A simple lottery test prototype

Business needs, so I made a simple prototype test. The main requirement of the function is: the higher the amount in the user account, the greater the chance of winning the prize.
This script can only be used from the command line, usage example:
php lucky.php 100

/**
 * Lottery program
 *
 * @File: lucky.php
 * @Author: zzxworld
 * @Email: zzxworld@gmail.com
 * @Date: 2012-05-09
*/

$timer = microtime(true);

/**Manually configured parameters **/
# Prize pool size
$lucky_size = 1000;
# highest The winning probability of the user cannot exceed the prize pool size
$star_user_rate = 100;
# First prize bonus
$lucky_first = 100;
# Second prize bonus
$lucky_second = 50;
# Third prize bonus
$lucky_third = 25;
# Maximum normal prize amount
$lucky_normal_max = 10;
# Minimum normal prize amount
$lucky_normal_min = 1;

/**Parameters that automatically take values ​​from the system **/
# Total bonus amount
$lucky_amount = 578;
# Owned The account amount of the user with the most assets
$star_user_amount = 134;

# Current user amount
$user_amount = isset($argv[1]) ? intval($argv[1]) : 0;
if ($user_amount < 1) {
 die('Please set a user amount after the command.' . chr(10));
}

# Calculate the current user's probability of winning
$user_rate = $star_user_rate/$lucky_size/$star_user_amount*$user_amount;

# Calculate the number of bonuses based on the probability of winning
$lucky_num = intval($user_rate * $lucky_size);

# Initialize the prize pool
$lucky_pool = array_fill(0, $lucky_size, 0);

# The probability of winning is less than 1 Adjust to 1
if ($lucky_num < 1) {
 $lucky_num = 1;
}

# Arrange the prizes in the prize pool
$lucky_items = array('first', 'second', 'third', 'normal' );
$lucky_num += 3;

# Remove the first, second and third prizes according to the total prize money
if ($lucky_amount < $lucky_first) {
 $lucky_num -= 1;
 unset($lucky_items['first' ]);
}

if ($lucky_amount < $lucky_second) {
 $lucky_num -= 1;
 unset($lucky_items['second']);
}

if ($lucky_amount < $lucky_third) {
 $lucky_num -= 1;
 unset($lucky_items['third']);
}

# Randomly generate prizes in the prize pool
foreach(array_rand($lucky_pool, $lucky_num) as $key) {
 $name = $lucky_items[array_rand($lucky_items)];
 if (!isset($create_lucky_first) && $name == 'first') {
 $lucky_pool[$key] = $lucky_first;
 $create_lucky_first = true;
 continue;
 }

 if (!isset($create_lucky_second) && $name == 'second') {
 $lucky_pool[$key] = $lucky_second;
 $create_lucky_second = true;
 continue;
 }

 if (!isset( $create_lucky_third) && $name == 'third') {
 $lucky_pool[$key] = $lucky_third;
 $create_lucky_third = true;
 continue;
 }

 if ($name == 'normal') {
 $ lucky_pool[$key] = rand($lucky_normal_min, $lucky_normal_max);
 }

}

# Lottery
$result = $lucky_pool[rand(0, $lucky_size)];

echo 'Prize pool size:' . $ lucky_size . chr(10);
echo 'Total bonus amount:' . $lucky_amount . chr(10);
echo 'First prize bonus:' . $lucky_first . chr(10);
echo 'Second prize bonus: ' . $lucky_second . chr(10);
echo 'Third prize bonus:' . $lucky_third . chr(10);
echo 'Normal prize bonus:' . $lucky_normal_min . ' - ' . $lucky_normal_max . chr(10 );
echo 'Total amount of funds for star users:' . $star_user_amount . chr(10);
echo 'Probability of winning for star users:' . ($star_user_rate/$lucky_size) . chr(10) . chr(10);

 echo 'Current user's total funds:' . $user_amount . chr(10);
echo 'Current user's probability of winning:' . $user_rate . chr(10);
echo 'Current user's prize pool:';
 foreach( $lucky_items as $name) {
 switch($name) {
 case 'first':
 echo 'First Prize (1),';
 $lucky_num--;
 break;
 case 'second':
 echo ' Second Prize(1),';
 $lucky_num--;
 break;
 case 'third':
 echo 'Third Prize(1),';
 $lucky_num--;
 break;
 case 'normal' :
 echo 'Common prize(' . $lucky_num . ')';
 break;
 }
 }
 echo chr(10);
echo 'Current user lottery result:';
 if ($result == $lucky_first) {
 echo 'First Prize' . $result . 'Yuan';
 } elseif($result == $lucky_second) {
 echo 'Second Prize' . $result . 'Yuan';
 } elseif($result = = $lucky_third) {
 echo 'Third Prize' . $result . 'Yuan';
 } elseif($result >= $lucky_normal_min && $result <= $lucky_normal_max) {
 echo 'Normal Prize' . $result . 'yuan';
 } else {
 echo 'No prize won';
 }
 echo chr(10);
 echo chr(10);

echo 'Execution time:' . (microtime(true) - $timer ) . 'Seconds' . chr(10);