JSON support for changeset upload

include/cgimap/api06/changeset_upload/osmchange_json_input_format.hpp

@@ -0,0 +1,325 @@
+/**
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ * This file is part of openstreetmap-cgimap (https://github.com/zerebubuth/openstreetmap-cgimap/).
+ *
+ * Copyright (C) 2009-2023 by the CGImap developer community.
+ * For a full list of authors see the git log.
+ */
+
+#ifndef OSMCHANGE_JSON_INPUT_FORMAT_HPP
+#define OSMCHANGE_JSON_INPUT_FORMAT_HPP
+
+#include "cgimap/api06/changeset_upload/node.hpp"
+#include "cgimap/api06/changeset_upload/osmobject.hpp"
+#include "cgimap/api06/changeset_upload/parser_callback.hpp"
+#include "cgimap/api06/changeset_upload/relation.hpp"
+#include "cgimap/api06/changeset_upload/way.hpp"
+#include "cgimap/types.hpp"
+
+#include "sjparser/sjparser.h"
+
+#include <fmt/core.h>
+
+#include <cassert>
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+
+namespace api06 {
+
+using SJParser::Array;
+using SJParser::Member;
+using SJParser::Object;
+using SJParser::Parser;
+using SJParser::Presence;
+using SJParser::SArray;
+using SJParser::SAutoObject;
+using SJParser::SMap;
+using SJParser::Value;
+using SJParser::Reaction;
+using SJParser::ObjectOptions;
+
+using std::placeholders::_1;
+
+class OSMChangeJSONParserFormat {
+
+  static auto getMemberParser() {
+    return SAutoObject{std::tuple{Member{"type", Value<std::string>{}},
+                                  Member{"ref", Value<int64_t>{}},
+                                  Member{"role", Value<std::string>{}, Presence::Optional, ""}},
+                                  ObjectOptions{Reaction::Ignore}
+                                  };
+  }
+
+  template <typename ElementParserCallback = std::nullptr_t>
+  static auto getElementsParser(ElementParserCallback element_parser_callback = nullptr) {
+    return Object{
+          std::tuple{
+            Member{"type", Value<std::string>{}},
+            Member{"action", Value<std::string>{}},
+            Member{"if-unused", Value<bool>{}, Presence::Optional, false},
+            Member{"id", Value<int64_t>{}},
+            Member{"lat", Value<double>{}, Presence::Optional},
+            Member{"lon", Value<double>{}, Presence::Optional},
+            Member{"version", Value<int64_t>{}, Presence::Optional},
+            Member{"changeset", Value<int64_t>{}},
+            Member{"tags", SMap{Value<std::string>{}}, Presence::Optional},
+            Member{"nodes", SArray{Value<int64_t>{}}, Presence::Optional},
+            Member{"members", SArray{getMemberParser()}, Presence::Optional}
+          },
+        ObjectOptions{Reaction::Ignore},
+        element_parser_callback};
+  }
+
+  template <typename ElementParserCallback = std::nullptr_t>
+  static auto getMainParser(ElementParserCallback element_parser_callback = nullptr) {
+    return Parser{
+       Object{
+        std::tuple{
+          Member{"version", Value<std::string>{}, Presence::Optional},
+          Member{"generator", Value<std::string>{}, Presence::Optional},
+          Member{"osmChange",  Array{getElementsParser(element_parser_callback)}}
+        },ObjectOptions{Reaction::Ignore}}};
+  }
+
+  friend class OSMChangeJSONParser;
+};
+
+class OSMChangeJSONParser {
+
+public:
+  explicit OSMChangeJSONParser(Parser_Callback& callback)
+      : m_callback(callback) { }
+
+  OSMChangeJSONParser(const OSMChangeJSONParser &) = delete;
+  OSMChangeJSONParser &operator=(const OSMChangeJSONParser &) = delete;
+
+  OSMChangeJSONParser(OSMChangeJSONParser &&) = delete;
+  OSMChangeJSONParser &operator=(OSMChangeJSONParser &&) = delete;
+
+  void process_message(const std::string &data) {
+
+    try {
+      m_callback.start_document();
+      _parser.parse(data);
+      _parser.finish();
+
+      if (_parser.parser().isEmpty()) {
+        throw payload_error("Empty JSON payload");
+      }
+
+      if (element_count == 0) {
+        throw payload_error("osmChange array is empty");
+      }
+
+      m_callback.end_document();
+    } catch (const std::exception& e) {
+      throw http::bad_request(e.what());    // rethrow JSON parser error as HTTP 400 Bad request
+    }
+  }
+
+private:
+
+  using ElementsParser = decltype(api06::OSMChangeJSONParserFormat::getElementsParser());
+  using MainParser = decltype(api06::OSMChangeJSONParserFormat::getMainParser());
+
+  MainParser _parser{api06::OSMChangeJSONParserFormat::getMainParser(std::bind(&api06::OSMChangeJSONParser::process_element, this, _1))};
+
+  // OSM element callback
+  bool process_element(ElementsParser &parser) {
+
+    element_count++;
+
+    // process action
+    process_action(parser);
+
+    // process if-unused flag for delete action
+    process_if_unused(parser);
+
+    // process type (node, way, relation)
+    process_type(parser);
+
+    return true;
+  }
+
+  void process_action(ElementsParser &parser) {
+
+    const std::string& action = parser.get<1>();
+
+    if (action == "create") {
+      m_operation = operation::op_create;
+    } else if (action == "modify") {
+      m_operation = operation::op_modify;
+    } else if (action == "delete") {
+      m_operation = operation::op_delete;
+    } else {
+      throw payload_error{fmt::format("Unknown action {}, choices are create, modify, delete", action)};
+    }
+  }
+
+  void process_if_unused(ElementsParser &parser) {
+
+    if (m_operation == operation::op_delete) {
+      m_if_unused = false;
+      if (parser.parser<2>().isSet()) {
+        m_if_unused = parser.get<2>();
+      }
+    }
+  }
+
+  void process_type(ElementsParser &parser) {
+
+    const std::string& type = parser.get<0>();
+
+    if (type == "node") {
+      process_node(parser);
+    } else if (type == "way") {
+      process_way(parser);
+    } else if (type == "relation") {
+      process_relation(parser);
+    } else {
+      throw payload_error{fmt::format("Unknown element {}, expecting node, way or relation", type)};
+    }
+  }
+
+  void process_node(ElementsParser& parser) {
+
+    Node node;
+    init_object(node, parser);
+
+    if (parser.parser<4>().isSet()) {
+      node.set_lat(parser.get<4>());
+    }
+
+    if (parser.parser<5>().isSet()) {
+      node.set_lon(parser.get<5>());
+    }
+
+    process_tags(node, parser);
+
+    if (!node.is_valid(m_operation)) {
+      throw payload_error{fmt::format("{} does not include all mandatory fields", node.to_string())};
+    }
+
+    m_callback.process_node(node, m_operation, m_if_unused);
+  }
+
+  void process_way(ElementsParser& parser) {
+
+    Way way;
+    init_object(way, parser);
+
+    // adding way nodes
+    if (parser.parser<9>().isSet()) {
+      for (const auto& value : parser.get<9>()) {
+          way.add_way_node(value);
+      }
+    }
+
+    process_tags(way, parser);
+
+    if (!way.is_valid(m_operation)) {
+      throw payload_error{fmt::format("{} does not include all mandatory fields", way.to_string())};
+    }
+
+    m_callback.process_way(way, m_operation, m_if_unused);
+  }
+
+  void process_relation(ElementsParser& parser) {
+
+    Relation relation;
+    init_object(relation, parser);
+
+    process_relation_members(relation, parser);
+
+    process_tags(relation, parser);
+
+    if (!relation.is_valid(m_operation)) {
+      throw payload_error{fmt::format("{} does not include all mandatory fields", relation.to_string())};
+    }
+
+    m_callback.process_relation(relation, m_operation, m_if_unused);
+  }
+
+  void process_relation_members(Relation &relation, ElementsParser& parser) {
+
+    if (!parser.parser<10>().isSet()) {
+      return;
+    }
+
+    for (auto &mbr : parser.get<10>()) {
+      const auto& [type, ref, role] = mbr;
+
+      RelationMember member;
+      member.set_type(type);
+      member.set_ref(ref);
+      member.set_role(role);
+
+      if (!member.is_valid()) {
+        throw payload_error{fmt::format("Missing mandatory field on relation member in {}", relation.to_string()) };
+      }
+      relation.add_member(member);
+    }
+  }
+
+  void process_tags(OSMObject &o, ElementsParser& parser) {
+
+    if (parser.parser<8>().isSet()) {
+      for (const auto &tag : parser.get<8>()) {
+         o.add_tag(tag.first, tag.second);
+      }
+    }
+  }
+
+  void init_object(OSMObject &object, ElementsParser& parser) {
+
+    // id
+    object.set_id(parser.get<3>());
+
+    // version
+    if (parser.parser<6>().isSet()) {
+      object.set_version(parser.get<6>());
+    }
+
+    // changeset
+    if (parser.parser<7>().isSet()) {
+      object.set_changeset(parser.get<7>());
+    }
+
+    // TODO: not needed, handled by sjparser
+    if (!object.has_id()) {
+     	throw payload_error{ "Mandatory field id missing in object" };
+    }
+
+    if (!object.has_changeset()) {
+      throw payload_error{fmt::format("Changeset id is missing for {}", object.to_string()) };
+    }
+
+    if (m_operation == operation::op_create) {
+      // we always override version number for create operations (they are not
+      // mandatory)
+      object.set_version(0u);
+    } else if (m_operation == operation::op_delete ||
+               m_operation == operation::op_modify) {
+      // objects for other operations must have a positive version number
+      if (!object.has_version()) {
+        throw payload_error{fmt::format("Version is required when updating {}", object.to_string()) };
+      }
+      if (object.version() < 1) {
+        throw payload_error{ fmt::format("Invalid version number {} in {}", object.version(), object.to_string()) };
+      }
+    }
+  }
+
+  operation m_operation = operation::op_undefined;
+  Parser_Callback& m_callback;
+  bool m_if_unused = false;
+  int element_count = 0;
+};
+
+} // namespace api06
+
+#endif // OSMCHANGE_JSON_INPUT_FORMAT_HPP

include/cgimap/json_formatter.hpp

@@ -42,6 +42,8 @@ class json_formatter : public output_formatter {
   void start_changeset(bool) override;
   void end_changeset(bool) override;
 
+  void start_diffresult() override;
+  void end_diffresult() override;
   void start_action(action_type type) override;
   void end_action(action_type type) override;
   void error(const std::exception &e) override;
@@ -63,6 +65,7 @@ class json_formatter : public output_formatter {
 				      const osm_nwr_signed_id_t old_id,
 				      const osm_nwr_id_t new_id,
 				      const osm_version_t new_version) override;
+
   void write_diffresult_delete(const element_type elem,
 			       const osm_nwr_signed_id_t old_id) override;
 

include/cgimap/osm_diffresult_responder.hpp

@@ -27,6 +27,8 @@ class osm_diffresult_responder : public osm_responder {
 
   ~osm_diffresult_responder() override;
 
+  // lists the standard types that OSM format can respond in
+  std::vector<mime::type> types_available() const override;
 
   void write(output_formatter& f,
              const std::string &generator,

include/cgimap/output_formatter.hpp

@@ -56,6 +56,23 @@ T element_type_name(element_type elt) noexcept {
   return "";
 }
 
+template <typename T = const char*>
+T action_type_name(action_type action) noexcept {
+
+  switch (action) {
+  case action_type::create:
+    return "create";
+    break;
+  case action_type::modify:
+    return "modify";
+    break;
+  case action_type::del:
+    return "delete";
+    break;
+  }
+  return "";
+}
+
 } // anonymous namespace
 
 struct element_info {
@@ -216,6 +233,11 @@ struct output_formatter {
 
   virtual void end_changeset(bool) = 0;
 
+  // marks the beginning of diffResult response processing
+  virtual void start_diffresult() = 0;
+
+  virtual void end_diffresult() = 0;
+
   // TODO: document me.
   virtual void start_action(action_type type) = 0;
   virtual void end_action(action_type type) = 0;

include/cgimap/text_formatter.hpp

@@ -38,6 +38,8 @@ class text_formatter : public output_formatter {
   void start_changeset(bool) override;
   void end_changeset(bool) override;
 
+  void start_diffresult() override;
+  void end_diffresult() override;
   void start_action(action_type type) override;
   void end_action(action_type type) override;
   void error(const std::exception &e) override;