From f38174097631931d4fb28232f2d9d77cc59f7b95 Mon Sep 17 00:00:00 2001
From: Don Cross <cosinekitty@gmail.com>
Date: Mon, 8 Jul 2019 16:05:56 -0400
Subject: [PATCH] Python: Convert rise/set direction kinds to an enumerated
 type Direction.

---
 generate/template/astronomy.py | 10 ++++++----
 generate/test.py               | 14 +++++++-------
 source/python/astronomy.py     | 10 ++++++----
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/generate/template/astronomy.py b/generate/template/astronomy.py
index e2d81330..62aa511b 100644
--- a/generate/template/astronomy.py
+++ b/generate/template/astronomy.py
@@ -1637,8 +1637,10 @@ def SearchHourAngle(body, observer, hourAngle, startTime):
         delta_days = (delta_sidereal_hours / 24.0) * _SOLAR_DAYS_PER_SIDEREAL_DAY
         time = time.AddDays(delta_days)
 
-DIRECTION_RISE = +1
-DIRECTION_SET  = -1
+@unique
+class Direction(IntEnum):
+    Rise = +1
+    Set  = -1
 
 class _peak_altitude_context:
     def __init__(self, body, direction, observer, body_radius_au):
@@ -1674,10 +1676,10 @@ def SearchRiseSet(body, observer, direction, startTime, limitDays):
     else:
         body_radius = 0.0
 
-    if direction == DIRECTION_RISE:
+    if direction == Direction.Rise:
         ha_before = 12.0    # minimum altitude (bottom) happens BEFORE the body rises.
         ha_after  =  0.0    # maximum altitude (culmination) happens AFTER the body rises.
-    elif direction == DIRECTION_SET:
+    elif direction == Direction.Set:
         ha_before =  0.0    # culmination happens BEFORE the body sets.
         ha_after  = 12.0    # bottom happens AFTER the body sets.
     else:
diff --git a/generate/test.py b/generate/test.py
index bf3a020f..8ffa35f2 100755
--- a/generate/test.py
+++ b/generate/test.py
@@ -617,7 +617,7 @@ def Test_RiseSet(filename):
             minute = int(m.group(8))
             kind = m.group(9)
             correct_time = astronomy.Time.Make(year, month, day, hour, minute, 0)
-            direction = astronomy.DIRECTION_RISE if kind == 'r' else astronomy.DIRECTION_SET
+            direction = astronomy.Direction.Rise if kind == 'r' else astronomy.Direction.Set
             body = astronomy.BodyCode(name)
             if body < 0:
                 print('Test_RiseSet({} line {}): invalid body name "{}"'.format(filename, lnum, name))
@@ -638,11 +638,11 @@ def Test_RiseSet(filename):
                 a_dir = b_dir
                 b_evt = None
             else:
-                r_evt = astronomy.SearchRiseSet(body, observer, astronomy.DIRECTION_RISE, r_search_date, 366.0)
+                r_evt = astronomy.SearchRiseSet(body, observer, astronomy.Direction.Rise, r_search_date, 366.0)
                 if r_evt is None:
                     print('Test_RiseSet({} line {}): rise search failed'.format(filename, lnum))
                     return 1
-                s_evt = astronomy.SearchRiseSet(body, observer, astronomy.DIRECTION_SET, s_search_date, 366.0)
+                s_evt = astronomy.SearchRiseSet(body, observer, astronomy.Direction.Set, s_search_date, 366.0)
                 if s_evt is None:
                     print('Test_RiseSet({} line {}): set search failed'.format(filename, lnum))
                     return 1
@@ -650,13 +650,13 @@ def Test_RiseSet(filename):
                 if r_evt.tt < s_evt.tt:
                     a_evt = r_evt
                     b_evt = s_evt
-                    a_dir = astronomy.DIRECTION_RISE
-                    b_dir = astronomy.DIRECTION_SET
+                    a_dir = astronomy.Direction.Rise
+                    b_dir = astronomy.Direction.Set
                 else:
                     a_evt = s_evt
                     b_evt = r_evt
-                    a_dir = astronomy.DIRECTION_SET
-                    b_dir = astronomy.DIRECTION_RISE                
+                    a_dir = astronomy.Direction.Set
+                    b_dir = astronomy.Direction.Rise
                 # Nudge the event times forward a tiny amount.
                 r_search_date = r_evt.AddDays(nudge_days)
                 s_search_date = s_evt.AddDays(nudge_days)
diff --git a/source/python/astronomy.py b/source/python/astronomy.py
index 828b3e22..c3301b27 100644
--- a/source/python/astronomy.py
+++ b/source/python/astronomy.py
@@ -3698,8 +3698,10 @@ def SearchHourAngle(body, observer, hourAngle, startTime):
         delta_days = (delta_sidereal_hours / 24.0) * _SOLAR_DAYS_PER_SIDEREAL_DAY
         time = time.AddDays(delta_days)
 
-DIRECTION_RISE = +1
-DIRECTION_SET  = -1
+@unique
+class Direction(IntEnum):
+    Rise = +1
+    Set  = -1
 
 class _peak_altitude_context:
     def __init__(self, body, direction, observer, body_radius_au):
@@ -3735,10 +3737,10 @@ def SearchRiseSet(body, observer, direction, startTime, limitDays):
     else:
         body_radius = 0.0
 
-    if direction == DIRECTION_RISE:
+    if direction == Direction.Rise:
         ha_before = 12.0    # minimum altitude (bottom) happens BEFORE the body rises.
         ha_after  =  0.0    # maximum altitude (culmination) happens AFTER the body rises.
-    elif direction == DIRECTION_SET:
+    elif direction == Direction.Set:
         ha_before =  0.0    # culmination happens BEFORE the body sets.
         ha_after  = 12.0    # bottom happens AFTER the body sets.
     else: