/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2010 Sam Lantinga

    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

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

#include "SDL_hints.h"

/* Assuming there aren't many hints set and they aren't being queried in

   critical performance paths, we'll just use a linked list here.

 */

typedef struct SDL_Hint {

    char *name;

    char *value;

    SDL_HintPriority priority;

    struct SDL_Hint *next;

} SDL_Hint;

static SDL_Hint *SDL_hints;

SDL_bool

SDL_SetHint(const char *name, const char *value, SDL_HintPriority priority)

{

    const char *env;

    SDL_Hint *prev, *hint;

    if (!name || !value) {

        return SDL_FALSE;

    }

    env = SDL_getenv(name);

    if (env && priority < SDL_HINT_OVERRIDE) {

        return SDL_FALSE;

    }

    prev = NULL;

    for (hint = SDL_hints; hint; prev = hint, hint = hint->next) {

        if (SDL_strcmp(name, hint->name) == 0) {

            if (priority < hint->priority) {

                return SDL_FALSE;

            }

            if (SDL_strcmp(hint->value, value) != 0) {

                SDL_free(hint->value);

                hint->value = SDL_strdup(value);

            }

            hint->priority = priority;

            return SDL_TRUE;

        }

    }

    /* Couldn't find the hint, add a new one */

    hint = (SDL_Hint *)SDL_malloc(sizeof(*hint));

    if (!hint) {

        return SDL_FALSE;

    }

    hint->name = SDL_strdup(name);

    hint->value = SDL_strdup(value);

    hint->priority = priority;

    hint->next = SDL_hints;

    SDL_hints = hint;

    return SDL_TRUE;

}

const char *

SDL_GetHint(const char *name)

{

    const char *env;

    SDL_Hint *hint;

    env = SDL_getenv(name);

    for (hint = SDL_hints; hint; hint = hint->next) {

        if (SDL_strcmp(name, hint->name) == 0) {

            if (!env || hint->priority == SDL_HINT_OVERRIDE) {

                return hint->value;

            }

            break;

        }

    }

    return env;

}

void SDL_ClearHints()

{

    SDL_Hint *hint;

    while (SDL_hints) {

        hint = SDL_hints;

        SDL_hints = hint->next;

        SDL_free(hint->name);

        SDL_free(hint->value);

        SDL_free(hint);

    }

}

/* vi: set ts=4 sw=4 expandtab: */