CREATE OR REPLACE FUNCTION mvlc_get_callnumber(
    cn_id bigint,
    target_lib integer)
  RETURNS integer AS
$BODY$
DECLARE
	existing_cn asset.call_number%ROWTYPE;
	new_cn BIGINT;
BEGIN
	SELECT INTO existing_cn * FROM asset.call_number WHERE id = cn_id;
	IF existing_cn.owning_lib = target_lib AND NOT existing_cn.deleted THEN
		RETURN existing_cn.id;
	ELSIF existing_cn.owning_lib = target_lib THEN
		SELECT INTO new_cn id FROM asset.call_number
			WHERE record = existing_cn.record
			AND owning_lib = target_lib
			AND label = existing_cn.label
			AND prefix = existing_cn.prefix
			AND suffix = existing_cn.suffix
			AND NOT deleted;
		IF FOUND THEN
			RETURN new_cn;
		ELSE
			UPDATE asset.call_number SET deleted = false WHERE id = existing_cn.id;
			RETURN existing_cn.id;
		END IF;
	ELSE
		SELECT INTO new_cn id FROM asset.call_number
			WHERE record = existing_cn.record
			AND owning_lib = target_lib
			AND label = existing_cn.label
			AND prefix = existing_cn.prefix
			AND suffix = existing_cn.suffix;
		IF FOUND THEN
			SELECT INTO new_cn evergreen.mvlc_get_callnumber(new_cn, target_lib); -- Let a recursive call handle "use or undelete"
		ELSE
			INSERT INTO asset.call_number (creator, editor, record, owning_lib, label, prefix, suffix, label_class)
				VALUES (existing_cn.creator, existing_cn.editor, existing_cn.record, target_lib, existing_cn.label, existing_cn.prefix, existing_cn.suffix, existing_cn.label_class)
				RETURNING id INTO new_cn;
		END IF;
		RETURN new_cn;
	END IF;
	RAISE EXCEPTION 'Something went wrong with mvlc_get_callnumber: % %', cn_id, target_lib;
	RETURN -1; -- Bring back as pre-cat?
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

CREATE OR REPLACE FUNCTION mvlc_relabel_callnumber(
    callnumber_id integer,
    new_label text)
  RETURNS integer AS
$BODY$
DECLARE
    callnumber asset.call_number%ROWTYPE;
    existing_cn asset.call_number%ROWTYPE;
BEGIN
    SELECT INTO callnumber *
    FROM asset.call_number WHERE id = callnumber_id AND NOT deleted;
    IF NOT FOUND THEN
        RETURN NULL;
    END IF;
    IF callnumber.label = new_label THEN
        RETURN callnumber.id;
    END IF;
    SELECT INTO existing_cn *
    FROM asset.call_number
    WHERE label = new_label
    AND owning_lib = callnumber.owning_lib
    AND record = callnumber.record
    AND prefix = callnumber.prefix
    AND suffix = callnumber.suffix
    AND NOT deleted;
    IF FOUND THEN
        UPDATE asset.copy SET call_number = existing_cn.id
        WHERE call_number = callnumber.id AND NOT deleted;
        UPDATE action.hold_request SET target = existing_cn.id
        WHERE taget = callnumber.id AND hold_type = 'V';
        DELETE FROM asset.call_number WHERE id = callnumber.id;
        RETURN existing_cn.id;
    ELSE
        UPDATE asset.call_number SET label = new_label WHERE id = callnumber.id;
        RETURN callnumber.id;
    END IF;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;