module Ferrum::Page::Frames

def frame_by(id: nil, name: nil, execution_id: nil)
  if id
    @frames[id]
  elsif name
    frames.find { |f| f.name == name }
  elsif execution_id
    frames.find { |f| f.execution_id == execution_id }
  else
    raise ArgumentError
  end
end

def frames
  @frames.values
end

def frames_subscribe
  subscribe_frame_attached
  subscribe_frame_detached
  subscribe_frame_started_loading
  subscribe_frame_navigated
  subscribe_frame_stopped_loading
  subscribe_navigated_within_document
  subscribe_request_will_be_sent
  subscribe_execution_context_created
  subscribe_execution_context_destroyed
  subscribe_execution_contexts_cleared
end

def idling?
  @frames.values.all? { |f| f.state == :stopped_loading }
end

def subscribe_execution_context_created
  on("Runtime.executionContextCreated") do |params|
    context_id = params.dig("context", "id")
    frame_id = params.dig("context", "auxData", "frameId")
    unless @main_frame.id
      root_frame = command("Page.getFrameTree").dig("frameTree", "frame", "id")
      if frame_id == root_frame
        @main_frame.id = frame_id
        @frames.put_if_absent(frame_id, @main_frame)
      end
    end
    frame = @frames.fetch_or_store(frame_id, Frame.new(frame_id, self))
    frame.execution_id = context_id
  end
end

def subscribe_execution_context_destroyed
  on("Runtime.executionContextDestroyed") do |params|
    execution_id = params["executionContextId"]
    frame = frame_by(execution_id: execution_id)
    frame&.execution_id = nil
  end
end

def subscribe_execution_contexts_cleared
  on("Runtime.executionContextsCleared") do
    @frames.each_value { |f| f.execution_id = nil }
  end
end

def subscribe_frame_attached
  on("Page.frameAttached") do |params|
    parent_frame_id, frame_id = params.values_at("parentFrameId", "frameId")
    @frames.put_if_absent(frame_id, Frame.new(frame_id, self, parent_frame_id))
  end
end

def subscribe_frame_detached
  on("Page.frameDetached") do |params|
    frame = @frames[params["frameId"]]
    if frame&.main?
      frame.execution_id = nil
    else
      @frames.delete(params["frameId"])
    end
  end
end

def subscribe_frame_navigated
  on("Page.frameNavigated") do |params|
    frame_id, name = params["frame"]&.values_at("id", "name")
    frame = @frames[frame_id]
    if frame
      frame.state = :navigated
      frame.name = name
    end
  end
end

def subscribe_frame_started_loading
  on("Page.frameStartedLoading") do |params|
    frame = @frames[params["frameId"]]
    frame.state = :started_loading if frame
    @event.reset
  end
end

def subscribe_frame_stopped_loading
  on("Page.frameStoppedLoading") do |params|
    # `DOM.performSearch` doesn't work without getting #document node first.
    # It returns node with nodeId 1 and nodeType 9 from which descend the
    # tree and we save it in a variable because if we call that again root
    # node will change the id and all subsequent nodes have to change id too.
    if @main_frame.id == params["frameId"]
      @event.set if idling?
      document_node_id
    end
    frame = @frames[params["frameId"]]
    frame&.state = :stopped_loading
    @event.set if idling?
  end
end

def subscribe_navigated_within_document
  on("Page.navigatedWithinDocument") do
    @event.set if idling?
  end
end

def subscribe_request_will_be_sent
  on("Network.requestWillBeSent") do |params|
    # Possible types:
    # Document, Stylesheet, Image, Media, Font, Script, TextTrack, XHR,
    # Fetch, EventSource, WebSocket, Manifest, SignedExchange, Ping,
    # CSPViolationReport, Other
    @event.reset if params["frameId"] == @main_frame.id && params["type"] == "Document"
  end
end