/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

/*!
 * \file file_utils.cc
 */
#include "file_utils.h"

#include <dmlc/json.h>
#include <dmlc/memory_io.h>
#include <tvm/runtime/logging.h>
#include <tvm/runtime/registry.h>
#include <tvm/runtime/serializer.h>

#include <fstream>
#include <unordered_map>
#include <vector>

namespace tvm {
namespace runtime {

void FunctionInfo::Save(dmlc::JSONWriter* writer) const {
  std::vector<std::string> sarg_types(arg_types.size());
  for (size_t i = 0; i < arg_types.size(); ++i) {
    sarg_types[i] = DLDataType2String(arg_types[i]);
  }
  writer->BeginObject();
  writer->WriteObjectKeyValue("name", name);
  writer->WriteObjectKeyValue("arg_types", sarg_types);
  writer->WriteObjectKeyValue("launch_param_tags", launch_param_tags);
  writer->EndObject();
}

void FunctionInfo::Load(dmlc::JSONReader* reader) {
  dmlc::JSONObjectReadHelper helper;
  std::vector<std::string> sarg_types;
  helper.DeclareField("name", &name);
  helper.DeclareField("arg_types", &sarg_types);
  helper.DeclareOptionalField("launch_param_tags", &launch_param_tags);
  helper.DeclareOptionalField("thread_axis_tags",
                              &launch_param_tags);  // for backward compatibility
  helper.ReadAllFields(reader);
  arg_types.resize(sarg_types.size());
  for (size_t i = 0; i < arg_types.size(); ++i) {
    arg_types[i] = String2DLDataType(sarg_types[i]);
  }
}

void FunctionInfo::Save(dmlc::Stream* writer) const {
  writer->Write(name);
  writer->Write(arg_types);
  writer->Write(launch_param_tags);
}

bool FunctionInfo::Load(dmlc::Stream* reader) {
  if (!reader->Read(&name)) return false;
  if (!reader->Read(&arg_types)) return false;
  if (!reader->Read(&launch_param_tags)) return false;
  return true;
}

std::string GetFileFormat(const std::string& file_name, const std::string& format) {
  std::string fmt = format;
  if (fmt.length() == 0) {
    size_t pos = file_name.find_last_of(".");
    if (pos != std::string::npos) {
      return file_name.substr(pos + 1, file_name.length() - pos - 1);
    } else {
      return "";
    }
  } else {
    return format;
  }
}

std::string GetCacheDir() {
  char* env_cache_dir;
  if ((env_cache_dir = getenv("TVM_CACHE_DIR"))) return env_cache_dir;
  if ((env_cache_dir = getenv("XDG_CACHE_HOME"))) {
    return std::string(env_cache_dir) + "/tvm";
  }
  if ((env_cache_dir = getenv("HOME"))) {
    return std::string(env_cache_dir) + "/.cache/tvm";
  }
  return ".";
}

std::string GetFileBasename(const std::string& file_name) {
  size_t last_slash = file_name.find_last_of("/");
  if (last_slash == std::string::npos) return file_name;
  return file_name.substr(last_slash + 1);
}

std::string GetMetaFilePath(const std::string& file_name) {
  size_t pos = file_name.find_last_of(".");
  if (pos != std::string::npos) {
    return file_name.substr(0, pos) + ".tvm_meta.json";
  } else {
    return file_name + ".tvm_meta.json";
  }
}

void LoadBinaryFromFile(const std::string& file_name, std::string* data) {
  std::ifstream fs(file_name, std::ios::in | std::ios::binary);
  ICHECK(!fs.fail()) << "Cannot open " << file_name;
  // get its size:
  fs.seekg(0, std::ios::end);
  size_t size = static_cast<size_t>(fs.tellg());
  fs.seekg(0, std::ios::beg);
  data->resize(size);
  fs.read(&(*data)[0], size);
}

void SaveBinaryToFile(const std::string& file_name, const std::string& data) {
  std::ofstream fs(file_name, std::ios::out | std::ios::binary);
  ICHECK(!fs.fail()) << "Cannot open " << file_name;
  fs.write(&data[0], data.length());
}

void SaveMetaDataToFile(const std::string& file_name,
                        const std::unordered_map<std::string, FunctionInfo>& fmap) {
  std::string version = "0.1.0";
  std::ofstream fs(file_name.c_str());
  ICHECK(!fs.fail()) << "Cannot open file " << file_name;
  dmlc::JSONWriter writer(&fs);
  writer.BeginObject();
  writer.WriteObjectKeyValue("tvm_version", version);
  writer.WriteObjectKeyValue("func_info", fmap);
  writer.EndObject();
  fs.close();
}

void LoadMetaDataFromFile(const std::string& file_name,
                          std::unordered_map<std::string, FunctionInfo>* fmap) {
  std::ifstream fs(file_name.c_str());
  ICHECK(!fs.fail()) << "Cannot open file " << file_name;
  std::string version;
  dmlc::JSONReader reader(&fs);
  dmlc::JSONObjectReadHelper helper;
  helper.DeclareField("tvm_version", &version);
  helper.DeclareField("func_info", fmap);
  helper.ReadAllFields(&reader);
  fs.close();
}

void RemoveFile(const std::string& file_name) { std::remove(file_name.c_str()); }

Map<String, NDArray> LoadParams(const std::string& param_blob) {
  dmlc::MemoryStringStream strm(const_cast<std::string*>(&param_blob));
  return LoadParams(&strm);
}
Map<String, NDArray> LoadParams(dmlc::Stream* strm) {
  Map<String, NDArray> params;
  uint64_t header, reserved;
  ICHECK(strm->Read(&header)) << "Invalid parameters file format";
  ICHECK(header == kTVMNDArrayListMagic) << "Invalid parameters file format";
  ICHECK(strm->Read(&reserved)) << "Invalid parameters file format";

  std::vector<std::string> names;
  ICHECK(strm->Read(&names)) << "Invalid parameters file format";
  uint64_t sz;
  strm->Read(&sz);
  size_t size = static_cast<size_t>(sz);
  ICHECK(size == names.size()) << "Invalid parameters file format";
  for (size_t i = 0; i < size; ++i) {
    // The data_entry is allocated on device, NDArray.load always load the array into CPU.
    NDArray temp;
    temp.Load(strm);
    params.Set(names[i], temp);
  }
  return params;
}

void SaveParams(dmlc::Stream* strm, const Map<String, NDArray>& params) {
  std::vector<std::string> names;
  std::vector<const DLTensor*> arrays;
  for (auto& p : params) {
    names.push_back(p.first);
    arrays.push_back(p.second.operator->());
  }

  uint64_t header = kTVMNDArrayListMagic, reserved = 0;
  strm->Write(header);
  strm->Write(reserved);
  strm->Write(names);
  {
    uint64_t sz = static_cast<uint64_t>(arrays.size());
    strm->Write(sz);
    for (size_t i = 0; i < sz; ++i) {
      tvm::runtime::SaveDLTensor(strm, arrays[i]);
    }
  }
}

std::string SaveParams(const Map<String, NDArray>& params) {
  std::string bytes;
  dmlc::MemoryStringStream strm(&bytes);
  dmlc::Stream* fo = &strm;
  SaveParams(fo, params);
  return bytes;
}

TVM_REGISTER_GLOBAL("runtime.SaveParams").set_body_typed([](const Map<String, NDArray>& params) {
  std::string s = ::tvm::runtime::SaveParams(params);
  // copy return array so it is owned by the ret value
  TVMRetValue rv;
  rv = TVMByteArray{s.data(), s.size()};
  return rv;
});
TVM_REGISTER_GLOBAL("runtime.LoadParams").set_body_typed([](const String& s) {
  return ::tvm::runtime::LoadParams(s);
});

}  // namespace runtime
}  // namespace tvm