/*
  util.c

  $Id: util.c 110 2000-05-19 15:12:45Z bears $
*/

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

#if TIME_WITH_SYS_TIME
#include <sys/time.h>
#include <time.h>
#else
#if HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <time.h>
#endif
#endif

#include "util.h"
#include <errno.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include "configfile.h"
#include "log.h"
#include "wildmat.h"
#include "portable.h"

#if defined(UTIL_TEST)
#define	Log_err	printf
#define	Log_dbg	printf
#endif

static const char *
nextWhiteSpace( const char *p )
{
    while ( *p && ! isspace( *p ) )
        ++p;
    return p;
}

static const char *
nextNonWhiteSpace( const char *p )
{
    while ( *p && isspace( *p ) )
        ++p;
    return p;
}

const char *
Utl_restOfLn( const char *line, unsigned int token )
{
    unsigned int i;
    const char *p;

    p = line;
    for ( i = 0; i < token; ++i )
    {
        p = nextNonWhiteSpace( p );
        p = nextWhiteSpace( p );
    }
    p = nextNonWhiteSpace( p );
    return p;
}

const char *
Utl_getLn( Str result, const char *pos )
{
    int len = 0;
    const char *p = pos;

    if ( ! p )
        return NULL;
    while ( *p != '\n' )
    {
        if ( *p == '\0' )
        {
            if ( len > 0 )
                Log_err( "Line not terminated by newline: '%s'", pos );
            return NULL;
        }
        *(result++) = *(p++);
        ++len;
        if ( len >= MAXCHAR - 1 )
        {
            *result = '\0';
            Log_err( "Utl_getLn: line too long: %s", result );
            return ++p;
        }
    }
    *result = '\0';
    return ++p;

}

const char *
Utl_ungetLn( const char *str, const char *p )
{
    if ( str == p )
        return FALSE;
    --p;
    if ( *p != '\n' )
    {
        Log_dbg( "Utl_ungetLn: not at beginning of line" );
        return NULL;
    }
    --p;
    while ( TRUE )
    {
        if ( p == str )
            return p;
        if ( *p == '\n' )
            return p + 1;
        --p;
    }
}

const char *
Utl_getHeaderLn( Str result, const char *p )
{
    const char * res = Utl_getLn( result, p );

    /* Look for followon line if this isn't a blank line. */
    if ( res != NULL && !isspace( result[ 0 ] ) )
	for(;;)
	{
	    Str nextLine;
	    const char *here;

	    here = res;
	    nextLine[ 0 ] = '\0';
	    res = Utl_getLn( nextLine, res );
	    if ( res == NULL || nextLine[ 0 ] == '\0'
		 || !isspace( nextLine[ 0 ] ) )
	    {
		res = here;
		break;
	    }
	    else
	    {
		Utl_catStr( result, "\n" );
		Utl_catStr( result, nextLine );
	    }
	}

    return res;
}

void
Utl_toLower( Str line )
{
    char *p;

    p = line;
    while ( *p )
    {
        *p = tolower( *p );
        ++p;
    }
}

char *
Utl_stripWhiteSpace( char *line )
{
    char *p;

    while ( isspace( *line ) )
        ++line;
    p = line + strlen( line ) - 1;
    while ( isspace( *p ) )
    {
        *p = '\0';
        --p;
    }
    return line;
}

void
Utl_stripComment( char *line )
{
    for ( ; *line != '\0'; line++ )
	if ( *line =='#' )
	{
	    *line = '\0';
	    break;
	}
}

void
Utl_cpyStr( Str dst, const char *src )
{
    dst[ 0 ] = '\0';
    strncat( dst, src, MAXCHAR );
}

void
Utl_cpyStrN( Str dst, const char *src, int n )
{
    if ( n > MAXCHAR )
    	n = MAXCHAR;
    dst[ 0 ] = '\0';
    strncat( dst, src, (size_t)n );
}

void
Utl_catStr( Str dst, const char *src )
{
    strncat( dst, src, MAXCHAR - strlen( dst ) );
}

void
Utl_catStrN( Str dst, const char *src, int n )
{
    size_t un;

    ASSERT( n >= 0 );
    un = (size_t)n;
    if ( un > MAXCHAR - strlen( dst ) )
    	 un = MAXCHAR - strlen( dst );
    strncat( dst, src, un );
}

void
Utl_stamp( Str file )
{
    FILE *f;
    time_t t;

    time( &t );
    if ( ! ( f = fopen( file, "w" ) ) )
    {
        Log_err( "Could not open %s for writing (%s)",
                 file, strerror( errno ) );
        return;
    }
    fprintf( f, "%lu\n", t );
    fclose( f );
}

Bool
Utl_getStamp( time_t *result, Str file )
{
    FILE *f;

    if ( ! ( f = fopen( file, "r" ) ) )
        return FALSE;
    if ( fscanf( f, "%lu", result ) != 1 )
    {
        Log_err( "File %s corrupted", file );
        fclose( f );
        return FALSE;
    }
    fclose( f );
    return TRUE;
}

static const char *DOTW[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri",
			      "Sat", NULL };
static const char *MON[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul",
			     "Aug", "Sep", "Oct", "Nov", "Dec", NULL };

void
Utl_newsDate( time_t t, Str res )
{    
    struct tm local, localAsGmt;
    time_t tlocalAsGmt;
    int tzdiff, hoffset, moffset;

    local = *localtime( &t );
    memset( &localAsGmt, 0, sizeof( localAsGmt ) );
    localAsGmt.tm_sec = local.tm_sec;
    localAsGmt.tm_min = local.tm_min;
    localAsGmt.tm_hour = local.tm_hour;
    localAsGmt.tm_mday = local.tm_mday;
    localAsGmt.tm_mon = local.tm_mon;
    localAsGmt.tm_year = local.tm_year;
    tlocalAsGmt = mktime( &localAsGmt );
    tzdiff = (int) ( ( (long) difftime( tlocalAsGmt, t ) ) / 60 );
    hoffset = tzdiff / 60;
    moffset = tzdiff % 60;
    if ( moffset < 0 ) moffset = -moffset;

    sprintf( res, "%s, %d %s %4d %02d:%02d:%02d %+03d%02d",
	     DOTW[local.tm_wday], local.tm_mday,
	     MON[local.tm_mon], local.tm_year + 1900,
	     local.tm_hour, local.tm_min, local.tm_sec,
	     hoffset, moffset );
}

time_t
Utl_parseNewsDate( const char *s )
{
    struct tm tm;
    int wday, tzoffset, hoffset, moffset;
    char *p;
    time_t res;

    memset( &tm, 0, sizeof( tm ) );
    wday = -1;
    
    s = nextNonWhiteSpace( s );

    /* Is this the day number, or a weekday? */
    if ( ! isdigit( *s ) )
    {
	if ( strlen( s ) < 4 )
	    return (time_t) -1;
	
	for ( wday = 0; DOTW[ wday ] != NULL; wday++ )
	    if ( strncmp( DOTW[ wday ], s, 3 ) == 0 )
		break;

	if( DOTW[ wday ] == NULL || s[3] != ',' )
	    return (time_t) -1;

	s += 4;
    }
    
    /* Get the day number */
    tm.tm_mday = (int) strtol( s, &p, 10 );
    if ( p == s )
	return (time_t) -1;
    s = p;

    /* Look for month name */
    s = nextNonWhiteSpace( s );
    if ( strlen( s ) < 4 )
	return (time_t) -1;
    for ( tm.tm_mon = 0; MON[ tm.tm_mon ] != NULL; tm.tm_mon++ )
	if ( strncmp( MON[ tm.tm_mon ], s, 3 ) == 0 )
	    break;

    if ( MON[ tm.tm_mon ] == NULL )
	return (time_t) -1;
    s += 3;

    /* Year next */
    tm.tm_year = (int) strtol( s, &p, 10 );
    if ( p == s || ( tm.tm_year >= 100 && tm.tm_year < 1900  ) )
	return (time_t) -1;
    if ( tm.tm_year >= 1900 )
	tm.tm_year -= 1900;
    s = p;  

    /* Hours */
    tm.tm_hour = (int) strtol( s, &p, 10 );
    if ( p == s || *p != ':' )
	return (time_t) -1;
    s = ++p;

    /* Minutes */
    tm.tm_min = (int) strtol( s, &p, 10 );
    if ( p == s || ( *p != ':' && *p != ' ' ) )
	return (time_t) -1;
    s = p;

    /* Seconds */
    if ( *s == ':' )
    {
	s++;
	tm.tm_sec = (int) strtol( s, &p, 10 );
	if ( p == s )
	    return (time_t) -1;
	s = p;
    }

    /* GMT/UT or timezone offset */
    tzoffset = 0;
    while ( isspace( *s ) )
	s++;
    if ( strncmp( s, "GMT", 3) == 0 )
	s += 3;
    else if ( strncmp( s, "UT", 2 ) == 0 )
	s += 2;
    else
    {
	tzoffset = (int) strtol( s, &p, 10 );
	s = p;
    }

    /* Check for following junk */
    if ( *s != '\0' && ! isspace( *s ) )
	return (time_t) -1;

    res = mktime( &tm );
    if ( res == (time_t) -1 )
	return res;
    
    if ( wday >= 0 && wday != tm.tm_wday )
	return (time_t) -1;

    moffset = tzoffset % 100;
    hoffset = tzoffset / 100;
    res = res - ( ( hoffset * 60 + moffset ) * 60 );
    return res;
}

void
Utl_allocAndCpy( char **dst, const char *src )
{
    int len = strlen( src );
    if ( ! ( *dst = malloc( (size_t)len + 1 ) ) )
    {
        Log_err( "Cannot allocate string with length %lu", strlen( src ) );
        exit( EXIT_FAILURE );
    }
    memcpy( *dst, src, (size_t)len + 1 );
}

#if defined(UTIL_TEST)

/* Test code borrowed from wildmat.c. Yep, still uses gets(). */
extern char	*gets();

int
main()
{
    Str line;
    time_t t;

    printf( "Util date tester.  Enter date to test.\n" );    
    printf( "A blank line exits the program.\n" );

    for ( ; ; )
    {
	printf( "\nEnter date:  " );
	(void) fflush( stdout );
	if ( gets( line ) == NULL || line[0] == '\0' )
	    break;

	t = Utl_parseNewsDate( line );
	if ( t == (time_t) -1 )
	    printf( "Date parse failed\n" );
	else
	{
	    Utl_newsDate( t, line );
	    printf( "Utl_newsDate -> '%s'\nctime() -> '%s'\n",
		    line, ctime( &t ) );
	}
    }

    exit(0);
    /* NOTREACHED */
}
#endif