// Copyright (c) 2012 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/chromeos/file_manager/open_util.h"

#include "base/bind.h"
#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/strings/utf_string_conversions.h"
#include "chrome/browser/chromeos/drive/file_system_util.h"
#include "chrome/browser/chromeos/file_manager/app_id.h"
#include "chrome/browser/chromeos/file_manager/file_browser_handlers.h"
#include "chrome/browser/chromeos/file_manager/file_tasks.h"
#include "chrome/browser/chromeos/file_manager/fileapi_util.h"
#include "chrome/browser/chromeos/file_manager/mime_util.h"
#include "chrome/browser/chromeos/file_manager/url_util.h"
#include "chrome/browser/extensions/api/file_handlers/app_file_handler_util.h"
#include "chrome/browser/extensions/extension_service.h"
#include "chrome/browser/extensions/extension_system.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/profiles/profile_manager.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_finder.h"
#include "chrome/browser/ui/browser_tabstrip.h"
#include "chrome/browser/ui/browser_window.h"
#include "chrome/browser/ui/extensions/application_launch.h"
#include "chrome/browser/ui/simple_message_box.h"
#include "chrome/common/extensions/api/file_browser_handlers/file_browser_handler.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/storage_partition.h"
#include "content/public/browser/user_metrics.h"
#include "google_apis/drive/task_util.h"
#include "grit/generated_resources.h"
#include "ui/base/l10n/l10n_util.h"
#include "webkit/browser/fileapi/file_system_backend.h"
#include "webkit/browser/fileapi/file_system_context.h"
#include "webkit/browser/fileapi/file_system_operation_runner.h"
#include "webkit/browser/fileapi/file_system_url.h"

using base::UserMetricsAction;
using content::BrowserContext;
using content::BrowserThread;
using extensions::Extension;
using extensions::app_file_handler_util::FindFileHandlersForFiles;
using extensions::app_file_handler_util::PathAndMimeTypeSet;
using fileapi::FileSystemURL;

namespace file_manager {
namespace util {
namespace {

// Shows a warning message box saying that the file could not be opened.
void ShowWarningMessageBox(Profile* profile, const base::FilePath& file_path) {
  Browser* browser = chrome::FindTabbedBrowser(
      profile, false, chrome::HOST_DESKTOP_TYPE_ASH);
  chrome::ShowMessageBox(
      browser ? browser->window()->GetNativeWindow() : NULL,
      l10n_util::GetStringFUTF16(
          IDS_FILE_BROWSER_ERROR_VIEWING_FILE_TITLE,
          base::UTF8ToUTF16(file_path.BaseName().value())),
      l10n_util::GetStringUTF16(IDS_FILE_BROWSER_ERROR_VIEWING_FILE),
      chrome::MESSAGE_BOX_TYPE_WARNING);
}

// Grants file system access to the file manager.
bool GrantFileSystemAccessToFileBrowser(Profile* profile) {
  // The file manager always runs in the site for its extension id, so that
  // is the site for which file access permissions should be granted.
  fileapi::ExternalFileSystemBackend* backend =
      GetFileSystemContextForExtensionId(
          profile, kFileManagerAppId)->external_backend();
  if (!backend)
    return false;
  backend->GrantFullAccessToExtension(kFileManagerAppId);
  return true;
}

// Executes the |task| for the file specified by |url|.
void ExecuteFileTaskForUrl(Profile* profile,
                           const file_tasks::TaskDescriptor& task,
                           const GURL& url) {
  // If the file manager has not been open yet then it did not request access
  // to the file system. Do it now.
  if (!GrantFileSystemAccessToFileBrowser(profile))
    return;

  fileapi::FileSystemContext* file_system_context =
      GetFileSystemContextForExtensionId(
          profile, kFileManagerAppId);

  // We are executing the task on behalf of the file manager.
  const GURL source_url = GetFileManagerMainPageUrl();
  std::vector<FileSystemURL> urls;
  urls.push_back(file_system_context->CrackURL(url));

  file_tasks::ExecuteFileTask(
      profile,
      source_url,
      kFileManagerAppId,
      task,
      urls,
      file_tasks::FileTaskFinishedCallback());
}

// Opens the file manager for the specified |file_path|. Used to implement
// internal handlers of special action IDs:
//
// "open" - Open the file manager for the given folder.
// "auto-open" - Open the file manager for the given removal drive and close
//               the file manager when the removal drive is unmounted.
// "select" - Open the file manager for the given file. The folder containing
//            the file will be opened with the file selected.
void OpenFileManagerWithInternalActionId(Profile* profile,
                                         const base::FilePath& file_path,
                                         const std::string& action_id) {
  DCHECK(action_id == "auto-open" ||
         action_id == "open" ||
         action_id == "select");

  content::RecordAction(UserMetricsAction("ShowFileBrowserFullTab"));

  GURL url;
  if (!ConvertAbsoluteFilePathToFileSystemUrl(
          profile, file_path, kFileManagerAppId, &url))
    return;

  file_tasks::TaskDescriptor task(kFileManagerAppId,
                                  file_tasks::TASK_TYPE_FILE_BROWSER_HANDLER,
                                  action_id);
  ExecuteFileTaskForUrl(profile, task, url);
}

// Opens the file specified by |file_path| by finding and executing a file
// task for the file. Returns false if failed to open the file (i.e. no file
// task is found).
bool OpenFile(Profile* profile, const base::FilePath& file_path) {
  GURL url;
  if (!ConvertAbsoluteFilePathToFileSystemUrl(
          profile, file_path, kFileManagerAppId, &url))
    return false;

  // The file is opened per the file extension, hence extension-less files
  // cannot be opened properly.
  std::string mime_type = GetMimeTypeForPath(file_path);
  extensions::app_file_handler_util::PathAndMimeTypeSet path_mime_set;
  path_mime_set.insert(std::make_pair(file_path, mime_type));

  std::vector<GURL> file_urls;
  file_urls.push_back(url);

  std::vector<file_tasks::FullTaskDescriptor> tasks;
  file_tasks::FindAllTypesOfTasks(
      profile,
      drive::util::GetDriveAppRegistryByProfile(profile),
      path_mime_set,
      file_urls,
      &tasks);
  if (tasks.empty())
    return false;

  const file_tasks::FullTaskDescriptor* chosen_task = &tasks[0];
  for (size_t i = 0; i < tasks.size(); ++i) {
    if (tasks[i].is_default()) {
      chosen_task = &tasks[i];
      break;
    }
  }

  ExecuteFileTaskForUrl(profile, chosen_task->task_descriptor(), url);
  return true;
}

// Used to implement OpenItem().
void ContinueOpenItem(Profile* profile,
                      const base::FilePath& file_path,
                      base::PlatformFileError error) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  if (error == base::PLATFORM_FILE_OK) {
    // A directory exists at |file_path|. Open it with the file manager.
    OpenFileManagerWithInternalActionId(profile, file_path, "open");
  } else {
    // |file_path| should be a file. Open it.
    if (!OpenFile(profile, file_path))
      ShowWarningMessageBox(profile, file_path);
  }
}

// Used to implement CheckIfDirectoryExists().
void CheckIfDirectoryExistsOnIOThread(
    scoped_refptr<fileapi::FileSystemContext> file_system_context,
    const GURL& url,
    const fileapi::FileSystemOperationRunner::StatusCallback& callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

  fileapi::FileSystemURL file_system_url = file_system_context->CrackURL(url);
  file_system_context->operation_runner()->DirectoryExists(
      file_system_url, callback);
}

// Checks if a directory exists at |url|.
void CheckIfDirectoryExists(
    scoped_refptr<fileapi::FileSystemContext> file_system_context,
    const GURL& url,
    const fileapi::FileSystemOperationRunner::StatusCallback& callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  BrowserThread::PostTask(
      BrowserThread::IO, FROM_HERE,
      base::Bind(&CheckIfDirectoryExistsOnIOThread,
                 file_system_context,
                 url,
                 google_apis::CreateRelayCallback(callback)));
}

}  // namespace

void OpenRemovableDrive(Profile* profile, const base::FilePath& file_path) {
  OpenFileManagerWithInternalActionId(profile, file_path, "auto-open");
}

void OpenItem(Profile* profile, const base::FilePath& file_path) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  GURL url;
  if (!ConvertAbsoluteFilePathToFileSystemUrl(
          profile, file_path, kFileManagerAppId, &url) ||
      !GrantFileSystemAccessToFileBrowser(profile)) {
    ShowWarningMessageBox(profile, file_path);
    return;
  }

  scoped_refptr<fileapi::FileSystemContext> file_system_context =
      GetFileSystemContextForExtensionId(
          profile, kFileManagerAppId);

  CheckIfDirectoryExists(file_system_context, url,
                         base::Bind(&ContinueOpenItem, profile, file_path));
}

void ShowItemInFolder(Profile* profile, const base::FilePath& file_path) {
  // This action changes the selection so we do not reuse existing tabs.
  OpenFileManagerWithInternalActionId(profile, file_path, "select");
}

}  // namespace util
}  // namespace file_manager