--
-- macavity: API surface -- points, status, arm/disarm bookkeeping.
--
-- No fault may fire in this file: every fault armed here uses an
-- occurrence far beyond the number of events the file produces.  The
-- default occurrence (1) and faults that really fire are covered by
-- macavity_faults.sql.
--
CREATE EXTENSION macavity;
-- Every advertised point must be implemented; this list is the contract.
SELECT point, description FROM macavity_points() ORDER BY point;
     point      |                         description                          
----------------+--------------------------------------------------------------
 before_abort   | during transaction abort processing (XACT_EVENT_ABORT)
 before_commit  | before transaction commit processing (XACT_EVENT_PRE_COMMIT)
 executor_end   | after executor execution completes (ExecutorEnd_hook)
 executor_start | before executor execution begins (ExecutorStart_hook)
(4 rows)

-- Nothing armed yet: armed is false, everything else NULL.
SELECT * FROM macavity_status();
 armed | point | action | occurrence | hits | remaining 
-------+-------+--------+------------+------+-----------
 f     |       |        |            |      |          
(1 row)

-- Arming reports through status().  The occurrence is remembered verbatim.
SELECT macavity_arm('executor_start', 'error', 400);
 macavity_arm 
--------------
 
(1 row)

SELECT armed, point, action, occurrence FROM macavity_status();
 armed |     point      | action | occurrence 
-------+----------------+--------+------------
 t     | executor_start | error  |        400
(1 row)

-- Arming again is refused rather than silently replacing the armed fault.
SELECT macavity_arm('executor_end', 'delay');
ERROR:  macavity: a fault is already armed in this session
DETAIL:  Fault point "executor_start" with action "error" is armed at occurrence 400 (2 matching events so far).
HINT:  Call macavity_disarm() first.
SELECT armed, point, action, occurrence FROM macavity_status();
 armed |     point      | action | occurrence 
-------+----------------+--------+------------
 t     | executor_start | error  |        400
(1 row)

-- Disarm returns us to the empty state ...
SELECT macavity_disarm();
 macavity_disarm 
-----------------
 
(1 row)

SELECT * FROM macavity_status();
 armed | point | action | occurrence | hits | remaining 
-------+-------+--------+------------+------+-----------
 f     |       |        |            |      |          
(1 row)

-- ... and is a no-op when nothing is armed.
SELECT macavity_disarm();
 macavity_disarm 
-----------------
 
(1 row)

SELECT macavity_disarm();
 macavity_disarm 
-----------------
 
(1 row)

SELECT armed FROM macavity_status();
 armed 
-------
 f
(1 row)

-- Arming does not count the arming statement itself.  Arm executor_end at
-- a high occurrence and watch the counter: right after arming hits is 0,
-- because the arming statement's own ExecutorEnd was skipped.  Every
-- statement after it -- including each status query -- counts one event, so
-- the second status query reports 2.
SELECT macavity_arm('executor_end', 'error', 500);
 macavity_arm 
--------------
 
(1 row)

SELECT hits, remaining FROM macavity_status();
 hits | remaining 
------+-----------
    0 |       500
(1 row)

SELECT 1 AS first_statement;
 first_statement 
-----------------
               1
(1 row)

SELECT hits, remaining FROM macavity_status();
 hits | remaining 
------+-----------
    2 |       498
(1 row)

SELECT macavity_disarm();
 macavity_disarm 
-----------------
 
(1 row)

SELECT armed FROM macavity_status();
 armed 
-------
 f
(1 row)