# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1459715993 -7200
# Node ID 08577002f5e9e09c94ebef2d871fe2ba0b006314
# Parent  564399c0a7aa4fb25b1f15fb9b4ae55b0169f647
Support an append method on collections; handle start/end-of-time points.

diff -r 564399c0a7aa -r 08577002f5e9 imiptools/period.py
--- a/imiptools/period.py	Sun Apr 03 22:37:54 2016 +0200
+++ b/imiptools/period.py	Sun Apr 03 22:39:53 2016 +0200
@@ -476,11 +476,14 @@
 
     # List emulation methods.
 
-    def __iadd__(self, other):
-        for period in other:
+    def __iadd__(self, periods):
+        for period in periods:
             self.insert_period(period)
         return self
 
+    def append(self, period):
+        self.insert_period(period)
+
     # Operations.
 
     def can_schedule(self, periods, uid, recurrenceid):
@@ -1024,7 +1027,13 @@
 
         "Return the entries in the collection at or after 'period'."
 
-        columns, values = ["start >= ?"], [format_datetime(period.get_start_point())]
+        start = format_datetime(period.get_start_point())
+
+        columns, values = [], []
+
+        if start:
+            columns.append("start >= ?")
+            values.append(start)
 
         query, values = self.get_query(
             "select %(columns)s from %(table)s :condition" % {
@@ -1041,7 +1050,13 @@
 
         "Return the entries in the collection before 'period'."
 
-        columns, values = ["start < ?"], [format_datetime(period.get_end_point())]
+        end = format_datetime(period.get_end_point())
+
+        columns, values = [], []
+
+        if end:
+            columns.append("start < ?")
+            values.append(end)
 
         query, values = self.get_query(
             "select %(columns)s from %(table)s :condition" % {
@@ -1061,7 +1076,7 @@
         'period'.
         """
 
-        columns, values = ["start < ?", "end > ?"], [format_datetime(period.get_end_point()), format_datetime(period.get_start_point())]
+        columns, values = self._get_period_values(period)
 
         query, values = self.get_query(
             "select %(columns)s from %(table)s :condition" % {
@@ -1080,7 +1095,7 @@
 
         self._check_mutable()
 
-        columns, values = ["start < ?", "end > ?"], [format_datetime(period.get_end_point()), format_datetime(period.get_start_point())]
+        columns, values = self._get_period_values(period)
 
         query, values = self.get_query(
             "delete from %(table)s :condition" % {
@@ -1090,6 +1105,22 @@
 
         self.cursor.execute(query, values)
 
+    def _get_period_values(self, period):
+
+        start = format_datetime(period.get_start_point())
+        end = format_datetime(period.get_end_point())
+
+        columns, values = [], []
+
+        if end:
+            columns.append("start < ?")
+            values.append(end)
+        if start:
+            columns.append("end > ?")
+            values.append(start)
+
+        return columns, values
+
 # Period layout.
 
 def get_scale(periods, tzid, view_period=None):