1 files changed, 149 insertions, 0 deletions
diff --git a/coffee/services/cache.coffee b/coffee/services/cache.coffee
new file mode 100644
index 000000000..194fca3f1
--- /dev/null
+++ b/coffee/services/cache.coffee
@@ -0,0 +1,149 @@
+angular.module('News').factory '_Cache', ->
+
+	class Cache
+
+		constructor: (@feedType, @feedModel, @folderModel) ->
+			@clear()
+
+
+		clear: ->
+			@feedCache = []
+			@folderCache = {}
+			@folderCacheLastModified = 0
+			@importantCache = []
+			@highestId = 0
+			@lowestId = 0
+			@highestTimestamp = 0
+			@lowestTimestamp = 0
+			@highestIds = {}
+			@lowestIds = {}
+			@highestTimestamps = {}
+			@lowestTimestamps = {}
+
+
+		add: (item) ->
+			# cache for feed access
+			if not @feedCache[item.feedId]
+				@feedCache[item.feedId] = []
+			@feedCache[item.feedId].push(item)
+			
+			# cache for non feeds
+			if @highestTimestamp < item.date
+				@highestTimestamp = item.date
+			if @lowestTimestamp > item.date
+				@lowestTimestamp = item.date
+			if @highestId < item.id
+				@highestId = item.id
+			if @lowestId > item.id
+				@lowestId = item.id
+
+
+			# cache for important
+			if item.isImportant
+				@importantCache.push(item)
+
+			# cache lowest and highest ids and timestamps for only fetching new
+			# items
+			if @highestTimestamps[item.feedId] == undefined or item.id > @highestTimestamps[item.feedId]
+				@highestTimestamps[item.feedId] = item.date
+			if @lowestTimestamps[item.feedId] == undefined or item.id > @lowestTimestamps[item.feedId]
+				@lowestTimestamps[item.feedId] = item.date
+			if @highestIds[item.feedId] == undefined or item.id > @highestIds[item.feedId]
+				@highestIds[item.feedId] = item.id
+			if @lowestIds[item.feedId] == undefined or item.id > @lowestIds[item.feedId]
+				@lowestIds[item.feedId] = item.id
+
+
+		getItemsOfFeed: (feedId) ->
+			return @feedCache[feedId]
+
+
+		getFeedIdsOfFolder: (folderId) ->
+			@buildFolderCache(folderId)
+			return @folderCache[folderId]
+
+
+		getImportantItems: ->
+			return @importantCache
+
+
+		buildFolderCache: (id) ->
+			# invalidate the foldercache if the last modified date is
+			# not the currently used one
+			if @folderCacheLastModified != @feedModel.getLastModified()
+				@folderCache = {}
+				@folderCacheLastModified = @feedModel.getLastModified()
+			
+			# if the folderarray does not yet exist, build it
+			# otherwise use the last generated one
+			if @folderCache[id] == undefined
+				@folderCache[id] = []
+				for feed in @feedModel.getItems()
+					if feed.folderId == id
+						@folderCache[id].push(feed.id)
+
+
+		getFeedsOfFolderId: (id) ->
+			@buildFolderCache(id)
+			return @folderCache[id]
+
+
+		removeItemInArray: (id, array) ->
+			removeItemIndex = null
+			counter = 0
+			for element in array
+				if element.id == id
+					removeItemIndex = counter
+					break
+				counter += 1
+
+			if removeItemIndex != null
+				array.splice(removeItemIndex, 1)
+
+
+		remove: (item) ->
+			@removeItemInArray(item.id, @feedCache[item.feedId])
+			@removeItemInArray(item.id, @importantCache)
+
+
+		setImportant: (item, isImportant) ->
+			if isImportant
+				@importantCache.push(item)
+			else
+				@removeItemInArray(item.id, @importantCache)
+			
+		getHighestId: (type, id) ->
+			if @isFeed(type)
+				return @highestIds[id] || 0
+			else
+				return @highestId
+
+
+		getHighestTimestamp: (type, id) ->
+			if @isFeed(type)
+				return @highestTimestamps[id] || 0
+			else
+				return @highestTimestamp
+
+
+		getLowestId: (type, id) ->
+			if @isFeed(type)
+				return @lowestIds[id] || 0
+			else
+				return @lowestId
+
+
+		getLowestTimestamp: (type, id) ->
+			if @isFeed(type)
+				return @lowestTimestamps[id] || 0
+			else
+				return @lowestTimestamp
+
+
+		isFeed: (type) ->
+			return type == @feedType.Feed
+
+
+	return Cache
+
+