[PHP] Conversion of units to other units. What a masterpiece

<?php

$command = explode(" ", "!convert 25 psi bar");

if(count($command) < 4 || !is_numeric($command[1])) {
    echo "usage";
    return;
}

//MEASUREMENTS =>


$Pressure = [
    "bar" => [
        "bar" => 1,
        "kg" => 1.02,
        "psi" => 14.5,
    ],
    "kg" => [
        "bar" => 0.98,
        "kg" => 1,
        "psi" => 14.2,
    ],
    "psi" => [
        "bar" => 0.069,
        "kg" => 0.0703,
        "psi" => 1,
    ],
];

if(!(in_array($command[2], array_keys($Pressure)) && in_array($command[3], array_keys($Pressure)))) {
    echo "usage";
    return;
}

print "{$command[1]} {$command[2]} = " . ($command[1] * $Pressure[$command[2]][$command[3]]) . " {$command[3]}\n";

//

$command = explode(" ", "!convert 1 miles millimeters");

if(count($command) < 4 || !is_numeric($command[1])) {
    echo "usage";
    return;
}

$Length = [
    "millimeters" => 1,
    "centimeters" => .1,
    "miles" => 0.0000006214,
    "inches" => 0.0393701,
    "meters" => 0.001,
    "kilometers" => 0.000001,
    "feet" => 0.00328084,
    "yards" => 0.00109361,
];

if(!(in_array($command[2], array_keys($Length)) && in_array($command[3], array_keys($Length)))) {
    echo "usage\n";
    return;
}

print "{$command[1]} {$command[2]} = " . ($Length[$command[3]] / $Length[$command[2]] * $command[1]) . " {$command[3]}\n";

//

$command = explode(" ", "!convert 1 grams oz");

if(count($command) < 4 || !is_numeric($command[1])) {
    echo "usage";
    return;
}

$Weight = [
    "grams" => 1,
    "oz" => 0.035274,
    "kilograms" => 0.001,
    "pounds" => 0.00220462,
    "metrictons" => 0.000001,
    "tons" => 0.0000010231,
];

if(!(in_array($command[2], array_keys($Weight)) && in_array($command[3], array_keys($Weight)))) {
    echo "usage\n";
    return;
}

print "{$command[1]} {$command[2]} = " . ($Weight[$command[3]] / $Weight[$command[2]] * $command[1]) . " {$command[3]}\n";

//

$command = explode(" ", "!convert 1 milliliters ounces");

if(count($command) < 4 || !is_numeric($command[1])) {
    echo "usage";
    return;
}

$Volume = [
    "milliliters" => 1,
    "ounces" => 0.033814,
    "quarts" => 0.00105669,
    "pints" => 0.00211338,
    "cups" => 0.00422675,
    "liters" => 0.001,
    "gallons" => 0.00026417,
];

if(!(in_array($command[2], array_keys($Volume)) && in_array($command[3], array_keys($Volume)))) {
    echo "usage\n";
    return;
}

print "{$command[1]} {$command[2]} = " . ($Volume[$command[3]] / $Volume[$command[2]] * $command[1]) . " {$command[3]}\n";

// BASE: base_convert

$command = explode(" ", "!convert 11111111 bin hdeci");

if(count($command) < 4 || !is_numeric($command[1])) {
    echo "usage";
    return;
}

$bases = [
    "hdeci" => 16,
    "dec" => 10,
    "oct" => 8,
    "bin" => 2,
];

if(!(in_array($command[2], array_keys($bases)) && in_array($command[3], array_keys($bases)))) {
    echo "usage\n";
    return;
}

print "{$command[1]} in {$command[2]} = " . strtoupper(base_convert($command[1], $bases[$command[2]], $bases[$command[3]])) . " in {$command[3]}\n";