nerves_bootstrap

# SPDX-FileCopyrightText: 2022 Jon Carstens
# SPDX-FileCopyrightText: 2025 Frank Hunleth
#
# SPDX-License-Identifier: Apache-2.0
#
defmodule Mix.Tasks.Nerves.Bootstrap do
  # Bootstrap Nerves tooling into the current Mix tooling
  #
  # The purpose of this task is to ensure the Nerves integration is compiled
  # first and available to be injected into the Mix tooling since NervesBootstrap
  # is available as an archive. (i.e. this is like having `:nerves` as a
  # dependency of this archive even though archives do not allow traditional
  # dependencies)
  #
  # It is not intended to be run manually

  @moduledoc false
  use Mix.Task

  alias NervesBootstrap.UpdateChecker

  @impl Mix.Task
  def run(_args) do
    UpdateChecker.check()

    nerves_ver = nerves_version()

    if is_nil(nerves_ver) do
      Mix.raise("""
      Your project is using Nerves bootstrap but doesn't depend on Nerves.

      Please check the dependency section of your mix.exs.
      """)
    end

    # Check that the Nerves version is new enough to support this
    # version of Nerves Bootstrap.
    #
    # This version of Nerves Bootstrap fails to install when the
    # Elixir version is less than 1.15, so we're guaranteed that
    # version. That forces a constraint on what Nerves versions
    # can be used. Here's a truncated list for convenience.
    #
    # | Nerves version | Min Elixir version          | Max Elixir |
    # |----------------|-----------------------------|------------|
    # | 1.11.3         | 1.13                        | 1.18       |
    # | 1.12.0         | 1.15.1                      | 1.19.      |
    # | 1.14.3         | 1.15.1 (inherited)          | 1.20.      |

    if Version.match?(nerves_ver, "< 1.11.3") do
      Mix.raise("""
      You are using :nerves #{nerves_ver} which is incompatible with this version
      of nerves_bootstrap and will result in compilation failures.

      Please update to :nerves >= 1.11.3.
      """)
    end

    if Mix.target() != :host and not Code.ensure_loaded?(Nerves.Env) do
      # The tooling mix tasks are maintained in :nerves so we need to
      # ensure it is compiled here first so the tasks are available.
      # If the target is host, then this will be handled by the regular
      # compilation process
      _ = Mix.Tasks.Deps.Loadpaths.run(["--no-compile"])
      Mix.Tasks.Deps.Compile.run(["nerves", "--include-children"])
    end

    # Do not call Nerves Bootstrap code from other modules here. The modules
    # aren't available in Elixir 1.18 and earlier if `:nerves` doesn't pull
    # them in.
  end

  defp nerves_version() do
    if path = Mix.Project.deps_paths()[:nerves] do
      Mix.Project.in_project(:nerves, path, fn _ -> Mix.Project.config()[:version] end)
    end
  catch
    _, _ -> nil
  end
end