[awattarar] Add aWATTar API class (openhab#17169)

Signed-off-by: Thomas Leber <thomas@tl-photography.at>

bundles/org.openhab.binding.awattar/src/main/java/org/openhab/binding/awattar/internal/AwattarPrice.java

@@ -20,6 +20,12 @@
  *
  * @author Wolfgang Klimt - initial contribution
  * @author Jan N. Klug - Refactored to record
+ *
+ * @param netPrice the net price in €/kWh
+ * @param grossPrice the gross price in €/kWh
+ * @param netTotal the net total price in €
+ * @param grossTotal the gross total price in €
+ * @param timerange the time range of the price
  */
 @NonNullByDefault
 public record AwattarPrice(double netPrice, double grossPrice, double netTotal, double grossTotal,

bundles/org.openhab.binding.awattar/src/main/java/org/openhab/binding/awattar/internal/api/AwattarApi.java

@@ -0,0 +1,165 @@
+/**
+ * Copyright (c) 2010-2024 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.binding.awattar.internal.api;
+
+import static org.eclipse.jetty.http.HttpMethod.GET;
+import static org.eclipse.jetty.http.HttpStatus.OK_200;
+
+import java.time.LocalDate;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.util.Comparator;
+import java.util.SortedSet;
+import java.util.TreeSet;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jetty.client.HttpClient;
+import org.eclipse.jetty.client.api.ContentResponse;
+import org.openhab.binding.awattar.internal.AwattarBridgeConfiguration;
+import org.openhab.binding.awattar.internal.AwattarPrice;
+import org.openhab.binding.awattar.internal.dto.AwattarApiData;
+import org.openhab.binding.awattar.internal.dto.Datum;
+import org.openhab.binding.awattar.internal.handler.TimeRange;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonSyntaxException;
+
+/**
+ * The {@link AwattarApi} class is responsible for encapsulating the aWATTar API
+ * and providing the data to the bridge.
+ *
+ * @author Thomas Leber - Initial contribution
+ */
+@NonNullByDefault
+public class AwattarApi {
+    private final Logger logger = LoggerFactory.getLogger(AwattarApi.class);
+
+    private static final String URL_DE = "https://api.awattar.de/v1/marketdata";
+    private static final String URL_AT = "https://api.awattar.at/v1/marketdata";
+    private String url = URL_DE;
+
+    private final HttpClient httpClient;
+
+    private double vatFactor;
+    private double basePrice;
+
+    private ZoneId zone;
+
+    private Gson gson;
+
+    /**
+     * Generic exception for the aWATTar API.
+     */
+    public class AwattarApiException extends Exception {
+        private static final long serialVersionUID = 1L;
+
+        public AwattarApiException(String message) {
+            super(message);
+        }
+    }
+
+    /**
+     * Constructor for the aWATTar API.
+     *
+     * @param httpClient the HTTP client to use
+     * @param zone the time zone to use
+     */
+    public AwattarApi(HttpClient httpClient, ZoneId zone, AwattarBridgeConfiguration config) {
+        this.zone = zone;
+        this.httpClient = httpClient;
+
+        this.gson = new Gson();
+
+        vatFactor = 1 + (config.vatPercent / 100);
+        basePrice = config.basePrice;
+
+        if (config.country.equals("DE")) {
+            this.url = URL_DE;
+        } else if (config.country.equals("AT")) {
+            this.url = URL_AT;
+        } else {
+            throw new IllegalArgumentException("Country code must be 'DE' or 'AT'");
+        }
+    }
+
+    /**
+     * Get the data from the aWATTar API.
+     * The data is returned as a sorted set of {@link AwattarPrice} objects.
+     * The data is requested from now minus one day to now plus three days.
+     *
+     * @return the data as a sorted set of {@link AwattarPrice} objects
+     * @throws AwattarApiException
+     * @throws InterruptedException if the thread is interrupted
+     * @throws TimeoutException if the request times out
+     * @throws ExecutionException if the request fails
+     * @throws EmptyDataResponseException if the response is empty
+     */
+    public SortedSet<AwattarPrice> getData() throws AwattarApiException {
+        try {
+            // we start one day in the past to cover ranges that already started yesterday
+            ZonedDateTime zdt = LocalDate.now(zone).atStartOfDay(zone).minusDays(1);
+            long start = zdt.toInstant().toEpochMilli();
+            // Starting from midnight yesterday we add three days so that the range covers
+            // the whole next day.
+            zdt = zdt.plusDays(3);
+            long end = zdt.toInstant().toEpochMilli();
+
+            StringBuilder request = new StringBuilder(url);
+            request.append("?start=").append(start).append("&end=").append(end);
+
+            logger.trace("aWATTar API request: = '{}'", request);
+            ContentResponse contentResponse = httpClient.newRequest(request.toString()).method(GET)
+                    .timeout(10, TimeUnit.SECONDS).send();
+            int httpStatus = contentResponse.getStatus();
+            String content = contentResponse.getContentAsString();
+            logger.trace("aWATTar API response: status = {}, content = '{}'", httpStatus, content);
+
+            if (content == null) {
+                throw new AwattarApiException("@text/error.empty.data");
+            } else if (httpStatus == OK_200) {
+                SortedSet<AwattarPrice> result = new TreeSet<>(Comparator.comparing(AwattarPrice::timerange));
+
+                AwattarApiData apiData = gson.fromJson(content, AwattarApiData.class);
+
+                for (Datum d : apiData.data) {
+                    // the API returns prices in €/MWh, we need €ct/kWh -> divide by 10 (100/1000)
+                    double netMarket = d.marketprice / 10.0;
+                    double grossMarket = netMarket * vatFactor;
+                    double netTotal = netMarket + basePrice;
+                    double grossTotal = netTotal * vatFactor;
+
+                    result.add(new AwattarPrice(netMarket, grossMarket, netTotal, grossTotal,
+                            new TimeRange(d.startTimestamp, d.endTimestamp)));
+                }
+
+                return result;
+            } else {
+                throw new AwattarApiException("@text/warn.awattar.statuscode" + httpStatus);
+            }
+        } catch (ExecutionException e) {
+            throw new AwattarApiException("@text/error.execution");
+        } catch (JsonSyntaxException e) {
+            throw new AwattarApiException("@text/error.json");
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new AwattarApiException("@text/error.interrupted");
+        } catch (TimeoutException e) {
+            throw new AwattarApiException("@text/error.timeout");
+        }
+    }
+}

bundles/org.openhab.binding.awattar/src/main/java/org/openhab/binding/awattar/internal/handler/AwattarBestPriceHandler.java

@@ -99,7 +99,7 @@ public void initialize() {
                  * here
                  */
                 thingRefresher = scheduler.scheduleAtFixedRate(this::refreshChannels,
-                        getMillisToNextMinute(1, timeZoneProvider), THING_REFRESH_INTERVAL * 1000,
+                        getMillisToNextMinute(1, timeZoneProvider), THING_REFRESH_INTERVAL * 1000L,
                         TimeUnit.MILLISECONDS);
             }
         }