Aggregate weather for entries when importing

src/main/handlebars/feed.handlebars

@@ -39,6 +39,7 @@
               {{/each}}
             </ul>
             {{count views '' '(Eine Ansicht)' '(# Ansichten)'}}
+            {{> partials/weather in=.}}
           </div>
 
           {{> partials/images in=. first=@first}}

src/main/handlebars/journey.handlebars

@@ -64,6 +64,7 @@ parent: feed
               {{/each}}
             </ul>
             {{count views '' '(Eine Ansicht)' '(# Ansichten)'}}
+            {{> partials/weather in=.}}
           </div>
           {{> partials/images in=.}}
 

src/main/handlebars/layout.handlebars

@@ -460,8 +460,22 @@
       }
     }
 
-    .meta, .meta a {
+    .meta {
+      margin-block: .25rem -.5rem;
       color: var(--meta-color);
+
+      a {
+        color: var(--meta-color);
+      }
+
+      .weather {
+        display: flex;
+
+        img {
+          width: 1lh;
+          height: 1lh;
+        }
+      }
     }
 
     ul.locations {

src/main/php/de/thekid/dialog/Helpers.php

@@ -33,6 +33,13 @@ public function helpers() {
       if ($time > $until) return 'passed';
       return 'current';
     };
+    yield 'temperature' => function($node, $context, $options) {
+      $diff= abs($options[0] - $options[1]);
+      return $diff <= ($options['tolerance'] ?? 1)
+        ? sprintf('%.1f', ($options[0] + $options[1]) / 2)
+        : $options[0].' — '.$options[1]
+      ;
+    };
     yield 'size-class' => function($node, $context, $options) {
       $s= (int)$options[0];
       return match {

src/main/php/de/thekid/dialog/OpenMeteo.php

@@ -0,0 +1,44 @@
+<?php namespace de\thekid\dialog;
+
+use lang\IllegalArgumentException;
+use util\{Date, TimeZone, URI};
+use webservices\rest\Endpoint;
+
+/**
+ * Open-Meteo is an open-source weather API and offers free access for non-commercial use.
+ *
+ * @see https://github.com/open-meteo/open-meteo
+ */
+class OpenMeteo {
+  private $base;
+  private $auth= [];
+  private $endpoints= [];
+
+  public function __construct(string|URI $base) {
+    $this->base= $base instanceof URI ? $base : new URI($base);
+  }
+
+  /** Returns a given API endpoint */
+  protected function endpoint(string $kind): Endpoint {
+    return $this->endpoints[$kind]??= new Endpoint($this->base->using()
+      ->host($kind.'.'.$this->base->host())
+      ->create()
+    );
+  }
+
+  public function lookup(string|float $lat, string|float $lon, Date $start, ?Date $end= null, TimeZone $tz= null): array<string, mixed> {
+    $params= $this->auth + [
+      'latitude'   => $lat,
+      'longitude'  => $lon,
+      'start_date' => $start->toString('Y-m-d'),
+      'end_date'   => ($end ?? $start)->toString('Y-m-d'),
+      'timezone'   => ($tz ?? $start->getTimeZone())->name(),
+      'daily'      => ['sunrise', 'sunset'],
+      'hourly'     => ['weather_code', 'apparent_temperature'],
+    ];
+    return $this->endpoint('archive-api')->resource('archive')->get($params)->match([
+      200 => fn($r) => $r->value(),
+      400 => fn($r) => throw new IllegalArgumentException($r->content()),
+    ]);
+  }
+}

src/main/php/de/thekid/dialog/import/LookupWeather.php

@@ -0,0 +1,58 @@
+<?php namespace de\thekid\dialog\import;
+
+use de\thekid\dialog\OpenMeteo;
+use lang\FormatException;
+use util\{Date, Dates, TimeZone, TimeInterval};
+use webservices\rest\Endpoint;
+
+/** Aggregates weather for entries using OpenMeteo */
+class LookupWeather extends Task {
+  private $weather= new OpenMeteo('https://open-meteo.com/v1');
+
+  public function __construct(private array<string, mixed> $entry, private array<mixed> $images) { }
+
+  public function execute(Endpoint $api) {
+    $weather= [];
+    $min= $max= null;
+    foreach ($this->entry['locations'] as $location) {
+      $tz= new TimeZone($location['timezone']);
+
+      // Infer date range from first and last images
+      $dates= [];
+      foreach ($this->images as $image) {
+        $dates[]= new Date(strtr($image['meta']['dateTime'], ['+00:00' => '']), $tz);
+      }
+      usort($dates, fn($a, $b) => $b->compareTo($a));
+      $first= current($dates);
+      $last= end($dates);
+
+      // Filter hourly weather for the duration of the images
+      $result= $this->weather->lookup($location['lat'], $location['lon'], $first, $last, $tz);
+      $start= array_search(Dates::truncate($first, TimeInterval::$HOURS)->toString('Y-m-d\TH:i'), $result['hourly']['time']);
+      $end= array_search(Dates::truncate($last, TimeInterval::$HOURS)->toString('Y-m-d\TH:i'), $result['hourly']['time']);
+
+      // Determine most common weather codes and temperature range
+      $codes= array_count_values(array_slice($result['hourly']['weather_code'], $min, 1 + ($end - $start)));
+      $temp= array_slice($result['hourly']['apparent_temperature'], $start, 1 + ($end - $start));
+      $min= null === $min ? min($temp) : min($min, min($temp));
+      $max= null === $max ? max($temp) : max($max, max($temp));
+
+      arsort($codes);
+      foreach ($codes as $code => $count) {
+        $weather[$code]??= 0;
+        $weather[$code]+= $count;
+      }
+
+      yield $location['name'] => sprintf('#%02d @ %.1f-%.1f °C', key($codes), min($temp), max($temp));
+    }
+
+    arsort($weather);
+    return [
+      'code' => sprintf('%02d', key($weather)),
+      'min'  => $min,
+      'max'  => $max,
+    ];
+  }
+
+  public function description(): string { return 'Looking up weather'; }
+}

src/main/php/de/thekid/dialog/import/Source.php

@@ -76,6 +76,7 @@ public function synchronize(Files $files) {
 
     if (isset($updated)) {
       $changes['locations']= yield new LookupLocationInfos($changes);
+      $changes['weather']= yield new LookupWeather($changes, $this->entry['images'] ?? []);
       $changes['published']= time();
       yield new PublishEntry($this->entry['slug'], $changes);
     }