// Copyright (c) 2009 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.

#include "chrome/browser/extensions/crx_installer.h"

#include "app/l10n_util.h"
#include "base/file_util.h"
#include "base/scoped_temp_dir.h"
#include "base/string_util.h"
#include "base/task.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/extensions/extension_file_util.h"
#include "chrome/common/extensions/extension_error_reporter.h"
#include "grit/chromium_strings.h"

namespace {
  // Helper function to delete files. This is used to avoid ugly casts which
  // would be necessary with PostMessage since file_util::Delete is overloaded.
  static void DeleteFileHelper(const FilePath& path, bool recursive) {
    file_util::Delete(path, recursive);
  }
}

void CrxInstaller::Start(const FilePath& crx_path,
                         const FilePath& install_directory,
                         Extension::Location install_source,
                         const std::string& expected_id,
                         bool delete_crx,
                         MessageLoop* file_loop,
                         ExtensionsService* frontend,
                         CrxInstallerClient* client) {
  // Note: We don't keep a reference because this object manages its own
  // lifetime.
  new CrxInstaller(crx_path, install_directory, install_source, expected_id,
                   delete_crx, file_loop, frontend, client);
}

CrxInstaller::CrxInstaller(const FilePath& crx_path,
                           const FilePath& install_directory,
                           Extension::Location install_source,
                           const std::string& expected_id,
                           bool delete_crx,
                           MessageLoop* file_loop,
                           ExtensionsService* frontend,
                           CrxInstallerClient* client)
    : crx_path_(crx_path),
      install_directory_(install_directory),
      install_source_(install_source),
      expected_id_(expected_id),
      delete_crx_(delete_crx),
      file_loop_(file_loop),
      ui_loop_(MessageLoop::current()),
      frontend_(frontend),
      client_(client) {

  extensions_enabled_ = frontend_->extensions_enabled();

  unpacker_ = new SandboxedExtensionUnpacker(
      crx_path, g_browser_process->resource_dispatcher_host(), this);

  file_loop->PostTask(FROM_HERE, NewRunnableMethod(unpacker_,
      &SandboxedExtensionUnpacker::Start));
}

CrxInstaller::~CrxInstaller() {
  // Delete the temp directory and crx file as necessary. Note that the
  // destructor might be called on any thread, so we post a task to the file
  // thread to make sure the delete happens there.
  if (!temp_dir_.value().empty()) {
    file_loop_->PostTask(FROM_HERE, NewRunnableFunction(&DeleteFileHelper,
        temp_dir_, true));  // recursive delete
  }

  if (delete_crx_) {
    file_loop_->PostTask(FROM_HERE, NewRunnableFunction(&DeleteFileHelper,
        crx_path_, false));  // non-recursive delete
  }
}

void CrxInstaller::OnUnpackFailure(const std::string& error_message) {
  DCHECK(MessageLoop::current() == file_loop_);
  ReportFailureFromFileThread(error_message);
}

void CrxInstaller::OnUnpackSuccess(const FilePath& temp_dir,
                                   const FilePath& extension_dir,
                                   Extension* extension) {
  DCHECK(MessageLoop::current() == file_loop_);

  // Note: We take ownership of |extension| and |temp_dir|.
  extension_.reset(extension);
  temp_dir_ = temp_dir;

  // The unpack dir we don't have to delete explicity since it is a child of
  // the temp dir.
  unpacked_extension_root_ = extension_dir;
  DCHECK(file_util::ContainsPath(temp_dir_, unpacked_extension_root_));

  // Determine whether to allow installation. We always allow themes and
  // external installs.
  if (!extensions_enabled_ && !extension->IsTheme() &&
      !Extension::IsExternalLocation(install_source_)) {
    ReportFailureFromFileThread("Extensions are not enabled.");
    return;
  }

  // Make sure the expected id matches.
  // TODO(aa): Also support expected version?
  if (!expected_id_.empty() && expected_id_ != extension->id()) {
    ReportFailureFromFileThread(StringPrintf(
        "ID in new extension manifest (%s) does not match expected id (%s)",
        extension->id().c_str(),
        expected_id_.c_str()));
    return;
  }

  if (client_.get()) {
    ui_loop_->PostTask(FROM_HERE, NewRunnableMethod(this,
        &CrxInstaller::ConfirmInstall));
  } else {
    CompleteInstall();
  }
}

void CrxInstaller::ConfirmInstall() {
  if (!client_->ConfirmInstall(extension_.get())) {
    // We're done. Since we don't post any more tasks to ourselves, our ref
    // count should go to zero and we die. The destructor will clean up the temp
    // dir.
    return;
  }

  file_loop_->PostTask(FROM_HERE, NewRunnableMethod(this,
      &CrxInstaller::CompleteInstall));
}

void CrxInstaller::CompleteInstall() {
  DCHECK(MessageLoop::current() == file_loop_);

  FilePath version_dir;
  Extension::InstallType install_type = Extension::INSTALL_ERROR;
  std::string error_msg;
  if (!extension_file_util::InstallExtension(unpacked_extension_root_,
                                             install_directory_,
                                             extension_->id(),
                                             extension_->VersionString(),
                                             &version_dir,
                                             &install_type, &error_msg)) {
    ReportFailureFromFileThread(error_msg);
    return;
  }

  if (install_type == Extension::DOWNGRADE) {
    ReportFailureFromFileThread("Attempted to downgrade extension.");
    return;
  }

  extension_->set_path(version_dir);
  extension_->set_location(install_source_);

  if (install_type == Extension::REINSTALL) {
    // We use this as a signal to switch themes.
    ReportOverinstallFromFileThread();
    return;
  }

  ReportSuccessFromFileThread();
}

void CrxInstaller::ReportFailureFromFileThread(const std::string& error) {
  DCHECK(MessageLoop::current() == file_loop_);
  ui_loop_->PostTask(FROM_HERE, NewRunnableMethod(this,
      &CrxInstaller::ReportFailureFromUIThread, error));
}

void CrxInstaller::ReportFailureFromUIThread(const std::string& error) {
  DCHECK(MessageLoop::current() == ui_loop_);

  // This isn't really necessary, it is only used because unit tests expect to
  // see errors get reported via this interface.
  //
  // TODO(aa): Need to go through unit tests and clean them up too, probably get
  // rid of this line.
  ExtensionErrorReporter::GetInstance()->ReportError(error, false);  // quiet

  if (client_)
    client_->OnInstallFailure(error);
}

void CrxInstaller::ReportOverinstallFromFileThread() {
  DCHECK(MessageLoop::current() == file_loop_);
  ui_loop_->PostTask(FROM_HERE, NewRunnableMethod(this,
      &CrxInstaller::ReportOverinstallFromUIThread));
}

void CrxInstaller::ReportOverinstallFromUIThread() {
  DCHECK(MessageLoop::current() == ui_loop_);

  if (client_.get())
    client_->OnOverinstallAttempted(extension_.get());

  frontend_->OnExtensionOverinstallAttempted(extension_->id());
}

void CrxInstaller::ReportSuccessFromFileThread() {
  DCHECK(MessageLoop::current() == file_loop_);
  ui_loop_->PostTask(FROM_HERE, NewRunnableMethod(this,
      &CrxInstaller::ReportSuccessFromUIThread));
}

void CrxInstaller::ReportSuccessFromUIThread() {
  DCHECK(MessageLoop::current() == ui_loop_);

  // If there is a client, tell the client about installation.
  if (client_.get())
    client_->OnInstallSuccess(extension_.get());

  // Tell the frontend about the installation and hand off ownership of
  // extension_ to it.
  frontend_->OnExtensionInstalled(extension_.release());

  // We're done. We don't post any more tasks to ourselves so we are deleted
  // soon.
}