class ActionDispatch::Journey::Router

def ast: () -> ActionDispatch::Journey::Nodes::Or

def ast
  routes.ast
end

def custom_routes: () -> untyped

def custom_routes
  routes.custom_routes
end

def eager_load!
  # Eagerly trigger the simulator's initialization so
  # it doesn't happen during a request cycle.
  simulator
  nil
end

def filter_routes(path)
  return [] unless ast
  simulator.memos(path) { [] }
end

def find_routes(req)
  path_info = req.path_info
  routes = filter_routes(path_info).concat custom_routes.find_all { |r|
    r.path.match?(path_info)
  }
  if req.head?
    routes = match_head_routes(routes, req)
  else
    routes.select! { |r| r.matches?(req) }
  end
  routes.sort_by!(&:precedence)
  routes.map! { |r|
    match_data = r.path.match(path_info)
    path_parameters = {}
    match_data.names.each_with_index { |name, i|
      val = match_data[i + 1]
      path_parameters[name.to_sym] = Utils.unescape_uri(val) if val
    }
    [match_data, path_parameters, r]
  }
end

def initialize(routes)
  @routes = routes
end

def match_head_routes(routes, req)
  head_routes = routes.select { |r| r.requires_matching_verb? && r.matches?(req) }
  return head_routes unless head_routes.empty?
  begin
    req.request_method = "GET"
    routes.select! { |r| r.matches?(req) }
    routes
  ensure
    req.request_method = "HEAD"
  end
end

def partitioned_routes
  routes.partition { |r|
    r.path.anchored && r.path.requirements_anchored?
  }
end

def recognize(rails_req)
  find_routes(rails_req).each do |match, parameters, route|
    unless route.path.anchored
      rails_req.script_name = match.to_s
      rails_req.path_info   = match.post_match
      rails_req.path_info   = "/" + rails_req.path_info unless rails_req.path_info.start_with? "/"
    end
    parameters = route.defaults.merge parameters
    yield(route, parameters)
  end
end

def serve(req)
  find_routes(req).each do |match, parameters, route|
    set_params  = req.path_parameters
    path_info   = req.path_info
    script_name = req.script_name
    unless route.path.anchored
      req.script_name = (script_name.to_s + match.to_s).chomp("/")
      req.path_info = match.post_match
      req.path_info = "/" + req.path_info unless req.path_info.start_with? "/"
    end
    tmp_params = set_params.merge route.defaults
    parameters.each_pair { |key, val|
      tmp_params[key] = val.force_encoding(::Encoding::UTF_8)
    }
    req.path_parameters = tmp_params
    status, headers, body = route.app.serve(req)
    if "pass" == headers["X-Cascade"]
      req.script_name     = script_name
      req.path_info       = path_info
      req.path_parameters = set_params
      next
    end
    return [status, headers, body]
  end
  [404, { "X-Cascade" => "pass" }, ["Not Found"]]
end

def simulator: () -> ActionDispatch::Journey::GTG::Simulator

def simulator
  routes.simulator
end

def visualizer
  tt     = GTG::Builder.new(ast).transition_table
  groups = partitioned_routes.first.map(&:ast).group_by(&:to_s)
  asts   = groups.values.map(&:first)
  tt.visualizer(asts)
end