## This Source Code Form is subject to the terms of the Mozilla Public
## License, v. 2.0. If a copy of the MPL was not distributed with this
## file, You can obtain one at https://mozilla.org/MPL/2.0/.
##
## Copyright (c) 2007-2020 VMware, Inc. or its affiliates.  All rights reserved.

defmodule RabbitMQ.CLI.Plugins.Commands.DirectoriesCommand do
  alias RabbitMQ.CLI.Plugins.Helpers, as: PluginHelpers
  alias RabbitMQ.CLI.Core.{DocGuide, Validators, Config}
  import RabbitMQ.CLI.Core.{CodePath, Paths}

  @behaviour RabbitMQ.CLI.CommandBehaviour

  def merge_defaults(args, %{offline: true} = opts) do
    {args, opts}
  end

  def merge_defaults(args, opts) do
    {args, Map.merge(%{online: true, offline: false}, opts)}
  end

  def distribution(%{offline: true}), do: :none
  def distribution(%{offline: false}), do: :cli

  def switches(), do: [online: :boolean, offline: :boolean]

  def validate(_, %{online: true, offline: true}) do
    {:validation_failure, {:bad_argument, "Cannot set both online and offline"}}
  end

  def validate(_, %{online: false, offline: false}) do
    {:validation_failure, {:bad_argument, "Cannot set online and offline to false"}}
  end

  def validate([_ | _], _) do
    {:validation_failure, :too_many_args}
  end

  def validate([], _) do
    :ok
  end

  def validate_execution_environment(args, %{offline: true} = opts) do
    Validators.chain(
      [
        &require_rabbit_and_plugins/2,
        &PluginHelpers.enabled_plugins_file/2,
        &plugins_dir/2
      ],
      [args, opts]
    )
  end

  def validate_execution_environment(args, %{online: true} = opts) do
    Validators.node_is_running(args, opts)
  end

  def run([], %{online: true, node: node_name}) do
    do_run(fn key ->
      :rabbit_misc.rpc_call(node_name, :rabbit_plugins, key, [])
    end)
  end

  def run([], %{offline: true} = opts) do
    do_run(fn key ->
      Config.get_option(key, opts)
    end)
  end

  def output({:ok, _map} = res, %{formatter: "json"}) do
    res
  end

  def output({:ok, map}, _opts) do
    s = """
    Plugin archives directory: #{Map.get(map, :plugins_dir)}
    Plugin expansion directory: #{Map.get(map, :plugins_expand_dir)}
    Enabled plugins file: #{Map.get(map, :enabled_plugins_file)}
    """

    {:ok, String.trim_trailing(s)}
  end

  def output({:error, err}, _opts) do
    {:error, RabbitMQ.CLI.Core.ExitCodes.exit_software(), err}
  end

  use RabbitMQ.CLI.DefaultOutput

  def banner([], %{offline: true}) do
    "Listing plugin directories inferred from local environment..."
  end

  def banner([], %{online: true, node: node}) do
    "Listing plugin directories used by node #{node}"
  end

  def usage, do: "directories [--offline] [--online]"

  def usage_additional() do
    [
      ["--offline", "do not contact target node. Try to infer directories from the environment."],
      ["--online", "infer directories from target node."]
    ]
  end

  def usage_doc_guides() do
    [
      DocGuide.plugins()
    ]
  end

  def help_section(), do: :observability_and_health_checks

  def description(), do: "Displays plugin directory and enabled plugin file paths"

  #
  # Implementation
  #

  defp do_run(fun) do
    # return an error or an {:ok, map} tuple
    Enum.reduce([:plugins_dir, :plugins_expand_dir, :enabled_plugins_file], {:ok, %{}}, fn
      _, {:error, err} ->
        {:error, err}

      key, {:ok, acc} ->
        case fun.(key) do
          {:error, err} -> {:error, err}
          val -> {:ok, Map.put(acc, key, :rabbit_data_coercion.to_binary(val))}
        end
    end)
  end
end
