From 53bb75a2c1d761ff593124ad2494e19aee8c7f48 Mon Sep 17 00:00:00 2001
From: "D. Berge" <dberge@aaltronav.eu>
Date: Mon, 7 Mar 2022 21:02:25 +0100
Subject: [PATCH] Add new database upgrade file 11.

Some of the things in new upgrade file 12 depend
on the functions defined here.
---
 .../upgrade11-v0.2.1-tstamp-functions.sql     | 137 ++++++++++++++++++
 1 file changed, 137 insertions(+)
 create mode 100644 etc/db/upgrades/upgrade11-v0.2.1-tstamp-functions.sql

diff --git a/etc/db/upgrades/upgrade11-v0.2.1-tstamp-functions.sql b/etc/db/upgrades/upgrade11-v0.2.1-tstamp-functions.sql
new file mode 100644
index 0000000..cee0bd4
--- /dev/null
+++ b/etc/db/upgrades/upgrade11-v0.2.1-tstamp-functions.sql
@@ -0,0 +1,137 @@
+-- Add function to retrieve sequence/shotpoint from timestamps and vice-versa
+--
+-- New schema version: 0.2.1
+--
+-- ATTENTION:
+--
+-- ENSURE YOU HAVE BACKED UP THE DATABASE BEFORE RUNNING THIS SCRIPT.
+--
+--
+-- NOTE: This upgrade affects the public schema.
+-- NOTE: Each application starts a transaction, which must be committed
+-- or rolled back.
+--
+-- Two new functions are defined:
+--
+-- sequence_shot_from_tstamp(tstamp, [tolerance]) → sequence, point, delta
+--
+-- Returns a sequence + shotpoint if one falls within `tolerance` seconds
+-- of `tstamp`. The tolerance may be omitted in which case it defaults to
+-- three seconds. If multiple values match, it returns the closest in time.
+--
+-- tstamp_from_sequence_shot(sequence, point) → tstamp
+--
+-- Returns a timestamp given a sequence and point number.
+--
+-- NOTE: This last function must be called from a search path including a
+-- project schema, as it accesses the raw_shots table.
+--
+-- To apply, run as the dougal user:
+--
+-- psql <<EOF
+-- \i $THIS_FILE
+-- COMMIT;
+-- EOF
+--
+-- NOTE: It can take a while if run on a large database.
+-- NOTE: It can be applied multiple times without ill effect.
+-- NOTE: This will lock the database while the transaction is active.
+--
+-- WARNING: Applying this upgrade drops the old tables. Ensure that you
+-- have migrated the data first.
+--
+-- NOTE: This is a patch version change so it does not require a
+-- backend restart.
+
+BEGIN;
+
+CREATE OR REPLACE PROCEDURE 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 $$
+BEGIN
+
+	RAISE NOTICE 'Updating schema %', schema_name;
+	-- We need to set the search path because some of the trigger
+	-- functions reference other tables in survey schemas assuming
+	-- they are in the search path.
+	EXECUTE format('SET search_path TO %I,public', schema_name);
+
+	CREATE OR REPLACE FUNCTION tstamp_from_sequence_shot(
+		IN s numeric,
+		IN p numeric,
+		OUT "ts" timestamptz)
+	AS $inner$
+		SELECT tstamp FROM raw_shots WHERE sequence = s AND point = p LIMIT 1;
+	$inner$ LANGUAGE SQL;
+
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE PROCEDURE pg_temp.upgrade_database () AS $$
+DECLARE
+	row RECORD;
+BEGIN
+
+
+	CREATE OR REPLACE FUNCTION public.sequence_shot_from_tstamp(
+		IN ts timestamptz,
+		IN tolerance numeric,
+		OUT "sequence" numeric,
+		OUT "point" numeric,
+		OUT "delta" numeric)
+	AS $inner$
+		SELECT
+			(meta->>'_sequence')::numeric AS sequence,
+			(meta->>'_point')::numeric AS point,
+			extract('epoch' FROM (meta->>'tstamp')::timestamptz - ts ) AS delta
+		FROM real_time_inputs
+		WHERE
+			meta ? '_sequence' AND
+			abs(extract('epoch' FROM (meta->>'tstamp')::timestamptz - ts )) < tolerance
+		ORDER BY abs(extract('epoch' FROM (meta->>'tstamp')::timestamptz - ts ))
+		LIMIT 1;
+	$inner$ LANGUAGE SQL;
+
+
+	CREATE OR REPLACE FUNCTION public.sequence_shot_from_tstamp(
+		IN ts timestamptz,
+		OUT "sequence" numeric,
+		OUT "point" numeric,
+		OUT "delta" numeric)
+	AS $inner$
+		SELECT * FROM public.sequence_shot_from_tstamp(ts, 3);
+	$inner$ LANGUAGE SQL;
+
+
+	FOR row IN
+		SELECT schema_name FROM information_schema.schemata
+		WHERE schema_name LIKE 'survey_%'
+		ORDER BY schema_name
+	LOOP
+		CALL pg_temp.upgrade_survey_schema(row.schema_name);
+	END LOOP;
+
+END;
+$$ LANGUAGE plpgsql;
+
+CALL pg_temp.upgrade_database();
+
+CALL show_notice('Cleaning up');
+DROP PROCEDURE pg_temp.upgrade_survey_schema (schema_name text);
+DROP PROCEDURE pg_temp.upgrade_database ();
+
+CALL show_notice('Updating db_schema version');
+
+
+INSERT INTO public.info VALUES ('version', '{"db_schema": "0.2.1"}')
+ON CONFLICT (key) DO UPDATE
+	SET value = public.info.value || '{"db_schema": "0.2.1"}' WHERE public.info.key = 'version';
+
+
+--
+--NOTE Run `COMMIT;` now if all went well
+--