{ lib
, stdenv
, stdenvNoCC
, fetchurl
, fetchFromGitHub
, cctools
, sigtool
, cereal
, glslang
, spirv-cross
, spirv-headers
, spirv-tools
, vulkan-headers
, AppKit
, Foundation
, Metal
, QuartzCore
}:

# Even though the derivation is currently impure, it is written to build successfully using
# `xcbuild`.  Once the SDK on x86_64-darwin is updated, it should be possible to switch from being
# an impure derivation.
#
# The `sandboxProfile` was copied from the iTerm2 derivation.  In order to build you at least need
# the `sandbox` option set to `relaxed` or `false`.  Xcode should be available in the default
# location.
let
  libcxx.dev = "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr";
in
stdenvNoCC.mkDerivation (finalAttrs: {
  pname = "MoltenVK";
  version = "1.1.9";

  buildInputs = [
    AppKit
    Foundation
    Metal
    QuartzCore
  ];

  outputs = [ "out" "bin" "dev" ];

  # MoltenVK requires specific versions of its dependencies.
  # Pin them here except for cereal, which is four years old and has several CVEs.
  passthru = {
    glslang = (glslang.overrideAttrs (old: {
      src = fetchFromGitHub {
        owner = "KhronosGroup";
        repo = "glslang";
        rev = "9bb8cfffb0eed010e07132282c41d73064a7a609";
        hash = "sha256-YLn/Mxuk6mXPGtBBgfwky5Nl1TCAW6i2g+AZLzqVz+A=";
      };
    })).override {
      inherit (finalAttrs.passthru) spirv-headers spirv-tools;
    };
    spirv-cross = spirv-cross.overrideAttrs (old: {
      cmakeFlags = (old.cmakeFlags or [ ]) ++ [
        "-DSPIRV_CROSS_NAMESPACE_OVERRIDE=MVK_spirv_cross"
      ];
      src = fetchFromGitHub {
        owner = "KhronosGroup";
        repo = "SPIRV-Cross";
        rev = "0d4ce028bf8b8a94d325dc1e1c20446153ba19c4";
        hash = "sha256-OluTxOEfDIGMdrXhvIifjpMgZBvyh9ofLKxKt0dX5ZU=";
      };
    });
    spirv-headers = spirv-headers.overrideAttrs (_: {
      src = fetchFromGitHub {
        owner = "KhronosGroup";
        repo = "spirv-headers";
        rev = "4995a2f2723c401eb0ea3e10c81298906bf1422b";
        hash = "sha256-LkIrTFWYvZffLVJJW3152um5LTEsMJEDEsIhBAdhBlk=";
      };
    });
    spirv-tools = (spirv-tools.overrideAttrs (old: {
      src = fetchFromGitHub {
        owner = "KhronosGroup";
        repo = "spirv-tools";
        rev = "eed5c76a57bb965f2e1b56d1dc40b50910b5ec1d";
        hash = "sha256-2Mr3HbhRslLpRfwHascl7e/UoPijhrij9Bjg3aCiqBM=";
      };
    })).override {
      inherit (finalAttrs.passthru) spirv-headers;
    };
    vulkan-headers = vulkan-headers.overrideAttrs (old: {
      src = fetchFromGitHub {
        owner = "KhronosGroup";
        repo = "Vulkan-Headers";
        rev = "76f00ef6cbb1886eb1162d1fa39bee8b51e22ee8";
        hash = "sha256-FqrcFHsUS8e4ZgZpxVc8nNZWdNltniFmMjyyWVoNc7w=";
      };
    });
  };

  src = fetchFromGitHub {
    owner = "KhronosGroup";
    repo = "MoltenVK";
    rev = "v${finalAttrs.version}";
    hash = "sha256-5ie1IGzZqaYbciFnrBJ1/9V0LEuz7JsEOFXXkG3hJzg=";
  };

  patches = [
    # Specify the libraries to link directly since XCFrameworks are not being used.
    ./createDylib.patch
    # Move `mvkGitRevDerived.h` to a stable location
    ./gitRevHeaderStability.patch
    # Fix the Xcode projects to play nicely with `xcbuild`.
    ./MoltenVKShaderConverter.xcodeproj.patch
    ./MoltenVK.xcodeproj.patch
  ];

  postPatch = ''
    substituteInPlace MoltenVKShaderConverter/MoltenVKShaderConverter.xcodeproj/project.pbxproj \
      --replace @@sourceRoot@@ $(pwd) \
      --replace @@libcxx@@ "${libcxx.dev}" \
      --replace @@glslang@@ "${finalAttrs.passthru.glslang}" \
      --replace @@spirv-cross@@ "${finalAttrs.passthru.spirv-cross}" \
      --replace @@spirv-tools@@ "${finalAttrs.passthru.glslang.spirv-tools}" \
      --replace @@spirv-headers@@ "${finalAttrs.passthru.glslang.spirv-headers}"
    substituteInPlace MoltenVK/MoltenVK.xcodeproj/project.pbxproj \
      --replace @@sourceRoot@@ $(pwd) \
      --replace @@libcxx@@ "${libcxx.dev}" \
      --replace @@cereal@@ "${cereal}" \
      --replace @@spirv-cross@@ "${finalAttrs.passthru.spirv-cross}" \
      --replace @@vulkan-headers@@ "${finalAttrs.passthru.vulkan-headers}"
    substituteInPlace Scripts/create_dylib.sh \
      --replace @@sourceRoot@@ $(pwd) \
      --replace @@glslang@@ "${finalAttrs.passthru.glslang}" \
      --replace @@spirv-tools@@ "${finalAttrs.passthru.glslang.spirv-tools}" \
      --replace @@spirv-cross@@ "${finalAttrs.passthru.spirv-cross}"
    substituteInPlace Scripts/gen_moltenvk_rev_hdr.sh \
      --replace @@sourceRoot@@ $(pwd) \
      --replace '$(git rev-parse HEAD)' ${finalAttrs.src.rev}
  '';

  dontConfigure = true;

  buildPhase = ''
    # Build each project on its own because `xcbuild` fails to build `MoltenVKPackaging.xcodeproj`.
    derived_data_path=$(pwd)/DerivedData
    pushd MoltenVKShaderConverter
      /usr/bin/xcodebuild build \
        -jobs $NIX_BUILD_CORES \
        -derivedDataPath "$derived_data_path" \
        -configuration Release \
        -project MoltenVKShaderConverter.xcodeproj \
        -scheme MoltenVKShaderConverter \
        -arch ${stdenv.targetPlatform.darwinArch}
    popd
    mkdir -p outputs/bin outputs/lib
    declare -A outputs=( [MoltenVKShaderConverter]=bin [libMoltenVKShaderConverter.a]=lib )
    for output in "''${!outputs[@]}"; do
      cp DerivedData/Build/Products/Release/$output "outputs/''${outputs[$output]}/$output"
    done

    pushd MoltenVK
      /usr/bin/xcodebuild build \
        -jobs $NIX_BUILD_CORES \
        -derivedDataPath "$derived_data_path" \
        -configuration Release \
        -project MoltenVK.xcodeproj \
        -scheme MoltenVK-macOS \
        -arch ${stdenv.targetPlatform.darwinArch}
    popd
    cp DerivedData/Build/Products/Release/dynamic/libMoltenVK.dylib outputs/lib/libMoltenVK.dylib
  '';

  installPhase = ''
    mkdir -p "$out/lib" "$out/share/vulkan/icd.d" "$bin/bin" "$dev/include/MoltenVK"
    cp outputs/bin/MoltenVKShaderConverter "$bin/bin/"
    cp outputs/lib/libMoltenVK.dylib "$out/lib/"
    cp MoltenVK/MoltenVK/API/* "$dev/include/MoltenVK"
    ${cctools}/bin/install_name_tool -id "$out/lib/libMoltenVK.dylib" "$out/lib/libMoltenVK.dylib"
    # FIXME: https://github.com/NixOS/nixpkgs/issues/148189
    /usr/bin/codesign -s - -f "$out/lib/libMoltenVK.dylib"
    install -m644 MoltenVK/icd/MoltenVK_icd.json "$out/share/vulkan/icd.d/MoltenVK_icd.json"
    substituteInPlace $out/share/vulkan/icd.d/MoltenVK_icd.json \
      --replace ./libMoltenVK.dylib "$out/lib/libMoltenVK.dylib"
  '';

  sandboxProfile = ''
    (allow file-read* file-write* process-exec mach-lookup)
    ; block homebrew dependencies
    (deny file-read* file-write* process-exec mach-lookup (subpath "/usr/local") (with no-log))
  '';

  meta = {
    description = "A Vulkan Portability implementation built on top of Apple’s Metal API";
    homepage = "https://github.com/KhronosGroup/MoltenVK";
    changelog = "https://github.com/KhronosGroup/MoltenVK/releases";
    maintainers = [ lib.maintainers.reckenrode ];
    hydraPlatforms = [ ]; # Prevent building on Hydra until MoltenVK no longer requires Xcode.
    license = lib.licenses.asl20;
    platforms = lib.platforms.darwin;
  };
})