tps/interface/map_def/sample_regex.sql

DROP FUNCTION IF EXISTS tps.test_regex(jsonb);
CREATE FUNCTION tps.test_regex(_defn jsonb) RETURNS jsonb
LANGUAGE plpgsql
AS
$f$
DECLARE
    _rslt jsonb;
BEGIN

    WITH

    --------------------apply regex operations to transactions---------------------------------------------------------------------------------

    rx AS (
    SELECT 
        t.srce,
        t.id,
        t.rec,
        m.target,
        m.seq,
        regex->>'function' regex_function,
        e.v ->> 'field' result_key_name,
        e.v ->> 'key' target_json_path,
        e.v ->> 'flag' regex_options_flag,
        e.v->>'map' map_intention,
        e.v->>'retain' retain_result,
        e.v->>'regex' regex_expression,
        e.rn target_item_number,
        COALESCE(mt.rn,rp.rn,1) result_number,
        mt.mt rx_match,
        rp.rp rx_replace,
        --------------------------json key name assigned to return value-----------------------------------------------------------------------
        CASE e.v->>'map'
            WHEN 'y' THEN
                e.v->>'field'
            ELSE
                null
        END map_key,
        --------------------------json value resulting from regular expression-----------------------------------------------------------------
        CASE e.v->>'map'
            WHEN 'y' THEN
                CASE regex->>'function'
                    WHEN 'extract' THEN
                        CASE WHEN array_upper(mt.mt,1)=1 
                            THEN to_json(mt.mt[1])
                            ELSE array_to_json(mt.mt)
                        END::jsonb
                    WHEN 'replace' THEN
                        to_jsonb(rp.rp)
                    ELSE
                        '{}'::jsonb
                END
            ELSE
                NULL
        END map_val,
        --------------------------flag for if retruned regex result is stored as a new part of the final json output---------------------------
        CASE e.v->>'retain'
            WHEN 'y' THEN
                e.v->>'field'
            ELSE
                NULL
        END retain_key,
        --------------------------push regex result into json object---------------------------------------------------------------------------
        CASE e.v->>'retain'
            WHEN 'y' THEN
                CASE regex->>'function'
                    WHEN 'extract' THEN
                        CASE WHEN array_upper(mt.mt,1)=1 
                            THEN to_json(trim(mt.mt[1]))
                            ELSE array_to_json(mt.mt)
                        END::jsonb
                    WHEN 'replace' THEN
                        to_jsonb(rtrim(rp.rp))
                    ELSE
                        '{}'::jsonb
                END
            ELSE
                NULL
        END retain_val
    FROM 
        --------------------------start with all regex maps------------------------------------------------------------------------------------
        (SELECT _defn->>'srce' srce, _defn->>'name' target, _defn->'regex' regex, (_defn->>'sequence')::numeric seq) m
        --------------------------isolate matching basis to limit map to only look at certain json---------------------------------------------
        JOIN LATERAL jsonb_array_elements(m.regex->'where') w(v) ON TRUE
        --------------------------break out array of regluar expressions in the map------------------------------------------------------------
        JOIN LATERAL jsonb_array_elements(m.regex->'defn') WITH ORDINALITY e(v, rn) ON true
        --------------------------join to main transaction table but only certain key/values are included--------------------------------------
        INNER JOIN tps.trans t ON 
            t.srce = m.srce AND
            t.rec @> w.v
        --------------------------each regex references a path to the target value, extract the target from the reference and do regex---------
        LEFT JOIN LATERAL regexp_matches(t.rec #>> ((e.v ->> 'key')::text[]), e.v ->> 'regex'::text,COALESCE(e.v ->> 'flag','')) WITH ORDINALITY mt(mt, rn) ON
            m.regex->>'function' = 'extract'
        --------------------------same as above but for a replacement type function------------------------------------------------------------
        LEFT JOIN LATERAL regexp_replace(t.rec #>> ((e.v ->> 'key')::text[]), e.v ->> 'regex'::text, e.v ->> 'replace'::text,e.v ->> 'flag') WITH ORDINALITY rp(rp, rn) ON
            m.regex->>'function' = 'replace'
    )

    --SELECT * FROM rx LIMIT 100


    , agg_to_target_items AS (
    SELECT 
        srce
        ,id
        ,target
        ,seq
        ,map_intention
        ,regex_function
        ,target_item_number
        ,result_key_name
        ,target_json_path
        ,CASE WHEN map_key IS NULL 
            THEN    
                NULL 
            ELSE 
                jsonb_build_object(
                    map_key,
                    CASE WHEN max(result_number) = 1
                        THEN
                            jsonb_agg(map_val ORDER BY result_number) -> 0
                        ELSE
                            jsonb_agg(map_val ORDER BY result_number)
                    END
                ) 
        END map_val
        ,CASE WHEN retain_key IS NULL 
            THEN 
                NULL 
            ELSE 
                jsonb_build_object(
                    retain_key,
                    CASE WHEN max(result_number) = 1
                        THEN
                            jsonb_agg(retain_val ORDER BY result_number) -> 0
                        ELSE
                            jsonb_agg(retain_val ORDER BY result_number)
                    END
                ) 
        END retain_val
    FROM 
        rx
    GROUP BY
        srce
        ,id
        ,target
        ,seq
        ,map_intention
        ,regex_function
        ,target_item_number
        ,result_key_name
        ,target_json_path
        ,map_key
        ,retain_key
    )

    --SELECT * FROM agg_to_target_items LIMIT 100


    , agg_to_target AS (
    SELECT
        srce
        ,id
        ,target
        ,seq
        ,map_intention
        ,tps.jsonb_concat_obj(COALESCE(map_val,'{}'::JSONB)) map_val
        ,jsonb_strip_nulls(tps.jsonb_concat_obj(COALESCE(retain_val,'{}'::JSONB))) retain_val
    FROM
        agg_to_target_items
    GROUP BY
        srce
        ,id
        ,target
        ,seq
        ,map_intention
    )


    , agg_to_ret AS (
    SELECT
        srce
        ,target
        ,seq
        ,map_intention
        ,map_val
        ,retain_val
        ,count(*) "count"
    FROM 
        agg_to_target
    GROUP BY
        srce
        ,target
        ,seq
        ,map_intention
        ,map_val
        ,retain_val
    )
    ,agg_to_id AS (
    SELECT
        l.srce
        ,l.target
        ,l.map_val
        ,l."count"
    FROM
        agg_to_ret l
    ORDER BY
        l.srce
        ,l.target
        ,l."count" desc
    )
    SELECT
        jsonb_agg(row_to_json(agg_to_id)::jsonb)
    INTO
        _rslt
    FROM
        agg_to_id;

    RETURN _rslt;
END;
$f$;