/*
 * Copyright 2011-2013 Blender Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifdef WITH_OPENCL

#  include "device/opencl/device_opencl.h"
#  include "device/device.h"
#  include "device/device_intern.h"

#  include "util/util_foreach.h"
#  include "util/util_logging.h"
#  include "util/util_set.h"
#  include "util/util_string.h"

CCL_NAMESPACE_BEGIN

Device *device_opencl_create(DeviceInfo &info, Stats &stats, Profiler &profiler, bool background)
{
  return opencl_create_split_device(info, stats, profiler, background);
}

bool device_opencl_init()
{
  static bool initialized = false;
  static bool result = false;

  if (initialized)
    return result;

  initialized = true;

  if (OpenCLInfo::device_type() != 0) {
    int clew_result = clewInit();
    if (clew_result == CLEW_SUCCESS) {
      VLOG(1) << "CLEW initialization succeeded.";
      result = true;
    }
    else {
      VLOG(1) << "CLEW initialization failed: "
              << ((clew_result == CLEW_ERROR_ATEXIT_FAILED) ? "Error setting up atexit() handler" :
                                                              "Error opening the library");
    }
  }
  else {
    VLOG(1) << "Skip initializing CLEW, platform is force disabled.";
    result = false;
  }

  return result;
}

static cl_int device_opencl_get_num_platforms_safe(cl_uint *num_platforms)
{
#  ifdef _WIN32
  __try {
    return clGetPlatformIDs(0, NULL, num_platforms);
  }
  __except (EXCEPTION_EXECUTE_HANDLER) {
    /* Ignore crashes inside the OpenCL driver and hope we can
     * survive even with corrupted OpenCL installs. */
    fprintf(stderr, "Cycles OpenCL: driver crashed, continuing without OpenCL.\n");
  }

  *num_platforms = 0;
  return CL_DEVICE_NOT_FOUND;
#  else
  return clGetPlatformIDs(0, NULL, num_platforms);
#  endif
}

void device_opencl_info(vector<DeviceInfo> &devices)
{
  cl_uint num_platforms = 0;
  device_opencl_get_num_platforms_safe(&num_platforms);
  if (num_platforms == 0) {
    return;
  }

  vector<OpenCLPlatformDevice> usable_devices;
  OpenCLInfo::get_usable_devices(&usable_devices);
  /* Devices are numbered consecutively across platforms. */
  int num_devices = 0;
  set<string> unique_ids;
  foreach (OpenCLPlatformDevice &platform_device, usable_devices) {
    /* Compute unique ID for persistent user preferences. */
    const string &platform_name = platform_device.platform_name;
    const string &device_name = platform_device.device_name;
    string hardware_id = platform_device.hardware_id;
    if (hardware_id == "") {
      hardware_id = string_printf("ID_%d", num_devices);
    }
    string id = string("OPENCL_") + platform_name + "_" + device_name + "_" + hardware_id;

    /* Hardware ID might not be unique, add device number in that case. */
    if (unique_ids.find(id) != unique_ids.end()) {
      id += string_printf("_ID_%d", num_devices);
    }
    unique_ids.insert(id);

    /* Create DeviceInfo. */
    DeviceInfo info;
    info.type = DEVICE_OPENCL;
    info.description = string_remove_trademark(string(device_name));
    info.num = num_devices;
    /* We don't know if it's used for display, but assume it is. */
    info.display_device = true;
    info.use_split_kernel = true;
    info.has_volume_decoupled = false;
    info.has_adaptive_stop_per_sample = false;
    info.id = id;

    /* Check OpenCL extensions */
    info.has_half_images = platform_device.device_extensions.find("cl_khr_fp16") != string::npos;

    devices.push_back(info);
    num_devices++;
  }
}

string device_opencl_capabilities()
{
  if (OpenCLInfo::device_type() == 0) {
    return "All OpenCL devices are forced to be OFF";
  }
  string result = "";
  string error_msg = ""; /* Only used by opencl_assert(), but in the future
                          * it could also be nicely reported to the console.
                          */
  cl_uint num_platforms = 0;
  opencl_assert(device_opencl_get_num_platforms_safe(&num_platforms));
  if (num_platforms == 0) {
    return "No OpenCL platforms found\n";
  }
  result += string_printf("Number of platforms: %u\n", num_platforms);

  vector<cl_platform_id> platform_ids;
  platform_ids.resize(num_platforms);
  opencl_assert(clGetPlatformIDs(num_platforms, &platform_ids[0], NULL));

  typedef char cl_string[1024];

#  define APPEND_INFO(func, id, name, what, type) \
    do { \
      type data; \
      memset(&data, 0, sizeof(data)); \
      opencl_assert(func(id, what, sizeof(data), &data, NULL)); \
      result += string_printf("%s: %s\n", name, to_string(data).c_str()); \
    } while (false)
#  define APPEND_STRING_EXTENSION_INFO(func, id, name, what) \
    do { \
      char data[1024] = "\0"; \
      size_t length = 0; \
      if (func(id, what, sizeof(data), &data, &length) == CL_SUCCESS) { \
        if (length != 0 && data[0] != '\0') { \
          result += string_printf("%s: %s\n", name, data); \
        } \
      } \
    } while (false)
#  define APPEND_PLATFORM_INFO(id, name, what, type) \
    APPEND_INFO(clGetPlatformInfo, id, "\tPlatform " name, what, type)
#  define APPEND_DEVICE_INFO(id, name, what, type) \
    APPEND_INFO(clGetDeviceInfo, id, "\t\t\tDevice " name, what, type)
#  define APPEND_DEVICE_STRING_EXTENSION_INFO(id, name, what) \
    APPEND_STRING_EXTENSION_INFO(clGetDeviceInfo, id, "\t\t\tDevice " name, what)

  vector<cl_device_id> device_ids;
  for (cl_uint platform = 0; platform < num_platforms; ++platform) {
    cl_platform_id platform_id = platform_ids[platform];

    result += string_printf("Platform #%u\n", platform);

    APPEND_PLATFORM_INFO(platform_id, "Name", CL_PLATFORM_NAME, cl_string);
    APPEND_PLATFORM_INFO(platform_id, "Vendor", CL_PLATFORM_VENDOR, cl_string);
    APPEND_PLATFORM_INFO(platform_id, "Version", CL_PLATFORM_VERSION, cl_string);
    APPEND_PLATFORM_INFO(platform_id, "Profile", CL_PLATFORM_PROFILE, cl_string);
    APPEND_PLATFORM_INFO(platform_id, "Extensions", CL_PLATFORM_EXTENSIONS, cl_string);

    cl_uint num_devices = 0;
    opencl_assert(
        clGetDeviceIDs(platform_ids[platform], CL_DEVICE_TYPE_ALL, 0, NULL, &num_devices));
    result += string_printf("\tNumber of devices: %u\n", num_devices);

    device_ids.resize(num_devices);
    opencl_assert(clGetDeviceIDs(
        platform_ids[platform], CL_DEVICE_TYPE_ALL, num_devices, &device_ids[0], NULL));
    for (cl_uint device = 0; device < num_devices; ++device) {
      cl_device_id device_id = device_ids[device];

      result += string_printf("\t\tDevice: #%u\n", device);

      APPEND_DEVICE_INFO(device_id, "Name", CL_DEVICE_NAME, cl_string);
      APPEND_DEVICE_STRING_EXTENSION_INFO(device_id, "Board Name", CL_DEVICE_BOARD_NAME_AMD);
      APPEND_DEVICE_INFO(device_id, "Vendor", CL_DEVICE_VENDOR, cl_string);
      APPEND_DEVICE_INFO(device_id, "OpenCL C Version", CL_DEVICE_OPENCL_C_VERSION, cl_string);
      APPEND_DEVICE_INFO(device_id, "Profile", CL_DEVICE_PROFILE, cl_string);
      APPEND_DEVICE_INFO(device_id, "Version", CL_DEVICE_VERSION, cl_string);
      APPEND_DEVICE_INFO(device_id, "Extensions", CL_DEVICE_EXTENSIONS, cl_string);
      APPEND_DEVICE_INFO(
          device_id, "Max clock frequency (MHz)", CL_DEVICE_MAX_CLOCK_FREQUENCY, cl_uint);
      APPEND_DEVICE_INFO(device_id, "Max compute units", CL_DEVICE_MAX_COMPUTE_UNITS, cl_uint);
      APPEND_DEVICE_INFO(device_id, "Max work group size", CL_DEVICE_MAX_WORK_GROUP_SIZE, size_t);
    }
  }

#  undef APPEND_STRING_INFO
#  undef APPEND_PLATFORM_STRING_INFO
#  undef APPEND_DEVICE_STRING_INFO

  return result;
}

CCL_NAMESPACE_END

#endif /* WITH_OPENCL */