WIP: promote job functions implementation snapshot

dhp-workflows/dhp-actionmanager/src/main/java/eu/dnetlib/dhp/actionmanager/PromoteActionSetFromHDFSFunctions.java

@@ -1,45 +1,134 @@
 package eu.dnetlib.dhp.actionmanager;
 
+import eu.dnetlib.dhp.schema.oaf.Oaf;
 import eu.dnetlib.dhp.schema.oaf.OafEntity;
+import eu.dnetlib.dhp.schema.oaf.Relation;
+import org.apache.spark.api.java.function.FilterFunction;
 import org.apache.spark.api.java.function.MapFunction;
 import org.apache.spark.api.java.function.ReduceFunction;
-import org.apache.spark.sql.Column;
 import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Encoder;
 import org.apache.spark.sql.Encoders;
+import org.apache.spark.sql.TypedColumn;
+import org.apache.spark.sql.expressions.Aggregator;
 import scala.Tuple2;
 
+import java.util.Objects;
 import java.util.Optional;
 import java.util.function.BiFunction;
+import java.util.function.Function;
 
 public class PromoteActionSetFromHDFSFunctions {
 
-    public static <T extends OafEntity> Dataset<T> groupEntitiesByIdAndMerge(Dataset<T> entityDS,
-                                                                             Class<T> clazz) {
-        return entityDS
-                .groupByKey((MapFunction<T, String>) OafEntity::getId, Encoders.STRING())
-                .reduceGroups((ReduceFunction<T>) (x1, x2) -> {
-                    x1.mergeFrom(x2);
-                    return x1;
-                })
-                .map((MapFunction<Tuple2<String, T>, T>) pair -> pair._2, Encoders.bean(clazz));
+    public static <T extends Oaf> Dataset<T> joinOafEntityWithActionPayloadAndMerge(Dataset<T> oafDS,
+                                                                                    Dataset<String> actionPayloadDS,
+                                                                                    SerializableSupplier<Function<T, String>> oafIdFn,
+                                                                                    SerializableSupplier<BiFunction<String, Class<T>, T>> actionPayloadToOafFn,
+                                                                                    SerializableSupplier<BiFunction<T, T, T>> mergeAndGetFn,
+                                                                                    Class<T> clazz) {
+        Dataset<Tuple2<String, T>> oafWithIdDS = oafDS
+                .map((MapFunction<T, Tuple2<String, T>>) value -> new Tuple2<>(oafIdFn.get().apply(value), value),
+                        Encoders.tuple(Encoders.STRING(), Encoders.kryo(clazz)));
+
+        Dataset<Tuple2<String, T>> actionPayloadWithIdDS = actionPayloadDS
+                .map((MapFunction<String, T>) value -> actionPayloadToOafFn.get().apply(value, clazz), Encoders.kryo(clazz))
+                .filter((FilterFunction<T>) Objects::nonNull)
+                .map((MapFunction<T, Tuple2<String, T>>) value -> new Tuple2<>(oafIdFn.get().apply(value), value),
+                        Encoders.tuple(Encoders.STRING(), Encoders.kryo(clazz)));
+
+        return oafWithIdDS
+                .joinWith(actionPayloadWithIdDS, oafWithIdDS.col("_1").equalTo(actionPayloadWithIdDS.col("_1")), "left_outer")
+                .map((MapFunction<Tuple2<Tuple2<String, T>, Tuple2<String, T>>, T>) value -> {
+                    T left = value._1()._2();
+                    return Optional
+                            .ofNullable(value._2())
+                            .map(Tuple2::_2)
+                            .map(x -> mergeAndGetFn.get().apply(left, x))
+                            .orElse(left);
+                }, Encoders.kryo(clazz));
     }
 
-    public static <T extends OafEntity, S> Dataset<T> joinEntitiesWithActionPayloadAndMerge(Dataset<T> entityDS,
-                                                                                            Dataset<S> actionPayloadDS,
-                                                                                            BiFunction<Dataset<T>, Dataset<S>, Column> entityToActionPayloadJoinExpr,
-                                                                                            BiFunction<S, Class<T>, T> actionPayloadToEntityFn,
-                                                                                            Class<T> clazz) {
-        return entityDS
-                .joinWith(actionPayloadDS, entityToActionPayloadJoinExpr.apply(entityDS, actionPayloadDS), "left_outer")
-                .map((MapFunction<Tuple2<T, S>, T>) pair -> Optional
-                        .ofNullable(pair._2())
-                        .map(x -> {
-                            T entity = actionPayloadToEntityFn.apply(x, clazz);
-                            pair._1().mergeFrom(entity);
-                            return pair._1();
-                        })
-                        .orElse(pair._1()), Encoders.bean(clazz));
+    public static <T extends Oaf> Dataset<T> groupOafByIdAndMerge(Dataset<T> oafDS,
+                                                                  SerializableSupplier<Function<T, String>> oafIdFn,
+                                                                  SerializableSupplier<BiFunction<T, T, T>> mergeAndGetFn,
+                                                                  Class<T> clazz) {
+        return oafDS
+                .groupByKey((MapFunction<T, String>) x -> oafIdFn.get().apply(x), Encoders.STRING())
+                .reduceGroups((ReduceFunction<T>) (v1, v2) -> mergeAndGetFn.get().apply(v1, v2))
+                .map((MapFunction<Tuple2<String, T>, T>) Tuple2::_2, Encoders.kryo(clazz));
     }
 
+    public static <T extends Oaf> Dataset<T> groupOafByIdAndMergeUsingAggregator(Dataset<T> oafDS,
+                                                                                 SerializableSupplier<T> zeroFn,
+                                                                                 SerializableSupplier<Function<T, String>> idFn,
+                                                                                 Class<T> clazz) {
+        TypedColumn<T, T> aggregator = new OafAggregator<>(zeroFn, clazz).toColumn();
+        return oafDS
+                .groupByKey((MapFunction<T, String>) x -> idFn.get().apply(x), Encoders.STRING())
+                .agg(aggregator)
+                .map((MapFunction<Tuple2<String, T>, T>) Tuple2::_2, Encoders.kryo(clazz));
+    }
 
-}
+    public static class OafAggregator<T extends Oaf> extends Aggregator<T, T, T> {
+        private SerializableSupplier<T> zero;
+        private Class<T> clazz;
+
+        public OafAggregator(SerializableSupplier<T> zero, Class<T> clazz) {
+            this.zero = zero;
+            this.clazz = clazz;
+        }
+
+        @Override
+        public T zero() {
+            return zero.get();
+        }
+
+        @Override
+        public T reduce(T b, T a) {
+            return mergeFrom(b, a);
+        }
+
+        @Override
+        public T merge(T b1, T b2) {
+            return mergeFrom(b1, b2);
+        }
+
+        private T mergeFrom(T left, T right) {
+            if (isNonNull(left)) {
+                if (left instanceof Relation) {
+                    ((Relation) left).mergeFrom((Relation) right);
+                    return left;
+                }
+                ((OafEntity) left).mergeFrom((OafEntity) right);
+                return left;
+            }
+
+            if (right instanceof Relation) {
+                ((Relation) right).mergeFrom((Relation) left);
+                return right;
+            }
+            ((OafEntity) right).mergeFrom((OafEntity) left);
+            return right;
+        }
+
+        private Boolean isNonNull(T a) {
+            return Objects.nonNull(a.getLastupdatetimestamp());
+        }
+
+        @Override
+        public T finish(T reduction) {
+            return reduction;
+        }
+
+        @Override
+        public Encoder<T> bufferEncoder() {
+            return Encoders.kryo(clazz);
+        }
+
+        @Override
+        public Encoder<T> outputEncoder() {
+            return Encoders.kryo(clazz);
+        }
+
+    }
+}