add timezone lookup from airport codes

.gitignore

@@ -1,3 +1,4 @@
 .DS_Store
 vendor/
 lib/config.php
+data/airports.csv

controllers/timezone.php

@@ -1,5 +1,28 @@
 <?php
 
+function timezone_for_location($lat, $lng) {
+
+  $tz = \p3k\Timezone::timezone_for_location($lat, $lng);
+  $timezone = false;
+  if($tz) {
+    $timezone = new p3k\timezone\Result($tz);
+  }
+
+  if($timezone) {
+    return [
+      'timezone' => $timezone->name,
+      'offset' => $timezone->offset,
+      'seconds' => $timezone->seconds,
+      'localtime' => $timezone->localtime
+    ];
+  } else {
+    return [
+      'error' => 'not_found',
+      'error_description' => 'No timezone was found for the requested location'
+    ];
+  }
+}
+
 $app->get('/api/timezone', function() use($app) {
   $params = $app->request()->params();
 
@@ -8,28 +31,34 @@ $app->get('/api/timezone', function() use($app) {
     $lat = (float)$params['latitude'];
     $lng = (float)$params['longitude'];
 
-    $tz = \p3k\Timezone::timezone_for_location($lat, $lng);
-    $timezone = false;
-    if($tz) {
-      $timezone = new p3k\timezone\Result($tz);
-    }
+    $result = timezone_for_location($lat, $lng);
+    json_response($app, $result);
+
+  } elseif(k($params, 'airport')) {
+
+    $code = $params['airport'];
+
+    $airport = \p3k\Airports::from_code($code);
+
+    if($airport) {
+      $result = timezone_for_location($airport['latitude'], $airport['longitude']);
+
+      if(!isset($result['error'])) {
+        $result['airport'] = $airport;
+      }
+
+      json_response($app, $result);
 
-    if($timezone) {
-      json_response($app, [
-        'timezone' => $timezone->name,
-        'offset' => $timezone->offset,
-        'seconds' => $timezone->seconds,
-        'localtime' => $timezone->localtime
-      ]);
     } else {
       json_response($app, [
-        'error' => 'not_found', 
-        'error_description' => 'No timezone was found for the requested location'
+        'error' => 'not_found',
+        'error_description' => 'The airport code was not found'
       ]);
     }
+
   } else {
     json_response($app, [
-      'error' => 'invalid_request', 
+      'error' => 'invalid_request',
       'error_description' => 'Request was missing parameters'
     ], 400);
   }

data/airports-csv-compact.php

@@ -0,0 +1,45 @@
+<?php
+
+// airports.csv is from
+// http://ourairports.com/data/
+// http://ourairports.com/data/airports.csv
+
+echo "Downloading...\n";
+file_put_contents('airports.csv', file_get_contents('http://ourairports.com/data/airports.csv'));
+
+echo "Processing...\n";
+
+$airports = [];
+
+$fp = fopen('airports.csv', 'r');
+while($line = fgetcsv($fp)) {
+  if($line[0] == 'id') {
+    $keys = $line;
+    continue;
+  }
+
+  if($line[13] == '') continue;
+
+  $data = [
+    $line[13], // Code
+    $line[4],  // Latitude
+    $line[5],  // Longitude
+    $line[3],  // Name
+  ];
+
+  $airports[] = $data;
+}
+
+fclose($fp);
+
+unlink('airports.csv');
+
+$fp = fopen('airports-compact.csv', 'w');
+
+foreach($airports as $line) {
+  fputcsv($fp, $line);
+}
+
+fclose($fp);
+
+echo "Done\n";

data/airports-csv-to-json.php

@@ -0,0 +1,36 @@
+<?php
+
+// airports.csv is from
+// http://ourairports.com/data/
+// http://ourairports.com/data/airports.csv
+
+echo "Downloading...\n";
+file_put_contents('airports.csv', file_get_contents('http://ourairports.com/data/airports.csv'));
+
+echo "Processing...\n";
+
+$airports = [];
+
+$fp = fopen('airports.csv', 'r');
+while($line = fgetcsv($fp)) {
+  if($line[0] == 'id') {
+    $keys = $line;
+    continue;
+  }
+
+  if($line[13] == '') continue;
+
+  $airports[$line[13]] = [];
+  foreach($keys as $i=>$k) {
+    $airports[$line[13]][$k] = $line[$i];
+  }
+
+}
+
+fclose($fp);
+
+unlink('airports.csv');
+
+file_put_contents('airports.json', json_encode($airports, JSON_PRETTY_PRINT|JSON_UNESCAPED_SLASHES));
+
+echo "Done\n";

p3k/Airports.php

@@ -0,0 +1,31 @@
+<?php
+namespace p3k;
+
+class Airports {
+
+  private static $fp = false;
+
+  public static function from_code($code) {
+    if(!self::$fp) {
+      $fp = fopen(__DIR__.'/../data/airports-compact.csv', 'r');
+    }
+
+    rewind($fp);
+
+    $airport = false;
+
+    while(!$airport && ($line=fgetcsv($fp))) {
+      if($line[0] == $code) {
+        $airport = [
+          'code' => $code,
+          'latitude' => $line[1],
+          'longitude' => $line[2],
+          'name' => $line[3],
+        ];
+      }
+    }
+
+    return $airport;
+  }
+
+}

views/index.php

@@ -6,6 +6,7 @@
 
     <ul>
       <li><a href="/api/timezone?latitude=45.5118&amp;longitude=-122.6433">/api/timezone?latitude=45.5118&amp;longitude=-122.6433</a></li>
+      <li><a href="/api/timezone?airport=PDX">/api/timezone?airport=PDX</a></li>
     </ul>
 
   <h2><i class="fa fa-globe"></i> Geocoder</h2>