# credo:disable-for-next-line Credo.Check.Refactor.ModuleDependencies
defmodule Mix.Tasks.Enumex.Static.Gen.Enum do
  @shortdoc "Generates an enum module with static values."

  args = [
    %{help: "Specifies an enum module", value_name: "MODULE"},
    %{help: "Specifies an enum name", value_name: "ENUM_NAME"},
    %{help: "Values in format 'name' or 'name:index'", value_name: "VALUE_1 VALUE_2 … VALUE_N"}
  ]

  flags = [
    %{help: "Specifies file path for enum", long: "--file", short: "-f", value_name: "FILE_PATH"}
  ]

  required_args = Enum.map(args, &Map.put(&1, :required, true))
  task = Enumex.Generator.Task.new("enumex.static.gen.enum", required_args, flags)

  if Mix.env() == :test do
    try do
      :meck.new(:io, [:unstick, :passthrough])
    rescue
      _exception -> :ok
    end

    :meck.expect(:io, :columns, fn -> {:ok, 80} end)
  end

  help = Enumex.Generator.Task.help(task, @shortdoc)
  @moduledoc Enumex.Generator.Task.moduledoc(help)

  use Mix.Task

  alias Enumex.Generator.Task
  alias Enumex.Value
  alias Mix.Generator

  require Generator

  @help help
  @opts [aliases: Task.aliases([:file]), strict: Task.options(file: :string)]
  @task_name task.name
  @version Task.version(task)

  @impl Mix.Task
  def run(args) do
    Task.run(@task_name, args, @help, @version, @opts, fn
      [_module], _opts -> Task.missing_args(@task_name, ["ENUM_NAME", "VALUE_1 VALUE_2 … VALUE_N"])
      [_module, _name], _opts -> Task.missing_args(@task_name, ["VALUE_1 VALUE_2 … VALUE_N"])
      [module, name | values], opts -> generate_enum(module, name, values, opts[:file])
    end)
  end

  @spec generate_enum(String.t(), String.t(), [], String.t()) :: :ok
  @spec generate_enum(String.t(), String.t(), [String.t()], String.t()) :: :ok
  defp generate_enum(_module, _name, values, _file) when length(values) < 2, do: not_enough_values()

  @spec generate_enum(String.t(), String.t(), OptionParser.argv(), String.t()) :: boolean()
  defp generate_enum(module, name, values, file) do
    Mix.Task.run("loadpaths")
    file_path = file || gen_file_path(module)
    values_string = Enum.map_join(values, "\n    ", &prepare_value/1)
    # credo:disable-for-next-line Credo.Check.Warning.UnsafeToAtom
    contents = enum_template(module: module, name: String.to_atom(name), values: values_string)

    file_path
    |> tap(fn path ->
      path
      |> Path.dirname()
      |> Generator.create_directory()
    end)
    |> tap(&Generator.create_file(&1, contents))
    |> List.wrap()
  end

  @spec gen_file_path(String.t()) :: Path.t()
  defp gen_file_path(module) do
    module
    |> Macro.underscore()
    |> then(&Path.join(["lib", &1 <> ".ex"]))
  end

  @spec prepare_value(String.t()) :: String.t()
  defp prepare_value(value) do
    case String.split(value, ":") do
      # credo:disable-for-next-line Credo.Check.Warning.UnsafeToAtom
      [id] -> value_template(id: String.to_atom(id))
      # credo:disable-for-next-line Credo.Check.Warning.UnsafeToAtom
      [id, index] -> value_with_index_template(id: String.to_atom(id), index: index)
    end
  end

  @spec not_enough_values :: :ok
  defp not_enough_values, do: Task.print_errors(@task_name, ["expected at least 2 values"])

  @spec enum_template(module: String.t(), name: atom(), values: String.t()) :: String.t()
  Generator.embed_template(:enum, """
  defmodule <%= @module %> do
    use Enumex.Static, components: [
      # Enumex.Static.Components.AbsinthePhase,
      # Enumex.Static.Components.Constant,
      # Enumex.Static.Components.EctoType,
      # Enumex.Static.Components.Guards,
      # Enumex.Static.Components.Index,
      # Enumex.Static.Components.List,
      # Enumex.Static.Components.Sort,
      # Enumex.Static.Components.Typespecs
    ]

    enum <%= inspect(@name) %> do
      <%= @values %>
    end
  end
  """)

  @spec value_template(id: Value.id()) :: String.t()
  Generator.embed_template(:value, ~s[value <%= inspect(@id) %>])

  @spec value_template(id: Value.id(), index: Value.index()) :: String.t()
  Generator.embed_template(:value_with_index, ~s[value <%= inspect(@id) %>, <%= @index %>])
end