From 6cd5ac2d0dc89c13fda7ff2046f41d64e2cf3420 Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Wed, 27 Sep 2017 15:06:37 +0100
Subject: [PATCH] Move readTime (parse_time) from options.cxx

---
 simgear/misc/strutils.cxx      | 27 +++++++++++++++++++++++++++
 simgear/misc/strutils.hxx      | 10 ++++++++++
 simgear/misc/strutils_test.cxx | 27 ++++++++++++++++++++++++++-
 3 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/simgear/misc/strutils.cxx b/simgear/misc/strutils.cxx
index 1f854ef6..f45e0ac8 100644
--- a/simgear/misc/strutils.cxx
+++ b/simgear/misc/strutils.cxx
@@ -538,6 +538,33 @@ namespace simgear {
     unsigned long long readNonNegativeInt<unsigned long long, 16>(
         const std::string& s);
 #endif
+        
+        // parse a time string ([+/-]%f[:%f[:%f]]) into hours
+        double readTime(const string& time_in)
+        {
+            if (time_in.empty()) {
+                return 0.0;
+            }
+            
+            const bool negativeSign = time_in.front() == '-';
+            const string_list pieces = split(time_in, ":");
+            if (pieces.size() > 3) {
+                throw sg_format_exception("Unable to parse time string, too many pieces", time_in);
+            }
+            
+            const int hours = std::abs(to_int(pieces.front()));
+            int minutes = 0, seconds = 0;
+            if (pieces.size() > 1) {
+                minutes = to_int(pieces.at(1));
+                if (pieces.size() > 2) {
+                    seconds = to_int(pieces.at(2));
+                }
+            }
+        
+            double result = hours + (minutes / 60.0) + (seconds / 3600.0);
+            return negativeSign ? -result : result;
+        }
+
 
     int compare_versions(const string& v1, const string& v2, int maxComponents)
     {
diff --git a/simgear/misc/strutils.hxx b/simgear/misc/strutils.hxx
index ed0ff014..b6126cd5 100644
--- a/simgear/misc/strutils.hxx
+++ b/simgear/misc/strutils.hxx
@@ -209,6 +209,16 @@ namespace simgear {
         typename = typename std::enable_if<std::is_integral<T>::value, T>::type >
     T readNonNegativeInt(const std::string& s);
 
+      
+      /**
+       * Read a time value, seperated by colons, as a value in hours.
+       * Allowable input is ([+/-]%f[:%f[:%f]]) 
+       * i.e 15:04:35 is parsed as 15 + (04 / 60) + (35 / 2600)
+       * This code is moved from flightgear's options.cxx where it was called
+       * parse_time(),
+       */
+      double readTime(const std::string& s);
+      
     /**
      * Convert a string representing a boolean, to a bool.
      * Accepted values include YES, true, 0, 1, false, no, True,
diff --git a/simgear/misc/strutils_test.cxx b/simgear/misc/strutils_test.cxx
index dd686fa2..84978da5 100644
--- a/simgear/misc/strutils_test.cxx
+++ b/simgear/misc/strutils_test.cxx
@@ -19,6 +19,7 @@
 #include <simgear/compiler.h>
 #include <simgear/misc/strutils.hxx>
 #include <simgear/structure/exception.hxx>
+#include <simgear/constants.h>
 
 using std::string;
 using std::vector;
@@ -581,6 +582,29 @@ void test_error_string()
   SG_CHECK_GT(strutils::error_string(saved_errno).size(), 0);
 }
 
+void test_readTime()
+{
+    SG_CHECK_EQUAL_EP(strutils::readTime(""), 0.0);
+
+    SG_CHECK_EQUAL_EP(strutils::readTime("11"), 11.0);
+    SG_CHECK_EQUAL_EP(strutils::readTime("+11"), 11.0);
+    SG_CHECK_EQUAL_EP(strutils::readTime("-11"), -11.0);
+    
+    SG_CHECK_EQUAL_EP(strutils::readTime("11:30"), 11.5);
+    SG_CHECK_EQUAL_EP(strutils::readTime("+11:15"), 11.25);
+    SG_CHECK_EQUAL_EP(strutils::readTime("-11:45"), -11.75);
+    
+    const double seconds = 1 / 3600.0;
+    SG_CHECK_EQUAL_EP(strutils::readTime("11:30:00"), 11.5);
+    SG_CHECK_EQUAL_EP(strutils::readTime("+11:15:05"), 11.25 + 5 * seconds);
+    SG_CHECK_EQUAL_EP(strutils::readTime("-11:45:15"), -(11.75 + 15 * seconds));
+
+    SG_CHECK_EQUAL_EP(strutils::readTime("0:0:0"), 0);
+    
+    SG_CHECK_EQUAL_EP(strutils::readTime("0:0:28"), 28 * seconds);
+    SG_CHECK_EQUAL_EP(strutils::readTime("-0:0:28"), -28 * seconds);
+}
+
 int main(int argc, char* argv[])
 {
     test_strip();
@@ -599,6 +623,7 @@ int main(int argc, char* argv[])
     test_md5_hex();
     test_error_string();
     test_propPathMatch();
-
+    test_readTime();
+    
     return EXIT_SUCCESS;
 }