From 4698ab90337466184e7fddab4511bc361002627c Mon Sep 17 00:00:00 2001
From: Patrick Urbanke <patrick@getml.com>
Date: Sun, 4 Feb 2024 06:36:18 +0100
Subject: [PATCH] Began developing the JSON schema definition; #25

---
 include/rfl/Field.hpp                      |  3 +
 include/rfl/internal/schema/Definition.hpp | 21 +++++++
 include/rfl/internal/schema/Type.hpp       | 62 +++++++++++++++++++
 include/rfl/internal/schema/make.hpp       | 69 ++++++++++++++++++++++
 4 files changed, 155 insertions(+)
 create mode 100644 include/rfl/internal/schema/Definition.hpp
 create mode 100644 include/rfl/internal/schema/Type.hpp
 create mode 100644 include/rfl/internal/schema/make.hpp

diff --git a/include/rfl/Field.hpp b/include/rfl/Field.hpp
index ae190b30..30c09c12 100644
--- a/include/rfl/Field.hpp
+++ b/include/rfl/Field.hpp
@@ -65,6 +65,9 @@ struct Field {
   /// Returns the underlying object.
   const Type& get() const { return value_; }
 
+  /// Returns the name of the fiels as a string.
+  static std::string name() const { return name_::str(); }
+
   /// Returns the underlying object.
   Type& operator()() { return value_; }
 
diff --git a/include/rfl/internal/schema/Definition.hpp b/include/rfl/internal/schema/Definition.hpp
new file mode 100644
index 00000000..f888b2b5
--- /dev/null
+++ b/include/rfl/internal/schema/Definition.hpp
@@ -0,0 +1,21 @@
+#ifndef RFL_INTERNAL_SCHEMA_DEFINITION_HPP_
+#define RFL_INTERNAL_SCHEMA_DEFINITION_HPP_
+
+#include <map>
+#include <string>
+
+#include "Type.hpp"
+
+namespace rfl::internal::schema {
+
+struct Definition {
+  /// Contains the root element of the schema definition.
+  Type root_;
+
+  /// Contains the definitions to be referenced by Type::Reference.
+  std::map<std::string, Type> definitions_;
+};
+
+}  // namespace rfl::internal::schema
+
+#endif
diff --git a/include/rfl/internal/schema/Type.hpp b/include/rfl/internal/schema/Type.hpp
new file mode 100644
index 00000000..a2b80595
--- /dev/null
+++ b/include/rfl/internal/schema/Type.hpp
@@ -0,0 +1,62 @@
+#ifndef RFL_INTERNAL_SCHEMA_TYPE_HPP_
+#define RFL_INTERNAL_SCHEMA_TYPE_HPP_
+
+#include <map>
+#include <string>
+#include <variant>
+#include <vector>
+
+#include "../../Ref.hpp"
+
+namespace rfl::internal::schema {
+
+struct Type {
+  struct Int32 {};
+
+  struct Int64 {};
+
+  struct UInt32 {};
+
+  struct UInt64 {};
+
+  struct Integer {};
+
+  struct Float {};
+
+  struct Double {};
+
+  struct String {};
+
+  struct Object {
+    std::map<std::string, Type> types_;
+  };
+
+  /// All values are assumed to be required unless explicitly stated otherwise
+  /// using this wrapper.
+  struct Optional {
+    Ref<Type> type_;
+  };
+
+  /// The is necessary to resolve circular definitions. Refers to something in
+  /// Definitions.
+  struct Reference {
+    std::string name_;
+  };
+
+  struct TypedArray {
+    Ref<Type> type_;
+  };
+
+  struct Variant {
+    std::vector<Type> types_;
+  };
+
+  /// A type can be determined to be any of the above.
+  std::variant<Int32, Int64, UInt32, UInt64, Integer, Float, Double, String,
+               Array, Object, Reference>
+      variant_;
+};
+
+}  // namespace rfl::internal::schema
+
+#endif
diff --git a/include/rfl/internal/schema/make.hpp b/include/rfl/internal/schema/make.hpp
new file mode 100644
index 00000000..334e343a
--- /dev/null
+++ b/include/rfl/internal/schema/make.hpp
@@ -0,0 +1,69 @@
+#ifndef RFL_INTERNAL_SCHEMA_MAKE_HPP_
+#define RFL_INTERNAL_SCHEMA_MAKE_HPP_
+
+#include <bits/utility.h>
+
+#include <cstddef>
+#include <cstdint>
+#include <map>
+#include <string>
+#include <type_traits>
+
+#include "../../parsing/is_required.hpp"
+#include "../is_named_tuple.hpp"
+#include "Type.hpp"
+
+namespace rfl::internal::schema {
+
+template <class T>
+Type make_type(std::map<std::string, Type>* _definitions);
+
+template <class T, size_t _i = 0>
+Type make_named_tuple_type(std::map<std::string, Type>* _definitions,
+                           std::map<std::string, Type> _values = {}) {
+  constexpr size_t size = T::size();
+  if constexpr (_i == size) {
+    return Type{Object{_values}};
+  } else {
+    using F = std::tuple_element_t<_i, typename T::Fields>;
+    _values[F::name()] = make_type<typename F::Type>(_definitions);
+    return make_named_tuple_type<T, _i + 1>(_definitions, _values);
+  }
+};
+
+template <class T>
+Type make_type(std::map<std::string, Type>* _definitions) {
+  using U = std::remove_cvref_t<T>;
+  if constexpr (std::is_same<U, std::int32_t>()) {
+    return Definition{.root_ = Type{Int32{}}};
+  } else if constexpr (std::is_same<U, std::int64_t>()) {
+    return Definition{.root_ = Type{Int64{}}};
+  } else if constexpr (std::is_same<U, std::uint32_t>()) {
+    return Definition{.root_ = Type{UInt32{}}};
+  } else if constexpr (std::is_same<U, std::uint64_t>()) {
+    return Definition{.root_ = Type{UInt64{}}};
+  } else if constexpr (std::is_integral<U>()) {
+    return Definition{.root_ = Type{Integer{}}};
+  } else if constexpr (std::is_same<U, float>()) {
+    return Definition{.root_ = Type{Float{}}};
+  } else if constexpr (std::is_same<U, double>()) {
+    return Definition{.root_ = Type{Double{}}};
+  } else if constexpr (std::is_same<U, std::string>()) {
+    return Definition{.root_ = Type{String{}}};
+  } else if constexpr (is_named_tuple_v<U>) {
+    return make_named_tuple_definition<U>();
+  } else if constexpr (!is_required<T, false>()) {
+    // TODO
+  }
+}
+
+template <class T>
+Definition make() {
+  std::map<std::string, Type> definitions;
+  auto root = make_type<T>(&definitions);
+  return Definition{.root_ = root, .definitions_ = definitions};
+}
+
+}  // namespace rfl::internal::schema
+
+#endif