# OpenCore EFI for the VM: OSX-KVM's proven ESP (OpenCore + Lilu/VirtualSMC/... kexts)
# with a config.plist rewritten for this image's SMBIOS identity.
# Output:
#   $out/EFI/        BOOT/BOOTx64.efi + OC/ — copied into the image's ESP
#   $out/boot.img    raw GPT disk with that ESP, used to boot the installer
#   $out/vmix.json   model, serial, mlb, uuid, mac (also copied to EFI/vmix/)
# Serial + MLB come from macserial when not given (random per build); everything
# derived from `seed` (MAC, UUID) is deterministic so the NixOS module knows it.
{ pkgs, lib, upstream, macserial, qemu, ... }:
{ name ? "opencore",
  model ? "MacPro7,1",
  mac,
  uuid,
  serial ? null,
  mlb ? null,
  bootArgs ? "keepsyms=1",
  resolution ? "1024x768",
  showPicker ? true,
  pickerTimeout ? 2,
  extraConfig ? {},
  memSize ? 8192,             # RAM described in SMBIOS (MacPro7,1 wants 4 DIMMs)
}:
let
  ocImage = pkgs.fetchurl { inherit (upstream.opencore.image) url sha256; name = "OSX-KVM-OpenCore.qcow2"; };
in
pkgs.runCommand "${name}-esp" {
  nativeBuildInputs = with pkgs; [ _7zz python3 mtools dosfstools gptfdisk jq macserial ];
  passthru = { inherit model mac uuid; };
} ''
  echo "=== vmix: extracting OSX-KVM OpenCore ESP ==="
  7zz x -y -oparts ${ocImage} 0.primary.img >/dev/null
  7zz x -y -oesp parts/0.primary.img >/dev/null
  [ -f esp/EFI/OC/config.plist ] || { echo "config.plist not found in OpenCore image"; exit 1; }

  SERIAL="${toString serial}"; MLB="${toString mlb}"
  if [ -z "$SERIAL" ] || [ -z "$MLB" ]; then
    echo "=== vmix: generating serial/MLB for ${model} with macserial ==="
    LINE=$(macserial --num 1 --model "${model}" 2>/dev/null | grep '|' | tail -1)
    [ -n "$LINE" ] || { echo "macserial produced nothing for ${model}"; exit 1; }
    [ -z "$SERIAL" ] && SERIAL=$(echo "$LINE" | awk -F' *\\| *' '{print $1}')
    [ -z "$MLB" ] && MLB=$(echo "$LINE" | awk -F' *\\| *' '{print $2}')
  fi
  echo "model=${model} serial=$SERIAL mlb=$MLB uuid=${uuid} mac=${mac}"

  mkdir -p $out/EFI/vmix
  cp -r esp/EFI/BOOT esp/EFI/OC $out/EFI/
  chmod -R u+w $out/EFI
  # hide OpenCore's own launcher from its picker (otherwise it is the default entry and loops)
  echo -n Disabled > $out/EFI/BOOT/.contentVisibility
  python3 ${./oc-config.py} --base esp/EFI/OC/config.plist --esp esp --out $out/EFI/OC/config.plist \
    --model "${model}" --serial "$SERIAL" --mlb "$MLB" --uuid "${uuid}" --mac "${mac}" \
    --nic-path "${qemu.nicDevicePath}" --boot-args "${bootArgs}" --resolution "${resolution}" \
    --show-picker "${lib.boolToString showPicker}" --timeout ${toString pickerTimeout} \
    --extra-json ${lib.escapeShellArg (builtins.toJSON extraConfig)} --memory-mb ${toString memSize}
  ocvalidate $out/EFI/OC/config.plist || echo "vmix: ocvalidate reported issues (OpenCore version may differ from validator), continuing"

  jq -n --arg model "${model}" --arg serial "$SERIAL" --arg mlb "$MLB" --arg uuid "${uuid}" --arg mac "${mac}" \
    '{model:$model, serial:$serial, mlb:$mlb, uuid:$uuid, mac:$mac}' > $out/vmix.json
  cp $out/vmix.json $out/EFI/vmix/vmix.json

  echo "=== vmix: building OpenCore boot disk ==="
  # 64 MiB raw GPT disk, ESP from sector 2048 to the end (minus backup GPT)
  truncate -s 64M $out/boot.img
  sgdisk -n 1:2048:0 -t 1:EF00 -c 1:EFI $out/boot.img >/dev/null
  SECTORS=$(( 64*1024*1024/512 - 2048 - 34 ))
  mkfs.vfat -F 32 -n OPENCORE --offset 2048 $out/boot.img $(( SECTORS / 2 )) >/dev/null
  mcopy -i $out/boot.img@@1M -s $out/EFI ::
  mdir -i $out/boot.img@@1M ::EFI/OC >/dev/null
''