defmodule ExUnit.ClusteredCase.Node do
  @moduledoc """
  This module handles starting new nodes

  You can specify various options when starting a node:

  - `:name`, takes either a string or an atom, in either long or short form,
    this sets the node name and id.
  - `:boot_timeout`, specifies the amount of time to wait for a node to perform it's
    initial boot sequence before timing out
  - `:init_timeout`, specifies the amount of time to wait for the node agent to complete
    initializing the node (loading and starting required applications, applying configuration,
    loading test modules, and executing post-start functions)
  - `:erl_flags`, a list of arguments to pass to `erl` when starting the node, e.g. `["-init_debug"]`
  - `:env`, a list of tuples containing environment variables to export in the node's environment,
    e.g. `[{"PORT", "8080"}]`
  - `:config`, a `Keyword` list containing configuration overrides to apply to the node,
    should be in the form of `[app: [key: value]]`
  - `:post_start_functions`, a list of functions, either captured or in `{module, function, args}` format,
    which will be invoked on the node after it is booted and initialized. Functions must be zero-arity.
  """

  alias ExUnit.ClusteredCaseError

  @type fun :: (() -> term) | {module, atom, [term]}
  @type node_opts :: [node_opt]
  @type node_opt ::
          {:name, String.t() | atom}
          | {:boot_timeout, pos_integer}
          | {:init_timeout, pos_integer}
          | {:erl_flags, [String.t()]}
          | {:env, [{String.t(), String.t()}]}
          | {:config, Keyword.t()}
          | {:post_start_functions, [fun]}
  @type node_error ::
          :already_started
          | :started_not_connected
          | :boot_timeout
          | :init_timeout
          | :not_alive

  @doc false
  @spec start(node_opts) :: {:ok, pid} | {:error, term}
  def start(opts) when is_list(opts) do
    do_start(opts, [])
  end

  @doc false
  @spec start_nolink(node_opts) :: {:ok, pid} | {:error, term}
  def start_nolink(opts) when is_list(opts) do
    do_start(opts, [:nolink])
  end

  defp do_start(opts, start_opts) do
    # We expect that the current node is already distributed
    unless Node.alive?() do
      raise ClusteredCaseError,
            "cannot run clustered test cases if distribution is not active! " <>
              "You can start distribution via Node.start/1, or with the --name flag."
    end

    if :nolink in start_opts do
      __MODULE__.Manager.start_nolink(opts)
    else
      __MODULE__.Manager.start_link(opts)
    end
  end

  @doc false
  @spec name(pid | String.t() | atom) :: node
  defdelegate name(pid), to: __MODULE__.Manager

  @doc false
  @spec connect(pid | String.t() | atom, [pid | String.t() | atom]) :: :ok
  defdelegate connect(name, nodes), to: __MODULE__.Manager

  @doc false
  @spec disconnect(pid | String.t() | atom, [pid | String.t() | atom]) :: :ok
  defdelegate disconnect(name, nodes), to: __MODULE__.Manager

  @doc false
  @spec stop(pid | String.t() | atom) :: :ok
  defdelegate stop(name), to: __MODULE__.Manager

  @doc false
  @spec kill(pid | String.t() | atom) :: :ok
  defdelegate kill(name), to: __MODULE__.Manager

  @doc false
  @spec alive?(pid | String.t() | atom) :: boolean
  defdelegate alive?(name), to: __MODULE__.Manager

  @doc false
  @spec log(pid | String.t() | atom) :: {:ok, binary}
  defdelegate log(name), to: __MODULE__.Manager

  @doc false
  @spec call(pid | String.t() | atom, fun) :: {:ok, term} | {:error, term}
  defdelegate call(name, fun), to: __MODULE__.Manager

  @doc false
  @spec call(pid | String.t() | atom, fun, Keyword.t()) :: {:ok, term} | {:error, term}
  defdelegate call(name, fun, opts), to: __MODULE__.Manager

  @doc false
  @spec call(pid | String.t() | atom, module, atom, [term]) :: {:ok, term} | {:error, term}
  defdelegate call(name, m, f, a), to: __MODULE__.Manager

  @doc false
  @spec call(pid | String.t() | atom, module, atom, [term], Keyword.t()) ::
          {:ok, term} | {:error, term}
  defdelegate call(name, m, f, a, opts), to: __MODULE__.Manager
end