If you cast a spell as a bonus action, draw a weapon, make three attacks, and move thirty feet; then I would say that the bonus action spell takes about a second, drawing a weapon takes about a second, making three attacks takes about five seconds, and moving thirty feet takes about six seconds. You can't draw a weapon at the same time you swing it, but the time it takes for the spell probably overlaps with the time spent making an attack, and you're moving constantly while you're doing everything else.