/*
 * Copyright (c) Advanced Micro Devices, Inc. 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 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 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.
 */

#include "amd_smi/impl/amd_smi_lib_loader.h"

#include <iostream>

#include "config/amd_smi_config.h"

namespace amd::smi {

std::vector<const char*> libdrm_amdgpu_sonames() {
  return {LIBDRM_AMDGPU_SONAME, "libdrm_amdgpu.so", "librocm_sysdeps_drm_amdgpu.so.1"};
}

AMDSmiLibraryLoader::AMDSmiLibraryLoader() : libHandler_(nullptr) {}

amdsmi_status_t AMDSmiLibraryLoader::load(const char* filename) {
  if (filename == nullptr) {
    return AMDSMI_STATUS_FAIL_LOAD_MODULE;
  }
  return load(std::vector<const char*>{filename});
}

amdsmi_status_t AMDSmiLibraryLoader::load(const std::vector<const char*>& filenames) {
  if (filenames.empty()) {
    return AMDSMI_STATUS_FAIL_LOAD_MODULE;
  }
  if (libHandler_ || library_loaded_) {
    unload();
  }

  std::lock_guard<std::mutex> guard(library_mutex_);
  std::string errors;
  for (const char* filename : filenames) {
    if (filename == nullptr) {
      continue;
    }
    // check if already loaded, return success if it is
    // dlopen(filename, RTLD_NOLOAD) == null only IFF library is not loaded
    void* isLibOpen = dlopen(filename, RTLD_NOLOAD);
    if (isLibOpen != nullptr) {
      // Keep the handle so load_symbol() resolves and unload() balances the
      // refcount that RTLD_NOLOAD incremented.
      libHandler_ = isLibOpen;
      library_loaded_ = true;
      return AMDSMI_STATUS_SUCCESS;
    }
    libHandler_ = dlopen(filename, RTLD_LAZY);
    if (libHandler_) {
      library_loaded_ = true;
      return AMDSMI_STATUS_SUCCESS;
    }
    errors += std::string(filename) + ": " + dlerror() + "; ";
  }
  std::cerr << "Fail to open library (tried " << filenames.size() << " candidate(s)): " << errors
            << std::endl;
  return AMDSMI_STATUS_FAIL_LOAD_MODULE;
}

amdsmi_status_t AMDSmiLibraryLoader::unload() {
  std::lock_guard<std::mutex> guard(library_mutex_);
  if (libHandler_) {
    dlclose(libHandler_);
    libHandler_ = nullptr;
    library_loaded_ = false;
  }
  return AMDSMI_STATUS_SUCCESS;
}

AMDSmiLibraryLoader::~AMDSmiLibraryLoader() { unload(); }

}  // namespace amd::smi
