1 files changed, 35 insertions, 0 deletions
diff --git a/lib/line_periods.rb b/lib/line_periods.rb
new file mode 100644
index 000000000..c176a7a08
--- /dev/null
+++ b/lib/line_periods.rb
@@ -0,0 +1,35 @@
+class LinePeriods
+
+  def initialize
+    @periods_by_line = Hash.new { |h,k| h[k] = [] }
+  end
+
+  def add(line_id, period)
+    @periods_by_line[line_id] << period
+  end
+
+  def each(&block)
+    @periods_by_line.each do |line_id, periods|
+      yield line_id, periods
+    end
+  end
+
+  def periods(line_id)
+    @periods_by_line[line_id]
+  end
+
+  def self.from_metadatas(metadatas)
+    line_periods = new
+
+    metadatas.each do |metadata|
+      metadata.line_ids.each do |line_id|
+        metadata.periodes.each do |period|
+          line_periods.add(line_id, period)
+        end
+      end
+    end
+
+    line_periods
+  end
+
+end