Imagine that A had to deliver goods to B's warehouse pursuant to a written contract with no specified time for delivery. Imagine further that, after waiting for several weeks for the goods to arrive, B terminated the contract for "A's unreasonable delay and breach of contract". Imagine finally that A sued B for damages on the basis that B's termination was "an unlawful repudiation of the contract". How would a court decide each of the following? 

What kind of contractual term had been breached ? Whether the delay by A was unreasonable?