-- =============================================================
-- BRONZE CONSTRAINTS AUDIT
-- Target Database: tracksolid_dwh
-- Purpose: Assert that every ON CONFLICT target used by Workflow 2
--          (dwh_load_bronze) is backed by a PRIMARY KEY or UNIQUE
--          constraint in the bronze schema. Fails loudly if a future
--          DDL edit removes a key the ingestion pipeline depends on.
-- Applies after: 260423_dwh_ddl_v1.sql
-- Idempotent: pure assertion, no DDL changes.
-- =============================================================

BEGIN;

DO $$
DECLARE
    missing TEXT := '';
    expected RECORD;
BEGIN
    -- Each row asserts: bronze.<table> has a PK/UNIQUE matching <cols>.
    -- If the pipeline's ON CONFLICT clause ever diverges from this list,
    -- update both here and the n8n load workflow in lockstep.
    FOR expected IN
        SELECT * FROM (VALUES
            ('devices',          'imei'),
            ('live_positions',   'imei'),
            ('position_history', 'imei,gps_time'),
            ('trips',            'id'),
            ('alarms',           'id'),
            ('parking_events',   'id'),
            ('device_events',    'id'),
            ('ingestion_log',    'id')
        ) AS t(table_name, cols)
    LOOP
        IF NOT EXISTS (
            SELECT 1
            FROM pg_constraint c
            JOIN pg_class r     ON r.oid = c.conrelid
            JOIN pg_namespace n ON n.oid = r.relnamespace
            CROSS JOIN LATERAL (
                SELECT string_agg(a.attname, ',' ORDER BY k.ord) AS keycols
                FROM unnest(c.conkey) WITH ORDINALITY AS k(attnum, ord)
                JOIN pg_attribute a
                  ON a.attrelid = c.conrelid AND a.attnum = k.attnum
            ) AS cols
            WHERE n.nspname = 'bronze'
              AND r.relname = expected.table_name
              AND c.contype IN ('p','u')
              AND cols.keycols = expected.cols
        ) THEN
            missing := missing
                    || format(E'\n  - bronze.%s missing PK/UNIQUE on (%s)',
                              expected.table_name, expected.cols);
        END IF;
    END LOOP;

    IF length(missing) > 0 THEN
        RAISE EXCEPTION E'Bronze constraint audit FAILED:%s', missing;
    END IF;

    RAISE NOTICE 'Bronze constraint audit OK: all 8 ON CONFLICT targets backed by PK/UNIQUE.';
END$$;

COMMIT;