defmodule NullaWeb.ActivityPub.InboxController do
  use NullaWeb, :controller
  alias Nulla.Snowflake
  alias Nulla.HTTPSignature
  alias Nulla.Sender
  alias Nulla.Utils
  alias Nulla.Models.User
  alias Nulla.Models.Actor
  alias Nulla.Models.Relation
  alias Nulla.Models.Activity

  def inbox(conn, %{
        "id" => _create_id,
        "type" => "Create",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _read_id,
        "type" => "Read",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _update_id,
        "type" => "Update",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _delete_id,
        "type" => "Delete",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _add_id,
        "type" => "Add",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _view_id,
        "type" => "View",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _move_id,
        "type" => "Move",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _undo_id,
        "type" => "Undo",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => follow_id,
        "type" => "Follow",
        "actor" => actor_uri,
        "object" => target_uri
      }) do
    accept_id = Snowflake.next_id()

    with local_actor <- Actor.get_actor(ap_id: target_uri),
         {:ok, remote_actor_json} <- Utils.fetch_remote_actor(actor_uri),
         :ok <- HTTPSignature.verify(conn, remote_actor_json["publicKey"]["publicKeyPem"]),
         {:ok, remote_actor} <- Actor.get_or_create_actor(remote_actor_json),
         {:ok, follow_activity} <-
           Activity.create_activity(%{
             ap_id: follow_id,
             type: "Follow",
             actor: remote_actor.ap_id,
             object: target_uri
           }),
         {:ok, accept_activity} <-
           Activity.create_activity(%{
             id: accept_id,
             ap_id: "https://#{local_actor.domain}/activities/accept/#{accept_id}",
             type: "Accept",
             actor: local_actor.ap_id,
             object: Jason.encode!(follow_activity)
           }),
         {:ok, _relation} <-
           Relation.get_or_create_relation(local_actor.id, remote_actor.id, followed_by: true) do
      user = User.get_user(id: local_actor.id)

      Sender.send_activity(
        :post,
        remote_actor.inbox,
        accept_activity,
        local_actor.publicKey["id"],
        user.privateKeyPem
      )

      send_resp(conn, 200, "")
    else
      error ->
        IO.inspect(error, label: "Follow error")
        json(conn, %{"error" => "Failed to process Follow"})
    end
  end

  def inbox(conn, %{
        "id" => _accept_id,
        "type" => "Accept",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _reject_id,
        "type" => "Reject",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _block_id,
        "type" => "Block",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _join_id,
        "type" => "Join",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _leave_id,
        "type" => "Leave",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _like_id,
        "type" => "Like",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _dislike_id,
        "type" => "Dislike",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _announce_id,
        "type" => "Announce",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, %{
        "id" => _question_id,
        "type" => "Question",
        "actor" => _actor_uri,
        "object" => _target_uri
      }) do
    send_resp(conn, 200, "")
  end

  def inbox(conn, _params) do
    send_resp(conn, 400, "")
  end
end