New date-range-based history extractor function signature.

1 files changed, 58 insertions, 15 deletions

diff --git a/talerbank/app/views.py b/talerbank/app/views.py
index fd8ec2a..9249cf3 100644
--- a/talerbank/app/views.py
+++ b/talerbank/app/views.py
@@ -559,9 +559,57 @@ def login_via_headers(view_func):
 
 
 ##
-# Helper function that sorts in a descending, or ascending
-# manner, the history elements returned by the internal routine
-# @a query_history_raw.
+# Build the DB query switch based on the "direction" history
+# argument given by the user.
+#
+# @param bank_account bank account of the user requesting history.
+# @param direction the "direction" URL parameter given by the user.
+#        Note: this values got sanity-checked before this function
+#        is called.
+def direction_switch(bank_account, direction):
+    direction_switch = {
+        "both": (Q(debit_account=bank_account) |
+                 Q(credit_account=bank_account)),
+        "credit": Q(credit_account=bank_account),
+        "debit": Q(debit_account=bank_account),
+        "cancel+": (Q(credit_account=bank_account) &
+                    Q(cancelled=True)),
+        "cancel-": (Q(debit_account=bank_account) &
+                    Q(cancelled=True)),
+    }
+    return direction_switch.get(direction)
+
+##
+# Main routine querying for histories, based on _date ranges_.
+#
+# @param bank_account the bank account object whose
+#        history is being extracted.
+# @param direction takes the following three values,
+#        * debit: only entries where the querying user has _paid_
+#                 will be returned.
+#        * credit: only entries where the querying user _got_
+#                  paid will be returned.
+#        * both: both of the cases above will be returned.
+#        * cancel+: only entries where the querying user cancelled
+#                   the _receiving_ of money will be returned.
+#        * cancel-: only entries where the querying user cancelled
+#                   the _paying_ of money will be returned.
+# @param start timestamp of the oldest element allowed in the
+#        result.
+# @param end timestamp of the youngest element allowed in the
+#        result.
+# @param descending if True, then the results will have the
+#        youngest entry in the first position.
+def query_history_range(bank_account,
+                        direction,
+                        start,
+                        end,
+                        descending):
+    pass
+
+
+##
+# Main routine querying for histories.
 #
 # @param bank_account the bank account object whose
 #        history is being extracted.
@@ -593,24 +641,13 @@ def query_history(bank_account,
                   sign,
                   descending=True):
 
-    direction_switch = {
-        "both": (Q(debit_account=bank_account) |
-                 Q(credit_account=bank_account)),
-        "credit": Q(credit_account=bank_account),
-        "debit": Q(debit_account=bank_account),
-        "cancel+": (Q(credit_account=bank_account) &
-                    Q(cancelled=True)),
-        "cancel-": (Q(debit_account=bank_account) &
-                    Q(cancelled=True)),
-    }
-
     sign_filter = {
         "+": Q(id__gt=start),
         "-": Q(id__lt=start),
     }
 
     qs = BankTransaction.objects.filter(
-        direction_switch.get(direction),
+        direction_switch(bank_account, direction),
         sign_filter.get(sign))
     
     order = "-id" if descending else "id"
@@ -674,6 +711,12 @@ def serve_history(request, user_account):
     if not start:
         start = 0 if "+" == sign else UINT64_MAX
 
+    # query_history_range (bank_account,
+    #                      direction,
+    #                      start,
+    #                      end,
+    #                      ordering)
+
     qs = query_history(user_account.bankaccount,
                        request.GET.get("direction"),
                        int(parsed_delta.group(2)),