Merge pull request #3675 from gratipay/charge-in-arrears

Charge in arrears

gratipay/billing/payday.py

@@ -19,7 +19,7 @@
 import aspen.utils
 from aspen import log
 from gratipay.billing.exchanges import (
-    cancel_card_hold, capture_card_hold, create_card_hold, upcharge,
+    cancel_card_hold, capture_card_hold, create_card_hold, upcharge, MINIMUM_CHARGE,
 )
 from gratipay.exceptions import NegativeBalance
 from gratipay.models import check_db
@@ -220,17 +220,23 @@ def f(p):
             if p.old_balance < 0:
                 amount -= p.old_balance
             if p.id in holds:
-                charge_amount = upcharge(amount)[0]
-                if holds[p.id].amount >= charge_amount:
-                    return
+                if amount >= MINIMUM_CHARGE:
+                    charge_amount = upcharge(amount)[0]
+                    if holds[p.id].amount >= charge_amount:
+                        return
+                    else:
+                        # The amount is too low, cancel the hold and make a new one
+                        cancel_card_hold(holds.pop(p.id))
                 else:
-                    # The amount is too low, cancel the hold and make a new one
+                    # not up to minimum charge level. cancel the hold
                     cancel_card_hold(holds.pop(p.id))
-            hold, error = create_card_hold(self.db, p, amount)
-            if error:
-                return 1
-            else:
-                holds[p.id] = hold
+                    return
+            if amount >= MINIMUM_CHARGE:
+                hold, error = create_card_hold(self.db, p, amount)
+                if error:
+                    return 1
+                else:
+                    holds[p.id] = hold
         threaded_map(f, participants)
 
         # Update the values of card_hold_ok in our temporary table
@@ -341,6 +347,7 @@ def update_balances(cursor):
                 SELECT *, (SELECT id FROM paydays WHERE extract(year from ts_end) = 1970)
                   FROM payday_payments;
         """)
+
         log("Updated the balances of %i participants." % len(participants))
 
 

gratipay/models/participant.py

@@ -854,10 +854,13 @@ def set_payment_instruction(self, team, amount, update_self=True, update_team=Tr
         """
         args = dict(participant=self.username, team=team.slug, amount=amount)
         t = (cursor or self.db).one(NEW_PAYMENT_INSTRUCTION, args)
+        t_dict = t._asdict()
 
         if update_self:
             # Update giving amount of participant
             self.update_giving(cursor)
+            # Carry over any existing due
+            self.update_due(t_dict['team'], t_dict['id'], cursor)
         if update_team:
             # Update receiving amount of team
             team.update_receiving(cursor)
@@ -890,6 +893,24 @@ def get_payment_instruction(self, team):
         """, (self.username, team.slug), back_as=dict, default=default)
 
 
+    def get_due(self, team):
+        """Given a slug, return a Decimal.
+        """
+        if not isinstance(team, Team):
+            team, slug = Team.from_slug(team), team
+            if not team:
+                raise NoTeam(slug)
+
+        return self.db.one("""\
+
+            SELECT due
+              FROM current_payment_instructions
+             WHERE participant = %s
+               AND team = %s
+
+        """, (self.username, team.slug))
+
+
     def get_giving_for_profile(self):
         """Return a list and a Decimal.
         """
@@ -984,6 +1005,31 @@ def update_giving(self, cursor=None):
 
         return updated
 
+    def update_due(self, team, id, cursor=None):
+        """Transfer existing due value to newly inserted record
+        """
+        # Copy due to new record
+        (cursor or self.db).run("""
+            UPDATE payment_instructions p
+               SET due = COALESCE((
+                      SELECT due
+                        FROM payment_instructions s
+                       WHERE participant=%(username)s
+                         AND team = %(team)s
+                         AND due > 0
+                   ), 0)
+             WHERE p.id = %(id)s
+        """, dict(username=self.username,team=team,id=id))
+
+        # Reset older due values to 0
+        (cursor or self.db).run("""
+            UPDATE payment_instructions p
+               SET due = 0
+             WHERE participant = %(username)s
+               AND team = %(team)s
+               AND due > 0
+               AND p.id != %(id)s
+        """, dict(username=self.username,team=team,id=id))
 
     def update_taking(self, cursor=None):
         (cursor or self.db).run("""

sql/branch.sql

@@ -0,0 +1,27 @@
+BEGIN;
+
+    ALTER TABLE payment_instructions ADD COLUMN due numeric(35,2) DEFAULT 0;
+
+    -- Recreate the current_payment_instructions view to pick up due.
+    DROP VIEW current_payment_instructions;
+    CREATE VIEW current_payment_instructions AS
+        SELECT DISTINCT ON (participant, team) *
+          FROM payment_instructions
+      ORDER BY participant, team, mtime DESC;
+
+    -- Allow updating is_funded and due via the current_payment_instructions view for convenience.
+    DROP FUNCTION update_payment_instruction();
+    CREATE FUNCTION update_payment_instruction() RETURNS trigger AS $$
+        BEGIN
+            UPDATE payment_instructions
+               SET is_funded = NEW.is_funded
+                 , due = NEW.due
+             WHERE id = NEW.id;
+            RETURN NULL;
+        END;
+    $$ LANGUAGE plpgsql;
+
+    CREATE TRIGGER update_current_payment_instruction
+        INSTEAD OF UPDATE ON current_payment_instructions
+        FOR EACH ROW EXECUTE PROCEDURE update_payment_instruction();
+END;

sql/payday.sql

@@ -55,7 +55,7 @@ CREATE TABLE payday_payments_done AS
 
 DROP TABLE IF EXISTS payday_payment_instructions;
 CREATE TABLE payday_payment_instructions AS
-    SELECT participant, team, amount
+    SELECT s.id, participant, team, amount, due
       FROM ( SELECT DISTINCT ON (participant, team) *
                FROM payment_instructions
               WHERE mtime < %(ts_start)s
@@ -77,11 +77,11 @@ CREATE INDEX ON payday_payment_instructions (team);
 ALTER TABLE payday_payment_instructions ADD COLUMN is_funded boolean;
 
 ALTER TABLE payday_participants ADD COLUMN giving_today numeric(35,2);
-UPDATE payday_participants
+UPDATE payday_participants pp
    SET giving_today = COALESCE((
-           SELECT sum(amount)
+           SELECT sum(amount + due)
              FROM payday_payment_instructions
-            WHERE participant = username
+            WHERE participant = pp.username
        ), 0);
 
 DROP TABLE IF EXISTS payday_takes;
@@ -108,6 +108,7 @@ RETURNS void AS $$
     DECLARE
         participant_delta numeric;
         team_delta numeric;
+        payload json;
     BEGIN
         IF ($3 = 0) THEN RETURN; END IF;
 
@@ -125,6 +126,17 @@ RETURNS void AS $$
         UPDATE payday_teams
            SET balance = (balance + team_delta)
          WHERE slug = $2;
+        UPDATE current_payment_instructions
+           SET due = 0
+         WHERE participant = $1
+           AND team = $2
+           AND due > 0;
+        IF ($4 = 'to-team') THEN
+            payload = '{"action":"pay","participant":"' || $1 || '", "team":"'
+                || $2 || '", "amount":' || $3 || '}';
+            INSERT INTO events(type, payload)
+                VALUES ('payday',payload);
+        END IF;
         INSERT INTO payday_payments
                     (participant, team, amount, direction)
              VALUES ( ( SELECT p.username
@@ -141,6 +153,27 @@ RETURNS void AS $$
     END;
 $$ LANGUAGE plpgsql;
 
+-- Add payments that were not met on to due
+
+CREATE OR REPLACE FUNCTION park(text, text, numeric)
+RETURNS void AS $$
+    DECLARE payload json;
+    BEGIN
+        IF ($3 = 0) THEN RETURN; END IF;
+
+        UPDATE current_payment_instructions
+           SET due = $3
+         WHERE participant = $1
+           AND team = $2;
+
+        payload = '{"action":"due","participant":"' || $1 || '", "team":"'
+            || $2 || '", "due":' || $3 || '}';
+        INSERT INTO events(type, payload)
+            VALUES ('payday',payload);
+
+    END;
+$$ LANGUAGE plpgsql;
+
 
 -- Create a trigger to process payment_instructions
 
@@ -153,9 +186,12 @@ CREATE OR REPLACE FUNCTION process_payment_instruction() RETURNS trigger AS $$
               FROM payday_participants p
              WHERE username = NEW.participant
         );
-        IF (NEW.amount <= participant.new_balance OR participant.card_hold_ok) THEN
-            EXECUTE pay(NEW.participant, NEW.team, NEW.amount, 'to-team');
+        IF (NEW.amount + NEW.due <= participant.new_balance OR participant.card_hold_ok) THEN
+            EXECUTE pay(NEW.participant, NEW.team, NEW.amount + NEW.due, 'to-team');
             RETURN NEW;
+        ELSE
+            EXECUTE park(NEW.participant, NEW.team, NEW.amount + NEW.due);
+            RETURN NULL;
         END IF;
         RETURN NULL;
     END;
@@ -166,7 +202,6 @@ CREATE TRIGGER process_payment_instruction BEFORE UPDATE OF is_funded ON payday_
     WHEN (NEW.is_funded IS true AND OLD.is_funded IS NOT true)
     EXECUTE PROCEDURE process_payment_instruction();
 
-
 -- Create a trigger to process takes
 
 CREATE OR REPLACE FUNCTION process_take() RETURNS trigger AS $$