-- pg_tre 1.0.0 -- native index AM for approximate regex matching.
--
-- Phase 0 scope: registers the `tre` access method, the legacy UDFs
-- inherited from 0.1.0, and the handler function.  The opclass is
-- declared so CREATE INDEX ... USING tre succeeds syntactically; scan
-- and insert paths are wired in by later phases and will raise a
-- clear "not yet implemented" error until then.
--
-- Do not run ALTER EXTENSION ... UPDATE on a production index; the
-- on-disk format is stabilized at 1.0.0.

-- ---------------------------------------------------------------------
-- Legacy UDFs (unchanged from 0.1.0)
-- ---------------------------------------------------------------------

CREATE FUNCTION tre_amatch(text, text, int4)
    RETURNS bool
    AS 'MODULE_PATHNAME', 'pg_tre_amatch'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_amatch_cost(text, text, int4)
    RETURNS int4
    AS 'MODULE_PATHNAME', 'pg_tre_amatch_cost'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_amatch(text, text, int4, int4, int4, int4)
    RETURNS bool
    AS 'MODULE_PATHNAME', 'pg_tre_amatch_with_costs'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_amatch_detail(text, text, int4)
    RETURNS TABLE(cost int4, num_ins int4, num_del int4, num_subst int4,
                  match_start int4, match_end int4)
    AS 'MODULE_PATHNAME', 'pg_tre_amatch_detail'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE
    ROWS 1;

CREATE FUNCTION tre_version()
    RETURNS text
    AS 'MODULE_PATHNAME', 'pg_tre_version'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

-- ---------------------------------------------------------------------
-- Debug UDFs (Phase 3)
-- ---------------------------------------------------------------------

CREATE FUNCTION tre_parse_debug(text)
    RETURNS text
    AS 'MODULE_PATHNAME', 'tre_parse_debug'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_extract_debug(text)
    RETURNS text
    AS 'MODULE_PATHNAME', 'tre_extract_debug'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_extract_debug(text, int)
    RETURNS text
    AS 'MODULE_PATHNAME', 'tre_extract_debug_k'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

-- ---------------------------------------------------------------------
-- Access method registration
-- ---------------------------------------------------------------------

CREATE FUNCTION tre_handler(internal)
    RETURNS index_am_handler
    AS 'MODULE_PATHNAME', 'tre_handler'
    LANGUAGE C;

CREATE ACCESS METHOD tre
    TYPE INDEX
    HANDLER tre_handler;

COMMENT ON ACCESS METHOD tre IS
    'approximate-regex index (pg_tre)';

-- ---------------------------------------------------------------------
-- tre_pattern type
-- ---------------------------------------------------------------------

CREATE TYPE tre_pattern;

CREATE FUNCTION tre_pattern_in(cstring)
    RETURNS tre_pattern
    AS 'MODULE_PATHNAME', 'tre_pattern_in'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_pattern_out(tre_pattern)
    RETURNS cstring
    AS 'MODULE_PATHNAME', 'tre_pattern_out'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_pattern_recv(internal)
    RETURNS tre_pattern
    AS 'MODULE_PATHNAME', 'tre_pattern_recv'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_pattern_send(tre_pattern)
    RETURNS bytea
    AS 'MODULE_PATHNAME', 'tre_pattern_send'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE TYPE tre_pattern (
    INPUT = tre_pattern_in,
    OUTPUT = tre_pattern_out,
    RECEIVE = tre_pattern_recv,
    SEND = tre_pattern_send,
    STORAGE = extended
);

-- Constructor functions

CREATE FUNCTION tre_pattern(text)
    RETURNS tre_pattern
    AS 'MODULE_PATHNAME', 'tre_pattern_make'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_pattern(text, int4)
    RETURNS tre_pattern
    AS 'MODULE_PATHNAME', 'tre_pattern_make_k'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_pattern(text, int4, int4, int4, int4)
    RETURNS tre_pattern
    AS 'MODULE_PATHNAME', 'tre_pattern_make_full'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

-- ---------------------------------------------------------------------
-- Operators
-- ---------------------------------------------------------------------

CREATE FUNCTION tre_match_scalar(text, tre_pattern)
    RETURNS bool
    AS 'MODULE_PATHNAME', 'tre_match_scalar'
    LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;

CREATE FUNCTION tre_pattern_sel(internal, oid, internal, int4)
    RETURNS float8
    AS 'MODULE_PATHNAME', 'tre_pattern_sel'
    LANGUAGE C STRICT;

CREATE OPERATOR %~~ (
    LEFTARG = text,
    RIGHTARG = tre_pattern,
    FUNCTION = tre_match_scalar,
    RESTRICT = tre_pattern_sel
);

COMMENT ON OPERATOR %~~ (text, tre_pattern) IS
    'approximate regex match (pg_tre)';

-- ---------------------------------------------------------------------
-- Opclass for text columns.
--
-- Strategy 1: text %~~ tre_pattern  (approximate regex match)
-- ---------------------------------------------------------------------

DROP OPERATOR CLASS IF EXISTS tre_text_ops USING tre CASCADE;

CREATE OPERATOR CLASS tre_text_ops
    DEFAULT FOR TYPE text USING tre AS
    OPERATOR 1 %~~ (text, tre_pattern),
    STORAGE text;