/*
 * Copyright © 2011 Intel Corporation
 *
 * 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
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * 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
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS 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:
 *    Benjamin Franzke <benjaminfranzke@googlemail.com>
 */

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <limits.h>

#include <sys/types.h>
#include <unistd.h>
#include <dlfcn.h>

#include <GL/gl.h> /* dri_interface needs GL types */
#include <GL/internal/dri_interface.h>

#include "gbm_driint.h"

#include "gbmint.h"

static __DRIimage *
dri_lookup_egl_image(__DRIscreen *screen, void *image, void *data)
{
   struct gbm_dri_device *dri = data;

   if (dri->lookup_image == NULL)
      return NULL;

   return dri->lookup_image(screen, image, dri->lookup_user_data);
}

const __DRIuseInvalidateExtension use_invalidate = {
   { __DRI_USE_INVALIDATE, 1 }
};

const __DRIimageLookupExtension image_lookup_extension = {
   { __DRI_IMAGE_LOOKUP, 1 },
   dri_lookup_egl_image
};

struct dri_extension_match {
   const char *name;
   int version;
   int offset;
};

static struct dri_extension_match dri_core_extensions[] = {
   { __DRI_IMAGE, 1, offsetof(struct gbm_dri_device, image) },
   { NULL, 0, 0 }
};

static struct dri_extension_match gbm_dri_device_extensions[] = {
   { __DRI_CORE, 1, offsetof(struct gbm_dri_device, core) },
   { __DRI_DRI2, 1, offsetof(struct gbm_dri_device, dri2) },
   { NULL, 0, 0 }
};

static int
dri_bind_extensions(struct gbm_dri_device *dri,
                    struct dri_extension_match *matches,
                    const __DRIextension **extensions)
{
   int i, j, ret = 0;
   void *field;

   for (i = 0; extensions[i]; i++) {
      for (j = 0; matches[j].name; j++) {
         if (strcmp(extensions[i]->name, matches[j].name) == 0 &&
             extensions[i]->version >= matches[j].version) {
            field = ((char *) dri + matches[j].offset);
            *(const __DRIextension **) field = extensions[i];
         }
      }
   }

   for (j = 0; matches[j].name; j++) {
      field = ((char *) dri + matches[j].offset);
      if (*(const __DRIextension **) field == NULL) {
         ret = -1;
      }
   }

   return ret;
}

static int
dri_load_driver(struct gbm_dri_device *dri)
{
   const __DRIextension **extensions;
   char path[PATH_MAX], *search_paths, *p, *next, *end;

   search_paths = NULL;
   if (geteuid() == getuid()) {
      /* don't allow setuid apps to use GBM_DRIVERS_PATH */
      search_paths = getenv("GBM_DRIVERS_PATH");
   }
   if (search_paths == NULL)
      search_paths = DEFAULT_DRIVER_DIR;

   dri->driver = NULL;
   end = search_paths + strlen(search_paths);
   for (p = search_paths; p < end && dri->driver == NULL; p = next + 1) {
      int len;
      next = strchr(p, ':');
      if (next == NULL)
         next = end;

      len = next - p;
#if GLX_USE_TLS
      snprintf(path, sizeof path,
               "%.*s/tls/%s_dri.so", len, p, dri->base.driver_name);
      dri->driver = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
#endif
      if (dri->driver == NULL) {
         snprintf(path, sizeof path,
                  "%.*s/%s_dri.so", len, p, dri->base.driver_name);
         dri->driver = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
         if (dri->driver == NULL)
            fprintf(stderr, "failed to open %s: %s\n", path, dlerror());
      }
   }

   if (dri->driver == NULL) {
      fprintf(stderr, "gbm: failed to open any driver (search paths %s)",
              search_paths);
      return -1;
   }

   extensions = dlsym(dri->driver, __DRI_DRIVER_EXTENSIONS);
   if (extensions == NULL) {
      fprintf(stderr, "gbm: driver exports no extensions (%s)", dlerror());
      dlclose(dri->driver);
      return -1;
   }


   if (dri_bind_extensions(dri, gbm_dri_device_extensions, extensions) < 0) {
      dlclose(dri->driver);
      fprintf(stderr, "failed to bind extensions\n");
      return -1;
   }

   return 0;
}

static int
dri_screen_create(struct gbm_dri_device *dri)
{
   const __DRIextension **extensions;
   int ret = 0;

   dri->base.driver_name = dri_fd_get_driver_name(dri->base.base.fd);
   if (dri->base.driver_name == NULL)
      return -1;

   ret = dri_load_driver(dri);
   if (ret) {
      fprintf(stderr, "failed to load driver: %s\n", dri->base.driver_name);
      return ret;
   };

   dri->extensions[0] = &image_lookup_extension.base;
   dri->extensions[1] = &use_invalidate.base;
   dri->extensions[2] = NULL;

   if (dri->dri2 == NULL)
      return -1;

   dri->screen = dri->dri2->createNewScreen(0, dri->base.base.fd,
                                            dri->extensions,
                                            &dri->driver_configs, dri);

   extensions = dri->core->getExtensions(dri->screen);
   if (dri_bind_extensions(dri, dri_core_extensions, extensions) < 0) {
      ret = -1;
      goto free_screen;
   }

   dri->lookup_image = NULL;
   dri->lookup_user_data = NULL;

   return 0;

free_screen:
   dri->core->destroyScreen(dri->screen);

   return ret;
}

static int
gbm_dri_is_format_supported(struct gbm_device *gbm,
                            enum gbm_bo_format format,
                            uint32_t usage)
{
   switch (format) {
   case GBM_BO_FORMAT_XRGB8888:
      break;
   case GBM_BO_FORMAT_ARGB8888:
      if (usage & GBM_BO_USE_SCANOUT)
         return 0;
      break;
   default:
      return 0;
   }

   if (usage & GBM_BO_USE_CURSOR_64X64 &&
       usage & GBM_BO_USE_RENDERING)
      return 0;

   return 1;
}

static void
gbm_dri_bo_destroy(struct gbm_bo *_bo)
{
   struct gbm_dri_device *dri = gbm_dri_device(_bo->gbm);
   struct gbm_dri_bo *bo = gbm_dri_bo(_bo);

   dri->image->destroyImage(bo->image);
   free(bo);
}

static struct gbm_bo *
gbm_dri_bo_create_from_egl_image(struct gbm_device *gbm,
                                 void *egl_dpy, void *egl_img,
                                 uint32_t width, uint32_t height,
                                 uint32_t usage)
{
   struct gbm_dri_device *dri = gbm_dri_device(gbm);
   struct gbm_dri_bo *bo;

   (void) egl_dpy;

   if (dri->lookup_image == NULL)
      return NULL;

   bo = calloc(1, sizeof *bo);
   if (bo == NULL)
      return NULL;

   bo->base.base.gbm = gbm;
   bo->base.base.width = width;
   bo->base.base.height = height;

   __DRIimage *tmp = dri->lookup_image(dri->screen, egl_img,
                                       dri->lookup_user_data);

   bo->image = dri->image->dupImage(tmp, bo);
   if (bo->image == NULL)
      return NULL;
   
   dri->image->queryImage(bo->image, __DRI_IMAGE_ATTRIB_HANDLE,
                          &bo->base.base.handle.s32);
   dri->image->queryImage(bo->image, __DRI_IMAGE_ATTRIB_STRIDE,
                          (int *) &bo->base.base.pitch);

   return &bo->base.base;
}

static struct gbm_bo *
gbm_dri_bo_create(struct gbm_device *gbm,
                  uint32_t width, uint32_t height,
                  enum gbm_bo_format format, uint32_t usage)
{
   struct gbm_dri_device *dri = gbm_dri_device(gbm);
   struct gbm_dri_bo *bo;
   int dri_format;
   unsigned dri_use = 0;

   bo = calloc(1, sizeof *bo);
   if (bo == NULL)
      return NULL;

   bo->base.base.gbm = gbm;
   bo->base.base.width = width;
   bo->base.base.height = height;

   switch (format) {
   case GBM_BO_FORMAT_XRGB8888:
      dri_format = __DRI_IMAGE_FORMAT_XRGB8888;
      break;
   case GBM_BO_FORMAT_ARGB8888:
      dri_format = __DRI_IMAGE_FORMAT_ARGB8888;
      break;
   default:
      return NULL;
   }

   if (usage & GBM_BO_USE_SCANOUT)
      dri_use |= __DRI_IMAGE_USE_SCANOUT;
   if (usage & GBM_BO_USE_CURSOR_64X64)
      dri_use |= __DRI_IMAGE_USE_CURSOR;

   bo->image =
      dri->image->createImage(dri->screen,
                              width, height,
                              dri_format, dri_use,
                              bo);
   if (bo->image == NULL)
      return NULL;

   dri->image->queryImage(bo->image, __DRI_IMAGE_ATTRIB_HANDLE,
                          &bo->base.base.handle.s32);
   dri->image->queryImage(bo->image, __DRI_IMAGE_ATTRIB_STRIDE,
                          (int *) &bo->base.base.pitch);

   return &bo->base.base;
}

static void
dri_destroy(struct gbm_device *gbm)
{
   struct gbm_dri_device *dri = gbm_dri_device(gbm);

   dri->core->destroyScreen(dri->screen);
   free(dri->driver_configs);
   dlclose(dri->driver);
   free(dri->base.driver_name);

   free(dri);
}

static struct gbm_device *
dri_device_create(int fd)
{
   struct gbm_dri_device *dri;
   int ret;

   dri = calloc(1, sizeof *dri);

   dri->base.base.fd = fd;
   dri->base.base.bo_create = gbm_dri_bo_create;
   dri->base.base.bo_create_from_egl_image = gbm_dri_bo_create_from_egl_image;
   dri->base.base.is_format_supported = gbm_dri_is_format_supported;
   dri->base.base.bo_destroy = gbm_dri_bo_destroy;
   dri->base.base.destroy = dri_destroy;

   dri->base.type = GBM_DRM_DRIVER_TYPE_DRI;
   dri->base.base.name = "drm";

   ret = dri_screen_create(dri);
   if (ret) {
      free(dri);
      return NULL;
   }

   return &dri->base.base;
}

struct gbm_backend gbm_dri_backend = {
   .backend_name = "dri",
   .create_device = dri_device_create,
};