const fs = require('fs');

function strictInput({ body = [], query = [], cleanupUploadedFile = false } = {}) {
    const allowedBody = new Set(body);
    const allowedQuery = new Set(query);

    return function validateInputShape(req, res, next) {
        const bodyKeys = Object.keys(req.body || {});
        const queryKeys = Object.keys(req.query || {});
        const unexpectedBody = bodyKeys.filter((key) => !allowedBody.has(key));
        const unexpectedQuery = queryKeys.filter((key) => !allowedQuery.has(key));

        if (unexpectedBody.length > 0 || unexpectedQuery.length > 0) {
            if (cleanupUploadedFile && req.file?.path) {
                fs.promises.unlink(req.file.path).catch(() => {});
            }
            return res.status(400).json({
                error: 'Unexpected request field(s)',
                fields: [...unexpectedBody, ...unexpectedQuery],
            });
        }

        next();
    };
}

module.exports = { strictInput };