# SPDX-License-Identifier: MIT
# SPDX-FileCopyrightText: 2021-2023 Alyssa Ross <hi@alyssa.is>

import ../../../lib/call-package.nix (
{ spectrum-build-tools, src, terminfo, pkgsMusl }:
pkgsMusl.callPackage (

{ lib, stdenvNoCC, nixos, runCommand, writeClosure
, erofs-utils, jq, s6-rc, util-linux, xorg
, busybox, dbus, execline, iwd, kmod, linuxPackagesFor, linux_latest
, mdevd, nftables, s6, s6-linux-init, spectrum-driver-tools, xdp-tools
}:

let
  inherit (lib) concatMapStringsSep;
  inherit (nixosAllHardware.config.hardware) firmware;

  kernelTarget =
    if stdenvNoCC.hostPlatform.isx86 then
      # vmlinux.bin is the stripped version of vmlinux.
      # Confusingly, compressed/vmlinux.bin is the stripped version of
      # the top-level vmlinux target, while the top-level vmlinux.bin
      # is the stripped version of compressed/vmlinux.  So we use
      # compressed/vmlinux.bin, since we want a stripped version of
      # the kernel that *hasn't* been built to be compressed.  Weird!
      "compressed/vmlinux.bin"
    else
      kernel.target;

  kernel = (linux_latest.override {
    structuredExtraConfig = with lib.kernel; {
      DRM_FBDEV_EMULATION = lib.mkForce no;
      EROFS_FS = yes;
      FONTS = lib.mkForce unset;
      FONT_8x8 = lib.mkForce unset;
      FONT_TER16x32 = lib.mkForce unset;
      FRAMEBUFFER_CONSOLE = lib.mkForce unset;
      FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER = lib.mkForce unset;
      FRAMEBUFFER_CONSOLE_DETECT_PRIMARY = lib.mkForce unset;
      FRAMEBUFFER_CONSOLE_ROTATION = lib.mkForce unset;
      RC_CORE = lib.mkForce unset;
      VIRTIO = yes;
      VIRTIO_BLK = yes;
      VIRTIO_CONSOLE = yes;
      VIRTIO_PCI = yes;
      VT = no;
    };
  }).overrideAttrs ({ installFlags ? [], ... }: {
    installFlags = installFlags ++ [
      "KBUILD_IMAGE=$(boot)/${kernelTarget}"
    ];
  });

  packages = [
    dbus execline kmod mdevd s6 s6-linux-init s6-rc xdp-tools

    (busybox.override {
      extraConfig = ''
        CONFIG_DEPMOD n
        CONFIG_INIT n
        CONFIG_INSMOD n
        CONFIG_LSMOD n
        CONFIG_MODINFO n
        CONFIG_MODPROBE n
        CONFIG_RMMOD n
      '';
    })

    (nftables.override { withCli = false; })
  ];

  # Packages that should be fully linked into /usr,
  # (not just their bin/* files).
  usrPackages = [
    dbus firmware iwd kernel.modules terminfo

    # for xdp-forwarder
    spectrum-driver-tools
  ];

  packagesSysroot = runCommand "packages-sysroot" {
    inherit packages;
    nativeBuildInputs = [ xorg.lndir ];
    passAsFile = [ "packages" ];
  } ''
    mkdir -p $out/usr/bin

    ln -st $out/usr/bin \
        ${concatMapStringsSep " " (p: "${p}/bin/*") packages}

    for pkg in ${lib.escapeShellArgs usrPackages}; do
        lndir -ignorelinks -silent "$pkg" "$out/usr"
    done
  '';

  nixosAllHardware = nixos ({ modulesPath, ... }: {
    boot.kernelPackages = linuxPackagesFor kernel;

    hardware.enableAllHardware = true;

    system.stateVersion = lib.trivial.release;
  });
in

stdenvNoCC.mkDerivation {
  name = "spectrum-netvm";

  src = lib.fileset.toSource {
    root = ../../..;
    fileset = lib.fileset.intersection src (lib.fileset.unions [
      ./.
      ../../../lib/common.mk
      ../../../scripts/make-erofs.sh
      ../../../scripts/make-gpt.sh
      ../../../scripts/sfdisk-field.awk
    ]);
  };
  sourceRoot = "source/vm/sys/net";

  nativeBuildInputs = [ erofs-utils jq spectrum-build-tools s6-rc util-linux ];

  env = {
    KERNEL = "${kernel}/${baseNameOf kernelTarget}";
    PACKAGES = runCommand "packages" {} ''
      printf "%s\n/\n" ${packagesSysroot} >$out
      sed p ${writeClosure [ packagesSysroot] } >>$out
    '';
  };

  makeFlags = [ "prefix=$(out)" ];

  dontInstall = true;

  enableParallelBuilding = true;

  __structuredAttrs = true;
  unsafeDiscardReferences = { out = true; };
  dontFixup = true;

  passthru = { inherit firmware kernel packagesSysroot; };

  meta = with lib; {
    license = licenses.eupl12;
    platforms = platforms.linux;
  };
}
) {}) ({ foot }: { inherit (foot) terminfo; })