Files.app: Add an private API to get a download URL

This patch just adds the API to get a download URL with an drive read only token.

BUG=305511
TEST=manually teste
R=asargent@chromium.org, hashimoto@chromium.org, kinaba@chromium.org
TBR=isherman@chromium.org

Review URL: https://codereview.chromium.org/371883003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283671 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 140 insertions, 4 deletions

diff --git a/chrome/browser/chromeos/extensions/file_manager/private_api_drive.cc b/chrome/browser/chromeos/extensions/file_manager/private_api_drive.cc
index e0685b2..9691914 100644
--- a/chrome/browser/chromeos/extensions/file_manager/private_api_drive.cc
+++ b/chrome/browser/chromeos/extensions/file_manager/private_api_drive.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/extensions/file_manager/private_api_drive.h"
 
+#include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/drive/drive_integration_service.h"
 #include "chrome/browser/chromeos/extensions/file_manager/private_api_util.h"
@@ -16,8 +17,13 @@
 #include "chrome/browser/drive/event_logger.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
-#include "chrome/common/extensions/api/file_browser_private.h"
+#include "chrome/browser/signin/profile_oauth2_token_service_factory.h"
+#include "chrome/browser/signin/signin_manager_factory.h"
+#include "chromeos/chromeos_switches.h"
+#include "components/signin/core/browser/profile_oauth2_token_service.h"
+#include "components/signin/core/browser/signin_manager.h"
 #include "content/public/browser/browser_thread.h"
+#include "google_apis/drive/auth_service.h"
 #include "webkit/common/fileapi/file_system_info.h"
 #include "webkit/common/fileapi/file_system_util.h"
 
@@ -887,4 +893,96 @@ void FileBrowserPrivateRequestDriveShareFunction::OnAddPermission(
   SendResponse(error == drive::FILE_ERROR_OK);
 }
 
+FileBrowserPrivateGetDownloadUrlFunction::
+    FileBrowserPrivateGetDownloadUrlFunction() {
+}
+
+FileBrowserPrivateGetDownloadUrlFunction::
+    ~FileBrowserPrivateGetDownloadUrlFunction() {
+}
+
+bool FileBrowserPrivateGetDownloadUrlFunction::RunAsync() {
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (!command_line->HasSwitch(
+          chromeos::switches::kEnableVideoPlayerChromecastSupport)) {
+    SetError("Cast support is disabled.");
+    SetResult(new base::StringValue(""));  // Intentionally returns a blank.
+    return false;
+  }
+
+  using extensions::api::file_browser_private::GetShareUrl::Params;
+  const scoped_ptr<Params> params(Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params);
+
+  // Start getting the file info.
+  drive::FileSystemInterface* const file_system =
+      drive::util::GetFileSystemByProfile(GetProfile());
+  if (!file_system) {
+    // |file_system| is NULL if Drive is disabled or not mounted.
+    SetError("Drive is disabled or not mounted.");
+    SetResult(new base::StringValue(""));  // Intentionally returns a blank.
+    return false;
+  }
+
+  const base::FilePath path = file_manager::util::GetLocalPathFromURL(
+      render_view_host(), GetProfile(), GURL(params->url));
+  DCHECK(drive::util::IsUnderDriveMountPoint(path));
+  base::FilePath file_path = drive::util::ExtractDrivePath(path);
+
+  file_system->GetResourceEntry(
+      file_path,
+      base::Bind(&FileBrowserPrivateGetDownloadUrlFunction::OnGetResourceEntry,
+                 this));
+  return true;
+}
+
+void FileBrowserPrivateGetDownloadUrlFunction::OnGetResourceEntry(
+    drive::FileError error,
+    scoped_ptr<drive::ResourceEntry> entry) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (error != drive::FILE_ERROR_OK) {
+    SetError("Download Url for this item is not available.");
+    SetResult(new base::StringValue(""));  // Intentionally returns a blank.
+    SendResponse(false);
+    return;
+  }
+
+  download_url_ =
+      google_apis::DriveApiUrlGenerator::kBaseDownloadUrlForProduction +
+      entry->resource_id();
+
+  ProfileOAuth2TokenService* oauth2_token_service =
+      ProfileOAuth2TokenServiceFactory::GetForProfile(GetProfile());
+  SigninManagerBase* signin_manager =
+      SigninManagerFactory::GetForProfile(GetProfile());
+  const std::string& account_id = signin_manager->GetAuthenticatedAccountId();
+  std::vector<std::string> scopes;
+  scopes.push_back("https://www.googleapis.com/auth/drive.readonly");
+
+  auth_service_.reset(
+      new google_apis::AuthService(oauth2_token_service,
+                                   account_id,
+                                   GetProfile()->GetRequestContext(),
+                                   scopes));
+  auth_service_->StartAuthentication(base::Bind(
+      &FileBrowserPrivateGetDownloadUrlFunction::OnTokenFetched, this));
+}
+
+void FileBrowserPrivateGetDownloadUrlFunction::OnTokenFetched(
+    google_apis::GDataErrorCode code,
+    const std::string& access_token) {
+  if (code != google_apis::HTTP_SUCCESS) {
+    SetError("Not able to fetch the token.");
+    SetResult(new base::StringValue(""));  // Intentionally returns a blank.
+    SendResponse(false);
+    return;
+  }
+
+  const std::string url = download_url_ + "?access_token=" + access_token;
+  SetResult(new base::StringValue(url));
+
+  SendResponse(true);
+}
+
 }  // namespace extensions
diff --git a/chrome/browser/chromeos/extensions/file_manager/private_api_drive.h b/chrome/browser/chromeos/extensions/file_manager/private_api_drive.h
index b3eec92..0db5964 100644
--- a/chrome/browser/chromeos/extensions/file_manager/private_api_drive.h
+++ b/chrome/browser/chromeos/extensions/file_manager/private_api_drive.h
@@ -18,6 +18,10 @@ class ResourceEntry;
 struct SearchResultInfo;
 }
 
+namespace google_apis {
+class AuthService;
+}
+
 namespace extensions {
 
 namespace api {
@@ -240,6 +244,34 @@ class FileBrowserPrivateRequestDriveShareFunction
   void OnAddPermission(drive::FileError error);
 };
 
+// Implements the chrome.fileBrowserPrivate.getDownloadUrl method.
+class FileBrowserPrivateGetDownloadUrlFunction
+    : public LoggedAsyncExtensionFunction {
+ public:
+  FileBrowserPrivateGetDownloadUrlFunction();
+
+  DECLARE_EXTENSION_FUNCTION("fileBrowserPrivate.getDownloadUrl",
+                             FILEBROWSERPRIVATE_GETDOWNLOADURL)
+
+ protected:
+  virtual ~FileBrowserPrivateGetDownloadUrlFunction();
+
+  // AsyncExtensionFunction overrides.
+  virtual bool RunAsync() OVERRIDE;
+
+  void OnGetResourceEntry(drive::FileError error,
+                          scoped_ptr<drive::ResourceEntry> entry);
+
+  // Callback with an |access_token|, called by
+  // drive::DriveReadonlyTokenFetcher.
+  void OnTokenFetched(google_apis::GDataErrorCode code,
+                      const std::string& access_token);
+
+ private:
+  std::string download_url_;
+  scoped_ptr<google_apis::AuthService> auth_service_;
+};
+
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_DRIVE_H_
diff --git a/chrome/common/extensions/api/file_browser_private.idl b/chrome/common/extensions/api/file_browser_private.idl
index 173d164..0a4a7a6 100644
--- a/chrome/common/extensions/api/file_browser_private.idl
+++ b/chrome/common/extensions/api/file_browser_private.idl
@@ -533,8 +533,8 @@ callback RequestAccessTokenCallback = void(DOMString accessToken);
 // |accessToken| OAuth2 access token, or an empty string if failed to fetch.
 callback RequestWebStoreAccessTokenCallback = void(DOMString accessToken);
 
-// |shareUrl| Share Url for the sharing dialog.
-callback GetShareUrlCallback = void(DOMString shareUrl);
+// |url| Result url.
+callback GetUrlCallback = void(DOMString url);
 
 // |profiles| List of profile information.
 // |runningProfile| ID of the profile that runs the application instance.
@@ -769,7 +769,12 @@ interface Functions {
   // Requests a share dialog url for the specified file.
   // |url| Url for the file.
   // |callback|
-  static void getShareUrl(DOMString url, GetShareUrlCallback callback);
+  static void getShareUrl(DOMString url, GetUrlCallback callback);
+
+  // Requests a download url to download the file contents.
+  // |url| Url for the file.
+  // |callback|
+  static void getDownloadUrl(DOMString url, GetUrlCallback callback);
 
   // Requests to share drive files.
   // |url| URL of a file to be shared.
diff --git a/extensions/browser/extension_function_histogram_value.h b/extensions/browser/extension_function_histogram_value.h
index 188ec7c..a8eeb79 100644
--- a/extensions/browser/extension_function_histogram_value.h
+++ b/extensions/browser/extension_function_histogram_value.h
@@ -899,6 +899,7 @@ enum HistogramValue {
   GCDPRIVATE_GETCOMMANDSLIST,
   APPVIEWINTERNAL_ATTACHFRAME,
   APPVIEWINTERNAL_DENYREQUEST,
+  FILEBROWSERPRIVATE_GETDOWNLOADURL,
   // Last entry: Add new entries above and ensure to update
   // tools/metrics/histograms/histograms/histograms.xml.
   ENUM_BOUNDARY