Add user generation feature

tooling/pipeline/src/json_handling/json_loader.cc

@@ -16,6 +16,8 @@
 #include <stdexcept>
 #include <string>
 #include <string_view>
+#include <unordered_map>
+#include <utility>
 
 static std::string ReadRequiredString(const boost::json::object& object,
                                       const char* key) {
@@ -59,6 +61,50 @@ static std::vector<std::string> ReadRequiredStringArray(
   return items;
 }
 
+namespace {
+
+boost::json::value ParseJsonFile(const std::filesystem::path& filepath,
+                                 const char* what) {
+  std::ifstream input(filepath);
+  if (!input.is_open()) {
+    throw std::runtime_error(std::format("Failed to open {} file: {}", what,
+                                         filepath.string()));
+  }
+
+  std::stringstream buffer;
+  buffer << input.rdbuf();
+
+  boost::system::error_code error;
+  boost::json::value root = boost::json::parse(buffer.str(), error);
+  if (error) {
+    throw std::runtime_error(
+        std::format("Failed to parse {} JSON: {}", what, error.message()));
+  }
+  return root;
+}
+
+/// @brief Returns the first element of a string array field, falling back to
+/// `fallback_key` if `key` is missing/empty (some source entries only have a
+/// "localized" form and no "romanized" form).
+std::string ReadFirstOfStringArray(const boost::json::object& object,
+                                   const char* key,
+                                   const char* fallback_key) {
+  for (const char* candidate_key : {key, fallback_key}) {
+    const boost::json::value* value = object.if_contains(candidate_key);
+    if (value == nullptr || !value->is_array()) {
+      continue;
+    }
+    const auto& array = value->as_array();
+    if (!array.empty() && array.front().is_string()) {
+      return std::string(array.front().as_string());
+    }
+  }
+  throw std::runtime_error(
+      std::format("Missing or invalid string array field: {}", key));
+}
+
+}  // namespace
+
 std::vector<Location> JsonLoader::LoadLocations(
     const std::filesystem::path& filepath, std::shared_ptr<ILogger> logger) {
   std::ifstream input(filepath);
@@ -108,3 +154,100 @@ std::vector<Location> JsonLoader::LoadLocations(
 
   return locations;
 }
+
+std::vector<UserPersona> JsonLoader::LoadPersonas(
+    const std::filesystem::path& filepath, std::shared_ptr<ILogger> logger) {
+  const boost::json::value root = ParseJsonFile(filepath, "personas");
+
+  if (!root.is_array()) {
+    throw std::runtime_error(
+        "Invalid personas JSON: root element must be an array");
+  }
+
+  std::vector<UserPersona> personas;
+  const auto& items = root.as_array();
+  personas.reserve(items.size());
+
+  for (const auto& item : items) {
+    if (!item.is_object()) {
+      throw std::runtime_error(
+          "Invalid personas JSON: each entry must be an object");
+    }
+
+    const auto& object = item.as_object();
+    personas.push_back(UserPersona{
+        .name = ReadRequiredString(object, "name"),
+        .description = ReadRequiredString(object, "description"),
+        .style_affinities =
+            ReadRequiredStringArray(object, "style_affinities"),
+    });
+  }
+
+  return personas;
+}
+
+NamesByCountry JsonLoader::LoadNamesByCountry(
+    const std::filesystem::path& forenames_filepath,
+    const std::filesystem::path& surnames_filepath,
+    std::shared_ptr<ILogger> logger) {
+  const boost::json::value forenames_root =
+      ParseJsonFile(forenames_filepath, "forenames-by-country");
+  const boost::json::value surnames_root =
+      ParseJsonFile(surnames_filepath, "surnames-by-country");
+
+  if (!forenames_root.is_object() || !surnames_root.is_object()) {
+    throw std::runtime_error(
+        "Invalid names-by-country JSON: root element must be an object "
+        "keyed by ISO 3166-1 country code");
+  }
+
+  std::unordered_map<std::string, std::vector<ForenameEntry>>
+      forenames_by_country;
+  for (const auto& [country_code, regions] : forenames_root.as_object()) {
+    if (!regions.is_array()) {
+      continue;
+    }
+    std::vector<ForenameEntry> entries;
+    for (const auto& region : regions.as_array()) {
+      if (!region.is_object()) {
+        continue;
+      }
+      const boost::json::value* names = region.as_object().if_contains("names");
+      if (names == nullptr || !names->is_array()) {
+        continue;
+      }
+      for (const auto& name_value : names->as_array()) {
+        if (!name_value.is_object()) {
+          continue;
+        }
+        const auto& name_object = name_value.as_object();
+        entries.push_back(ForenameEntry{
+            .name = ReadFirstOfStringArray(name_object, "romanized",
+                                           "localized"),
+            .gender = ReadRequiredString(name_object, "gender"),
+        });
+      }
+    }
+    forenames_by_country.emplace(country_code, std::move(entries));
+  }
+
+  std::unordered_map<std::string, std::vector<std::string>>
+      surnames_by_country;
+  for (const auto& [country_code, name_entries] : surnames_root.as_object()) {
+    if (!name_entries.is_array()) {
+      continue;
+    }
+    std::vector<std::string> surnames;
+    for (const auto& name_value : name_entries.as_array()) {
+      if (!name_value.is_object()) {
+        continue;
+      }
+      surnames.push_back(ReadFirstOfStringArray(name_value.as_object(),
+                                                "romanized", "localized"));
+    }
+    surnames_by_country.emplace(country_code, std::move(surnames));
+  }
+
+  return NamesByCountry(std::move(forenames_by_country),
+                        std::move(surnames_by_country));
+}