Squashed 'third_party/flatbuffers/' content from commit acc9990ab

Change-Id: I48550d40d78fea996ebe74e9723a5d1f910de491
git-subtree-dir: third_party/flatbuffers
git-subtree-split: acc9990abd2206491480291b0f85f925110102ea
diff --git a/src/idl_gen_json_schema.cpp b/src/idl_gen_json_schema.cpp
new file mode 100644
index 0000000..27e2cd4
--- /dev/null
+++ b/src/idl_gen_json_schema.cpp
@@ -0,0 +1,216 @@
+/*
+ * Copyright 2014 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <iostream>
+#include "flatbuffers/code_generators.h"
+#include "flatbuffers/idl.h"
+#include "flatbuffers/util.h"
+
+namespace flatbuffers {
+
+static std::string GeneratedFileName(const std::string &path,
+                                     const std::string &file_name) {
+  return path + file_name + ".schema.json";
+}
+
+namespace jsons {
+
+std::string GenNativeType(BaseType type) {
+  switch (type) {
+    case BASE_TYPE_BOOL: return "boolean";
+    case BASE_TYPE_CHAR:
+    case BASE_TYPE_UCHAR:
+    case BASE_TYPE_SHORT:
+    case BASE_TYPE_USHORT:
+    case BASE_TYPE_INT:
+    case BASE_TYPE_UINT:
+    case BASE_TYPE_LONG:
+    case BASE_TYPE_ULONG:
+    case BASE_TYPE_FLOAT:
+    case BASE_TYPE_DOUBLE: return "number";
+    case BASE_TYPE_STRING: return "string";
+    case BASE_TYPE_ARRAY: return "array";
+    default: return "";
+  }
+}
+
+template<class T> std::string GenFullName(const T *enum_def) {
+  std::string full_name;
+  const auto &name_spaces = enum_def->defined_namespace->components;
+  for (auto ns = name_spaces.cbegin(); ns != name_spaces.cend(); ++ns) {
+    full_name.append(*ns + "_");
+  }
+  full_name.append(enum_def->name);
+  return full_name;
+}
+
+template<class T> std::string GenTypeRef(const T *enum_def) {
+  return "\"$ref\" : \"#/definitions/" + GenFullName(enum_def) + "\"";
+}
+
+std::string GenType(const std::string &name) {
+  return "\"type\" : \"" + name + "\"";
+}
+
+std::string GenType(const Type &type) {
+  if (type.enum_def != nullptr && !type.enum_def->is_union) {
+    // it is a reference to an enum type
+    return GenTypeRef(type.enum_def);
+  }
+  switch (type.base_type) {
+    case BASE_TYPE_ARRAY: FLATBUFFERS_FALLTHROUGH();  // fall thru
+    case BASE_TYPE_VECTOR: {
+      std::string typeline;
+      typeline.append("\"type\" : \"array\", \"items\" : { ");
+      if (type.element == BASE_TYPE_STRUCT) {
+        typeline.append(GenTypeRef(type.struct_def));
+      } else {
+        typeline.append(GenType(GenNativeType(type.element)));
+      }
+      typeline.append(" }");
+      return typeline;
+    }
+    case BASE_TYPE_STRUCT: {
+      return GenTypeRef(type.struct_def);
+    }
+    case BASE_TYPE_UNION: {
+      std::string union_type_string("\"anyOf\": [");
+      const auto &union_types = type.enum_def->Vals();
+      for (auto ut = union_types.cbegin(); ut < union_types.cend(); ++ut) {
+        auto &union_type = *ut;
+        if (union_type->union_type.base_type == BASE_TYPE_NONE) { continue; }
+        if (union_type->union_type.base_type == BASE_TYPE_STRUCT) {
+          union_type_string.append(
+              "{ " + GenTypeRef(union_type->union_type.struct_def) + " }");
+        }
+        if (union_type != *type.enum_def->Vals().rbegin()) {
+          union_type_string.append(",");
+        }
+      }
+      union_type_string.append("]");
+      return union_type_string;
+    }
+    case BASE_TYPE_UTYPE: return GenTypeRef(type.enum_def);
+    default: return GenType(GenNativeType(type.base_type));
+  }
+}
+
+class JsonSchemaGenerator : public BaseGenerator {
+ private:
+  CodeWriter code_;
+
+ public:
+  JsonSchemaGenerator(const Parser &parser, const std::string &path,
+                      const std::string &file_name)
+      : BaseGenerator(parser, path, file_name, "", "") {}
+
+  explicit JsonSchemaGenerator(const BaseGenerator &base_generator)
+      : BaseGenerator(base_generator) {}
+
+  bool generate() {
+    code_.Clear();
+    code_ += "{";
+    code_ += "  \"$schema\": \"http://json-schema.org/draft-04/schema#\",";
+    code_ += "  \"definitions\": {";
+    for (auto e = parser_.enums_.vec.cbegin(); e != parser_.enums_.vec.cend();
+         ++e) {
+      code_ += "    \"" + GenFullName(*e) + "\" : {";
+      code_ += "      " + GenType("string") + ",";
+      std::string enumdef("      \"enum\": [");
+      for (auto enum_value = (*e)->Vals().begin();
+           enum_value != (*e)->Vals().end(); ++enum_value) {
+        enumdef.append("\"" + (*enum_value)->name + "\"");
+        if (*enum_value != (*e)->Vals().back()) { enumdef.append(", "); }
+      }
+      enumdef.append("]");
+      code_ += enumdef;
+      code_ += "    },";  // close type
+    }
+    for (auto s = parser_.structs_.vec.cbegin();
+         s != parser_.structs_.vec.cend(); ++s) {
+      const auto &structure = *s;
+      code_ += "    \"" + GenFullName(structure) + "\" : {";
+      code_ += "      " + GenType("object") + ",";
+      std::string comment;
+      const auto &comment_lines = structure->doc_comment;
+      for (auto comment_line = comment_lines.cbegin();
+           comment_line != comment_lines.cend(); ++comment_line) {
+        comment.append(*comment_line);
+      }
+      if (comment.size() > 0) {
+        code_ += "      \"description\" : \"" + comment + "\",";
+      }
+      code_ += "      \"properties\" : {";
+
+      const auto &properties = structure->fields.vec;
+      for (auto prop = properties.cbegin(); prop != properties.cend(); ++prop) {
+        const auto &property = *prop;
+        std::string arrayInfo = "";
+        if (IsArray(property->value.type)) {
+          arrayInfo = ",\n                \"minItems\": " +
+                      NumToString(property->value.type.fixed_length) +
+                      ",\n                \"maxItems\": " +
+                      NumToString(property->value.type.fixed_length);
+        }
+        std::string typeLine =
+            "        \"" + property->name + "\" : {\n" + "                " +
+            GenType(property->value.type) + arrayInfo + "\n              }";
+        if (property != properties.back()) { typeLine.append(","); }
+        code_ += typeLine;
+      }
+      code_ += "      },";  // close properties
+
+      std::vector<FieldDef *> requiredProperties;
+      std::copy_if(properties.begin(), properties.end(),
+                   back_inserter(requiredProperties),
+                   [](FieldDef const *prop) { return prop->required; });
+      if (requiredProperties.size() > 0) {
+        std::string required_string("      \"required\" : [");
+        for (auto req_prop = requiredProperties.cbegin();
+             req_prop != requiredProperties.cend(); ++req_prop) {
+          required_string.append("\"" + (*req_prop)->name + "\"");
+          if (*req_prop != requiredProperties.back()) {
+            required_string.append(", ");
+          }
+        }
+        required_string.append("],");
+        code_ += required_string;
+      }
+      code_ += "      \"additionalProperties\" : false";
+      std::string closeType("    }");
+      if (*s != parser_.structs_.vec.back()) { closeType.append(","); }
+      code_ += closeType;  // close type
+    }
+    code_ += "  },";  // close definitions
+
+    // mark root type
+    code_ += "  \"$ref\" : \"#/definitions/" +
+             GenFullName(parser_.root_struct_def_) + "\"";
+
+    code_ += "}";  // close schema root
+    const std::string file_path = GeneratedFileName(path_, file_name_);
+    const std::string final_code = code_.ToString();
+    return SaveFile(file_path.c_str(), final_code, false);
+  }
+};
+}  // namespace jsons
+
+bool GenerateJsonSchema(const Parser &parser, const std::string &path,
+                        const std::string &file_name) {
+  jsons::JsonSchemaGenerator generator(parser, path, file_name);
+  return generator.generate();
+}
+}  // namespace flatbuffers