<?php
//What you have in stock
$inventory = array(
	'm3_nut' => 10,
	'nema17_stepper' => 2
);

//What is required to build item
$kit_requirements = array(
	'm3_nut' => 2,
	'nema17_stepper' => 1
);

$has_enough = true;
$available_kits = 0;

//See how many we can make
while($has_enough){
	foreach($kit_requirements as $item=>$qty)
	{
		if($inventory[$item] >= $qty){ //We have enough to continue;
			$inventory[$item] = $inventory[$item] - $qty;
		}else{
			$has_enough = false;
		}
	}

	if($has_enough){
		$available_kits++;
	}
}

//See what is left
$remnant_parts = array();

foreach($kit_requirements as $item=>$qty)
{
	$remnant_parts[$item] = array(
		'qty_available' => $inventory[$item],
		'qty_required' => $qty,
		'qty_needed' => ($qty - $inventory[$item] > 0) ? $qty - $inventory[$item] : 0
	);
}

echo("Available kits: $available_kits\n");
echo("Parts Needed: \n");
print_r($remnant_parts); die;
?>