- save/load reading progress

src/library.cr

@@ -70,7 +70,70 @@ class Title
 	def get_entry(name)
 		@entries.find { |e| e.title == name }
 	end
+	def save_progress(username, entry, page)
+		info = TitleInfo.new @dir
+		if info.progress[username]?.nil?
+			info.progress[username] = {entry => page}
+			info.save @dir
+			return
+		end
+		info.progress[username][entry] = page
+		info.save @dir
+	end
+	def load_progress(username, entry : String)
+		info = TitleInfo.new @dir
+		if info.progress[username]?.nil?
+			return 0
+		end
+		if info.progress[username][entry]?.nil?
+			return 0
+		end
+		info.progress[username][entry]
+	end
+	def load_percetage(username, entry : String)
+		info = TitleInfo.new @dir
+		page = load_progress username, entry
+		entry_obj = get_entry entry
+		return 0 if entry_obj.nil?
+		page / entry_obj.pages
+	end
+	def load_percetage(username)
+		read_pages = 0
+		total_pages = 0
+		@entries.each do |e|
+			read_pages += load_progress username, e.title
+			total_pages += e.pages
+		end
+		read_pages / total_pages
+	end
+end
 
+class TitleInfo
+	# { user1: { entry1: 10, entry2: 0 } }
+	include JSON::Serializable
+
+	@[JSON::Field(key: "comment")]
+	property comment = "Generated by Mango. DO NOT EDIT!"
+
+	@[JSON::Field(key: "progress")]
+	property progress : Hash(String, Hash(String, Int32))
+
+	def initialize(title_dir)
+		info = nil
+
+		json_path = File.join title_dir, "info.json"
+		if File.exists? json_path
+			info = TitleInfo.from_json File.read json_path
+		else
+			info = TitleInfo.from_json "{\"progress\": {}}"
+		end
+
+		@progress = info.progress.clone
+	end
+	def save(title_dir)
+		json_path = File.join title_dir, "info.json"
+		File.write json_path, self.to_pretty_json
+	end
 end
 
 class Library