/*
 * Debugging functions
 *
 * Copyright 2000 Alexandre Julliard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include "config.h"
#include "wine/port.h"

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#include "wine/debug.h"
#include "ntdll_misc.h"

WINE_DECLARE_DEBUG_CHANNEL(pid);
WINE_DECLARE_DEBUG_CHANNEL(timestamp);

static BOOL init_done;
static struct debug_info initial_info;  /* debug info for initial thread */
static unsigned char default_flags = (1 << __WINE_DBCL_ERR) | (1 << __WINE_DBCL_FIXME);
static int nb_debug_options = -1;
static int options_size;
static struct __wine_debug_channel *debug_options;

static const char * const debug_classes[] = { "fixme", "err", "warn", "trace" };

/* get the debug info pointer for the current thread */
static inline struct debug_info *get_info(void)
{
    if (!init_done) return &initial_info;
    return ntdll_get_thread_data()->debug_info;
}

/* add a string to the output buffer */
static int append_output( struct debug_info *info, const char *str, size_t len )
{
    if (len >= sizeof(info->output) - info->out_pos)
    {
       fprintf( stderr, "wine_dbg_output: debugstr buffer overflow (contents: '%s')\n", info->output );
       info->out_pos = 0;
       abort();
    }
    memcpy( info->output + info->out_pos, str, len );
    info->out_pos += len;
    return len;
}

/* add a new debug option at the end of the option list */
static void add_option( const char *name, unsigned char set, unsigned char clear )
{
    int min = 0, max = nb_debug_options - 1, pos, res;

    if (!name[0])  /* "all" option */
    {
        default_flags = (default_flags & ~clear) | set;
        return;
    }
    if (strlen(name) >= sizeof(debug_options[0].name)) return;

    while (min <= max)
    {
        pos = (min + max) / 2;
        res = strcmp( name, debug_options[pos].name );
        if (!res)
        {
            debug_options[pos].flags = (debug_options[pos].flags & ~clear) | set;
            return;
        }
        if (res < 0) max = pos - 1;
        else min = pos + 1;
    }
    if (nb_debug_options >= options_size)
    {
        options_size = max( options_size * 2, 16 );
        debug_options = realloc( debug_options, options_size * sizeof(debug_options[0]) );
    }

    pos = min;
    if (pos < nb_debug_options) memmove( &debug_options[pos + 1], &debug_options[pos],
                                         (nb_debug_options - pos) * sizeof(debug_options[0]) );
    strcpy( debug_options[pos].name, name );
    debug_options[pos].flags = (default_flags & ~clear) | set;
    nb_debug_options++;
}

/* parse a set of debugging option specifications and add them to the option list */
static void parse_options( const char *str )
{
    char *opt, *next, *options;
    unsigned int i;

    if (!(options = strdup(str))) return;
    for (opt = options; opt; opt = next)
    {
        const char *p;
        unsigned char set = 0, clear = 0;

        if ((next = strchr( opt, ',' ))) *next++ = 0;

        p = opt + strcspn( opt, "+-" );
        if (!p[0]) p = opt;  /* assume it's a debug channel name */

        if (p > opt)
        {
            for (i = 0; i < ARRAY_SIZE(debug_classes); i++)
            {
                int len = strlen(debug_classes[i]);
                if (len != (p - opt)) continue;
                if (!memcmp( opt, debug_classes[i], len ))  /* found it */
                {
                    if (*p == '+') set |= 1 << i;
                    else clear |= 1 << i;
                    break;
                }
            }
            if (i == ARRAY_SIZE(debug_classes)) /* bad class name, skip it */
                continue;
        }
        else
        {
            if (*p == '-') clear = ~0;
            else set = ~0;
        }
        if (*p == '+' || *p == '-') p++;
        if (!p[0]) continue;

        if (!strcmp( p, "all" ))
            default_flags = (default_flags & ~clear) | set;
        else
            add_option( p, set, clear );
    }
    free( options );
}

/* print the usage message */
static void debug_usage(void)
{
    static const char usage[] =
        "Syntax of the WINEDEBUG variable:\n"
        "  WINEDEBUG=[class]+xxx,[class]-yyy,...\n\n"
        "Example: WINEDEBUG=+relay,warn-heap\n"
        "    turns on relay traces, disable heap warnings\n"
        "Available message classes: err, warn, fixme, trace\n";
    write( 2, usage, sizeof(usage) - 1 );
    exit(1);
}

/* initialize all options at startup */
static void init_options(void)
{
    char *wine_debug = getenv("WINEDEBUG");
    struct stat st1, st2;

    nb_debug_options = 0;

    /* check for stderr pointing to /dev/null */
    if (!fstat( 2, &st1 ) && S_ISCHR(st1.st_mode) &&
        !stat( "/dev/null", &st2 ) && S_ISCHR(st2.st_mode) &&
        st1.st_rdev == st2.st_rdev)
    {
        default_flags = 0;
        return;
    }
    if (!wine_debug) return;
    if (!strcmp( wine_debug, "help" )) debug_usage();
    parse_options( wine_debug );
}

/***********************************************************************
 *		__wine_dbg_get_channel_flags  (NTDLL.@)
 *
 * Get the flags to use for a given channel, possibly setting them too in case of lazy init
 */
unsigned char __cdecl __wine_dbg_get_channel_flags( struct __wine_debug_channel *channel )
{
    int min, max, pos, res;

    if (nb_debug_options == -1) init_options();

    min = 0;
    max = nb_debug_options - 1;
    while (min <= max)
    {
        pos = (min + max) / 2;
        res = strcmp( channel->name, debug_options[pos].name );
        if (!res) return debug_options[pos].flags;
        if (res < 0) max = pos - 1;
        else min = pos + 1;
    }
    /* no option for this channel */
    if (channel->flags & (1 << __WINE_DBCL_INIT)) channel->flags = default_flags;
    return default_flags;
}

/***********************************************************************
 *		__wine_dbg_strdup  (NTDLL.@)
 */
const char * __cdecl __wine_dbg_strdup( const char *str )
{
    struct debug_info *info = get_info();
    unsigned int pos = info->str_pos;
    size_t n = strlen( str ) + 1;

    assert( n <= sizeof(info->strings) );
    if (pos + n > sizeof(info->strings)) pos = 0;
    info->str_pos = pos + n;
    return memcpy( info->strings + pos, str, n );
}

/***********************************************************************
 *		__wine_dbg_output  (NTDLL.@)
 */
int __cdecl __wine_dbg_output( const char *str )
{
    struct debug_info *info = get_info();
    const char *end = strrchr( str, '\n' );
    int ret = 0;

    if (end)
    {
        ret += append_output( info, str, end + 1 - str );
        write( 2, info->output, info->out_pos );
        info->out_pos = 0;
        str = end + 1;
    }
    if (*str) ret += append_output( info, str, strlen( str ));
    return ret;
}

/***********************************************************************
 *		__wine_dbg_header  (NTDLL.@)
 */
int __cdecl __wine_dbg_header( enum __wine_debug_class cls, struct __wine_debug_channel *channel,
                               const char *function )
{
    static const char * const classes[] = { "fixme", "err", "warn", "trace" };
    struct debug_info *info = get_info();
    char buffer[200], *pos = buffer;

    if (!(__wine_dbg_get_channel_flags( channel ) & (1 << cls))) return -1;

    /* only print header if we are at the beginning of the line */
    if (info->out_pos) return 0;

    if (init_done)
    {
        if (TRACE_ON(timestamp))
        {
            ULONG ticks = NtGetTickCount();
            pos += sprintf( pos, "%3u.%03u:", ticks / 1000, ticks % 1000 );
        }
        if (TRACE_ON(pid)) pos += sprintf( pos, "%04x:", GetCurrentProcessId() );
        pos += sprintf( pos, "%04x:", GetCurrentThreadId() );
    }
    if (function && cls < ARRAY_SIZE( classes ))
        snprintf( pos, sizeof(buffer) - (pos - buffer), "%s:%s:%s ",
                  classes[cls], channel->name, function );

    return append_output( info, buffer, strlen( buffer ));
}

/***********************************************************************
 *		debug_init
 */
void debug_init(void)
{
    setbuf( stdout, NULL );
    setbuf( stderr, NULL );
    ntdll_get_thread_data()->debug_info = &initial_info;
    init_done = TRUE;
}