Add database upgrade file 25.

This defines a midnight_shots view and a log_midnight_shots() procedure
(with some overloads). The view returns all points straddling midnight
UTC and belonging to the same sequence (so last shot of the day and
first shot of the next day).

The procedure inserts the corresponding events (optionally constrained
by an earliest and a latest date) in the event log, unless the events
already exist.

Related to #223.

etc/db/upgrades/upgrade25-v0.3.12-add-midnight-shots-procedure.sql

@@ -0,0 +1,177 @@
+-- Fix not being able to edit a time-based event.
+--
+-- New schema version: 0.3.12
+--
+-- ATTENTION:
+--
+-- ENSURE YOU HAVE BACKED UP THE DATABASE BEFORE RUNNING THIS SCRIPT.
+--
+--
+-- NOTE: This upgrade affects all schemas in the database.
+-- NOTE: Each application starts a transaction, which must be committed
+-- or rolled back.
+--
+-- This defines a midnight_shots view and a log_midnight_shots() procedure
+-- (with some overloads). The view returns all points straddling midnight
+-- UTC and belonging to the same sequence (so last shot of the day and
+-- first shot of the next day).
+--
+-- The procedure inserts the corresponding events (optionally constrained
+-- by an earliest and a latest date) in the event log, unless the events
+-- already exist.
+--
+-- To apply, run as the dougal user:
+--
+-- psql <<EOF
+-- \i $THIS_FILE
+-- COMMIT;
+-- EOF
+--
+-- NOTE: It can be applied multiple times without ill effect.
+--
+
+BEGIN;
+
+CREATE OR REPLACE PROCEDURE pg_temp.show_notice (notice text) AS $$
+BEGIN
+	RAISE NOTICE '%', notice;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE PROCEDURE pg_temp.upgrade_survey_schema (schema_name text) AS $outer$
+BEGIN
+
+	RAISE NOTICE 'Updating schema %', schema_name;
+	-- We need to set the search path because some of the trigger
+	-- functions reference other tables in survey schemas assuming
+	-- they are in the search path.
+	EXECUTE format('SET search_path TO %I,public', schema_name);
+
+	CREATE OR REPLACE VIEW midnight_shots AS
+	WITH straddlers AS (
+		-- Get sequence numbers straddling midnight UTC
+		SELECT sequence
+		FROM raw_shots
+		GROUP BY sequence
+		HAVING min(date(tstamp)) != max(date(tstamp))
+	),
+	ts AS (
+		-- Get earliest and latest timestamps for each day
+		-- for each of the above sequences.
+		-- This will return the timestamps for:
+		-- FSP, LDSP, FDSP, LSP.
+		SELECT
+			rs.sequence,
+			min(rs.tstamp) AS ts0,
+			max(rs.tstamp) AS ts1
+		FROM raw_shots rs INNER JOIN straddlers USING (sequence)
+		GROUP BY rs.sequence, (date(rs.tstamp))
+		ORDER BY rs.sequence, date(rs.tstamp)
+	),
+	spts AS (
+		-- Filter out FSP, LSP from the above.
+		-- NOTE: This *should* in theory be able to cope with
+		-- a sequence longer than 24 hours (so with more than
+		-- one LDSP, FDSP) but that hasn't been tested.
+		SELECT DISTINCT
+			sequence,
+			min(ts1) OVER (PARTITION BY sequence) ldsp,
+			max(ts0) OVER (PARTITION BY sequence) fdsp
+		FROM ts
+		ORDER BY sequence
+	), evt AS (
+		SELECT
+			rs.tstamp,
+			rs.sequence,
+			point,
+			'Last shotpoint of the day' remarks,
+			'{LDSP}'::text[] labels
+		FROM raw_shots rs
+			INNER JOIN spts ON rs.sequence = spts.sequence AND rs.tstamp = spts.ldsp
+		UNION SELECT
+			rs.tstamp,
+			rs.sequence,
+			point,
+			'First shotpoint of the day' remarks,
+			'{FDSP}'::text[] labels
+		FROM raw_shots rs
+			INNER JOIN spts ON rs.sequence = spts.sequence AND rs.tstamp = spts.fdsp
+		ORDER BY tstamp
+	)
+	SELECT * FROM evt;
+
+
+	CREATE OR REPLACE PROCEDURE log_midnight_shots (dt0 date, dt1 date)
+	LANGUAGE sql
+	AS $$
+		INSERT INTO event_log (sequence, point, remarks, labels)
+		SELECT sequence, point, remarks, labels
+		FROM midnight_shots ms
+		WHERE
+			(dt0 IS NULL OR ms.tstamp >= dt0) AND
+			(dt1 IS NULL OR ms.tstamp <= dt1) AND
+			NOT EXISTS (
+				SELECT 1
+				FROM event_log el
+				WHERE ms.sequence = el.sequence AND ms.point = el.point AND el.labels @> ms.labels
+			);
+	$$;
+
+	COMMENT ON PROCEDURE log_midnight_shots (date, date)
+		IS 'Add midnight shots between two dates dt0 and dt1 to the event_log, unless the events already exist.';
+
+
+	CREATE OR REPLACE PROCEDURE log_midnight_shots (dt0 date)
+	LANGUAGE sql
+	AS $$
+		CALL log_midnight_shots(dt0, NULL);
+	$$;
+
+	COMMENT ON PROCEDURE log_midnight_shots (date)
+		IS 'Overload taking only a dt0 (adds events on that date or after).';
+
+	CREATE OR REPLACE PROCEDURE log_midnight_shots ()
+	LANGUAGE sql
+	AS $$
+		CALL log_midnight_shots(NULL, NULL);
+	$$;
+
+	COMMENT ON PROCEDURE log_midnight_shots ()
+		IS 'Overload taking no arguments (adds all missing events).';
+
+END;
+$outer$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE PROCEDURE pg_temp.upgrade () AS $outer$
+DECLARE
+	row RECORD;
+BEGIN
+
+	FOR row IN
+		SELECT schema_name FROM information_schema.schemata
+		WHERE schema_name LIKE 'survey_%'
+		ORDER BY schema_name
+	LOOP
+		CALL pg_temp.upgrade_survey_schema(row.schema_name);
+	END LOOP;
+END;
+$outer$ LANGUAGE plpgsql;
+
+CALL pg_temp.upgrade();
+
+CALL pg_temp.show_notice('Cleaning up');
+DROP PROCEDURE pg_temp.upgrade_survey_schema (schema_name text);
+DROP PROCEDURE pg_temp.upgrade ();
+
+CALL pg_temp.show_notice('Updating db_schema version');
+INSERT INTO public.info VALUES ('version', '{"db_schema": "0.3.12"}')
+ON CONFLICT (key) DO UPDATE
+	SET value = public.info.value || '{"db_schema": "0.3.12"}' WHERE public.info.key = 'version';
+
+
+CALL pg_temp.show_notice('All done. You may now run "COMMIT;" to persist the changes');
+DROP PROCEDURE pg_temp.show_notice (notice text);
+
+--
+--NOTE Run `COMMIT;` now if all went well
+--