
	if (guess_chk(GUESS_RUBY))
	    strcat(guess, "^lib.*-ruby[[:digit:].]*$|");
	if (guess_chk(GUESS_MONO))
	    strcat(guess, "^libmono|");
	if (guess_chk(GUESS_DEV))
	    strcat(guess, "-dev$|");
	if (guess_chk(GUESS_DEBUG))
	    strcat(guess, "-dbg(|sym)$|");
	if (guess_chk(GUESS_COMMON))
	    strcat(guess, "-common$|");
	if (guess_chk(GUESS_DATA))
	    strcat(guess, "-(data|music)$|");
	if (guess_chk(GUESS_DOC))
	    strcat(guess, "-doc$|");
	if (guess_chk(GUESS_KERNEL))
	    strcat(guess, "(-modules|^nvidia-kernel)-.*[[:digit:]]+\\.[[:digit:]]+\\.[[:digit:]]+");
	if (guess_chk(GUESS_SECTION)) {
	    regcomp(&re_gnugrepv, "(-perl|-dev|-doc|-dbg)$|^lib(mono|pam|reoffice)|-(ruby[[:digit:].]*|bin|tools|utils|dbgsym)$", 
		    REG_EXTENDED | REG_FLAGS);
	}

	/* GUESS_DUMMY is a fake. It is not handled like other guess options
	 * because the package's name is not really checked, but its
	 * description line. The reason we sort of pretend it's a real
	 * guess option is that we can combine it with --guess-only and
	 * guess-all.
	 */
	if (guess_chk(GUESS_DUMMY)) {
	    regcomp(&re_descdummy, "^Description:.*dummy", 
		    REG_EXTENDED | REG_FLAGS);
	    regcomp(&re_desctransit, "^Description:.*transition(|n)($|ing|al|ary| package| purposes)", 
		    REG_EXTENDED | REG_FLAGS);
	}
	if (guess[strlen(guess)-1] == '|')
	    guess[strlen(guess)-1] = '\0';

        if (!guess_unique(GUESS_SECTION))
	    regcomp(&re_namedev, guess, REG_EXTENDED | REG_FLAGS);
    }
}

void
free_pkg_regex()
{
    regfree(&re_statusinst);
    regfree(&re_statusnotinst);
    regfree(&re_statushold);
    regfree(&re_statusconfig);
    regfree(&re_status);
    regfree(&re_namedev);
    regfree(&re_gnugrepv);
    regfree(&re_descdummy);
    regfree(&re_desctransit);
}

/* A similar "hack" was created by Paul Martin a while ago. It was not
 * implemented then for various reasons. This selects the function to
 * call to get the info, based on the first few characters.
 * Not as versatile as regular expressions, but it makes up for that in
 * speed.
 */
void
get_pkg_info(const char *line, pkg_info * package, int *multiarch)
{
    const char c = upcase(line[0]);
    char t;

    if (strchr(line, ':') == 0) {
	exit_invalid_statusfile();
    }

    switch (c) {
    case 'P':
	t = upcase(line[2]);
	switch (t) {
	case 'I':		/* PrIority */
	    get_pkg_priority(line, package);
	    break;
	case 'C':		/* PaCkage */
	    get_pkg_name(line, package);
	    break;
	case 'O':		/* PrOvides */
	    get_pkg_provides(line, package);
	    break;
	case 'E':		/* PrE-depends */
	    get_pkg_deps(line, package);
	    break;
	}
	break;
    case 'D':
	switch (upcase(line[2])) {
	    case 'P':   /* DePends */
		get_pkg_deps(line, package);
		break;
	    case 'S':   /* DeScription */
		get_pkg_dummy(line, package);
		break;
	}
	break;
    case 'E': 			/* Essential */
	get_pkg_essential(line, package);
	break;
    case 'I':
	get_pkg_installed_size(line, package);
	break;
    case 'R':
	switch (upcase(line[2])) {
	    case 'C':		/* ReCommends */
		if (!options[IGNORE_RECOMMENDS] && options[NICE_MODE])
		    get_pkg_deps(line, package);
		break;
	}
	break;
    case 'S':
	t = upcase(line[1]);
	switch (t) {
	case 'E':		/* SEction */
	    get_pkg_section(line, package);
	    break;
	case 'T':		/* STatus */
	    get_pkg_status(line, package);
	    break;
	case 'U':		/* SUggests */
	    if (!options[IGNORE_SUGGESTS] && options[NICE_MODE])
		get_pkg_deps(line, package);
	    break;
	}
	break;
    case 'A':
	if (strncmp("Architecture:", line, sizeof("Architecture:") - 1) == 0) {
	    static char *firstarchfound = NULL;
	    /* Spaces are removed from the line, so the field's value starts
	     * directly after the colon. */
	    const char *arch = line + sizeof("Architecture:") - 1;
	    package->self.arch = xstrdup(arch);
	    if (*multiarch == 1
		    || strcmp(arch, "all") == 0)
		break;
	    if (firstarchfound == NULL)
		firstarchfound = xstrdup(arch);
	    else if (strcmp(arch, firstarchfound) != 0) {
		*multiarch = 1;
		/* The variable firstarchfound is only needed to detect if
		 * packages from multiple architectures are installed (we can't
		 * ask dpkg because the read status file might belong to
		 * a different system).  Now that we know that the status file
		 * contains multiple architectures we can free firstarchfound.*/
		free(firstarchfound);
		firstarchfound = NULL;
	    }
	}
	break;
    }
}

void
get_pkg_essential(const char *line, pkg_info *package)
{
    if (strcasecmp(line, "Essential:yes") == 0)
	package->essential = 1;
}

void
get_pkg_installed_size(const char *line, pkg_info *package)
{
    if (strncasecmp(line, "Installed-Size:", 15) == 0)
	package->installed_size = strtol(line + 15, NULL, 10);
}

void
get_pkg_dummy(const char *line, pkg_info *package)
{
    if (!guess_chk(GUESS_DUMMY)) 
	return;

    if (regexec(&re_descdummy, line, 0, NULL, 0) == 0 || 
        regexec(&re_desctransit, line, 0, NULL, 0) == 0) {
	package->dummy = 1;
    }
}

void
get_pkg_deps(const char *line, pkg_info * package)
{
    char *tok, *line2, *version = NULL;
    signed int num_deps, i;
    unsigned int dup = 0;
    dep d;

    line2 = strchr(line, ':')+1;

    num_deps = package->deps_cnt;

    for (; (tok = strsep(&line2, ",|")); num_deps++) {
	/* Versions are up to dpkg. */
        if ((version = strchr(tok, '(')))
            *version = '\0';

	(void) set_dep(&d, tok);
	dup = 0;
	for (i = 0; i<num_deps; i++ ) {
	    if (pkgcmp(package->deps[i], d)) {
		dup = 1;
                /*@innerbreak@*/
		break;
	    }
	}

	if (dup)
	    num_deps--;
	else {
	    if (num_deps >= package->deps_max) {
		/* grow deps[] array */
		package->deps_max = package->deps_max ? package->deps_max*2 : INIT_DEPENDS_COUNT;
#ifdef DEBUG
		fprintf(stderr, "Growing deps field to %d.\n", package->deps_max);
		fflush(stderr);
#endif /* DEBUG */
		package->deps = xrealloc( package->deps, package->deps_max * sizeof(package->deps[0]) );
	    }
	    package->deps[num_deps] = d;
	}
    }

    package->deps_cnt = num_deps;
}

void
get_pkg_priority(const char *line, pkg_info * package)
{
    set_priority(package, strchr(line, ':')+1);
}

void
get_pkg_provides(const char *line, pkg_info * package)
{
    char *prov, *name;
    int i = 0;

    prov = strchr(line, ':') + 1;

    for (i = 0; (name = strsep(&prov, ",")) || !i; i++) {
	if (!name)
	    name = prov;
	(void) set_provides(package, name, i);
    }
    package->provides_cnt = i;
}

void
get_pkg_name(const char *line, pkg_info * package)
{
    char *name = strchr(line, ':') + 1;

    package->self.name = xstrdup(name);
    package->self.namehash = strhash(name);
}

void
get_pkg_status(const char *line, pkg_info * package)
{
    if (!regexec(&re_statusinst, line, 0, NULL, 0)) {
	set_install(package);
	if (!options[FORCE_HOLD]) {
	    if (!regexec(&re_statushold, line, 0, NULL, 0))
		set_hold(package);
	}
    } else if (!regexec(&re_statusconfig, line, 0, NULL, 0)) {
	if (options[FIND_CONFIG]) set_config(package);
    } else if (regexec(&re_statusnotinst, line, 0, NULL, 0)) {
	/* The package state is neither installed, config-files nor
	 * not-installed.  It is also possible that get_pkg_info()
	 * wrongly detected the current line as a status line.
	 *
	 * Abort with error message "improper state" if we
	 * really parsed a status line.
	 */
	if (!regexec(&re_status, line, 0, NULL, 0))
	    exit_improperstate();
    }
}

/* Okay, this function does not really check the libraryness of a package,
 * but it checks wether the package should be checked (1) or not (0).
 */
unsigned int
is_library(pkg_info *package, int search_libdevel)
{
    if (options[ALL_PACKAGES])
	return 1;

    if (!package->section)
	return 0;

#ifndef IGNORE_ESSENTIAL
    if (package->essential)
	return 0;
#endif

    /* Mono libraries must be handeled especially since Mono puts its
     * development libraries in section libs.
     */
    if (!guess_chk(GUESS_MONO) && !strncmp(package->self.name, "libmono", 7))
	    return 0;

    if (!options[GUESS_ONLY]) {
	if (strstr(package->section, "/libs") || 
	    strstr(package->section, "/oldlibs") ||
	    (search_libdevel && strstr(package->section, "/libdevel")))
	    return 1;
    }

    if (!options[GUESS])
	return 0;

    /* See comments in init_pkg_regex(). */
    if (guess_chk(GUESS_DUMMY) && package->dummy)
	return 1;

    /* Avoid checking package name if we're only checking dummy,
     * which we get from the description line. 
     */
    if (guess_unique(GUESS_DUMMY))
	return 0;

    /* ^lib has been removed from re_namedev in deborphan 1.7.28, thus mark
     * this package as to be checked when re_namedev matches. When
     * GUESS_SECTION is set unique the regex always matches wrongly.
     */
    if (!guess_unique(GUESS_SECTION))
	if (!regexec(&re_namedev, package->self.name, 0, NULL, 0))
	    return 1;

    if (!guess_chk(GUESS_SECTION))
        return 0;

    /* Check whether the package begins with lib, but not if it ends in one of:
     * -dbg, -doc, -perl or -dev. This is what --guess-section does.
     */
    if (!strncmp(package->self.name, "lib", 3))
	if (regexec(&re_gnugrepv, package->self.name, 0, NULL, 0))
	    return 1;

    return 0;
}

void
get_pkg_section(const char *line, pkg_info * package)
{
    char *section;

    section = strchr(line, ':')+1;

    if (strchr(section, '/'))
	set_section(package, section, NULL);
    else
	set_section(package, section, "main");
}