defmodule RockboxFfi.MixProject do
  use Mix.Project

  @version "0.4.0"
  @source_url "https://github.com/tsirysndr/rockboxd"
  @source_ref "master"

  # Precompiled NIF artifacts are hosted on ONE rolling GitHub release so we
  # never have to edit the URL on every version bump: elixir_make only
  # substitutes `@{artefact_filename}` (which already embeds the version), not
  # `@version`. The CI workflow `bindings-elixir-release.yml` uploads every
  # version's tarballs to this same tag.
  @precompiled_tag "rockbox-ffi-nif"

  def project do
    [
      app: :rockbox_ex_ffi,
      version: @version,
      elixir: "~> 1.15",
      # elixir_make + cc_precompiler: on a consumer machine this DOWNLOADS the
      # prebuilt `priv/rockbox_ffi_nif.so` for the current target instead of
      # running the Makefile (which needs the Rust workspace + 30 MB static
      # archive that are NOT shipped in the Hex package). Falls back to a local
      # `make` build only when `make_force_build` is true — see below.
      compilers: [:elixir_make | Mix.compilers()],
      make_precompiler: {:nif, CCPrecompiler},
      make_precompiler_url:
        "#{@source_url}/releases/download/#{@precompiled_tag}/@{artefact_filename}",
      make_precompiler_filename: "rockbox_ffi_nif",
      # The Rust static archive is arch-specific, so each arch MUST be built on
      # its own native runner — cross-tarring an arm64 .so as x86_64 is
      # impossible. `only_listed_targets: true` (+ CC_PRECOMPILER_PRECOMPILE_ONLY_LOCAL=true
      # in CI) collapses the compile set to exactly the native target, and pins
      # the fetch set to the triples listed below. Consumers on anything else
      # (musl, Windows, …) get no prebuilt NIF — build from a monorepo checkout
      # with ROCKBOX_FFI_BUILD=1.
      cc_precompiler: [
        only_listed_targets: true,
        compilers: %{
          {:unix, :darwin} => %{
            "aarch64-apple-darwin" => {"cc", "c++"},
            "x86_64-apple-darwin" => {"cc", "c++"}
          },
          {:unix, :linux} => %{
            "x86_64-linux-gnu" => {"gcc", "g++"},
            "aarch64-linux-gnu" => {"gcc", "g++"}
          },
          # *BSD amd64 — best-effort (built in a VM). cc_precompiler's own
          # detection yields an OS-version-suffixed triple (e.g.
          # "amd64-portbld-freebsd14.0"), so CI pins these canonical triples via
          # TARGET_ARCH/TARGET_OS/TARGET_ABI. A BSD consumer whose auto-detected
          # triple differs must set the same TARGET_* env vars to fetch the
          # prebuilt NIF, or build from source (ROCKBOX_FFI_BUILD=1).
          {:unix, :freebsd} => %{"x86_64-unknown-freebsd" => {"cc", "c++"}},
          {:unix, :netbsd} => %{"x86_64-unknown-netbsd" => {"cc", "c++"}}
        }
      ],
      # The package requires OTP 27+ (uses the built-in `:json`), and OTP 26/27/28
      # all report NIF version 2.17 — so a single 2.17 build covers every
      # supported OTP. (If OTP 25/24 support is ever added, also build a 2.16
      # artifact and list it here; newer OTPs fall back to the closest ≤ match.)
      make_precompiler_nif_versions: [versions: ["2.17"]],
      # Force a from-source `make` build (only works inside the monorepo, which
      # has the Cargo workspace + include/ header). Set ROCKBOX_FFI_BUILD=1, or
      # any "-dev" version string, to opt in.
      make_force_build: force_build?(),
      make_targets: ["all"],
      make_clean: ["clean"],
      erlc_paths: ["src"],
      deps: deps(),
      description: "Elixir bindings for the Rockbox DSP / metadata / playback engine",
      package: package(),
      name: "rockbox_ex_ffi",
      source_url: @source_url,
      docs: docs()
    ]
  end

  def application, do: [extra_applications: [:crypto]]

  defp force_build?,
    do: System.get_env("ROCKBOX_FFI_BUILD") in ["1", "true"] or String.ends_with?(@version, "-dev")

  defp deps do
    [
      {:elixir_make, "~> 0.8", runtime: false},
      {:cc_precompiler, "~> 0.1", runtime: false},
      {:ex_doc, "~> 0.34", only: :dev, runtime: false}
    ]
  end

  defp docs do
    [
      main: "readme",
      extras: ["README.md"],
      source_url: @source_url,
      source_ref: @source_ref,
      # This package lives in a monorepo subdirectory, so ExDoc's file paths
      # (relative to bindings/elixir/) must be prefixed with that path for the
      # "source" links — on modules, functions, and the README — to resolve.
      source_url_pattern: "#{@source_url}/blob/#{@source_ref}/bindings/elixir/%{path}#L%{line}",
      groups_for_modules: [
        Core: [Rockbox],
        Metadata: [Rockbox.Metadata],
        DSP: [Rockbox.Dsp],
        Playback: [Rockbox.Player, Rockbox.InsertPosition]
      ]
    ]
  end

  defp package do
    [
      licenses: ["GPL-2.0-or-later"],
      # `checksum.exs` is generated by `mix elixir_make.checksum` and MUST ship
      # in the package: it's how consumers verify the downloaded precompiled NIF.
      # elixir_make >= 0.8 writes/reads a fixed `checksum.exs` (older versions
      # used `checksum-<app>.exs`); match what the installed elixir_make emits.
      files: ~w(lib src c_src Makefile mix.exs README.md checksum.exs),
      links: %{"GitHub" => "https://github.com/tsirysndr/rockboxd"}
    ]
  end
end