Refactor common schema code into SchemaLoader

Author: wravery

include/ClientGenerator.h

@@ -6,228 +6,11 @@
 #ifndef CLIENTGENERATOR_H
 #define CLIENTGENERATOR_H
 
-#include "graphqlservice/GraphQLGrammar.h"
-#include "graphqlservice/GraphQLParse.h"
-#include "graphqlservice/GraphQLResponse.h"
-#include "graphqlservice/GraphQLSchema.h"
-
-#include <array>
-#include <cstdio>
-#include <unordered_map>
-#include <unordered_set>
-
-namespace graphql::client {
-
-// These are the set of built-in types in GraphQL.
-enum class BuiltinType
-{
-	Int,
-	Float,
-	String,
-	Boolean,
-	ID,
-};
-
-using BuiltinTypeMap = std::map<std::string_view, BuiltinType>;
-
-// These are the C++ types we'll use for them.
-using CppTypeMap = std::array<std::string_view, static_cast<size_t>(BuiltinType::ID) + 1>;
-
-// Types that we understand and use to generate the skeleton of a service.
-enum class SchemaType
-{
-	Scalar,
-	Enum,
-	Input,
-	Union,
-	Interface,
-	Object,
-	Operation,
-};
-
-using SchemaTypeMap = std::map<std::string_view, SchemaType>;
-
-// Keep track of the positions of each type declaration in the file.
-using PositionMap = std::unordered_map<std::string_view, tao::graphqlpeg::position>;
-
-// For all of the named types we track, we want to keep them in order in a vector but
-// be able to lookup their offset quickly by name.
-using TypeNameMap = std::unordered_map<std::string_view, size_t>;
-
-// Any type can also have a list and/or non-nullable wrapper, and those can be nested.
-// Since it's easier to express nullability than non-nullability in C++, we'll invert
-// the presence of NonNull modifiers.
-using TypeModifierStack = std::vector<service::TypeModifier>;
-
-// Scalar types are opaque to the generator, it's up to the service implementation
-// to handle parsing, validating, and serializing them. We just need to track which
-// scalar type names have been declared so we recognize the references.
-struct ScalarType
-{
-	std::string_view type;
-	std::string_view description;
-};
-
-using ScalarTypeList = std::vector<ScalarType>;
-
-// Enum types map a type name to a collection of valid string values.
-struct EnumValueType
-{
-	std::string_view value;
-	std::string_view cppValue;
-	std::string_view description;
-	std::optional<std::string_view> deprecationReason;
-	std::optional<tao::graphqlpeg::position> position;
-};
-
-struct EnumType
-{
-	std::string_view type;
-	std::string_view cppType;
-	std::vector<EnumValueType> values;
-	std::string_view description;
-};
-
-using EnumTypeList = std::vector<EnumType>;
-
-// Input types are complex types that have a set of named fields. Each field may be
-// a scalar type (including lists or non-null wrappers) or another nested input type,
-// but it cannot include output object types.
-enum class InputFieldType
-{
-	Builtin,
-	Scalar,
-	Enum,
-	Input,
-};
-
-struct InputField
-{
-	std::string_view type;
-	std::string_view name;
-	std::string_view cppName;
-	std::string_view defaultValueString;
-	response::Value defaultValue;
-	InputFieldType fieldType = InputFieldType::Builtin;
-	TypeModifierStack modifiers;
-	std::string_view description;
-	std::optional<tao::graphqlpeg::position> position;
-};
-
-using InputFieldList = std::vector<InputField>;
-
-struct InputType
-{
-	std::string_view type;
-	std::string_view cppType;
-	InputFieldList fields;
-	std::string_view description;
-};
-
-using InputTypeList = std::vector<InputType>;
-
-// Directives are defined with arguments and a list of valid locations.
-struct Directive
-{
-	std::string_view name;
-	std::vector<std::string_view> locations;
-	InputFieldList arguments;
-	std::string_view description;
-};
-
-using DirectiveList = std::vector<Directive>;
-
-// Union types map a type name to a set of potential concrete type names.
-struct UnionType
-{
-	std::string_view type;
-	std::string_view cppType;
-	std::vector<std::string_view> options;
-	std::string_view description;
-};
-
-using UnionTypeList = std::vector<UnionType>;
-
-// Output types are scalar types or complex types that have a set of named fields. Each
-// field may be a scalar type (including lists or non-null wrappers) or another nested
-// output type, but it cannot include input object types. Each field can also take
-// optional arguments which are all input types.
-enum class OutputFieldType
-{
-	Builtin,
-	Scalar,
-	Enum,
-	Union,
-	Interface,
-	Object,
-};
-
-constexpr std::string_view strGet = "get";
-constexpr std::string_view strApply = "apply";
-
-struct OutputField
-{
-	std::string_view type;
-	std::string_view name;
-	std::string_view cppName;
-	InputFieldList arguments;
-	OutputFieldType fieldType = OutputFieldType::Builtin;
-	TypeModifierStack modifiers;
-	std::string_view description;
-	std::optional<std::string_view> deprecationReason;
-	std::optional<tao::graphqlpeg::position> position;
-	bool interfaceField = false;
-	bool inheritedField = false;
-	std::string_view accessor { strGet };
-};
-
-using OutputFieldList = std::vector<OutputField>;
-
-// Interface types are abstract complex output types that have a set of fields. They
-// are inherited by concrete object output types which support all of the fields in
-// the interface, and the concrete object matches the interface for fragment type
-// conditions. The fields can include any output type.
-struct InterfaceType
-{
-	std::string_view type;
-	std::string_view cppType;
-	OutputFieldList fields;
-	std::string_view description;
-};
-
-using InterfaceTypeList = std::vector<InterfaceType>;
-
-// Object types are concrete complex output types that have a set of fields. They
-// may inherit multiple interfaces.
-struct ObjectType
-{
-	std::string_view type;
-	std::string_view cppType;
-	std::vector<std::string_view> interfaces;
-	std::vector<std::string_view> unions;
-	OutputFieldList fields;
-	std::string_view description;
-};
-
-using ObjectTypeList = std::vector<ObjectType>;
-
-// The client maps operation types to named types.
-struct OperationType
-{
-	std::string_view type;
-	std::string_view cppType;
-	std::string_view operation;
-};
+#include "SchemaLoader.h"
 
-using OperationTypeList = std::vector<OperationType>;
+#include "graphqlservice/GraphQLSchema.h"
 
-struct GeneratorClient
-{
-	const std::string schemaFilename;
-	const std::string requestFilename;
-	const std::string filenamePrefix;
-	const std::string clientNamespace;
-};
+namespace graphql::generator::client {
 
 struct GeneratorPaths
 {
@@ -237,7 +20,7 @@ struct GeneratorPaths
 
 struct GeneratorOptions
 {
-	const GeneratorClient client;
+	const std::string requestFilename;
 	const std::optional<GeneratorPaths> paths;
 	const bool verbose = false;
 	const bool noIntrospection = false;
@@ -247,7 +30,7 @@ class Generator
 {
 public:
 	// Initialize the generator with the introspection client or a custom GraphQL client.
-	explicit Generator(GeneratorOptions&& options);
+	explicit Generator(SchemaOptions&& schemaOptions, GeneratorOptions&& options);
 
 	// Run the generator and return a list of filenames that were output.
 	std::vector<std::string> Build() const noexcept;
@@ -258,82 +41,10 @@ class Generator
 	std::string getHeaderPath() const noexcept;
 	std::string getSourcePath() const noexcept;
 
-	void visitDefinition(const peg::ast_node& definition);
-
-	void visitClientDefinition(const peg::ast_node& clientDefinition);
-	void visitClientExtension(const peg::ast_node& clientExtension);
-	void visitScalarTypeDefinition(const peg::ast_node& scalarTypeDefinition);
-	void visitEnumTypeDefinition(const peg::ast_node& enumTypeDefinition);
-	void visitEnumTypeExtension(const peg::ast_node& enumTypeExtension);
-	void visitInputObjectTypeDefinition(const peg::ast_node& inputObjectTypeDefinition);
-	void visitInputObjectTypeExtension(const peg::ast_node& inputObjectTypeExtension);
-	void visitUnionTypeDefinition(const peg::ast_node& unionTypeDefinition);
-	void visitUnionTypeExtension(const peg::ast_node& unionTypeExtension);
-	void visitInterfaceTypeDefinition(const peg::ast_node& interfaceTypeDefinition);
-	void visitInterfaceTypeExtension(const peg::ast_node& interfaceTypeExtension);
-	void visitObjectTypeDefinition(const peg::ast_node& objectTypeDefinition);
-	void visitObjectTypeExtension(const peg::ast_node& objectTypeExtension);
-	void visitDirectiveDefinition(const peg::ast_node& directiveDefinition);
-
-	static std::string_view getSafeCppName(std::string_view type) noexcept;
-	static OutputFieldList getOutputFields(const peg::ast_node::children_t& fields);
-	static InputFieldList getInputFields(const peg::ast_node::children_t& fields);
-
-	// Recursively visit a Type node until we reach a NamedType and we've
-	// taken stock of all of the modifier wrappers.
-	class TypeVisitor
-	{
-	public:
-		std::pair<std::string_view, TypeModifierStack> getType();
-
-		void visit(const peg::ast_node& typeName);
-
-	private:
-		void visitNamedType(const peg::ast_node& namedType);
-		void visitListType(const peg::ast_node& listType);
-		void visitNonNullType(const peg::ast_node& nonNullType);
-
-		std::string_view _type;
-		TypeModifierStack _modifiers;
-		bool _nonNull = false;
-	};
-
-	// Recursively visit a Value node representing the default value on an input field
-	// and build a JSON representation of the hardcoded value.
-	class DefaultValueVisitor
-	{
-	public:
-		response::Value getValue();
-
-		void visit(const peg::ast_node& value);
-
-	private:
-		void visitIntValue(const peg::ast_node& intValue);
-		void visitFloatValue(const peg::ast_node& floatValue);
-		void visitStringValue(const peg::ast_node& stringValue);
-		void visitBooleanValue(const peg::ast_node& booleanValue);
-		void visitNullValue(const peg::ast_node& nullValue);
-		void visitEnumValue(const peg::ast_node& enumValue);
-		void visitListValue(const peg::ast_node& listValue);
-		void visitObjectValue(const peg::ast_node& objectValue);
-
-		response::Value _value;
-	};
-
-	void validateSchema();
-	void fixupOutputFieldList(OutputFieldList& fields,
-		const std::optional<std::unordered_set<std::string_view>>& interfaceFields,
-		const std::optional<std::string_view>& accessor);
-	void fixupInputFieldList(InputFieldList& fields);
-
 	void validateQuery() const;
 	std::shared_ptr<schema::Schema> buildSchema() const;
 	void addTypesToSchema(const std::shared_ptr<schema::Schema>& schema) const;
 
-	std::string_view getCppType(std::string_view type) const noexcept;
-	std::string getInputCppType(const InputField& field) const noexcept;
-	std::string getOutputCppType(const OutputField& field) const noexcept;
-
 	bool outputHeader() const noexcept;
 	void outputObjectDeclaration(
 		std::ostream& headerFile, const ObjectType& objectType, bool isQueryType) const;
@@ -356,39 +67,15 @@ class Generator
 		const std::shared_ptr<schema::Schema>& schema, std::string_view type,
 		TypeModifierStack modifiers, bool nonNull = true) noexcept;
 
-	static const BuiltinTypeMap s_builtinTypes;
-	static const CppTypeMap s_builtinCppTypes;
-	static const std::string_view s_scalarCppType;
-	static const std::string s_currentDirectory;
-
+	SchemaLoader _loader;
 	const GeneratorOptions _options;
-	std::string_view _clientNamespace;
 	const std::string _headerDir;
 	const std::string _sourceDir;
 	const std::string _headerPath;
 	const std::string _sourcePath;
-	peg::ast _schema;
 	peg::ast _request;
-
-	SchemaTypeMap _clientTypes;
-	PositionMap _typePositions;
-	TypeNameMap _scalarNames;
-	ScalarTypeList _scalarTypes;
-	TypeNameMap _enumNames;
-	EnumTypeList _enumTypes;
-	TypeNameMap _inputNames;
-	InputTypeList _inputTypes;
-	TypeNameMap _unionNames;
-	UnionTypeList _unionTypes;
-	TypeNameMap _interfaceNames;
-	InterfaceTypeList _interfaceTypes;
-	TypeNameMap _objectNames;
-	ObjectTypeList _objectTypes;
-	DirectiveList _directives;
-	PositionMap _directivePositions;
-	OperationTypeList _operationTypes;
 };
 
-} /* namespace graphql::client */
+} /* namespace graphql::generator::client */
 
 #endif // CLIENTGENERATOR_H