// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// This file declares util functions for setup project.

#include "chrome/installer/setup/setup_util.h"

#include "base/file_util.h"
#include "base/logging.h"
#include "base/string_util.h"
#include "chrome/installer/util/installer_state.h"
#include "chrome/installer/util/util_constants.h"
#include "courgette/courgette.h"
#include "third_party/bspatch/mbspatch.h"

namespace installer {

int ApplyDiffPatch(const FilePath& src,
                   const FilePath& patch,
                   const FilePath& dest,
                   const InstallerState* installer_state) {
  VLOG(1) << "Applying patch " << patch.value() << " to file " << src.value()
          << " and generating file " << dest.value();

  if (installer_state != NULL)
    installer_state->UpdateStage(installer::ENSEMBLE_PATCHING);

  // Try Courgette first.  Courgette checks the patch file first and fails
  // quickly if the patch file does not have a valid Courgette header.
  courgette::Status patch_status =
      courgette::ApplyEnsemblePatch(src.value().c_str(),
                                    patch.value().c_str(),
                                    dest.value().c_str());
  if (patch_status == courgette::C_OK)
    return 0;

  VLOG(1) << "Failed to apply patch " << patch.value() << " using courgette.";

  if (installer_state != NULL)
    installer_state->UpdateStage(installer::BINARY_PATCHING);

  return ApplyBinaryPatch(src.value().c_str(), patch.value().c_str(),
                          dest.value().c_str());
}

Version* GetMaxVersionFromArchiveDir(const FilePath& chrome_path) {
  VLOG(1) << "Looking for Chrome version folder under " << chrome_path.value();
  Version* version = NULL;
  file_util::FileEnumerator version_enum(chrome_path, false,
      file_util::FileEnumerator::DIRECTORIES);
  // TODO(tommi): The version directory really should match the version of
  // setup.exe.  To begin with, we should at least DCHECK that that's true.

  scoped_ptr<Version> max_version(Version::GetVersionFromString("0.0.0.0"));
  bool version_found = false;

  while (!version_enum.Next().empty()) {
    file_util::FileEnumerator::FindInfo find_data = {0};
    version_enum.GetFindInfo(&find_data);
    VLOG(1) << "directory found: " << find_data.cFileName;

    scoped_ptr<Version> found_version(
        Version::GetVersionFromString(WideToASCII(find_data.cFileName)));
    if (found_version.get() != NULL &&
        found_version->CompareTo(*max_version.get()) > 0) {
      max_version.reset(found_version.release());
      version_found = true;
    }
  }

  return (version_found ? max_version.release() : NULL);
}

// Open |path| with minimal access to obtain information about it, returning
// true and populating |handle| on success.
// static
bool ProgramCompare::OpenForInfo(const FilePath& path,
                                 base::win::ScopedHandle* handle) {
  DCHECK(handle);
  handle->Set(base::CreatePlatformFile(path, base::PLATFORM_FILE_OPEN, NULL,
                                       NULL));
  return handle->IsValid();
}

// Populate |info| for |handle|, returning true on success.
// static
bool ProgramCompare::GetInfo(const base::win::ScopedHandle& handle,
                             BY_HANDLE_FILE_INFORMATION* info) {
  DCHECK(handle.IsValid());
  return GetFileInformationByHandle(
      const_cast<base::win::ScopedHandle&>(handle), info) != 0;
}

ProgramCompare::ProgramCompare(const FilePath& path_to_match)
    : path_to_match_(path_to_match),
      file_handle_(base::kInvalidPlatformFileValue),
      file_info_() {
  DCHECK(!path_to_match_.empty());
  if (!OpenForInfo(path_to_match_, &file_handle_)) {
    PLOG(WARNING) << "Failed opening " << path_to_match_.value()
                  << "; falling back to path string comparisons.";
  } else if (!GetInfo(file_handle_, &file_info_)) {
    PLOG(WARNING) << "Failed getting information for "
                  << path_to_match_.value()
                  << "; falling back to path string comparisons.";
    file_handle_.Close();
  }
}

ProgramCompare::~ProgramCompare() {
}

bool ProgramCompare::Evaluate(const std::wstring& value) const {
  // Suss out the exe portion of the value, which is expected to be a command
  // line kinda (or exactly) like:
  // "c:\foo\bar\chrome.exe" -- "%1"
  FilePath program(CommandLine::FromString(value).GetProgram());
  if (program.empty()) {
    LOG(WARNING) << "Failed to parse an executable name from command line: \""
                 << value << "\"";
    return false;
  }

  // Try the simple thing first: do the paths happen to match?
  if (FilePath::CompareEqualIgnoreCase(path_to_match_.value(), program.value()))
    return true;

  // If the paths don't match and we couldn't open the expected file, we've done
  // our best.
  if (!file_handle_.IsValid())
    return false;

  // Open the program and see if it references the expected file.
  base::win::ScopedHandle handle;
  BY_HANDLE_FILE_INFORMATION info = {};

  return (OpenForInfo(program, &handle) &&
          GetInfo(handle, &info) &&
          info.dwVolumeSerialNumber == file_info_.dwVolumeSerialNumber &&
          info.nFileIndexHigh == file_info_.nFileIndexHigh &&
          info.nFileIndexLow == file_info_.nFileIndexLow);
}

}  // namespace installer