const ISO_ORDER_YEAR_SQL = "substring(data_pedido from '^(\\d{4})[-/]')::int";
const ISO_ORDER_MONTH_SQL = "substring(data_pedido from '^\\d{4}[-/](\\d{1,2})[-/]')::int";
const ISO_ORDER_DAY_SQL = "substring(data_pedido from '^\\d{4}[-/]\\d{1,2}[-/](\\d{1,2})')::int";
const BR_ORDER_DAY_SQL = "substring(data_pedido from '^(\\d{1,2})[-/]')::int";
const BR_ORDER_MONTH_SQL = "substring(data_pedido from '^\\d{1,2}[-/](\\d{1,2})[-/]')::int";
const BR_ORDER_YEAR_SQL = "substring(data_pedido from '^\\d{1,2}[-/]\\d{1,2}[-/](\\d{4})')::int";

const buildSafeDateSql = ({ yearSql, monthSql, daySql }) => {
    const candidateDateSql = `(make_date(${yearSql}, ${monthSql}, 1) + ((${daySql} - 1) * INTERVAL '1 day'))::date`;

    return `
        CASE
            WHEN ${yearSql} BETWEEN 1 AND 9999
             AND ${monthSql} BETWEEN 1 AND 12
             AND ${daySql} BETWEEN 1 AND 31
             AND EXTRACT(MONTH FROM ${candidateDateSql})::int = ${monthSql}
            THEN ${candidateDateSql}
            ELSE NULL
        END
    `;
};

const ORDER_DATE_SQL = `
    COALESCE(
        data_pedido_date,
        CASE
            WHEN data_pedido ~ '^\\d{4}[-/]\\d{1,2}[-/]\\d{1,2}' THEN ${buildSafeDateSql({
                yearSql: ISO_ORDER_YEAR_SQL,
                monthSql: ISO_ORDER_MONTH_SQL,
                daySql: ISO_ORDER_DAY_SQL
            })}
            WHEN data_pedido ~ '^\\d{1,2}[-/]\\d{1,2}[-/]\\d{4}' THEN ${buildSafeDateSql({
                yearSql: BR_ORDER_YEAR_SQL,
                monthSql: BR_ORDER_MONTH_SQL,
                daySql: BR_ORDER_DAY_SQL
            })}
            ELSE NULL
        END
    )
`;

module.exports = {
    ORDER_DATE_SQL
};