Hazard service updates

• Updated Hazard controller and service to only support required arguments as slash-delimited and optional arguments via query, e.g. .../hazard/longitude/latitude/vs30?truncate=true&maxdir=true
• Updated .../hazard/usage to just be the context path for the service .../hazard and refer to it's response in docs and Swagger as service metadata.
• Switched to relying on Swagger/micronaut for basic URI validation (e.g. required parameters present). This simplified and reduced annotations and code required. Parameter metadata in the controller only applies to the Swagger index page so global and/or model validation of parameter values is still needed.
• Added handling for truncate and maxdir query arguments; service now adjusts the returned curves as requested.

Resolves #450 (closed) Resolves #453 (closed) Resolves #454

src/main/java/gov/usgs/earthquake/nshmp/www/services/HazardService.java

 package gov.usgs.earthquake.nshmp.www.services;
 
-import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static gov.usgs.earthquake.nshmp.calc.HazardExport.curvesBySource;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.EnumMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.concurrent.ExecutionException;
 import java.util.function.Function;
 
@@ -46,22 +45,10 @@ import io.micronaut.http.HttpResponse;
  */
 public final class HazardService {
 
-  /*
-   * Developer notes:
-   *
-   * Calculations are designed to leverage all available processors by default,
-   * distributing work using the ServletUtil.CALC_EXECUTOR.
-   */
-
   private static final String NAME = "Hazard Service";
 
-  /**
-   * Handler for {@link HazardController#doGetUsage}. Returns the usage for the
-   * hazard service.
-   *
-   * @param urlHelper The URL helper
-   */
-  public static HttpResponse<String> handleDoGetUsage(UrlHelper urlHelper) {
+  /** HazardController.doGetUsage() handler. */
+  public static HttpResponse<String> handleDoGetMetadata(UrlHelper urlHelper) {
     try {
       var usage = new RequestMetadata(ServletUtil.model());// SourceServices.ResponseData();
       var response = new Response<>(Status.USAGE, NAME, urlHelper.url, usage, urlHelper);
@@ -72,22 +59,17 @@ public final class HazardService {
     }
   }
 
-  /**
-   * Handler for {@link HazardController#doGetHazard}. Returns the usage or the
-   * hazard result.
-   *
-   * @param query The query
-   * @param urlHelper The URL helper
-   */
+  /** HazardController.doGetHazard() handler. */
   public static HttpResponse<String> handleDoGetHazard(
       QueryParameters query,
       UrlHelper urlHelper) {
 
     try {
-      if (query.isEmpty()) {
-        return handleDoGetUsage(urlHelper);
-      }
-      query.checkParameters();
+      // TODO still need to validate
+      // if (query.isEmpty()) {
+      // return handleDoGetUsage(urlHelper);
+      // }
+      // query.checkParameters();
       var data = new RequestData(query);
       var response = process(data, urlHelper);
       var svcResponse = ServletUtil.GSON.toJson(response);
@@ -142,35 +124,37 @@ public final class HazardService {
 
   public static class QueryParameters {
 
-    Optional<Double> longitude;
-    Optional<Double> latitude;
-    Optional<Integer> vs30;
+    final double longitude;
+    final double latitude;
+    final int vs30;
+    final boolean truncate;
+    final boolean maxdir;
 
     public QueryParameters(
-        Optional<Double> longitude,
-        Optional<Double> latitude,
-        Optional<Integer> vs30) {
+        double longitude,
+        double latitude,
+        int vs30,
+        boolean truncate,
+        boolean maxdir) {
 
       this.longitude = longitude;
       this.latitude = latitude;
       this.vs30 = vs30;
+      this.truncate = truncate;
+      this.maxdir = maxdir;
     }
 
-    public boolean isEmpty() {
-      return longitude.isEmpty() && latitude.isEmpty() && vs30.isEmpty();
-    }
-
-    public void checkParameters() {
-      checkParameter(longitude, "longitude");
-      checkParameter(latitude, "latitude");
-      checkParameter(vs30, "vs30");
-    }
+    // void checkParameters() {
+    // checkParameter(longitude, "longitude");
+    // checkParameter(latitude, "latitude");
+    // checkParameter(vs30, "vs30");
+    // }
   }
 
-  private static void checkParameter(Object param, String id) {
-    checkNotNull(param, "Missing parameter: %s", id);
-    // TODO check range here
-  }
+  // private static void checkParameter(Object param, String id) {
+  // checkNotNull(param, "Missing parameter: %s", id);
+  // // TODO check range here
+  // }
 
   /* Service request and model metadata */
   static class RequestMetadata {
@@ -208,11 +192,15 @@ public final class HazardService {
     final double longitude;
     final double latitude;
     final double vs30;
+    final boolean truncate;
+    final boolean maxdir;
 
     RequestData(QueryParameters query) {
-      this.longitude = query.longitude.orElseThrow();
-      this.latitude = query.latitude.orElseThrow();
-      this.vs30 = query.vs30.orElseThrow();
+      this.longitude = query.longitude;
+      this.latitude = query.latitude;
+      this.vs30 = query.vs30;
+      this.truncate = query.truncate;
+      this.maxdir = query.maxdir;
     }
   }
 
@@ -271,9 +259,7 @@ public final class HazardService {
 
     Curve(String component, XySequence values) {
       this.component = component;
-      this.values = XySequence.create(
-          values.xValues().map(Math::exp).toArray(),
-          values.yValues().toArray());
+      this.values = values;
     }
   }
 
@@ -341,12 +327,16 @@ public final class HazardService {
         var curves = new ArrayList<Curve>();
 
         // total curve
-        curves.add(new Curve(TOTAL_KEY, totalMap.get(imt)));
+        curves.add(new Curve(
+            TOTAL_KEY,
+            updateCurve(request, totalMap.get(imt), imt)));
 
         // component curves
         var typeMap = componentMaps.get(imt);
         for (SourceType type : typeMap.keySet()) {
-          curves.add(new Curve(type.toString(), typeMap.get(type)));
+          curves.add(new Curve(
+              type.toString(),
+              updateCurve(request, typeMap.get(type), imt)));
         }
 
         hazards.add(new HazardResponse(imt, List.copyOf(curves)));
@@ -359,6 +349,44 @@ public final class HazardService {
     }
   }
 
+  private static final double TRUNCATION_LIMIT = 1e-4;
+
+  /* Convert to linear and possibly truncate and scale to max-direction. */
+  private static XySequence updateCurve(
+      RequestData request,
+      XySequence curve,
+      Imt imt) {
+
+    /*
+     * If entire curve is <1e-4, this method will return a curve consisting of
+     * just the first point in the supplied curve.
+     *
+     * TODO We probably want to move the TRUNCATION_LIMIT out to a config.
+     */
+
+    double[] yValues = curve.yValues().toArray();
+    int limit = request.truncate ? truncationLimit(yValues) : yValues.length;
+    yValues = Arrays.copyOf(yValues, limit);
+
+    double scale = request.maxdir ? MaxDirection.FACTORS.get(imt) : 1.0;
+    double[] xValues = curve.xValues()
+        .limit(yValues.length)
+        .map(Math::exp)
+        .map(x -> x * scale)
+        .toArray();
+
+    return XySequence.create(xValues, yValues);
+  }
+
+  private static int truncationLimit(double[] yValues) {
+    int limit = 1;
+    double y = yValues[0];
+    while (y > TRUNCATION_LIMIT && limit < yValues.length) {
+      y = yValues[limit++];
+    }
+    return limit;
+  }
+
   @Deprecated
   public static class Query extends ServiceQueryData {
     Integer vs30;