// for clangd
#include "../include/global_info.hpp"

namespace info {

void GlobalInfo::NamespaceVisitor::AddImport(ImportInfo&& import_info,
                                             const std::optional<std::string>& name) {
  if (name.has_value()) {
    global_info_.usages_[name.value()] = std::move(import_info);
  } else {
    global_info_.imports_.push_back(std::move(import_info));
  }
}

void GlobalInfo::NamespaceVisitor::AddEnterNamespace(const std::string& name,
                                                     const std::optional<NamespaceInfo::Modifier>& modifier,
                                                     const std::optional<std::string>& variable) {
  NamespaceInfo* namespace_info = nullptr;
  if (variable.has_value()) {
    namespace_info = &namespace_stack_.back()->variable_namespaces[name].emplace_back();
    namespace_stack_.push_back(namespace_info);

    namespace_info->modifier = modifier;
    namespace_info->variable = variable;
  } else {
    namespace_info = &namespace_stack_.back()->namespaces[name];
    namespace_stack_.push_back(namespace_info);
  }

  namespace_info->type_name = name;
}

void GlobalInfo::NamespaceVisitor::EnterNamespace(const std::string& name) { // TODO: enter sibling namespace, etc.
  namespace_stack_.push_back(&namespace_stack_.back()->namespaces[name]);
}

void GlobalInfo::NamespaceVisitor::ExitNamespace() {
  if (namespace_stack_.size() <= 1) {
    // error
    return;
  }

  namespace_stack_.pop_back();
}

void GlobalInfo::NamespaceVisitor::ToGlobalNamespace() {
  namespace_stack_.clear();
  namespace_stack_.push_back(&global_info_.global_namespace_);
}

utils::IdType GlobalInfo::NamespaceVisitor::AddFunctionDeclaration(const std::string& name,
    FunctionDeclarationInfo&& function_declaration_info) {
  FunctionInfo* function_info = &namespace_stack_.back()->functions[name];

  function_info->declaration = std::move(function_declaration_info);

  return global_info_.functions_.GetId(function_info);
}

utils::IdType GlobalInfo::NamespaceVisitor::AddFunctionDefinition(const std::string& name,
    FunctionDefinitionInfo&& function_definition_info) {
  FunctionInfo* function_info = &namespace_stack_.back()->functions[name];

  function_info->definition = std::move(function_definition_info);

  return global_info_.functions_.GetId(function_info);
}

utils::IdType GlobalInfo::NamespaceVisitor::AddType(const std::string& type,
                                                    TypeInfo&& type_info) {
  namespace_stack_.back()->types[type] = std::move(type_info);
}

utils::IdType GlobalInfo::NamespaceVisitor::AddTypeclass(const std::string& typeclass,
                                                         TypeclassInfo&& typeclass_info) {
  namespace_stack_.back()->typeclasses[typeclass] = std::move(typeclass_info);

  return global_info_.functions_.GetId(typeclass_info);
}

std::optional<NamespaceInfo*> GlobalInfo::NamespaceVisitor::FindNamespace(const std::optional<std::vector<std::string>>& path) {
  return FindSomething<NamespaceInfo>(path,
      [] (NamespaceInfo* current_namespace) -> std::optional<NamespaceInfo*> {
    return current_namespace;
  });
}

std::optional<utils::IdType> GlobalInfo::NamespaceVisitor::FindFunction(
    const std::optional<std::vector<std::string>>& path,
    const std::string& name) {
  auto result = FindSomething<FunctionInfo>(path,
      [name] (NamespaceInfo* current_namespace) -> std::optional<FunctionInfo*> {

    auto function_info_iter = current_namespace->functions.find(name);
    if (function_info_iter == current_namespace->functions.end()) {
      return std::nullopt;
    }

    return &function_info_iter->second;
  });

  if (result.has_value()) {
    return global_info_.functions_.GetId(result.value());
  } else {
    return std::nullopt;
  }
}

std::optional<utils::IdType> GlobalInfo::NamespaceVisitor::FindMethod(
    const std::optional<std::vector<std::string>>& path,
    const std::string& type,
    const std::string& name) {
  // TODO: remove overhead

  auto result = GlobalInfo::NamespaceVisitor::FindSomething<FunctionInfo>(path,
      [type, name] (NamespaceInfo* current_namespace) -> std::optional<FunctionInfo*> {

    auto variable_namespaces_iter = current_namespace->variable_namespaces.find(type);
    if (variable_namespaces_iter == current_namespace->variable_namespaces.end()) {
      return std::nullopt;
    }

    for (auto& variable_namespace : variable_namespaces_iter->second) {
      auto method_iter = variable_namespace.functions.find(name);

      if (method_iter == variable_namespace.functions.end()) {
        continue;
      }

      return &method_iter->second;
    }

    return std::nullopt;
  });

  if (result.has_value()) {
    return global_info_.functions_.GetId(result.value());
  } else {
    return std::nullopt;
  }
}

std::optional<utils::IdType> GlobalInfo::NamespaceVisitor::FindType(
    const std::optional<std::vector<std::string>>& path,
    const std::string type) {
  auto result = FindSomething<TypeInfo>(path,
      [type] (NamespaceInfo* current_namespace) -> std::optional<TypeInfo*> {

    auto type_info_iter = current_namespace->types.find(type);
    if (type_info_iter == current_namespace->types.end()) {
      return std::nullopt;
    }

    return &type_info_iter->second;
  });

  if (result.has_value()) {
    return global_info_.types_.GetId(result.value());
  } else {
    return std::nullopt;
  }
}

std::optional<utils::IdType> GlobalInfo::NamespaceVisitor::FindTypeclass(
    const std::optional<std::vector<std::string>>& path,
    const std::string typeclass) {
  auto result = FindSomething<TypeclassInfo>(path,
      [typeclass] (NamespaceInfo* current_namespace) -> std::optional<TypeclassInfo*> {

    auto typeclass_info_iter = current_namespace->typeclasses.find(typeclass);
    if (typeclass_info_iter == current_namespace->typeclasses.end()) {
      return std::nullopt;
    }

    return &typeclass_info_iter->second;
  });

  if (result.has_value()) {
    return global_info_.typeclasses_.GetId(result.value());
  } else {
    return std::nullopt;
  }
}

template<typename T>
std::optional<T*> GlobalInfo::NamespaceVisitor::FindSomething(
    const std::optional<std::vector<std::string>>& path,
    std::function<std::optional<T*>(NamespaceInfo*)> search_func) {
  for (ssize_t i = namespace_stack_.size() - 1; i >= 0; --i) {
    NamespaceInfo* current_namespace = nullptr;
    if (path.has_value()) {
      auto maybe_namespace = FindNamespaceIn(namespace_stack_[i], path.value());

      if (!maybe_namespace.has_value()) {
        continue;
      }
    } else {
      current_namespace = namespace_stack_[i];
    }

    std::optional<T*> result = search_func(current_namespace);

    if (result.has_value()) {
      return result.value();
    }
  }

  return std::nullopt;
}

std::optional<NamespaceInfo*> GlobalInfo::NamespaceVisitor::FindNamespaceIn(
    NamespaceInfo* current_namespace,
    const std::vector<std::string>& path) {
  NamespaceInfo* next_namespace = current_namespace;
  for (auto& name : path) {
    auto next_namespace_iter = next_namespace->namespaces.find(name);
    if (next_namespace_iter == next_namespace->namespaces.end()) {
      return std::nullopt;
    }
    next_namespace = &next_namespace_iter->second;
  }

  return next_namespace;
}

} // namespace info