/*
 * (C) Copyright 2016, NVIDIA CORPORATION.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, and/or sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
 * IBM AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Kyle Brenneman <kbrenneman@nvidia.com>
 */

#include "egldispatchstubs.h"
#include "g_egldispatchstubs.h"

#include <string.h>
#include <stdlib.h>

#include "eglcurrent.h"

static const __EGLapiExports *exports;

const int __EGL_DISPATCH_FUNC_COUNT = __EGL_DISPATCH_COUNT;
int __EGL_DISPATCH_FUNC_INDICES[__EGL_DISPATCH_COUNT + 1];

static int Compare(const void *l, const void *r)
{
    const char *s = *(const char **)r;
    return strcmp(l, s);
}

static int FindProcIndex(const char *name)
{
    const char **match = bsearch(name, __EGL_DISPATCH_FUNC_NAMES,
            __EGL_DISPATCH_COUNT, sizeof(const char *), Compare);

    if (match == NULL)
        return __EGL_DISPATCH_COUNT;

    return match - __EGL_DISPATCH_FUNC_NAMES;
}

void __eglInitDispatchStubs(const __EGLapiExports *exportsTable)
{
    int i;
    exports = exportsTable;
    for (i=0; i<__EGL_DISPATCH_FUNC_COUNT; i++) {
        __EGL_DISPATCH_FUNC_INDICES[i] = -1;
    }
}

void __eglSetDispatchIndex(const char *name, int dispatchIndex)
{
    int index = FindProcIndex(name);
    __EGL_DISPATCH_FUNC_INDICES[index] = dispatchIndex;
}

void *__eglDispatchFindDispatchFunction(const char *name)
{
    int index = FindProcIndex(name);
    return (void *) __EGL_DISPATCH_FUNCS[index];
}

static __eglMustCastToProperFunctionPointerType FetchVendorFunc(__EGLvendorInfo *vendor,
        int index, EGLint errorCode)
{
    __eglMustCastToProperFunctionPointerType func = NULL;

    if (vendor != NULL) {
        func = exports->fetchDispatchEntry(vendor, __EGL_DISPATCH_FUNC_INDICES[index]);
    }
    if (func == NULL) {
        if (errorCode != EGL_SUCCESS) {
            // Since we have no vendor, the follow-up eglGetError() call will
            // end up using the GLVND error code. Set it here.
            if (vendor == NULL) {
                exports->setEGLError(errorCode);
            }
            _eglError(errorCode, __EGL_DISPATCH_FUNC_NAMES[index]);
        }
        return NULL;
    }

    if (!exports->setLastVendor(vendor)) {
        // Don't bother trying to set an error code in libglvnd. If
        // setLastVendor failed, then setEGLError would also fail.
        _eglError(errorCode, __EGL_DISPATCH_FUNC_NAMES[index]);
        return NULL;
    }

    return func;
}

__eglMustCastToProperFunctionPointerType __eglDispatchFetchByCurrent(int index)
{
    __EGLvendorInfo *vendor;

    // Note: This is only used for the eglWait* functions. For those, if
    // there's no current context, then they're supposed to do nothing but
    // return success.
    exports->threadInit();
    vendor = exports->getCurrentVendor();
    return FetchVendorFunc(vendor, index, EGL_SUCCESS);
}

__eglMustCastToProperFunctionPointerType __eglDispatchFetchByDisplay(EGLDisplay dpy, int index)
{
    __EGLvendorInfo *vendor;

    exports->threadInit();
    vendor = exports->getVendorFromDisplay(dpy);
    return FetchVendorFunc(vendor, index, EGL_BAD_DISPLAY);
}

__eglMustCastToProperFunctionPointerType __eglDispatchFetchByDevice(EGLDeviceEXT dev, int index)
{
    __EGLvendorInfo *vendor;

    exports->threadInit();
    vendor = exports->getVendorFromDevice(dev);
    return FetchVendorFunc(vendor, index, EGL_BAD_DEVICE_EXT);
}