public static class CompilerResult {

private final Document document;

private final Map<String, Object> variables;

public CompilerResult(Document document, Map<String, Object> variables) {

this.document = document;

this.variables = variables;

}

public Document getDocument() {

return document;

}

public Map<String, Object> getVariables() {

return variables;

}

}

public static CompilerResult compileToDocument(@NotNull GraphQLSchema schema,

@NotNull OperationDefinition.Operation operationKind,

@Nullable String operationName,

@NotNull List<ExecutableNormalizedField> topLevelFields,

@Nullable VariablePredicate variablePredicate) {

GraphQLObjectType operationType = getOperationType(schema, operationKind);

VariableAccumulator variableAccumulator = new VariableAccumulator(variablePredicate);

List<Selection<?>> selections = subselectionsForNormalizedField(schema, operationType.getName(), topLevelFields, variableAccumulator);

SelectionSet selectionSet = new SelectionSet(selections);

OperationDefinition.Builder definitionBuilder = OperationDefinition.newOperationDefinition()

.name(operationName)

.operation(operationKind)

.selectionSet(selectionSet);

definitionBuilder.variableDefinitions(variableAccumulator.getVariableDefinitions());

return new CompilerResult(

Document.newDocument()

.definition(definitionBuilder.build())

.build(),

variableAccumulator.getVariablesMap()

);

}

private static List<Selection<?>> subselectionsForNormalizedField(GraphQLSchema schema,

@NotNull String parentOutputType,

List<ExecutableNormalizedField> executableNormalizedFields,

VariableAccumulator variableAccumulator) {

ImmutableList.Builder<Selection<?>> selections = ImmutableList.builder();

// All conditional fields go here instead of directly to selections, so they can be grouped together

// in the same inline fragment in the output

Map<String, List<Field>> fieldsByTypeCondition = new LinkedHashMap<>();

for (ExecutableNormalizedField nf : executableNormalizedFields) {

if (nf.isConditional(schema)) {

selectionForNormalizedField(schema, nf, variableAccumulator)

.forEach((objectTypeName, field) ->

fieldsByTypeCondition

.computeIfAbsent(objectTypeName, ignored -> new ArrayList<>())

.add(field));

} else {

selections.add(selectionForNormalizedField(schema, parentOutputType, nf, variableAccumulator));

}

}

fieldsByTypeCondition.forEach((objectTypeName, fields) -> {

TypeName typeName = newTypeName(objectTypeName).build();

InlineFragment inlineFragment = newInlineFragment()

.typeCondition(typeName)

.selectionSet(selectionSet(fields))

.build();

selections.add(inlineFragment);

});

return selections.build();

}

/**

private static Map<String, Field> selectionForNormalizedField(GraphQLSchema schema,

ExecutableNormalizedField executableNormalizedField,

VariableAccumulator variableAccumulator) {

Map<String, Field> groupedFields = new LinkedHashMap<>();

for (String objectTypeName : executableNormalizedField.getObjectTypeNames()) {

groupedFields.put(objectTypeName, selectionForNormalizedField(schema, objectTypeName, executableNormalizedField, variableAccumulator));

}

return groupedFields;

}

/**

private static Field selectionForNormalizedField(GraphQLSchema schema,

String objectTypeName,

ExecutableNormalizedField executableNormalizedField,

VariableAccumulator variableAccumulator) {

final List<Selection<?>> subSelections;

if (executableNormalizedField.getChildren().isEmpty()) {

subSelections = emptyList();

} else {

GraphQLFieldDefinition fieldDef = getFieldDefinition(schema, objectTypeName, executableNormalizedField);

GraphQLUnmodifiedType fieldOutputType = unwrapAll(fieldDef.getType());

subSelections = subselectionsForNormalizedField(

schema,

fieldOutputType.getName(),

executableNormalizedField.getChildren(),

variableAccumulator

);

}

SelectionSet selectionSet = selectionSetOrNullIfEmpty(subSelections);

List<Argument> arguments = createArguments(executableNormalizedField, variableAccumulator);

return newField()

.name(executableNormalizedField.getFieldName())

.alias(executableNormalizedField.getAlias())

.selectionSet(selectionSet)

.arguments(arguments)

.build();

}

@Nullable

private static SelectionSet selectionSetOrNullIfEmpty(List<Selection<?>> selections) {

return selections.isEmpty() ? null : newSelectionSet().selections(selections).build();

}

private static SelectionSet selectionSet(List<Field> fields) {

return newSelectionSet().selections(fields).build();

}

private static List<Argument> createArguments(ExecutableNormalizedField executableNormalizedField,

VariableAccumulator variableAccumulator) {

ImmutableList.Builder<Argument> result = ImmutableList.builder();

ImmutableMap<String, NormalizedInputValue> normalizedArguments = executableNormalizedField.getNormalizedArguments();

for (String argName : normalizedArguments.keySet()) {

NormalizedInputValue normalizedInputValue = normalizedArguments.get(argName);

Value<?> value = argValue(executableNormalizedField, argName, normalizedInputValue, variableAccumulator);

Argument argument = newArgument()

.name(argName)

.value(value)

.build();

result.add(argument);

}

return result.build();

}

@SuppressWarnings("unchecked")

private static Value<?> argValue(ExecutableNormalizedField executableNormalizedField,

String argName,

@Nullable Object value,

VariableAccumulator variableAccumulator) {

if (value instanceof List) {

ArrayValue.Builder arrayValue = ArrayValue.newArrayValue();

arrayValue.values(map((List<Object>) value, val -> argValue(executableNormalizedField, argName, val, variableAccumulator)));

return arrayValue.build();

}

if (value instanceof Map) {

ObjectValue.Builder objectValue = ObjectValue.newObjectValue();

Map<String, Object> map = (Map<String, Object>) value;

for (String fieldName : map.keySet()) {

Value<?> fieldValue = argValue(executableNormalizedField, argName, (NormalizedInputValue) map.get(fieldName), variableAccumulator);

objectValue.objectField(ObjectField.newObjectField().name(fieldName).value(fieldValue).build());

}

return objectValue.build();

}

if (value == null) {

return NullValue.newNullValue().build();

}

return (Value<?>) value;

}

@NotNull

private static Value<?> argValue(ExecutableNormalizedField executableNormalizedField,

String argName,

NormalizedInputValue normalizedInputValue,

VariableAccumulator variableAccumulator) {

if (variableAccumulator.shouldMakeVariable(executableNormalizedField, argName, normalizedInputValue)) {

VariableValueWithDefinition variableWithDefinition = variableAccumulator.accumulateVariable(normalizedInputValue);

return variableWithDefinition.getVariableReference();

} else {

return argValue(executableNormalizedField, argName, normalizedInputValue.getValue(), variableAccumulator);

}

}

@NotNull

private static GraphQLFieldDefinition getFieldDefinition(GraphQLSchema schema,

String parentType,

ExecutableNormalizedField nf) {

return Introspection.getFieldDef(schema, (GraphQLCompositeType) schema.getType(parentType), nf.getName());

}

@Nullable

private static GraphQLObjectType getOperationType(@NotNull GraphQLSchema schema,

@NotNull OperationDefinition.Operation operationKind) {

switch (operationKind) {

case QUERY:

return schema.getQueryType();

case MUTATION:

return schema.getMutationType();

case SUBSCRIPTION:

return schema.getSubscriptionType();

}

return Assert.assertShouldNeverHappen("Unknown operation kind " + operationKind);

}