#!/bin/sh
#SPDX-License-Identifier: LGPL-3.0-only
#SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®

# Bootstrap: compile crafter-build by hand, without crafter-build. The
# self-host build through project.cpp follows (`./bin/crafter-build`).
set -eu

# The toolchain. CRAFTER_BUILD_LLVM_DIR names an LLVM prefix (the Flatpak
# sets /app); otherwise the tools come from PATH. The same rule the built
# binary applies at run time (Crafter.Build:Toolchain).
if [ -n "${CRAFTER_BUILD_LLVM_DIR:-}" ]; then
    CXX="$CRAFTER_BUILD_LLVM_DIR/bin/clang++"
    CC="$CRAFTER_BUILD_LLVM_DIR/bin/clang"
    AR="$CRAFTER_BUILD_LLVM_DIR/bin/llvm-ar"
    LLVM_CONFIG="$CRAFTER_BUILD_LLVM_DIR/bin/llvm-config"
    # A prefix other than the system one keeps its libc++ off both the
    # linker's search path (clang looks in lib/<triple> and the system dirs,
    # not <prefix>/lib) and the loader's; -L and an rpath cover the two.
    if [ "$CRAFTER_BUILD_LLVM_DIR" != /usr ]; then
        LIBCXX_LINK_FLAGS="-L$CRAFTER_BUILD_LLVM_DIR/lib -Wl,-rpath,$CRAFTER_BUILD_LLVM_DIR/lib"
    else
        LIBCXX_LINK_FLAGS=""
    fi
    if [ -f "$CRAFTER_BUILD_LLVM_DIR/share/libc++/v1/std.cppm" ]; then
        STD_CPPM="$CRAFTER_BUILD_LLVM_DIR/share/libc++/v1/std.cppm"
    else
        STD_CPPM=/usr/share/libc++/v1/std.cppm
    fi
else
    CXX=clang++
    CC=clang
    AR=llvm-ar
    LLVM_CONFIG=llvm-config
    LIBCXX_LINK_FLAGS=""
    STD_CPPM=/usr/share/libc++/v1/std.cppm
fi

# The version baked into the binary: the environment (CI sets it from the
# tag), else the nearest tag, else a development marker. `latest` is the
# rolling CI tag and never a version.
VERSION="${CRAFTER_BUILD_VERSION:-$(git describe --tags --always --dirty --exclude=latest 2>/dev/null || echo 0.0.0-dev)}"

mkdir -p build bin lib share/crafter-build share/crafter-build/wasi-runtime

cp wasi-runtime/runtime.js share/crafter-build/wasi-runtime/
cp wasi-runtime/index.html.in share/crafter-build/wasi-runtime/

# Partition order is the import order: every unit is listed before the
# units that import it, and the umbrella last.
PARTITIONS="Toolchain Shader Platform Interface Implementation External Clang Test Lint Progress Asset"

cp interfaces/Crafter.Build.cppm share/crafter-build/
for p in $PARTITIONS; do
    cp "interfaces/Crafter.Build-$p.cppm" share/crafter-build/
done

if [ ! -d build/glslang/.git ]; then
    git clone --depth 1 https://github.com/KhronosGroup/glslang.git build/glslang
fi

current_dir=$(pwd)

cd build/glslang
cmake -B build \
  -DCMAKE_C_COMPILER="$CC" \
  -DCMAKE_CXX_COMPILER="$CXX" \
  -DCMAKE_CXX_FLAGS="-stdlib=libc++" \
  -DCMAKE_EXE_LINKER_FLAGS="-stdlib=libc++ $LIBCXX_LINK_FLAGS" \
  -DCMAKE_SHARED_LINKER_FLAGS="-stdlib=libc++ $LIBCXX_LINK_FLAGS" \
  -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_ARCHIVE_OUTPUT_DIRECTORY="$current_dir/build" \
  -DCMAKE_LIBRARY_OUTPUT_DIRECTORY="$current_dir/build" \
  -DENABLE_OPT=OFF
cmake --build build --config Release
cd ../../

MARCH="${CRAFTER_BUILD_MARCH:-native}"
MTUNE="${CRAFTER_BUILD_MTUNE:-native}"
# The bootstrap targets the toolchain's own triple: x86_64-pc-linux-gnu on
# glibc distros, x86_64-unknown-linux-gnu for the bundled LLVM,
# x86_64-alpine-linux-musl on Alpine. Override with CRAFTER_BUILD_TARGET.
TARGET="${CRAFTER_BUILD_TARGET:-$("$CXX" -print-target-triple)}"
TARGET_DEFINE="CRAFTER_BUILD_CONFIGURATION_TARGET_$(printf '%s' "$TARGET" | tr - _)"

# Crafter.Build-Lint includes libclang's clang-c/Index.h. glibc distros keep
# it in /usr/include; other prefixes keep it under their own include dir, so
# ask llvm-config and add the dir when it is not already on the default path
# (never add /usr/include itself: that breaks libc++'s #include_next).
LLVM_INCDIR="$("$LLVM_CONFIG" --includedir 2>/dev/null || true)"
case "$LLVM_INCDIR" in ""|/usr/include) LLVM_INCFLAG="" ;; *) LLVM_INCFLAG="-I$LLVM_INCDIR" ;; esac

common_options="--target=$TARGET -stdlib=libc++ -I./build/glslang $LLVM_INCFLAG -std=c++26 -O3 -march=$MARCH -mtune=$MTUNE -fprebuilt-module-path=./build -D $TARGET_DEFINE -D CRAFTER_BUILD_CONFIGURATION_TYPE_EXECUTABLE -D CRAFTER_BUILD_VERSION=\"$VERSION\" -c"

"$CXX" --target="$TARGET" -std=c++26 -stdlib=libc++ -O3 -march="$MARCH" -mtune="$MTUNE" -Wno-reserved-identifier -Wno-reserved-module-identifier --precompile "$STD_CPPM" -o ./build/std.pcm

# Asset partition: bootstrap compiles it WITHOUT CRAFTER_BUILD_HAS_ASSET so
# CompressAsset takes the stub branch and the impl unit doesn't try to
# `import Crafter.Asset` (no Crafter.Asset PCM exists at this stage — the
# self-host pass that follows wires in the real dep).
OBJECTS=""
for p in $PARTITIONS; do
    "$CXX" $common_options -fmodule-output "interfaces/Crafter.Build-$p.cppm" -o "./build/Crafter.Build-$p.o"
    OBJECTS="$OBJECTS ./build/Crafter.Build-$p.o"
done
"$CXX" $common_options -fmodule-output interfaces/Crafter.Build.cppm -o ./build/Crafter.Build.o
OBJECTS="$OBJECTS ./build/Crafter.Build.o"

for p in $PARTITIONS; do
    "$CXX" $common_options "./implementations/Crafter.Build-$p.cpp" -o "./build/Crafter.Build-${p}_impl.o"
    OBJECTS="$OBJECTS ./build/Crafter.Build-${p}_impl.o"
done
"$CXX" $common_options ./implementations/main.cpp -o ./build/main.o

# A fresh archive each time: `ar rcs` into an existing one keeps members a
# previous layout left behind.
rm -f ./lib/libcrafter-build.a
"$AR" rcs ./lib/libcrafter-build.a $OBJECTS

"$CXX" --target="$TARGET" -std=c++26 -stdlib=libc++ -O3 -march="$MARCH" -mtune="$MTUNE" -fuse-ld=lld \
    -Wl,--export-dynamic $LIBCXX_LINK_FLAGS \
    -L./build \
    $OBJECTS \
    ./build/main.o \
    -lSPIRV -lGenericCodeGen -lglslang -lOSDependent -lMachineIndependent -lglslang-default-resource-limits \
    -ldl \
    -o ./bin/crafter-build