/** \ingroup rpmbuild

 * \file build/parseChangelog.c

 *  Parse %changelog section from spec file.

 */

#include "system.h"

#include <rpm/header.h>

#include <rpm/rpmlog.h>

#include "build/rpmbuild_internal.h"

#include "debug.h"

#define SKIPSPACE(s) { while (*(s) && risspace(*(s))) (s)++; }

#define SKIPNONSPACE(s) { while (*(s) && !risspace(*(s))) (s)++; }

static void addChangelogEntry(Header h, time_t time, const char *name, const char *text)

{

    rpm_time_t mytime = time;	/* XXX convert to header representation */

    headerPutUint32(h, RPMTAG_CHANGELOGTIME, &mytime, 1);

    headerPutString(h, RPMTAG_CHANGELOGNAME, name);

    headerPutString(h, RPMTAG_CHANGELOGTEXT, text);

}

static int sameDate(const struct tm *ot, const struct tm *nt)

{

    return (ot->tm_year == nt->tm_year &&

	    ot->tm_mon == nt->tm_mon &&

	    ot->tm_mday == nt->tm_mday &&

	    ot->tm_wday == nt->tm_wday);

}

/**

 * Parse date string to seconds.

 * accepted date formats are "Mon Jun 6 2016" (original one)

 * and "Thu Oct  6 06:48:39 CEST 2016" (extended one)

 * @param datestr	date string (e.g. 'Wed Jan 1 1997')

 * @retval secs		secs since the unix epoch

 * @return 		0 on success, -1 on error

 */

static int dateToTimet(const char * datestr, time_t * secs, int * date_words)

{

    int rc = -1; /* assume failure */

    struct tm time, ntime;

    const char * const * idx;

    char *p, *pe, *q, *date, *tz;

    char tz_name[10];               /* name of timezone (if extended format is used) */

    static const char * const days[] =

	{ "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", NULL };

    static const char * const months[] =

	{ "Jan", "Feb", "Mar", "Apr", "May", "Jun",

 	  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec", NULL };

    static const char lengths[] =

	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

    memset(&time, 0, sizeof(time));

    memset(&ntime, 0, sizeof(ntime));

    date = xstrdup(datestr);

    pe = date;

    /* day of week */

    p = pe; SKIPSPACE(p);

    if (*p == '\0') goto exit;

    pe = p; SKIPNONSPACE(pe); if (*pe != '\0') *pe++ = '\0';

    for (idx = days; *idx && !rstreq(*idx, p); idx++)

	{};

    if (*idx == NULL) goto exit;

    time.tm_wday = idx - days;

    /* month */

    p = pe; SKIPSPACE(p);

    if (*p == '\0') goto exit;

    pe = p; SKIPNONSPACE(pe); if (*pe != '\0') *pe++ = '\0';

    for (idx = months; *idx && !rstreq(*idx, p); idx++)

	{};

    if (*idx == NULL) goto exit;

    time.tm_mon = idx - months;

    /* day */

    p = pe; SKIPSPACE(p);

    if (*p == '\0') goto exit;

    pe = p; SKIPNONSPACE(pe); if (*pe != '\0') *pe++ = '\0';

    time.tm_mday = strtol(p, &q, 10);

    if (!(q && *q == '\0')) goto exit;

    if (time.tm_mday < 0 || time.tm_mday > lengths[time.tm_mon]) goto exit;

    /* first part of year entry (original format) / time entry (extended format)*/

    p = pe;

    SKIPSPACE(p);

    if (*p == '\0')

	goto exit;

    /* in the original format here is year record (e.g. 1999),

     * in the extended one here is time stamp (e.g. 10:22:30).

     * Choose the format

     */

    if ((p[1]==':') || ((p[1]!='\0') && ((p[2]==':')))) {

	/* it can be extended format */

	*date_words = 6;

	/* second part of time entry */

	/* hours */

	time.tm_hour = strtol(p, &q, 10);

	if ( (time.tm_hour < 0) || (time.tm_hour > 23) )

	   goto exit;

	if (*q!=':')

	   goto exit;

	p = ++q;

	/* minutes */

	time.tm_min = strtol(p, &q, 10);

	if ( (time.tm_min < 0) || (time.tm_min > 59) )

	   goto exit;

	if (*q != ':')

	   goto exit;

	p = ++q;

	/* time - seconds */

	time.tm_sec = strtol(p, &q, 10);

	if ( (time.tm_sec < 0) || (time.tm_sec > 59) )

	   goto exit;

	p = q;

	/* time zone name */

	SKIPSPACE(p);

	if (*p == '\0')

	   goto exit;

	pe = p;

	SKIPNONSPACE(pe);

	if (*pe != '\0')

	   *pe++ = '\0';

	if (((int)(pe-p) + 1) > 9 )

	   goto exit;

	strncpy(tz_name, p, (int)(pe-p));

	tz_name[(int)(pe-p)] = '\0';

	/* first part of year entry */

	p = pe;

	SKIPSPACE(p);

	if (*p == '\0')

	   goto exit;

    } else {

	*date_words = 4;

	/* the original format */

	/* make this noon so the day is always right (as we make this UTC) */

	time.tm_hour = 12;

   }

    /* year - second part */

    pe = p;

    SKIPNONSPACE(pe);

    if (*pe != '\0')

	*pe = '\0';

    time.tm_year = strtol(p, &q, 10);

    if (!(q && *q == '\0')) goto exit;

    if (time.tm_year < 1990 || time.tm_year >= 3000) goto exit;

    time.tm_year -= 1900;

    /* change time zone and compute calendar time representation */

    tz = getenv("TZ");

    if (tz)

	tz = xstrdup(tz);

    if (*date_words == 6) {

	/* changelog date is in read time zone */

	setenv("TZ", tz_name, 1);

    } else {

	/* changelog date is always in UTC */

	setenv("TZ", "UTC", 1);

    }

    ntime = time; /* struct assignment */

    *secs = mktime(&ntime);

    unsetenv("TZ");

    if (tz) {

	setenv("TZ", tz, 1);

	free(tz);

    }

    if (*secs == -1) goto exit;

    /* XXX Turn this into a hard error in a release or two */

    if (!sameDate(&time, &ntime))

	rpmlog(RPMLOG_WARNING, _("bogus date in %%changelog: %s\n"), datestr);

    rc = 0;

exit:

    free(date);

    return rc;

}

/**

 * Add %changelog section to header.

 * @param h		header

 * @param sb		changelog strings

 * @return		RPMRC_OK on success

 */

static rpmRC addChangelog(Header h, ARGV_const_t sb)

{

    rpmRC rc = RPMRC_FAIL; /* assume failure */

    char *s, *sp;

    int i;

    time_t time;

    time_t lastTime = 0;

    time_t trimtime = rpmExpandNumeric("%{?_changelog_trimtime}");

    char *date, *name, *text, *next;

    int date_words;      /* number of words in date string */

    s = sp = argvJoin(sb, "");

    /* skip space */

    SKIPSPACE(s);

    while (*s != '\0') {

	if (*s != '*') {

	    rpmlog(RPMLOG_ERR, _("%%changelog entries must start with *\n"));

	    goto exit;

	}

	/* find end of line */

	date = s;

	while (*s && *s != '\n') s++;

	if (! *s) {

	    rpmlog(RPMLOG_ERR, _("incomplete %%changelog entry\n"));

	    goto exit;

	}

	*s = '\0';

	text = s + 1;

	/* 4 fields of date */

	date++;

	s = date;

	SKIPSPACE(date);

	if (dateToTimet(date, &time, &date_words)) {

	    rpmlog(RPMLOG_ERR, _("bad date in %%changelog: %s\n"), date);

	    goto exit;

	}

	if (lastTime && lastTime < time) {

	    rpmlog(RPMLOG_ERR,

		     _("%%changelog not in descending chronological order\n"));

	    goto exit;

	}

	for (i = 0; i < date_words; i++) {

	    SKIPSPACE(s);

	    SKIPNONSPACE(s);

	}

	lastTime = time;

	/* skip space to the name */

	SKIPSPACE(s);

	if (! *s) {

	    rpmlog(RPMLOG_ERR, _("missing name in %%changelog\n"));

	    goto exit;

	}

	/* name */

	name = s;

	while (*s != '\0') s++;

	while (s > name && risspace(*s)) {

	    *s-- = '\0';

	}

	if (s == name) {

	    rpmlog(RPMLOG_ERR, _("missing name in %%changelog\n"));

	    goto exit;

	}

	/* text */

	SKIPSPACE(text);

	if (! *text) {

	    rpmlog(RPMLOG_ERR, _("no description in %%changelog\n"));

	    goto exit;

	}

	/* find the next leading '*' (or eos) */

	s = text;

	do {

	   s++;

	} while (*s && (*(s-1) != '\n' || *s != '*'));

	next = s;

	s--;

	/* backup to end of description */

	while ((s > text) && risspace(*s)) {

	    *s-- = '\0';

	}

	if ( !trimtime || time >= trimtime ) {

	    addChangelogEntry(h, time, name, text);

	} else break;

	s = next;

    }

    rc = RPMRC_OK;

exit:

    free(sp);

    return rc;

}

int parseChangelog(rpmSpec spec)

{

    int nextPart, rc, res = PART_ERROR;

    ARGV_t sb = NULL;

    if (headerIsEntry(spec->packages->header, RPMTAG_CHANGELOGTIME)) {

	rpmlog(RPMLOG_ERR, _("line %d: second %%changelog\n"), spec->lineNum);

	goto exit;

    }

    /* There are no options to %changelog */

    if ((rc = readLine(spec, STRIP_COMMENTS)) > 0) {

	res = PART_NONE;

	goto exit;

    } else if (rc < 0) {

	goto exit;

    }

    while (! (nextPart = isPart(spec->line))) {

	argvAdd(&sb, spec->line);

	if ((rc = readLine(spec, STRIP_COMMENTS)) > 0) {

	    nextPart = PART_NONE;

	    break;

	} else if (rc < 0) {

	    goto exit;

	}

    }

    if (sb && addChangelog(spec->packages->header, sb)) {

	goto exit;

    }

    res = nextPart;

exit:

    argvFree(sb);

    return res;

}