/**
 * MojoSetup; a portable, flexible installation application.
 *
 * Please see the file LICENSE.txt in the source's root directory.
 *
 *  This file written by Ryan C. Gordon.
 *
     Copyright (c) 2006-2010 Ryan C. Gordon and others.

   This software is provided 'as-is', without any express or implied warranty.
   In no event will the authors be held liable for any damages arising from
   the use of this software.

   Permission is granted to anyone to use this software for any purpose,
   including commercial applications, and to alter it and redistribute it
   freely, subject to the following restrictions:

   1. The origin of this software must not be misrepresented; you must not
   claim that you wrote the original software. If you use this software in a
   product, an acknowledgment in the product documentation would be
   appreciated but is not required.

   2. Altered source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.

   3. This notice may not be removed or altered from any source distribution.

       Ryan C. Gordon <icculus@icculus.org>
 *
 */

#include "gui.h"
#include "platform.h"
#include "fileio.h"

typedef struct S_PLUGINLIST
{
    void *lib;
    const MojoGui *gui;
    MojoGuiPluginPriority priority;
    struct S_PLUGINLIST *next;
} PluginList;

const MojoGui *GGui = NULL;
static PluginList *pluginDetails = NULL;

static const MojoGuiEntryPoint staticGui[] =
{
#if GUI_STATIC_LINK_STDIO
    MojoGuiPlugin_stdio,
#endif
#if GUI_STATIC_LINK_COCOA
    MojoGuiPlugin_cocoa,
#endif
#if GUI_STATIC_LINK_GTKPLUS2
    MojoGuiPlugin_gtkplus2,
#endif
#if GUI_STATIC_LINK_WWW
    MojoGuiPlugin_www,
#endif
#if GUI_STATIC_LINK_NCURSES
    MojoGuiPlugin_ncurses,
#endif
    NULL
};


static MojoGuiPluginPriority calcGuiPriority(const MojoGui *gui)
{
    MojoGuiPluginPriority retval;

    retval = gui->priority(MojoPlatform_istty());

    // If the plugin isn't saying "don't try me at all" then see if the
    //  user explicitly wants this one.
    if (retval != MOJOGUI_PRIORITY_NEVER_TRY)
    {
        static const char *envr = NULL;
        if (envr == NULL)
            envr = cmdlinestr("ui", "MOJOSETUP_UI", NULL);
        if ((envr != NULL) && (strcasecmp(envr, gui->name()) == 0))
            retval = MOJOGUI_PRIORITY_USER_REQUESTED;
    } // if

    return retval;
} // calcGuiPriority


static PluginList *initGuiPluginsByPriority(PluginList *plugins)
{
    MojoGuiPluginPriority p;
    for (p = MOJOGUI_PRIORITY_USER_REQUESTED; p < MOJOGUI_PRIORITY_TOTAL; p++)
    {
        PluginList *i;
        for (i = plugins->next; i != NULL; i = i->next)
        {
            if ( (i->priority == p) && (i->gui->init()) )
            {
                logInfo("Selected '%0' UI.", i->gui->name());
                return i;
            } // if
        } // for
    } // for

    return NULL;
} // initGuiPluginsByPriority


static void deleteGuiPlugin(PluginList *plugin)
{
    if (plugin != NULL)
    {
        if (plugin->gui)
            plugin->gui->deinit();
        if (plugin->lib)
            MojoPlatform_dlclose(plugin->lib);
        free(plugin);
    } // if
} // deleteGuiPlugin


static boolean tryGuiPlugin(PluginList *plugins, MojoGuiEntryPoint entry)
{
    boolean retval = false;
    const MojoGui *gui = entry(MOJOGUI_INTERFACE_REVISION, &GEntryPoints);
    if (gui != NULL)
    {
        PluginList *plug = xmalloc(sizeof (PluginList));
        plug->lib = NULL;
        plug->gui = gui;
        plug->priority = calcGuiPriority(gui);
        plug->next = plugins->next;
        plugins->next = plug;
        retval = true;
    } // if

    return retval;
} // tryGuiPlugin


static void loadStaticGuiPlugins(PluginList *plugins)
{
    int i;
    for (i = 0; staticGui[i] != NULL; i++)
        tryGuiPlugin(plugins, staticGui[i]);
} // loadStaticGuiPlugins


static boolean loadDynamicGuiPlugin(PluginList *plugins, MojoArchive *ar)
{
    boolean rc = false;
    void *lib = NULL;
    MojoInput *io = ar->openCurrentEntry(ar);
    if (io != NULL)
    {
        const uint32 imglen = (uint32) io->length(io);
        uint8 *img = (uint8 *) xmalloc(imglen);
        const uint32 br = (uint32) io->read(io, img, imglen);
        io->close(io);
        if (br == imglen)
            lib = MojoPlatform_dlopen(img, imglen);
        free(img);
    } // if

    if (lib != NULL)
    {
        void *addr = MojoPlatform_dlsym(lib, MOJOGUI_ENTRY_POINT_STR);
        MojoGuiEntryPoint entry = (MojoGuiEntryPoint) addr;
        if (entry != NULL)
        {
            if ((rc = tryGuiPlugin(plugins, entry)) == false)
                MojoPlatform_dlclose(lib);
        } // if
    } // if

    return rc;
} // loadDynamicGuiPlugin


static void loadDynamicGuiPlugins(PluginList *plugins)
{
    if (GBaseArchive->enumerate(GBaseArchive))
    {
        const MojoArchiveEntry *entinfo;
        while ((entinfo = GBaseArchive->enumNext(GBaseArchive)) != NULL)
        {
            if (entinfo->type != MOJOARCHIVE_ENTRY_FILE)
                continue;

            if (strncmp(entinfo->filename, "guis/", 5) != 0)
                continue;

            loadDynamicGuiPlugin(plugins, GBaseArchive);
        } // while
    } // if
} // loadDynamicGuiPlugins


const MojoGui *MojoGui_initGuiPlugin(void)
{
    PluginList plugins;
    PluginList *i = NULL;

    if (pluginDetails != NULL)
        return pluginDetails->gui;

    memset(&plugins, '\0', sizeof (plugins));
    assert(GGui == NULL);

    loadDynamicGuiPlugins(&plugins);
    loadStaticGuiPlugins(&plugins);

    pluginDetails = initGuiPluginsByPriority(&plugins);

    // cleanout unused plugins...
    i = plugins.next;
    while (i != NULL)
    {
        PluginList *next = i->next;
        if (i != pluginDetails)
            deleteGuiPlugin(i);
        i = next;
    } // while

    if (pluginDetails != NULL)
    {
        GGui = pluginDetails->gui;
        pluginDetails->next = NULL;
    } // if

    return GGui;
} // MojoGui_findGuiPlugin


void MojoGui_deinitGuiPlugin(void)
{
    GGui = NULL;
    deleteGuiPlugin(pluginDetails);
    pluginDetails = NULL;
} // MojoGui_deinitGuiPlugin

// end of gui.c ...