Calc work hours

src/dayoff.cr

@@ -1,6 +1,29 @@
-# TODO: Write documentation for `Dayoff`
+require "json"
+
 module Dayoff
   VERSION = "0.1.0"
 
-  # TODO: Put your code here
+  class WorkDate
+    JSON.mapping(
+      date: String,
+      hours: Int32,
+    )
+  end
+
+  class App
+    def initialize(wh_path)
+      content = File.open(wh_path) do |file|
+        file.gets_to_end
+      end
+      @wdates = Array(WorkDate).from_json(content)
+    end
+
+    def get_work_hours
+      sum = 0
+      @wdates.each do |wd|
+        sum += wd.hours
+      end
+      sum
+    end
+  end
 end