Improved bookmarks sharing interface

iphone/Maps/Core/Bookmarks/MWMBookmarksManager.mm

@@ -175,8 +175,13 @@ using TLoopBlock = void (^)(Observer observer);
 
 + (NSURL *)beginShareCategory:(MWMMarkGroupID)groupId
 {
-  auto const filePath = GetFramework().GetBookmarkManager().BeginSharing(groupId);
-  NSURL * url = [NSURL fileURLWithPath:@(filePath.c_str()) isDirectory:NO];
+  auto const sharingResult = GetFramework().GetBookmarkManager().BeginSharing(groupId);
+  if (sharingResult.m_code != BookmarkManager::SharingResult::Code::Success)
+  {
+    //TODO(igrechuhin): show smth
+    return nil;
+  }
+  NSURL * url = [NSURL fileURLWithPath:@(sharingResult.m_sharingPath.c_str()) isDirectory:NO];
   NSAssert(url != nil, @"Invalid share category url");
   return url;
 }

map/bookmark_manager.cpp

@@ -1172,24 +1172,25 @@ void BookmarkManager::SetInvalidTokenHandler(Cloud::InvalidTokenHandler && onInv
   m_bookmarkCloud.SetInvalidTokenHandler(std::move(onInvalidToken));
 }
 
-std::string BookmarkManager::BeginSharing(df::MarkGroupID categoryId)
+BookmarkManager::SharingResult BookmarkManager::BeginSharing(df::MarkGroupID categoryId)
 {
   auto const it = m_activeSharing.find(categoryId);
   if (it != m_activeSharing.end())
   {
+    // In case if the sharing has already begun.
     if (GetPlatform().IsFileExistsByFullPath(it->second))
-      return it->second;
+      return SharingResult(it->second);
   }
 
-  auto const f = GetFileForSharing(categoryId);
-  if (f.empty())
+  auto const result = GetFileForSharing(categoryId);
+  if (result.m_code != SharingResult::Code::Success)
   {
     m_activeSharing.erase(categoryId);
-    return {};
+    return result;
   }
 
-  m_activeSharing[categoryId] = f;
-  return f;
+  m_activeSharing[categoryId] = result.m_sharingPath;
+  return result;
 }
 
 void BookmarkManager::EndSharing(df::MarkGroupID categoryId)
@@ -1204,11 +1205,19 @@ void BookmarkManager::EndSharing(df::MarkGroupID categoryId)
   m_activeSharing.erase(categoryId);
 }
 
-std::string BookmarkManager::GetFileForSharing(df::MarkGroupID categoryId)
+bool BookmarkManager::IsCategoryEmpty(df::MarkGroupID categoryId) const
 {
+  return GetUserMarkIds(categoryId).empty() && GetTrackIds(categoryId).empty();
+}
+
+BookmarkManager::SharingResult BookmarkManager::GetFileForSharing(df::MarkGroupID categoryId)
+{
+  if (IsCategoryEmpty(categoryId))
+    return SharingResult(SharingResult::Code::EmptyCategory);
+
   auto const filePath = GetCategoryFileName(categoryId);
   if (!GetPlatform().IsFileExistsByFullPath(filePath))
-    return {};
+    return SharingResult(SharingResult::Code::FileError, "Bookmarks file does not exist.");
 
   auto ext = my::GetFileExtension(filePath);
   strings::AsciiToLower(ext);
@@ -1218,15 +1227,16 @@ std::string BookmarkManager::GetFileForSharing(df::MarkGroupID categoryId)
   auto const tmpFilePath = my::JoinFoldersToPath(GetPlatform().TmpDir(), fileName + KMZ_EXTENSION);
   if (ext == KMZ_EXTENSION)
   {
-    if (!my::CopyFileX(filePath, tmpFilePath))
-      return {};
-    return tmpFilePath;
+    if (my::CopyFileX(filePath, tmpFilePath))
+      return SharingResult(tmpFilePath);
+
+    return SharingResult(SharingResult::Code::FileError, "Could not copy file.");
   }
 
-  if (CreateZipFromPathDeflatedAndDefaultCompression(filePath, tmpFilePath))
-    return tmpFilePath;
+  if (!CreateZipFromPathDeflatedAndDefaultCompression(filePath, tmpFilePath))
+    return SharingResult(SharingResult::Code::ArchiveError, "Could not create archive.");
 
-  return {};
+  return SharingResult(tmpFilePath);
 }
 
 df::GroupIDSet BookmarkManager::MarksChangesTracker::GetAllGroupIds() const

map/bookmark_manager.hpp

@@ -192,9 +192,39 @@ public:
   std::unique_ptr<User::Subscriber> GetUserSubscriber();
   void SetInvalidTokenHandler(Cloud::InvalidTokenHandler && onInvalidToken);
 
-  std::string BeginSharing(df::MarkGroupID categoryId);
+  struct SharingResult
+  {
+    enum class Code
+    {
+      Success,
+      EmptyCategory,
+      ArchiveError,
+      FileError
+    };
+    Code m_code;
+    std::string m_sharingPath;
+    std::string m_errorString;
+
+    explicit SharingResult(std::string const & sharingPath)
+      : m_code(Code::Success)
+      , m_sharingPath(sharingPath)
+    {}
+
+    explicit SharingResult(Code code)
+      : m_code(code)
+    {}
+
+    SharingResult(Code code, std::string const & errorString)
+      : m_code(code)
+      , m_errorString(errorString)
+    {}
+  };
+
+  SharingResult BeginSharing(df::MarkGroupID categoryId);
   void EndSharing(df::MarkGroupID categoryId);
 
+  bool IsCategoryEmpty(df::MarkGroupID categoryId) const;
+
   /// These functions are public for unit tests only. You shouldn't call them from client code.
   void SaveToKML(df::MarkGroupID groupId, std::ostream & s);
   void CreateCategories(KMLDataCollection && dataCollection, bool autoSave = true);
@@ -331,7 +361,7 @@ private:
 
   void SaveToKML(BookmarkCategory * group, std::ostream & s);
 
-  std::string GetFileForSharing(df::MarkGroupID categoryId);
+  SharingResult GetFileForSharing(df::MarkGroupID categoryId);
 
   Callbacks m_callbacks;
   MarksChangesTracker m_changesTracker;