Add time grain to GraphQL schema

elide-core/src/main/java/com/yahoo/elide/core/EntityDictionary.java

@@ -29,6 +29,7 @@
 import com.google.common.collect.BiMap;
 import com.google.common.collect.HashBiMap;
 import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
 
 import org.antlr.v4.runtime.tree.ParseTree;
 import org.apache.commons.lang3.StringUtils;
@@ -1422,6 +1423,16 @@ public void addArgumentsToAttributes(Class<?> cls, String attributeName, Set<Arg
         getEntityBinding(cls).addArgumentsToAttribute(attributeName, arguments);
     }
 
+    /**
+     * Add a single argument to the attribute
+     * @param cls The entity
+     * @param attributeName attribute name to which argument has to be added
+     * @param argument A single argument
+     */
+    public void addArgumentToAttribute(Class<?> cls, String attributeName, ArgumentType argument) {
+        this.addArgumentsToAttributes(cls, attributeName, Sets.newHashSet(argument));
+    }
+
     /**
      * Returns the Collection of all attributes of an argument.
      * @param cls The entity

elide-core/src/main/java/com/yahoo/elide/core/PersistentResource.java

@@ -1104,10 +1104,20 @@ public RelationshipType getRelationshipType(String relation) {
      * @param attr Attribute name
      * @return Object value for attribute
      */
+    @Deprecated
     public Object getAttribute(String attr) {
         return this.getValueChecked(attr);
     }
 
+    /**
+     * Get the value for a particular attribute (i.e. non-relational field)
+     * @param attr the Attribute
+     * @return Object value for attribute
+     */
+    public Object getAttribute(Attribute attr) {
+        return this.getValueChecked(attr);
+    }
+
     /**
      * Wrapped Entity bean.
      *
@@ -1363,13 +1373,26 @@ protected void nullValue(String fieldName, PersistentResource oldValue) {
      * @param fieldName the field name
      * @return value value
      */
+    @Deprecated
     protected Object getValueChecked(String fieldName) {
         requestScope.publishLifecycleEvent(this, CRUDEvent.CRUDAction.READ);
         requestScope.publishLifecycleEvent(this, fieldName, CRUDEvent.CRUDAction.READ, Optional.empty());
         checkFieldAwareDeferPermissions(ReadPermission.class, fieldName, (Object) null, (Object) null);
         return getValue(getObject(), fieldName, requestScope);
     }
 
+    /**
+     * Gets a value from an entity and checks read permissions.
+     * @param attribute the attribute to fetch.
+     * @return value value
+     */
+    protected Object getValueChecked(Attribute attribute) {
+        requestScope.publishLifecycleEvent(this, CRUDEvent.CRUDAction.READ);
+        requestScope.publishLifecycleEvent(this, attribute.getName(), CRUDEvent.CRUDAction.READ, Optional.empty());
+        checkFieldAwareDeferPermissions(ReadPermission.class, attribute.getName(), (Object) null, (Object) null);
+        return transaction.getAttribute(getObject(), attribute, requestScope);
+    }
+
     /**
      * Retrieve an object without checking read permissions (i.e. value is used internally and not sent to others)
      *

elide-core/src/main/java/com/yahoo/elide/security/FilterExpressionCheck.java

@@ -43,7 +43,6 @@ public final boolean ok(User user) {
         throw new UnsupportedOperationException();
     }
 
-
     /**
      * The filter expression is evaluated in memory if it cannot be pushed to the data store by elide for any reason.
      *

elide-datastore/elide-datastore-aggregation/src/main/java/com/yahoo/elide/datastores/aggregation/AggregationDataStore.java

@@ -5,9 +5,12 @@
  */
 package com.yahoo.elide.datastores.aggregation;
 
+import com.yahoo.elide.core.ArgumentType;
 import com.yahoo.elide.core.DataStore;
 import com.yahoo.elide.core.DataStoreTransaction;
 import com.yahoo.elide.core.EntityDictionary;
+import com.yahoo.elide.datastores.aggregation.schema.Schema;
+import com.yahoo.elide.datastores.aggregation.schema.dimension.TimeDimensionColumn;
 
 /**
  * DataStore that supports Aggregation. Uses {@link QueryEngine} to return results.
@@ -28,6 +31,14 @@ public AggregationDataStore(QueryEngineFactory queryEngineFactory) {
     @Override
     public void populateEntityDictionary(EntityDictionary dictionary) {
         queryEngine = queryEngineFactory.buildQueryEngine(dictionary);
+
+        /* Add 'grain' argument to each TimeDimensionColumn */
+        for (Schema schema: queryEngine.getSchemas()) {
+            for (TimeDimensionColumn timeDim : schema.getTimeDimensions()) {
+                dictionary.addArgumentToAttribute(schema.getEntityClass(), timeDim.getName(),
+                        new ArgumentType("grain", String.class));
+            }
+        }
     }
 
     @Override

elide-datastore/elide-datastore-aggregation/src/main/java/com/yahoo/elide/datastores/aggregation/AggregationDataStoreHelper.java

@@ -31,6 +31,7 @@
 
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
@@ -101,7 +102,6 @@ private void splitFilters() {
         }
     }
 
-    //TODO - Add tests in the next PR.
     /**
      * Gets time dimensions based on relationships and attributes from {@link EntityProjection}.
      *
@@ -129,7 +129,7 @@ private Set<TimeDimensionProjection> resolveTimeDimensions() {
                                         String.format("Requested default grain, no grain defined on %s",
                                                 attribute.getName())));
                     } else {
-                        String requestedGrainName = timeGrainArgument.getValue().toString();
+                        String requestedGrainName = timeGrainArgument.getValue().toString().toUpperCase(Locale.ENGLISH);
 
                         TimeGrain requestedGrain;
                         try {

elide-datastore/elide-datastore-aggregation/src/main/java/com/yahoo/elide/datastores/aggregation/QueryEngine.java

@@ -10,6 +10,8 @@
 import com.yahoo.elide.datastores.aggregation.query.Query;
 import com.yahoo.elide.datastores.aggregation.schema.Schema;
 
+import java.util.List;
+
 /**
  * A {@link QueryEngine} is an abstraction that an AggregationDataStore leverages to run analytic queries (OLAP style)
  * against an underlying persistence layer.
@@ -68,5 +70,16 @@ public interface QueryEngine {
      * @param entityClass The class to map to a schema.
      * @return The schema that represents the provided entity.
      */
-    Schema getSchema(Class<?> entityClass);
+    default Schema getSchema(Class<?> entityClass) {
+        return getSchemas().stream()
+                .filter(schema -> schema.getEntityClass().equals(entityClass))
+                .findFirst()
+                .orElse(null);
+    }
+
+    /**
+     * Returns all schemas managed by the engine.
+     * @return The schemas of the managed entities.
+     */
+    List<Schema> getSchemas();
 }

elide-datastore/elide-datastore-aggregation/src/main/java/com/yahoo/elide/datastores/aggregation/queryengines/sql/SQLQueryEngine.java

@@ -23,6 +23,7 @@
 import com.yahoo.elide.datastores.aggregation.queryengines.sql.annotation.JoinTo;
 import com.yahoo.elide.datastores.aggregation.queryengines.sql.schema.SQLDimensionColumn;
 import com.yahoo.elide.datastores.aggregation.queryengines.sql.schema.SQLSchema;
+import com.yahoo.elide.datastores.aggregation.queryengines.sql.schema.SQLTimeDimensionColumn;
 import com.yahoo.elide.datastores.aggregation.schema.Schema;
 import com.yahoo.elide.datastores.aggregation.schema.dimension.DimensionColumn;
 import com.yahoo.elide.datastores.aggregation.schema.metric.Aggregation;
@@ -82,6 +83,11 @@ public Schema getSchema(Class<?> entityClass) {
         return schemas.get(entityClass);
     }
 
+    @Override
+    public List<Schema> getSchemas() {
+        return schemas.values().stream().collect(Collectors.toList());
+    }
+
     @Override
     public Iterable<Object> executeQuery(Query query) {
         EntityManager entityManager = null;
@@ -460,8 +466,7 @@ private String extractProjection(Query query) {
      * @return The SQL GROUP BY clause
      */
     private String extractGroupBy(Query query) {
-        return "GROUP BY " + extractDimensionProjections(query).stream()
-                .collect(Collectors.joining(","));
+       return "GROUP BY " + extractDimensionProjections(query).stream().collect(Collectors.joining(","));
     }
 
     /**
@@ -470,11 +475,21 @@ private String extractGroupBy(Query query) {
      * @return
      */
     private List<String> extractDimensionProjections(Query query) {
-        return query.getDimensions().stream()
+        List<String> dimensionStrings = query.getGroupDimensions().stream()
                 .map(requestedDim -> query.getSchema().getDimension(requestedDim.getName()))
                 .map((SQLDimensionColumn.class::cast))
                 .map(SQLDimensionColumn::getColumnReference)
                 .collect(Collectors.toList());
+
+        dimensionStrings.addAll(query.getTimeDimensions().stream()
+                .map(requestedDim -> {
+                    SQLTimeDimensionColumn timeDim = (SQLTimeDimensionColumn)
+                            query.getSchema().getTimeDimension(requestedDim.getName());
+
+                    return timeDim.getColumnReference(requestedDim.getTimeGrain().grain());
+                }).collect(Collectors.toList()));
+
+        return dimensionStrings;
     }
 
     /**

elide-datastore/elide-datastore-aggregation/src/main/java/com/yahoo/elide/datastores/aggregation/queryengines/sql/schema/SQLSchema.java

@@ -20,7 +20,6 @@
 import com.yahoo.elide.datastores.aggregation.schema.metric.Metric;
 
 import org.hibernate.annotations.Subselect;
-
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.ToString;

elide-datastore/elide-datastore-aggregation/src/main/java/com/yahoo/elide/datastores/aggregation/queryengines/sql/schema/SQLTimeDimensionColumn.java

@@ -9,6 +9,7 @@
 import com.yahoo.elide.core.Path;
 import com.yahoo.elide.datastores.aggregation.annotation.TimeGrainDefinition;
 import com.yahoo.elide.datastores.aggregation.schema.dimension.TimeDimensionColumn;
+import com.yahoo.elide.datastores.aggregation.time.TimeGrain;
 
 import java.util.Set;
 import java.util.TimeZone;
@@ -20,21 +21,23 @@
 public class SQLTimeDimensionColumn extends SQLDimensionColumn implements TimeDimensionColumn {
     /**
      * Constructor.
-     * @param dimension a wrapped dimension.
+     *
+     * @param dimension   a wrapped dimension.
      * @param columnAlias The column alias in SQL to refer to this dimension.
-     * @param tableAlias The table alias in SQL where this dimension lives.
+     * @param tableAlias  The table alias in SQL where this dimension lives.
      */
     public SQLTimeDimensionColumn(TimeDimensionColumn dimension, String columnAlias, String tableAlias) {
         super(dimension, columnAlias, tableAlias);
     }
 
     /**
      * Constructor.
-     * @param dimension a wrapped dimension.
+     *
+     * @param dimension   a wrapped dimension.
      * @param columnAlias The column alias in SQL to refer to this dimension.
-     * @param tableAlias The table alias in SQL where this dimension lives.
-     * @param joinPath A '.' separated path through the entity relationship graph that describes
-     *                 how to join the time dimension into the current AnalyticView.
+     * @param tableAlias  The table alias in SQL where this dimension lives.
+     * @param joinPath    A '.' separated path through the entity relationship graph that describes
+     *                    how to join the time dimension into the current AnalyticView.
      */
     public SQLTimeDimensionColumn(TimeDimensionColumn dimension, String columnAlias, String tableAlias, Path joinPath) {
         super(dimension, columnAlias, tableAlias, joinPath);
@@ -50,4 +53,20 @@ public TimeZone getTimeZone() {
     public Set<TimeGrainDefinition> getSupportedGrains() {
         return ((TimeDimensionColumn) wrapped).getSupportedGrains();
     }
+
+    /**
+     * Returns a String that identifies this dimension in a SQL query.
+     * @param requestedGrain The requested time grain.
+     *
+     * @return Something like "table_alias.column_name"
+     */
+    public String getColumnReference(TimeGrain requestedGrain) {
+        TimeGrainDefinition definition = getSupportedGrains().stream()
+                .filter(grainDef -> grainDef.grain().equals(requestedGrain))
+                .findFirst()
+                .orElseThrow(() -> new IllegalStateException("Requested time grain not supported."));
+
+        //TODO - We will likely migrate to a templating language when we support parameterized metrics.
+        return String.format(definition.expression(), getColumnReference());
+    }
 }

elide-datastore/elide-datastore-aggregation/src/main/java/com/yahoo/elide/datastores/aggregation/schema/Schema.java

@@ -124,6 +124,17 @@ public TimeDimensionColumn getTimeDimension(String dimensionName) {
         return null;
     }
 
+    /**
+     * Returns the complete list of time dimensions.
+     * @return the complete list of time dimensions.
+     */
+    public List<TimeDimensionColumn> getTimeDimensions() {
+        return dimensions.values().stream()
+                .filter(dim -> dim instanceof TimeDimensionColumn)
+                .map(TimeDimensionColumn.class::cast)
+                .collect(Collectors.toList());
+    }
+
     /**
      * Finds the {@link Metric} by name.
      *

elide-datastore/elide-datastore-aggregation/src/test/java/com/yahoo/elide/datastores/aggregation/AggregationDataStoreIntegrationTest.java

@@ -477,6 +477,36 @@ public void aggregationComputedMetricTest() throws Exception {
         runQueryWithExpectedResult(graphQLRequest, expected);
     }
 
+    @Test
+    public void timeGrainAggregationTest() throws Exception {
+        String graphQLRequest = document(
+                selection(
+                        field(
+                                "playerStats",
+                                selections(
+                                        field("highScore"),
+                                        field("recordedDate", arguments(
+                                                argument("grain", "\"month\"")
+                                        ))
+                                )
+                        )
+                )
+        ).toQuery();
+
+        String expected = document(
+                selections(
+                        field(
+                                "playerStats",
+                                selections(
+                                        field("highScore", 2412),
+                                        field("recordedDate", "2019-07-01T00:00Z")
+                                )
+                        )
+                )).toResponse();
+
+        runQueryWithExpectedResult(graphQLRequest, expected);
+    }
+
     private void create(String query, Map<String, Object> variables) throws IOException {
         runQuery(toJsonQuery(query, variables));
     }

elide-datastore/elide-datastore-aggregation/src/test/java/com/yahoo/elide/datastores/aggregation/example/PlayerStats.java

@@ -41,6 +41,9 @@
 @FromTable(name = "playerStats")
 public class PlayerStats {
 
+    public static final String DAY_FORMAT = "PARSEDATETIME(FORMATDATETIME(%s, 'yyyy-MM-dd'), 'yyyy-MM-dd')";
+    public static final String MONTH_FORMAT = "PARSEDATETIME(FORMATDATETIME(%s, 'yyyy-MM-01'), 'yyyy-MM-dd')";
+
     /**
      * PK.
      */
@@ -161,7 +164,10 @@ public void setPlayer(final Player player) {
      * {@link EntityDimensionTest#testCardinalityScan()}.
      * @return the date of the player session.
      */
-    @Temporal(grains = { @TimeGrainDefinition(grain = TimeGrain.DAY, expression = "") }, timeZone = "UTC")
+    @Temporal(grains = {
+            @TimeGrainDefinition(grain = TimeGrain.DAY, expression = DAY_FORMAT),
+            @TimeGrainDefinition(grain = TimeGrain.MONTH, expression = MONTH_FORMAT)
+    }, timeZone = "UTC")
     public Date getRecordedDate() {
         return recordedDate;
     }

elide-datastore/elide-datastore-aggregation/src/test/java/com/yahoo/elide/datastores/aggregation/example/SubCountry.java

@@ -18,7 +18,7 @@
 import javax.persistence.Id;
 
 /**
- * A root level entity for testing AggregationDataStore with @Subselect annotation
+ * A root level entity for testing AggregationDataStore with @Subselect annotation.
  */
 @Data
 @Entity