setup_cross_compile.sh

#!/bin/bash
set -e

# 1. Install xwin if needed (Handled by Nix now)
# if ! command -v xwin &> /dev/null; then
#     echo "xwin not found, installing via cargo..."
#     cargo install xwin
#     export PATH="$HOME/.cargo/bin:$PATH"
# fi

# 2. Download MSVC headers
echo "Downloading MSVC headers to .xwin-cache..."
mkdir -p .xwin-cache
xwin --accept-license splat --output .xwin-cache

# 3. Create Toolchain file
echo "Creating toolchain.cmake..."
cat > toolchain.cmake <<EOF
set(CMAKE_SYSTEM_NAME Windows)
set(CMAKE_SYSTEM_PROCESSOR x86_64)

# Use absolute path to unwrapped compiler from Nix
set(CMAKE_C_COMPILER "${CLANG_CL_UNWRAPPED_BIN}")
set(CMAKE_CXX_COMPILER "${CLANG_CL_UNWRAPPED_BIN}")
set(CMAKE_RC_COMPILER llvm-rc)
set(CMAKE_MT llvm-mt)
set(CMAKE_LINKER lld-link)

# Fix for target architecture
set(TRIPLE_FLAGS "--target=x86_64-pc-windows-msvc")

# Disable PIC flag which causes errors on Windows target
set(CMAKE_C_COMPILE_OPTIONS_PIC "")
set(CMAKE_CXX_COMPILE_OPTIONS_PIC "")

# Configure ASM_MASM to use llvm-ml
set(CMAKE_ASM_MASM_COMPILER llvm-ml)
set(CMAKE_ASM_MASM_FLAGS "-m64")

# Point to xwin cache
set(XWIN_CACHE "\${CMAKE_CURRENT_LIST_DIR}/.xwin-cache")

set(XWIN_INCLUDE_FLAGS
    "/imsvc\${XWIN_CACHE}/crt/include"
    "/imsvc\${XWIN_CACHE}/sdk/include/ucrt"
    "/imsvc\${XWIN_CACHE}/sdk/include/shared"
    "/imsvc\${XWIN_CACHE}/sdk/include/um"
    "/imsvc\${XWIN_CACHE}/sdk/include/winrt"
)

set(XWIN_LIB_FLAGS
    "/libpath:\${XWIN_CACHE}/crt/lib/x86_64"
    "/libpath:\${XWIN_CACHE}/sdk/lib/ucrt/x86_64"
    "/libpath:\${XWIN_CACHE}/sdk/lib/um/x86_64"
)

# Apply flags
string(REPLACE ";" " " XWIN_INCLUDE_FLAGS_STR "\${XWIN_INCLUDE_FLAGS}")
string(REPLACE ";" " " XWIN_LIB_FLAGS_STR "\${XWIN_LIB_FLAGS}")

# Force Release Runtime (DLL) globally to bypass missing Debug CRT
set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreadedDLL")
set(CMAKE_C_FLAGS_DEBUG_INIT "/MD /Zi /Ob0 /Od /RTC1")
set(CMAKE_CXX_FLAGS_DEBUG_INIT "/MD /Zi /Ob0 /Od /RTC1")
set(CMAKE_C_FLAGS_RELEASE_INIT "/MD /Zi /O2 /Ob2 /DNDEBUG")
set(CMAKE_CXX_FLAGS_RELEASE_INIT "/MD /Zi /O2 /Ob2 /DNDEBUG")

set(CMAKE_C_FLAGS "\${CMAKE_C_FLAGS} \${XWIN_INCLUDE_FLAGS_STR} \${TRIPLE_FLAGS} -Wno-unused-command-line-argument -fuse-ld=lld /EHsc /DPLATFORM_WINDOWS /DPLATFORM_MICROSOFT /DUBT_COMPILED_PLATFORM=Win64 /DOVERRIDE_PLATFORM_HEADER_NAME=Windows /DUE_BUILD_SHIPPING=1")
set(CMAKE_CXX_FLAGS "\${CMAKE_CXX_FLAGS} \${XWIN_INCLUDE_FLAGS_STR} \${TRIPLE_FLAGS} -Wno-unused-command-line-argument -fuse-ld=lld /EHsc /DPLATFORM_WINDOWS /DPLATFORM_MICROSOFT /DUBT_COMPILED_PLATFORM=Win64 /DOVERRIDE_PLATFORM_HEADER_NAME=Windows /DUE_BUILD_SHIPPING=1")

# Generate PDB debug symbols for crash-dump analysis
set(CMAKE_EXE_LINKER_FLAGS "\${CMAKE_EXE_LINKER_FLAGS} \${XWIN_LIB_FLAGS_STR} /DEBUG:FULL")
set(CMAKE_SHARED_LINKER_FLAGS "\${CMAKE_SHARED_LINKER_FLAGS} \${XWIN_LIB_FLAGS_STR} /DEBUG:FULL")
set(CMAKE_MODULE_LINKER_FLAGS "\${CMAKE_MODULE_LINKER_FLAGS} \${XWIN_LIB_FLAGS_STR} /DEBUG:FULL")

# RC Flags
set(CMAKE_RC_FLAGS "\${CMAKE_RC_FLAGS} \${XWIN_INCLUDE_FLAGS_STR} \${TRIPLE_FLAGS} -Wno-unused-command-line-argument")

# Fix for checking compiler
set(CMAKE_TRY_COMPILE_TARGET_TYPE_STATIC_LIBRARY ON)

EOF

echo "Toolchain created at toolchain.cmake"

# 4. Run CMake
BUILD_TYPE="${BUILD_TYPE:-Game__Shipping__Win64}"
BUILD_DIR="${BUILD_DIR:-build-cross}"
echo "Running CMake with build type: $BUILD_TYPE (build dir: $BUILD_DIR)"

# Build CMake args
CMAKE_ARGS=(
    -B "$BUILD_DIR"
    -G Ninja
    -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake
    -DCMAKE_BUILD_TYPE="$BUILD_TYPE"
)

# Add proxy path if specified (default: dwmapi.dll)
if [ -n "${UE4SS_PROXY_PATH:-}" ]; then
    echo "Using custom proxy path: $UE4SS_PROXY_PATH"
    CMAKE_ARGS+=(-DUE4SS_PROXY_PATH="$UE4SS_PROXY_PATH")
fi

# Add UE4SS source dir if specified (for Nix flake input)
if [ -n "${UE4SS_SOURCE_DIR:-}" ]; then
    echo "Using UE4SS source from: $UE4SS_SOURCE_DIR"
    CMAKE_ARGS+=(-DUE4SS_SOURCE_DIR="$UE4SS_SOURCE_DIR")
fi

# Set XWIN_DIR for UE4SS's internal toolchain (requires absolute path)
XWIN_DIR="$(pwd)/.xwin-cache"
export XWIN_DIR

cmake "${CMAKE_ARGS[@]}" .

echo "Build configuration done. Run 'cmake --build $BUILD_DIR' to compile."