defmodule OrgGarden.Quartz do
  @moduledoc """
  Manages Quartz Node.js process as an Erlang Port.

  Required environment:
  - QUARTZ_PATH: path to quartz repo (with node_modules)
  - NODE_PATH: path to node executable (default: "node")

  Starts Quartz in serve mode (`npx quartz build --serve`) and forwards
  all stdout/stderr output to the Logger with a `[quartz]` prefix.

  If Quartz exits, this GenServer will stop, which triggers the supervisor
  to restart the entire supervision tree (strategy: :one_for_all).
  """
  use GenServer

  require Logger

  defstruct [:port, :quartz_path, :content_dir, :http_port, :ws_port]

  # -------------------------------------------------------------------
  # Client API
  # -------------------------------------------------------------------

  @doc """
  Start the Quartz process as a linked GenServer.

  ## Options

    * `:content_dir` — directory where markdown files are located (required)
    * `:port`        — HTTP server port (default: 8080)
    * `:ws_port`     — WebSocket hot reload port (default: 3001)
  """
  def start_link(opts) do
    GenServer.start_link(__MODULE__, opts, name: __MODULE__)
  end

  # -------------------------------------------------------------------
  # GenServer callbacks
  # -------------------------------------------------------------------

  @impl true
  def init(opts) do
    quartz_path =
      System.get_env("QUARTZ_PATH") ||
        raise "QUARTZ_PATH environment variable not set"

    node_path = System.get_env("NODE_PATH", "node")

    content_dir = Keyword.fetch!(opts, :content_dir)
    http_port = Keyword.get(opts, :port, 8080)
    ws_port = Keyword.get(opts, :ws_port, 3001)

    cli_path = Path.join(quartz_path, "quartz/bootstrap-cli.mjs")

    unless File.exists?(cli_path) do
      raise "Quartz CLI not found at #{cli_path}. Check QUARTZ_PATH."
    end

    args = [
      cli_path,
      "build",
      "--serve",
      "--directory", content_dir,
      "--port", to_string(http_port),
      "--wsPort", to_string(ws_port)
    ]

    Logger.info("[quartz] Starting: #{node_path} #{Enum.join(args, " ")}")
    Logger.info("[quartz] Working directory: #{quartz_path}")

    port =
      Port.open({:spawn_executable, node_path}, [
        :binary,
        :exit_status,
        :stderr_to_stdout,
        args: args,
        cd: quartz_path,
        env: [{~c"NODE_NO_WARNINGS", ~c"1"}]
      ])

    state = %__MODULE__{
      port: port,
      quartz_path: quartz_path,
      content_dir: content_dir,
      http_port: http_port,
      ws_port: ws_port
    }

    {:ok, state}
  end

  @impl true
  def handle_info({port, {:data, data}}, %{port: port} = state) do
    data
    |> String.split("\n", trim: true)
    |> Enum.each(&Logger.info("[quartz] #{&1}"))

    {:noreply, state}
  end

  @impl true
  def handle_info({port, {:exit_status, status}}, %{port: port} = state) do
    Logger.error("[quartz] Process exited with status #{status}")
    {:stop, {:quartz_exit, status}, state}
  end

  @impl true
  def terminate(_reason, %{port: port}) when is_port(port) do
    # Attempt graceful shutdown
    Port.close(port)
    :ok
  rescue
    _ -> :ok
  end

  def terminate(_reason, _state), do: :ok
end