{
  description = "polymodel: AT Protocol-native model/project sharing app built with Rust/Dioxus/Jacquard";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    rust-overlay.url = "github:oxalica/rust-overlay";
    # Use nixpkgs dioxus-cli; do not import the upstream Dioxus flake because it may be ahead of Cargo.toml.



  };

  outputs = {
    self,
    nixpkgs,
    flake-utils,
    rust-overlay,

    ...
  }:
    flake-utils.lib.eachDefaultSystem (system: let
      pkgs = import nixpkgs {
        inherit system;
        overlays = [
          (import rust-overlay)



        ];
      };

      rustToolchain = pkgs.rust-bin.selectLatestNightlyWith (toolchain:
        toolchain.default.override {
          targets = ["wasm32-unknown-unknown"];
          extensions = [
            "rust-src"
            "rust-analyzer"
            "clippy"
            "rustfmt"
          ];
        });

      ldparseRev = "0fe78dcee22982f26cceced1b483340faa4d04e9";
      immerRev = "141af37e46a75fce48318b13bf2bf71f51950de8";
      coroutinesRev = "a26a43912319fd2c40823dc96755990da765bc8f";
      ldparse = pkgs.fetchFromGitHub {
        owner = "elfprince13";
        repo = "LDParse";
        rev = ldparseRev;
        sha256 = "04frdxpb6kvrzggvbfq66cb95w7g6lf7yzyqaw3qyqvsnqbyw7r0";
      };
      immerSrc = pkgs.fetchFromGitHub {
        owner = "arximboldi";
        repo = "immer";
        rev = immerRev;
        sha256 = "10drhxqgr6pp4bih9kbcdk0x39gdz8r85zryfydisqq7gwp4ibfz";
      };
      coroutinesSrc = pkgs.fetchFromGitHub {
        owner = "Geopipe";
        repo = "CxxBidirectionalCoroutines";
        rev = coroutinesRev;
        sha256 = "10bdz6l5i1qgniysgm7fmrds76yh9kj59wfv7zk9kzvj76qqkdpq";
      };
      ldrawParts = pkgs.stdenv.mkDerivation {
        pname = "ldraw-parts";
        version = "2026-06";
        src = pkgs.fetchurl {
          url = "https://library.ldraw.org/library/updates/complete.zip";
          sha256 = "sha256-YAny6UIExNOmOkyBIBC1yQutjFrLGbiCyFn9rGNzTq4=";
        };
        nativeBuildInputs = [ pkgs.unzip ];
        unpackPhase = "unzip $src";
        installPhase = ''
          runHook preInstall
          mkdir -p $out
          cp -r ldraw/* $out/
          runHook postInstall
        '';
      };
      ldrawOracle = pkgs.stdenv.mkDerivation {
        pname = "ldraw-oracle";
        version = ldparseRev;
        src = ldparse;
        nativeBuildInputs = [ pkgs.cmake pkgs.pkg-config ];
        buildInputs = [ pkgs.boost pkgs.glm pkgs.fmt ];
        patches = [ ./patches/ldparse-oracle-access.patch ];
        cmakeFlags = [ "-DCMAKE_POLICY_VERSION_MINIMUM=3.5" ];
        postPatch = ''
          test "${ldparseRev}" = "0fe78dcee22982f26cceced1b483340faa4d04e9"
          # Place separately-fetched submodules into deps/
          rm -rf deps/immer deps/CxxBidirectionalCoroutines
          cp -r ${immerSrc} deps/immer
          cp -r ${coroutinesSrc} deps/CxxBidirectionalCoroutines
          # Disable face-unwrapper (not needed for oracle) and fix case mismatch:
          # GitHub archive has ParseTest/ but CMakeLists references lowercase parsetest
          sed -i '/add_subdirectory(face-unwrapper)/d' CMakeLists.txt
          sed -i 's/add_subdirectory(parsetest)/add_subdirectory(ParseTest)/' CMakeLists.txt
          # GCC 15 requires explicit <memory> include for std::unique_ptr in Cache.hpp
          sed -i '1i #include <memory>' include/LDParse/Cache.hpp
          # GCC 15 requires explicit lambda capture for offset in Geom.hpp
          sed -i 's/\[\](uint32_t &index){ index += offset; }/[offset](uint32_t \&index){ index += offset; }/' include/LDParse/Geom.hpp
          cp ${./tools/ldraw-oracle/oracle.cpp} oracle.cpp
          grep -F 'lineCallback.retarget(model);' include/LDParse/ModelBuilder/ModelBuilderDefs.hpp
          grep -F 'optLineCallback.retarget(model);' include/LDParse/ModelBuilder/ModelBuilderDefs.hpp
        '';
        buildPhase = ''
          runHook preBuild
          cmake --build . --parallel "$NIX_BUILD_CORES"
          ldparse_lib=$(find . -type f -name 'libLDParse.so*' -print -quit)
          test -n "$ldparse_lib"
          ldparse_lib_dir=$(dirname "$ldparse_lib")
          c++ -std=c++17 -I../include -I../deps/immer -I../deps/CxxBidirectionalCoroutines/include -I${pkgs.boost.dev}/include -I${pkgs.glm}/include -I${pkgs.fmt.dev}/include ${./tools/ldraw-oracle/oracle.cpp} -L"$ldparse_lib_dir" -Wl,-rpath,"\$$ORIGIN/../lib" -lLDParse -lboost_filesystem -o ldraw-oracle
          runHook postBuild
        '';
        installPhase = ''
          runHook preInstall
          unset LD_LIBRARY_PATH
          mkdir -p "$out/lib" "$out/bin" "$out/share/ldraw-oracle"
          ldparse_lib=$(find . -type f -name 'libLDParse.so*' -print -quit)
          test -n "$ldparse_lib"
          install -m755 "$ldparse_lib" "$out/lib/$(basename "$ldparse_lib")"
          install -m755 ldraw-oracle "$out/bin/ldraw-oracle"
          install -m644 ${./tools/ldraw-oracle/oracle.cpp} "$out/share/ldraw-oracle/oracle.cpp"
          install -m644 ${./patches/ldparse-oracle-access.patch} "$out/share/ldraw-oracle/ldparse-oracle-access.patch"
          cat > "$out/share/ldraw-oracle/provenance.txt" <<EOF
          LDParse revision: ${ldparseRev}
          immer revision: ${immerRev}
          CxxBidirectionalCoroutines revision: ${coroutinesRev}
          Oracle schema: ldraw-oracle-v4
          Oracle wrapper schema: wrapper-v4
          Oracle projection rules: pm-78-oracle-only-v4
          Oracle patch identity: ldparse-oracle-access.patch@pm-78-v2
          EOF
          runHook postInstall
        '';
      };
    in {
      packages.ldraw-parts = ldrawParts;
      packages.ldraw-oracle = ldrawOracle;
      packages.default = ldrawOracle;
      devShells.default = pkgs.mkShell {
        packages = with pkgs; [
          rustToolchain
          rust-analyzer
          cargo-nextest
          cargo-insta
          cargo-bloat
          # Provides the `cargo sqlx` subcommand (package name in nixpkgs is sqlx-cli).
          sqlx-cli

          dioxus-cli
          wasm-bindgen-cli
          wasm-pack
          binaryen.out
          wabt
          twiggy

          llvmPackages_18.clang-unwrapped
          llvmPackages_18.llvm
          llvmPackages_18.libclang
          llvmPackages_18.bintools-unwrapped

          sqlite
          pkg-config
          openssl
          patchelf

          nodejs
          esbuild
          chromium
          chromedriver
          playwright-driver.browsers

          just
          jq
          nixd
          alejandra
        ];

        nativeBuildInputs = with pkgs; [
          llvmPackages_18.clang-unwrapped
          llvmPackages_18.bintools-unwrapped
          rustPlatform.bindgenHook
        ];

        buildInputs = with pkgs;
          [
            sqlite
            pkg-config
            openssl
          ]
          ++ lib.optionals stdenv.isDarwin [
            libiconv
          ];

        RUST_BACKTRACE = "1";
        LDRAWDIR = "${ldrawParts}";
        NIX_LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath [
          pkgs.stdenv.cc.cc
          pkgs.openssl
          pkgs.sqlite
          pkgs.libx11
          pkgs.libxext
          pkgs.libxcursor
          pkgs.libxi
          pkgs.libxrandr
          pkgs.libxrender
          pkgs.libxcb
          pkgs.wayland
          pkgs.libxkbcommon
          pkgs.libGL
          pkgs.libglvnd
          pkgs.mesa
        ];
        NIX_LD = pkgs.lib.fileContents "${pkgs.stdenv.cc}/nix-support/dynamic-linker";

        PLAYWRIGHT_BROWSERS_PATH = "${pkgs.playwright-driver.browsers}";
        PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD = "1";
        PLAYWRIGHT_SKIP_VALIDATE_HOST_REQUIREMENTS = true;
        PLAYWRIGHT_HOST_PLATFORM_OVERRIDE = "ubuntu-24.04";

        shellHook = ''
          export POLYMODEL_NIX_SHELL=1
          export PATH="${pkgs.dioxus-cli}/bin:${pkgs.wasm-bindgen-cli}/bin:$PATH"; export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$NIX_LD_LIBRARY_PATH"
          export CARGO_TARGET_WASM32_UNKNOWN_UNKNOWN_RUNNER="wasm-bindgen-test-runner"
          export CHROME="${pkgs.chromium}/bin/chromium"
          export CC_wasm32_unknown_unknown="${pkgs.llvmPackages_18.clang-unwrapped}/bin/clang"
          export AR_wasm32_unknown_unknown="${pkgs.llvmPackages_18.bintools-unwrapped}/bin/llvm-ar"

          CLANG_MAJOR_VERSION="18"
          CLANG_RESOURCE_DIR="${pkgs.llvmPackages_18.clang-unwrapped}/lib/clang/$CLANG_MAJOR_VERSION"
          LIBCLANG_INCLUDE="${pkgs.llvmPackages_18.libclang.lib}/lib/clang/$CLANG_MAJOR_VERSION/include"

          export LIBCLANG_PATH="${pkgs.llvmPackages_18.libclang.lib}/lib"
          export BINDGEN_EXTRA_CLANG_ARGS="-isystem ${pkgs.glibc.dev}/include -isystem $LIBCLANG_INCLUDE"
          export CFLAGS_wasm32_unknown_unknown="-isystem $LIBCLANG_INCLUDE -resource-dir $CLANG_RESOURCE_DIR"
          export CPPFLAGS="-isystem $LIBCLANG_INCLUDE -resource-dir $CLANG_RESOURCE_DIR"

          echo "polymodel dev shell: Rust + Dioxus + Jacquard + SQLite + Playwright"
        '';
      };
    });
}