/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying

   file LICENSE.rst or https://cmake.org/licensing for details.  */

#include "cmPlistParser.h"

#include <iterator>

#include <sstream>

#include <string>

#include <utility>

#include <vector>

#include <cm3p/json/value.h>

#include "cmJSONState.h"

#include "cmSystemTools.h"

#include "cmUVProcessChain.h"

#include "cmUVStream.h"

namespace {

std::vector<std::string> PlistToJsonCommand(std::string const& filename)

{

  static std::string const plutil = cmSystemTools::FindProgram("plutil");

  if (!plutil.empty()) {

    return { plutil, "-convert", "json", "-o", "-", filename };

  }

  static std::string const plistutil = cmSystemTools::FindProgram("plistutil");

  if (!plistutil.empty()) {

    return { plistutil, "-f", "json", "-o", "-", "-i", filename };

  }

  return {};

}

}

cm::optional<Json::Value> cmParsePlist(std::string const& filename)

{

  std::vector<std::string> command = PlistToJsonCommand(filename);

  if (command.empty()) {

    return cm::nullopt;

  }

  cmUVProcessChainBuilder builder;

  builder.AddCommand(std::move(command));

  builder.SetBuiltinStream(cmUVProcessChainBuilder::Stream_OUTPUT);

  auto chain = builder.Start();

  chain.Wait();

  auto const& status = chain.GetStatus(0);

  if (status.ExitStatus != 0) {

    return cm::nullopt;

  }

  // Buffer plutil's output into a seekable stream. cmJSONState must be able

  // peek at a leading BOM, which the process pipe behind cmUVIStream can't

  // handle.

  cmUVIStream outputStream(chain.OutputStream());

  std::string output{ std::istreambuf_iterator<char>(outputStream),

                      std::istreambuf_iterator<char>() };

  std::istringstream jsonStream(output);

  Json::Value value;

  cmJSONState parseState(jsonStream, &value, cmJSONState::StrictMode::Relaxed);

  if (!parseState.errors.empty()) {

    return cm::nullopt;

  }

  return cm::optional<Json::Value>(value);

}