Switch to a single instructions table

To include both payments and payroll.

sql/branch.sql

@@ -1,37 +1,41 @@
 BEGIN;
 
     -- https://github.com/gratipay/inside.gratipay.com/issues/117
-    -- payment_instructions - A user instructs Gratipay to make voluntary payments to a Team.
+    -- instructions - A user instructs Gratipay to make voluntary payments to a Team.
+
+    CREATE TYPE kind_of_instruction AS ENUM ('payment', 'payroll');
+
     ALTER TABLE subscriptions RENAME COLUMN subscriber TO participant;
     ALTER TABLE subscriptions RENAME CONSTRAINT subscriptions_subscriber_fkey
-                                             TO payment_instructions_participant_fkey;
+                                             TO instructions_participant_fkey;
     ALTER TABLE subscriptions RENAME CONSTRAINT subscriptions_team_fkey
-                                             TO payment_instructions_team_fkey;
-    ALTER TABLE subscriptions RENAME TO payment_instructions;
-    ALTER INDEX subscriptions_pkey RENAME TO payment_instructions_pkey;
-    ALTER INDEX subscriptions_all RENAME TO payment_instructions_all;
-    ALTER SEQUENCE subscriptions_id_seq RENAME TO payment_instructions_id_seq;
+                                             TO instructions_team_fkey;
+    ALTER TABLE subscriptions ADD COLUMN kind kind_of_instruction NOT NULL DEFAULT 'payment';
+    ALTER TABLE subscriptions RENAME TO instructions;
+    ALTER INDEX subscriptions_pkey RENAME TO instructions_pkey;
+    ALTER INDEX subscriptions_all RENAME TO instructions_all;
+    ALTER SEQUENCE subscriptions_id_seq RENAME TO instructions_id_seq;
 
     DROP TRIGGER update_current_subscription ON current_subscriptions;
     DROP VIEW current_subscriptions;
-    CREATE VIEW current_payment_instructions AS
+    CREATE VIEW current_instructions AS
         SELECT DISTINCT ON (participant, team) *
-          FROM payment_instructions
+          FROM instructions
       ORDER BY participant, team, mtime DESC;
 
-    -- Allow updating is_funded via the current_payment_instructions view for convenience
+    -- Allow updating is_funded via the current_instructions view for convenience
     DROP FUNCTION update_subscription();
-    CREATE FUNCTION update_payment_instruction() RETURNS trigger AS $$
+    CREATE FUNCTION update_instruction() RETURNS trigger AS $$
         BEGIN
-            UPDATE payment_instructions
+            UPDATE instructions
                SET is_funded = NEW.is_funded
              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();
+    CREATE TRIGGER update_current_instruction
+    INSTEAD OF UPDATE ON current_instructions
+        FOR EACH ROW EXECUTE PROCEDURE update_instruction();
 
 END;