From 2b94fc641813bbf8ae85e54da793c106f59ed985 Mon Sep 17 00:00:00 2001
From: Paul Beckingham <paul@beckingham.net>
Date: Wed, 13 Apr 2016 23:43:08 -0400
Subject: [PATCH] helpers: Added intervalToFileNames

---
 src/helper.cpp | 39 +++++++++++++++++++++++++++++++++++++++
 src/timew.h    |  1 +
 2 files changed, 40 insertions(+)

diff --git a/src/helper.cpp b/src/helper.cpp
index af788928..83a2870e 100644
--- a/src/helper.cpp
+++ b/src/helper.cpp
@@ -258,3 +258,42 @@ std::string jsonFromIntervals (const std::vector <Interval>& intervals)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// Given an interval, determine which files names need to be written.
+std::vector <std::string> intervalToFileNames (const Interval& interval)
+{
+  std::vector <std::string> files;
+
+  auto start_y = interval.start ().year ();
+  auto start_m = interval.start ().month ();
+
+  auto end = interval.end ();
+  if (end.toEpoch () == 0)
+    end = Datetime ();
+
+  auto end_y = end.year ();
+  auto end_m = end.month ();
+
+  while (start_y <= end_y ||
+         (start_y == end_y && start_m <= end_m))
+  {
+    std::stringstream name;
+    name << std::setw (4) << std::setfill ('0') << start_y
+         << '-'
+         << std::setw (2) << std::setfill ('0') << start_m
+         << ".data";
+
+    files.push_back (name.str ());
+
+    // Next month.
+    start_m += 1;
+    if (start_m > 12)
+    {
+      start_y += 1;
+      start_m = 1;
+    }
+  }
+
+  return files;
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/src/timew.h b/src/timew.h
index 77f2eb0e..0334c312 100644
--- a/src/timew.h
+++ b/src/timew.h
@@ -53,6 +53,7 @@ Timeline createTimelineFromData (const Rules&, Database&, const Filter&);
 Interval getLatestInterval (Database&);
 bool intervalMatchesFilter (const Interval&, const Filter&);
 std::string jsonFromIntervals (const std::vector <Interval>&);
+std::vector <std::string> intervalToFileNames (const Interval&);
 
 // utiŀ.cpp
 std::string osName ();