From e626d9304411660c999a95db7b0a4770e5911703 Mon Sep 17 00:00:00 2001
From: Paul Beckingham <paul@beckingham.net>
Date: Thu, 21 Apr 2016 23:57:33 -0400
Subject: [PATCH] helper: Added combineHolidaysAndExclusions

---
 src/helper.cpp | 45 +++++++++++++++++++++++++++++++++++++++++++++
 src/timew.h    |  1 +
 2 files changed, 46 insertions(+)

diff --git a/src/helper.cpp b/src/helper.cpp
index 5473038e..8feacde0 100644
--- a/src/helper.cpp
+++ b/src/helper.cpp
@@ -479,3 +479,48 @@ Daterange overallRangeFromIntervals (const std::vector <Interval>& intervals)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+std::vector <Daterange> combineHolidaysAndExclusions (
+  const Daterange& range,
+  const Rules& rules,
+  const std::vector <Exclusion>& exclusions)
+{
+  // Start with the set of all holidays, intersected with range.
+  std::vector <Daterange> results;
+  results = addRanges (range, results, rangesFromHolidays (rules));
+
+  // Find exclusions 'exc day on <date>' and remove from holidays.
+  // Find exlcusions 'exc day off <date>' and add to holidays.
+  std::vector <Daterange> daysOn;
+  std::vector <Daterange> daysOff;
+  for (auto& exclusion : exclusions)
+  {
+    if (exclusion.tokens ()[1] == "day")
+    {
+      if (exclusion.additive ())
+        for (auto& range : exclusion.ranges (range))
+          daysOn.push_back (range);
+      else
+        for (auto& range : exclusion.ranges (range))
+          daysOff.push_back (range);
+    }
+  }
+
+  // daysOff are combined with existing holidays.
+  results = addRanges (range, results, daysOff);
+
+  // daysOn are subtracted from the existing holidays.
+  results = subtractRanges (range, results, daysOn);
+
+  // Expand all exclusions that are not 'exc day ...' into excluded ranges that
+  // overlage with range.
+  std::vector <Daterange> exclusionRanges;
+  for (auto& exclusion : exclusions)
+    if (exclusion.tokens ()[1] != "day")
+      for (auto& range : exclusion.ranges (range))
+        exclusionRanges.push_back (range);
+
+  results = addRanges (range, results, exclusionRanges);
+  return results;
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/src/timew.h b/src/timew.h
index 36b1496f..dc335d31 100644
--- a/src/timew.h
+++ b/src/timew.h
@@ -58,6 +58,7 @@ std::vector <Daterange> rangesFromHolidays (const Rules&);
 std::vector <Daterange> addRanges (const Daterange&, const std::vector <Daterange>&, const std::vector <Daterange>&);
 std::vector <Daterange> subtractRanges (const Daterange&, const std::vector <Daterange>&, const std::vector <Daterange>&);
 Daterange overallRangeFromIntervals (const std::vector <Interval>&);
+std::vector <Daterange> combineHolidaysAndExclusions (const Daterange&, const Rules&, const std::vector <Exclusion>&);
 
 // utiŀ.cpp
 std::string osName ();