/**
 * Test for the functions replace_encoding
 *
 * Every test does raise division by zero if it failes
 */
BEGIN;

-- Test if the function exists
WITH test AS
	(
		SELECT count(*) AS exist
		FROM pg_catalog.pg_proc
		WHERE proname = 'replace_encoding'
	)
SELECT 3 / test.exist = 1 AS res
FROM test
;

-- Test if all three implementations exists
WITH test AS
	(
		SELECT count(*) AS exist
			, 0 AS zero
		FROM pg_catalog.pg_proc
		WHERE proname = 'replace_encoding'
	)
SELECT
	CASE
		WHEN test.exist = 3 THEN
			TRUE
		ELSE
			(1 / test.zero)::BOOLEAN
	END AS res
FROM test
;

-- Test of the first implementation which replaces none latin1 characters with
-- empty strings
WITH test AS
	(
		SELECT 'ağbƵcğeƵ'::TEXT AS test_string
			, 'latin1'::TEXT AS enc
		, 0 AS zero
	)
SELECT
	CASE
		WHEN length(test_string) = 8 AND length(replace_encoding(test_string, enc)) = 4 THEN
			TRUE
		ELSE
			(1 / test.zero)::BOOLEAN
	END AS res_1
	, CASE
		WHEN is_encoding(replace_encoding(test_string, enc), enc) THEN
			TRUE
		ELSE
			(1 / test.zero)::BOOLEAN
	END AS res_2
FROM test
;

-- Test of the second implementation which replaces none latin1 characters with
-- second parameter
WITH test AS
	(
		SELECT 'ağbcğe'::TEXT AS test_string
			, 'latin1'::TEXT AS enc
			, 'g'::TEXT AS replacement
			, 0 AS zero
	)
SELECT
	CASE
		WHEN length(test_string) = length(replace_encoding(test_string, enc, replacement)) THEN
			TRUE
		ELSE
			(1 / test.zero)::BOOLEAN
	END AS res_1
	, CASE
		WHEN is_encoding(replace_encoding(test_string, enc, replacement), enc) THEN
			TRUE
		ELSE
			(1 / test.zero)::BOOLEAN
	END AS res_2
FROM test
;

-- Test of the third implementation which replaces given none latin1 characters
-- in an array as second parameter with latin1 characters given in an array as
-- the third paramater
WITH test AS
	(
		SELECT 'ağbƵcğeƵ'::TEXT AS test_string
			, string_to_array('ğ,Ƶ'::TEXT, ',') AS to_replace
			, string_to_array('g,Z'::TEXT, ',') AS replacement
			, 0 AS zero
	)
SELECT
	CASE
		WHEN length(test_string) = length(replace_encoding(test_string, to_replace, replacement)) THEN
			TRUE
		ELSE
			(1 / test.zero)::BOOLEAN
	END AS res_1
	, CASE
		WHEN is_latin1(replace_encoding(test_string, to_replace, replacement)) THEN
			TRUE
		ELSE
			(1 / test.zero)::BOOLEAN
	END AS res_2
FROM test
;

ROLLBACK;