-- Add one explicit active Booking source batch for full-workbook replacement imports.
-- PostgreSQL 15+. Migrations 008-013 remain immutable.

BEGIN;

DO $$
BEGIN
    IF current_database() <> 'booking_test' THEN
        RAISE EXCEPTION
            'ARR Booking current-source migration is allowed only in booking_test';
    END IF;
    IF to_regclass('booking.source_batches') IS NULL
       OR to_regclass('booking.current_row_parses') IS NULL
       OR NOT EXISTS (
           SELECT 1
           FROM information_schema.columns
           WHERE table_schema = 'ingestion'
             AND table_name = 'processing_runs'
             AND column_name = 'uploaded_filename'
       ) THEN
        RAISE EXCEPTION
            'ARR migrations 008 through 013 must be applied first';
    END IF;
    IF to_regclass('booking.current_source_batch') IS NOT NULL THEN
        RAISE EXCEPTION
            'ARR Booking current-source migration is already applied';
    END IF;
END;
$$;

CREATE TABLE booking.current_source_batch (
    singleton boolean PRIMARY KEY DEFAULT true CHECK (singleton),
    source_batch_id bigint NOT NULL UNIQUE
        REFERENCES booking.source_batches(id),
    activated_at timestamptz NOT NULL DEFAULT now()
);

COMMENT ON TABLE booking.current_source_batch IS
  'Singleton pointer to the one accepted full Booking source batch used by Finance matching and company reports.';

CREATE OR REPLACE FUNCTION booking.validate_current_source_batch()
RETURNS trigger
LANGUAGE plpgsql
AS $$
BEGIN
    IF NOT EXISTS (
        SELECT 1
        FROM booking.source_batches AS batch
        WHERE batch.id = NEW.source_batch_id
          AND batch.batch_status = 'accepted'
    ) THEN
        RAISE EXCEPTION
            'current Booking source must reference an accepted source batch';
    END IF;
    RETURN NEW;
END;
$$;

CREATE TRIGGER current_source_batch_acceptance_guard
BEFORE INSERT OR UPDATE ON booking.current_source_batch
FOR EACH ROW
EXECUTE FUNCTION booking.validate_current_source_batch();

INSERT INTO booking.current_source_batch (
    singleton,
    source_batch_id,
    activated_at
)
SELECT
    true,
    accepted.id,
    COALESCE(accepted.finished_at, accepted.validated_at, accepted.created_at)
FROM booking.source_batches AS accepted
WHERE accepted.batch_status = 'accepted'
ORDER BY
    accepted.finished_at DESC NULLS LAST,
    accepted.id DESC
LIMIT 1;

CREATE OR REPLACE VIEW booking.v_current_room_items AS
SELECT
    source.id AS source_row_id,
    source.source_batch_id,
    source.source_worksheet,
    source.source_row_no,
    source.group_code_raw,
    source.group_code_key,
    source.type_of_room_raw,
    source.no_of_rooms AS source_no_of_rooms,
    parsed.id AS parse_version_id,
    parsed.version_no AS parse_version_no,
    item.item_no,
    item.room_type_raw,
    item.room_type_code,
    item.quantity,
    item.unit_price,
    item.currency_code,
    item.price_token_raw,
    item.source_fragment
FROM booking.current_source_batch AS active_source
JOIN booking.source_rows AS source
  ON source.source_batch_id = active_source.source_batch_id
JOIN booking.current_row_parses AS current_parse
  ON current_parse.source_row_id = source.id
JOIN booking.parse_versions AS parsed
  ON parsed.id = current_parse.parse_version_id
JOIN booking.source_batches AS batch
  ON batch.id = source.source_batch_id
JOIN booking.room_items AS item
  ON item.parse_version_id = parsed.id
WHERE active_source.singleton
  AND batch.batch_status = 'accepted'
  AND parsed.parse_status = 'accepted';

COMMENT ON VIEW booking.v_current_room_items IS
  'Accepted room items from the one active full Booking source batch; historical batches remain immutable but inactive.';

COMMIT;