Code for America challenge - Summary of Building Code Violations in 2012

violations.php

<?php

$csv_contents = file_get_contents('http://forever.codeforamerica.org/fellowship-2015-tech-interview/Violations-2012.csv');

$csv_data = explode(PHP_EOL, $csv_contents);
$results = array();

for ($i = 1; $i < count($csv_data); $i++) {
  $row_data = explode(',', $csv_data[$i]);
  $violation_category = trim($row_data[2]);
  $violation_datetime = strtotime(trim($row_data[3]));

  if (!empty($results[$violation_category])) {
    $category_data = $results[$violation_category];
  } else {
    $category_data = array(
      'total' => 0,
      'max_date' => $violation_datetime,
      'min_date' => $violation_datetime,
    );
  }

  $category_data['total']++;
  $category_data['max_date'] = ($category_data['max_date'] < $violation_datetime) ? $violation_datetime : $category_data['max_date'];
  $category_data['min_date'] = ($category_data['min_date'] > $violation_datetime) ? $violation_datetime : $category_data['min_date'];

  $results[$violation_category] = $category_data;
}
?>

<h1>Summary of building code violations in 2012</h1>
<table cellpadding="10">
  <tr>
    <th align="left">Category</th>
    <th align="left">Earliest date</th>
    <th align="left">Latest date</th>
    <th align="left">Total violations</th>
  </tr>
  <?php foreach ($results as $category => $category_data): ?>
  <tr>
    <td><?php print $category; ?></td>
    <td><?php print date('F j, Y', $category_data['min_date']); ?></td>
    <td><?php print date('F j, Y', $category_data['max_date']); ?></td>
    <td><?php print $category_data['total']; ?></td>
  </tr>
  <?php endforeach; ?>
</table>