class Steep::Services::HoverProvider::RBS

def content_for(target:, path:, line:, column:)
  service = self.service.signature_services[target.name]
  env = service.latest_env
  buffer = env.buffers.find {|buf| buf.name.to_s == path.to_s } or return
  (dirs, decls = env.signatures[buffer]) or raise
  locator = ::RBS::Locator.new(buffer: buffer, dirs: dirs, decls: decls)
  loc_key, path = locator.find2(line: line, column: column) || return
  head, *_tail = path
  case head
  when ::RBS::Types::Alias
    alias_decl = service.latest_env.type_alias_decls[head.name]&.decl or raise
    TypeAliasContent.new(
      location: head.location || raise,
      decl: alias_decl
    )
  when ::RBS::Types::ClassInstance, ::RBS::Types::ClassSingleton
    if loc_key == :name
      location = head.location&.[](:name) or raise
      class_entry = service.latest_env.module_class_entry(head.name) or raise
      case class_entry
      when ::RBS::Environment::ClassEntry, ::RBS::Environment::ModuleEntry
        class_decl = class_entry.primary.decl
      when ::RBS::Environment::ClassAliasEntry, ::RBS::Environment::ModuleAliasEntry
        class_decl = class_entry.decl
      end
      ClassContent.new(
        location: location,
        decl: class_decl
      )
    end
  when ::RBS::Types::Interface
    env = service.latest_env
    interface_decl = env.interface_decls[head.name]&.decl or raise
    location = head.location&.[](:name) or raise
    InterfaceContent.new(
      location: location,
      decl: interface_decl
    )
  when ::RBS::AST::Declarations::ClassAlias, ::RBS::AST::Declarations::ModuleAlias
    if loc_key == :old_name
      location = head.location&.[](:old_name) or raise
      class_entry = service.latest_env.module_class_entry(head.old_name) or raise
      case class_entry
      when ::RBS::Environment::ClassEntry, ::RBS::Environment::ModuleEntry
        class_decl = class_entry.primary.decl
      when ::RBS::Environment::ClassAliasEntry, ::RBS::Environment::ModuleAliasEntry
        class_decl = class_entry.decl
      end
      ClassContent.new(location: location, decl: class_decl)
    end
  end
end

def initialize(service:)
  @service = service
end

def project
  service.project
end