Feature for automatically creating database from GraphQL schema

src/main/java/com/arangodb/graphql/create/ArgumentIndexMapping.java

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+package com.arangodb.graphql.create;
+
+import com.arangodb.graphql.schema.ArangoVertexDirective;
+import graphql.schema.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ArgumentIndexMapping {
+
+    private GraphQLFieldDefinition fieldDefinition;
+
+    private List<String> fields;
+
+    private String collection;
+
+    public ArgumentIndexMapping(GraphQLFieldDefinition fieldDefinition){
+        this.fieldDefinition = fieldDefinition;
+        init();
+    }
+
+
+    private void init(){
+
+        fields = new ArrayList<>();
+
+        List<GraphQLArgument> arguments = fieldDefinition.getArguments();
+
+        boolean firstMandatoryArgFound = false;
+        for(GraphQLArgument argument : arguments){
+            if(firstMandatoryArgFound){
+                fields.add(argument.getName());
+            }
+            else {
+                boolean nonNull = GraphQLTypeUtil.isNonNull(argument.getType());
+                if (nonNull) {
+                    firstMandatoryArgFound = true;
+                    fields.add(0, argument.getName());
+                } else {
+                    fields.add(argument.getName());
+                }
+            }
+
+        }
+
+        GraphQLUnmodifiedType type = GraphQLTypeUtil.unwrapAll(fieldDefinition.getType());
+        if(type instanceof GraphQLDirectiveContainer) {
+            ArangoVertexDirective vertexDirective = new ArangoVertexDirective((GraphQLDirectiveContainer)type);
+            this.collection = vertexDirective.getCollection();
+        }
+    }
+
+    public String getCollection() {
+        return collection;
+    }
+
+    public List<String> getFields() {
+        return fields;
+    }
+}

src/main/java/com/arangodb/graphql/create/DatabaseObjectCreator.java

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+package com.arangodb.graphql.create;
+
+import com.arangodb.ArangoDB;
+import com.arangodb.ArangoDatabase;
+import com.arangodb.entity.CollectionType;
+import com.arangodb.graphql.schema.ArangoEdgeDirective;
+import com.arangodb.graphql.schema.ArangoVertexDirective;
+import com.arangodb.model.CollectionCreateOptions;
+import com.arangodb.model.HashIndexOptions;
+import graphql.schema.GraphQLArgument;
+import graphql.schema.GraphQLObjectType;
+import graphql.schema.GraphQLSchema;
+import graphql.schema.GraphQLType;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.*;
+
+public class DatabaseObjectCreator {
+
+    private final Logger logger = LoggerFactory.getLogger(this.getClass());
+    private final ArangoDB arango;
+    private final String databaseName;
+    private final GraphQLSchema graphQLSchema;
+
+    public DatabaseObjectCreator(ArangoDB arango, String databaseName, GraphQLSchema graphQLSchema) {
+        this.arango = arango;
+        this.databaseName = databaseName;
+        this.graphQLSchema = graphQLSchema;
+    }
+
+    private List<TypeCollectionMapping> createTypeMappings(){
+
+        List<GraphQLType> types = graphQLSchema.getAllTypesAsList();
+
+        List<TypeCollectionMapping> mappings = new ArrayList<>();
+        types.forEach(type -> {
+            if(type instanceof GraphQLObjectType){
+                GraphQLObjectType objectType = (GraphQLObjectType) type;
+                ArangoVertexDirective vertexDirective = new ArangoVertexDirective(objectType);
+                String collection = vertexDirective.getCollection();
+                if(collection != null){
+                    TypeCollectionMapping mapping = new TypeCollectionMapping(collection);
+
+                    objectType.getFieldDefinitions().forEach(graphQLFieldDefinition -> {
+                        ArangoEdgeDirective arangoEdgeDirective = new ArangoEdgeDirective(graphQLFieldDefinition);
+                        String edgeCollectionName = arangoEdgeDirective.getCollection();
+                        if(edgeCollectionName != null){
+                            mapping.addEdgeCollection(edgeCollectionName);
+                        }
+                    });
+
+                    mappings.add(mapping);
+
+                }
+            }
+        });
+
+        return mappings;
+
+    }
+
+    public void createDatabase(){
+        ArangoDatabase db = arango.db(databaseName);
+        if(!db.exists()){
+            logger.info("Auto Create Database {}", databaseName);
+            db.create();
+        }
+        else{
+            logger.info("Database {} already exists", databaseName);
+        }
+    }
+
+    public void createCollections(){
+
+        List<TypeCollectionMapping> mappings = createTypeMappings();
+        mappings.forEach(mapping -> {
+            String vertex = mapping.getVertexCollection();
+            createCollection(vertex, CollectionType.DOCUMENT);
+            Set<String> edgeCollections = mapping.getEdgeCollections();
+            edgeCollections.forEach(edgeCollection -> {
+                createCollection(edgeCollection, CollectionType.EDGES);
+            });
+        });
+
+    }
+
+    public void createIndexes(){
+
+        ArangoDatabase database = arango.db(databaseName);
+        GraphQLObjectType queryType = graphQLSchema.getQueryType();
+        queryType.getFieldDefinitions().forEach(graphQLFieldDefinition -> {
+            ArgumentIndexMapping mapping = new ArgumentIndexMapping(graphQLFieldDefinition);
+
+            String collection = mapping.getCollection();
+            if(collection != null){
+                logger.info("Auto Create Index on collection {} for fields {}", collection, mapping.getFields());
+                database.collection(collection).ensureHashIndex(mapping.getFields(), new HashIndexOptions());
+            }
+
+        });
+    }
+
+    protected CollectionCreateOptions createCollectionCreateOptions(CollectionType collectionType){
+        return new CollectionCreateOptions().type(collectionType);
+    }
+
+    private void createCollection(String name, CollectionType collectionType) {
+
+        CollectionCreateOptions collectionCreateOptions = createCollectionCreateOptions(collectionType);
+        ArangoDatabase database = arango.db(databaseName);
+
+        if(!database.collection(name).exists()){
+            logger.info("Auto Create Collection {}:{}", name, collectionType);
+            database.collection(name).create(collectionCreateOptions);
+        }
+        else{
+            logger.info("Collection already exists {}:{}", name, collectionType);
+        }
+
+    }
+
+}

src/main/java/com/arangodb/graphql/create/TypeCollectionMapping.java

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+package com.arangodb.graphql.create;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class TypeCollectionMapping {
+
+    private final String vertexCollection;
+
+    private final Set<String> edgeCollections;
+
+    public TypeCollectionMapping(String vertexCollection){
+        this.vertexCollection = vertexCollection;
+        this.edgeCollections = new HashSet<>();
+    }
+
+    public void addEdgeCollection(String edgeCollection){
+        this.edgeCollections.add(edgeCollection);
+    }
+
+
+    public String getVertexCollection() {
+        return vertexCollection;
+    }
+
+    public Set<String> getEdgeCollections() {
+        return edgeCollections;
+    }
+}