class RubyLsp::Requests::SignatureHelp

def adjust_for_nested_target(target, parent, position)
  # If the parent node is not a method call, then make no adjustments
  return target unless parent.is_a?(Prism::CallNode)
  # If the parent is a method call, but the target isn't, then return the parent
  return parent unless target.is_a?(Prism::CallNode)
  # If both are method calls, we check the arguments of the inner method call. If there are no arguments, then
  # we're providing signature help for the outer method call.
  #
  # If there are arguments, then we check if the arguments node covers the requested position. If it doesn't
  # cover, then we're providing signature help for the outer method call.
  arguments = target.arguments
  arguments.nil? || !node_covers?(arguments, position) ? parent : target
end

def initialize(document, global_state, position, context, dispatcher, sorbet_level) # rubocop:disable Metrics/ParameterLists
  super()
  char_position = document.create_scanner.find_char_position(position)
  delegate_request_if_needed!(global_state, document, char_position)
  node_context = RubyDocument.locate(document.parse_result.value, char_position, node_types: [Prism::CallNode])
  target = adjust_for_nested_target(node_context.node, node_context.parent, position)
  @target = T.let(target, T.nilable(Prism::Node))
  @dispatcher = dispatcher
  @response_builder = T.let(ResponseBuilders::SignatureHelp.new, ResponseBuilders::SignatureHelp)
  Listeners::SignatureHelp.new(@response_builder, global_state, node_context, dispatcher, sorbet_level)
end

def node_covers?(node, position)
  location = node.location
  start_line = location.start_line - 1
  start_character = location.start_column
  end_line = location.end_line - 1
  end_character = location.end_column
  start_covered = start_line < position[:line] ||
    (start_line == position[:line] && start_character <= position[:character])
  end_covered = end_line > position[:line] ||
    (end_line == position[:line] && end_character >= position[:character])
  start_covered && end_covered
end

def perform
  return unless @target
  @dispatcher.dispatch_once(@target)
  @response_builder.response
end

def provider
  # Identifier characters are automatically included, such as A-Z, a-z, 0-9, _, * or :
  Interface::SignatureHelpOptions.new(
    trigger_characters: ["(", " ", ","],
  )
end