defmodule LSGWeb.ContextPlug do
  import Plug.Conn
  import Phoenix.Controller

  def init(opts \\ []) do
    opts || []
  end

  def get_account(conn) do
    cond do
      get_session(conn, :account) -> get_session(conn, :account)
      get_session(conn, :oidc_id) -> if account = IRC.Account.find_meta_account("identity-id", get_session(conn, :oidc_id)), do: account.id
      true -> nil
    end
  end

  def call(conn, opts) do
    account = with \
         {:account, account_id} when is_binary(account_id) <- {:account, get_account(conn)},
         {:account, account} when not is_nil(account) <- {:account, IRC.Account.get(account_id)}
    do
      account
    else
      _ -> nil
    end

    network = Map.get(conn.params, "network")
    network = if network == "-", do: nil, else: network

    oidc_account = IRC.Account.find_meta_account("identity-id", get_session(conn, :oidc_id))

    conns = IRC.Connection.get_network(network)
    chan = if c = Map.get(conn.params, "chan") do
      LSGWeb.reformat_chan(c)
    end
    chan_conn = IRC.Connection.get_network(network, chan)

    memberships = if account do
      IRC.Membership.of_account(account)
    end

    auth_required = cond do
      Keyword.get(opts, :restrict) == :public -> false
      account == nil -> true
      network == nil -> false
      Keyword.get(opts, :restrict) == :logged_in -> false
      network && chan ->
        !Enum.member?(memberships, {network, chan})
      network ->
        !Enum.any?(memberships, fn({n, _}) -> n == network end)
    end

    bot = cond do
      network && chan && chan_conn -> chan_conn.nick
      network && conns -> conns.nick
      true -> nil
    end


    cond do
      account && auth_required ->
        conn
        |> put_status(404)
        |> text("Page not found")
        |> halt()
      auth_required ->
        conn
        |> put_status(403)
        |> render(LSGWeb.AlcoologView, "auth.html", bot: bot, no_header: true, network: network)
        |> halt()
      (network && !conns) ->
        conn
        |> put_status(404)
        |> text("Page not found")
        |> halt()
      (chan && !chan_conn) ->
        conn
        |> put_status(404)
        |> text("Page not found")
        |> halt()
      true ->
        conn = conn
           |> assign(:network, network)
           |> assign(:chan, chan)
           |> assign(:bot, bot)
           |> assign(:account, account)
           |> assign(:oidc_account, oidc_account)
           |> assign(:memberships, memberships)
    end
  end

end