--
-- Rules queries
-- All SQL for api/routes/rules.js
--

SET search_path TO dataflow, public;

-- ── CRUD ─────────────────────────────────────────────────────────────────────

CREATE OR REPLACE FUNCTION list_rules(p_source_name TEXT)
RETURNS SETOF dataflow.rules AS $$
    SELECT * FROM dataflow.rules
    WHERE source_name = p_source_name
    ORDER BY sequence, name;
$$ LANGUAGE sql STABLE;

CREATE OR REPLACE FUNCTION get_rule(p_id INT)
RETURNS dataflow.rules AS $$
    SELECT * FROM dataflow.rules WHERE id = p_id;
$$ LANGUAGE sql STABLE;

CREATE OR REPLACE FUNCTION create_rule(
    p_source_name  TEXT,
    p_name         TEXT,
    p_field        TEXT,
    p_pattern      TEXT,
    p_output_field TEXT,
    p_function_type TEXT DEFAULT 'extract',
    p_flags        TEXT DEFAULT '',
    p_replace_value TEXT DEFAULT '',
    p_enabled      BOOLEAN DEFAULT TRUE,
    p_retain       BOOLEAN DEFAULT FALSE,
    p_sequence     INT DEFAULT 0
)
RETURNS dataflow.rules AS $$
    INSERT INTO dataflow.rules
        (source_name, name, field, pattern, output_field, function_type, flags, replace_value, enabled, retain, sequence)
    VALUES
        (p_source_name, p_name, p_field, p_pattern, p_output_field, p_function_type, p_flags, p_replace_value, p_enabled, p_retain, p_sequence)
    RETURNING *;
$$ LANGUAGE sql;

CREATE OR REPLACE FUNCTION update_rule(
    p_id           INT,
    p_name         TEXT DEFAULT NULL,
    p_field        TEXT DEFAULT NULL,
    p_pattern      TEXT DEFAULT NULL,
    p_output_field TEXT DEFAULT NULL,
    p_function_type TEXT DEFAULT NULL,
    p_flags        TEXT DEFAULT NULL,
    p_replace_value TEXT DEFAULT NULL,
    p_enabled      BOOLEAN DEFAULT NULL,
    p_retain       BOOLEAN DEFAULT NULL,
    p_sequence     INT DEFAULT NULL
)
RETURNS dataflow.rules AS $$
    UPDATE dataflow.rules SET
        name          = COALESCE(p_name, name),
        field         = COALESCE(p_field, field),
        pattern       = COALESCE(p_pattern, pattern),
        output_field  = COALESCE(p_output_field, output_field),
        function_type = COALESCE(p_function_type, function_type),
        flags         = COALESCE(p_flags, flags),
        replace_value = COALESCE(p_replace_value, replace_value),
        enabled       = COALESCE(p_enabled, enabled),
        retain        = COALESCE(p_retain, retain),
        sequence      = COALESCE(p_sequence, sequence)
    WHERE id = p_id
    RETURNING *;
$$ LANGUAGE sql;

CREATE OR REPLACE FUNCTION delete_rule(p_id INT)
RETURNS TABLE (id INT, name TEXT) AS $$
    DELETE FROM dataflow.rules WHERE id = p_id RETURNING id, name;
$$ LANGUAGE sql;

-- ── Preview (ad-hoc pattern, no saved rule) ───────────────────────────────────

CREATE OR REPLACE FUNCTION preview_rule(
    p_source        TEXT,
    p_field         TEXT,
    p_pattern       TEXT,
    p_flags         TEXT DEFAULT '',
    p_function_type TEXT DEFAULT 'extract',
    p_replace_value TEXT DEFAULT '',
    p_limit         INT  DEFAULT 20
)
RETURNS TABLE (id BIGINT, raw_value TEXT, extracted_value JSONB) AS $$
BEGIN
    IF p_function_type = 'replace' THEN
        RETURN QUERY
        SELECT
            r.id,
            r.data ->> p_field,
            to_jsonb(regexp_replace(r.data ->> p_field, p_pattern, p_replace_value, p_flags))
        FROM dataflow.records r
        WHERE source_name = p_source AND data ? p_field
        ORDER BY r.id DESC LIMIT p_limit;
    ELSE
        RETURN QUERY
        SELECT
            r.id,
            r.data ->> p_field,
            CASE
                WHEN agg.match_count = 0 THEN NULL
                WHEN agg.match_count = 1 THEN agg.matches -> 0
                ELSE agg.matches
            END
        FROM dataflow.records r
        CROSS JOIN LATERAL (
            SELECT
                jsonb_agg(
                    CASE WHEN array_length(mt, 1) = 1 THEN to_jsonb(mt[1]) ELSE to_jsonb(mt) END
                    ORDER BY rn
                ) AS matches,
                count(*)::int AS match_count
            FROM regexp_matches(r.data ->> p_field, p_pattern, p_flags)
            WITH ORDINALITY AS m(mt, rn)
        ) agg
        WHERE r.source_name = p_source AND r.data ? p_field
        ORDER BY r.id DESC LIMIT p_limit;
    END IF;
END;
$$ LANGUAGE plpgsql STABLE;

-- ── Test (saved rule against real records) ────────────────────────────────────

CREATE OR REPLACE FUNCTION test_rule(p_rule_id INT, p_limit INT DEFAULT 20)
RETURNS TABLE (rule JSONB, results JSONB) AS $$
DECLARE
    v_rule dataflow.rules%ROWTYPE;
    v_results JSONB;
BEGIN
    SELECT * INTO v_rule FROM dataflow.rules WHERE id = p_rule_id;
    IF NOT FOUND THEN RETURN; END IF;

    SELECT jsonb_agg(row_to_json(t)) INTO v_results FROM (
        SELECT
            r.id,
            r.data ->> v_rule.field AS raw_value,
            CASE
                WHEN agg.match_count = 0 THEN NULL
                WHEN agg.match_count = 1 AND array_length(agg.matches[1], 1) = 1
                    THEN to_jsonb(agg.matches[1][1])
                WHEN agg.match_count = 1
                    THEN to_jsonb(agg.matches[1])
                WHEN array_length(agg.matches[1], 1) = 1
                    THEN (SELECT jsonb_agg(m[1] ORDER BY idx) FROM unnest(agg.matches) WITH ORDINALITY u(m, idx))
                ELSE to_jsonb(agg.matches)
            END AS extracted_value
        FROM dataflow.records r
        CROSS JOIN LATERAL (
            SELECT array_agg(mt ORDER BY rn) AS matches, count(*)::int AS match_count
            FROM regexp_matches(r.data ->> v_rule.field, v_rule.pattern, COALESCE(v_rule.flags, ''))
            WITH ORDINALITY AS m(mt, rn)
        ) agg
        WHERE r.source_name = v_rule.source_name AND r.data ? v_rule.field
        ORDER BY r.id DESC LIMIT p_limit
    ) t;

    RETURN QUERY SELECT
        jsonb_build_object(
            'id', v_rule.id, 'name', v_rule.name,
            'field', v_rule.field, 'pattern', v_rule.pattern,
            'output_field', v_rule.output_field
        ),
        COALESCE(v_results, '[]'::jsonb);
END;
$$ LANGUAGE plpgsql STABLE;