-- Fix preplot_lines_summary view
--
-- New schema version: 0.5.2
--
-- WARNING: This update is buggy and does not give the desired
-- results. Schema version 0.5.4 fixes this.
--
-- 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.
--
-- Following introduction of `preplot_saillines` (0.5.0), the incr and
-- ntba statuses are stored in a separate table, not in `preplot_lines`
-- (TODO: a future upgrade should remove those columns from `preplot_lines`)
--
-- Now any views referencing `incr` and `ntba` must be updated to point to
-- the new location of those attributes.
--
-- This update fixes #312.
--
-- 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 preplot_lines_summary
	AS
	WITH summary AS (
		SELECT DISTINCT pp.line, pp.class,
			first_value(pp.point) OVER w AS p0,
			last_value(pp.point) OVER w AS p1,
			count(pp.point) OVER w AS num_points,
			st_distance(first_value(pp.geometry) OVER w, last_value(pp.geometry) OVER w) AS length,
			st_azimuth(first_value(pp.geometry) OVER w, last_value(pp.geometry) OVER w) * 180::double precision / pi() AS azimuth0,
			st_azimuth(last_value(pp.geometry) OVER w, first_value(pp.geometry) OVER w) * 180::double precision / pi() AS azimuth1
		FROM preplot_points pp
		WHERE pp.class = 'V'::bpchar
		WINDOW w AS (PARTITION BY pp.line ORDER BY pp.point ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)
	)
	SELECT psl.line,
		CASE
			WHEN psl.incr THEN s.p0
			ELSE s.p1
		END AS fsp,
		CASE
			WHEN psl.incr THEN s.p1
			ELSE s.p0
		END AS lsp,
		s.num_points,
		s.length,
		CASE
			WHEN psl.incr THEN s.azimuth0
			ELSE s.azimuth1
		END AS azimuth,
		psl.incr,
		psl.remarks
	FROM summary s
		JOIN preplot_saillines psl ON psl.sailline_class = s.class AND s.line = psl.line
	ORDER BY psl.line, incr;


	ALTER TABLE preplot_lines_summary
		OWNER TO postgres;
	COMMENT ON VIEW preplot_lines_summary
		IS 'Summarises ''V'' (vessel sailline) preplot lines.';



END;
$outer$ LANGUAGE plpgsql;

CREATE OR REPLACE PROCEDURE pg_temp.upgrade () AS $outer$
DECLARE
	row RECORD;
	current_db_version TEXT;
BEGIN

	SELECT value->>'db_schema' INTO current_db_version FROM public.info WHERE key = 'version';

	IF current_db_version >= '0.5.2' THEN
		RAISE EXCEPTION
			USING MESSAGE='Patch already applied';
	END IF;

	IF current_db_version != '0.5.1' THEN
		RAISE EXCEPTION
			USING MESSAGE='Invalid database version: ' || current_db_version,
				HINT='Ensure all previous patches have been applied.';
	END IF;

	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": "0.5.2"}')
ON CONFLICT (key) DO UPDATE
	SET value = public.info.value || '{"db_schema": "0.5.2"}' 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
--