class Steep::Project::CompletionProvider

def items_for_trigger(position:)
  node, *parents = source.find_nodes(line: position.line, column: position.column)
  node ||= source.node
  return [] unless node
  items = []
  context = typing.context_at(line: position.line, column: position.column)
  case
  when node.type == :send && node.children[0] == nil && at_end?(position, of: node.loc.selector)
    # foo ←
    prefix = node.children[1].to_s
    method_items_for_receiver_type(context.self_type,
                                   include_private: true,
                                   prefix: prefix,
                                   position: position,
                                   items: items)
    local_variable_items_for_context(context, position: position, prefix: prefix, items: items)
  when node.type == :lvar && at_end?(position, of: node.loc)
    # foo ← (lvar)
    local_variable_items_for_context(context, position: position, prefix: node.children[0].name.to_s, items: items)
  when node.type == :send && node.children[0] && at_end?(position, of: node.loc.selector)
    # foo.ba ←
    receiver_type = case (type = typing.type_of(node: node.children[0]))
                    when AST::Types::Self
                      context.self_type
                    else
                      type
                    end
    prefix = node.children[1].to_s
    method_items_for_receiver_type(receiver_type,
                                   include_private: false,
                                   prefix: prefix,
                                   position: position,
                                   items: items)
  when node.type == :const && node.children[0] == nil && at_end?(position, of: node.loc)
    # Foo ← (const)
    prefix = node.children[1].to_s
    method_items_for_receiver_type(context.self_type,
                                   include_private: false,
                                   prefix: prefix,
                                   position: position,
                                   items: items)
  when node.type == :send && at_end?(position, of: node.loc.dot)
    # foo.← ba
    receiver_type = case (type = typing.type_of(node: node.children[0]))
                    when AST::Types::Self
                      context.self_type
                    else
                      type
                    end
    method_items_for_receiver_type(receiver_type,
                                   include_private: false,
                                   prefix: "",
                                   position: position,
                                   items: items)
  when node.type == :ivar && at_end?(position, of: node.loc)
    # @fo ←
    instance_variable_items_for_context(context, position: position, prefix: node.children[0].to_s, items: items)
  else
    method_items_for_receiver_type(context.self_type,
                                   include_private: true,
                                   prefix: "",
                                   position: position,
                                   items: items)
    local_variable_items_for_context(context, position: position, prefix: "", items: items)
    instance_variable_items_for_context(context, position: position, prefix: "", items: items)
  end
  items
end