# Red Bear OS — GRUB Boot Manager
#
# Builds GRUB for the HOST machine (not the Redox target).
# GRUB is a build tool that produces standalone EFI binaries.
# The resulting grub.efi chainloads the Redox bootloader.
#
# Output: /usr/lib/boot/grub.efi, /usr/lib/boot/grub.cfg
# Required local source: ../grub-redoxfs/src/{redoxfs.c,redoxfs.h,seahash.c}
#
# Build: make r.grub
# Install into image (Phase 1):  ./local/scripts/install-grub.sh build/x86_64/harddrive.img
# Install into image (Phase 2):  make all CONFIG_NAME=redbear-full-grub
#
# Requires: gcc, make, bison, flex, autoconf, automake on host

[source]
tar = "https://ftp.gnu.org/gnu/grub/grub-2.12.tar.xz"
blake3 = "13c48453f9becf4a6e49618749dc7cb83a2c4a0d7600eeeadc6c7c2772c0b877"

[build]
template = "custom"
script = """
# GRUB must be built for the HOST machine, not the Redox target.
# It is a build tool that produces EFI binaries for bare-metal boot.
# Override cookbook cross-compilation environment.

# Force HOST compiler — cookbook sets CC to Redox cross-compiler.
# GRUB is a host build tool, not a Redox binary.
unset CC CXX CPP LD AR NM RANLIB OBJCOPY STRIP PKG_CONFIG
unset CFLAGS CXXFLAGS CPPFLAGS LDFLAGS

# Verify host tools are available before starting the build.
for tool in gcc make bison flex; do
    if ! command -v "${tool}" &>/dev/null; then
        echo "ERROR: Required host tool '${tool}' not found" >&2
        exit 1
    fi
done

# We patch Makefile.core.def for local RedoxFS support. Regenerate autotools
# files once to avoid version-skew failures in incremental rebuild rules.
for tool in autoreconf automake aclocal autoconf; do
    if ! command -v "${tool}" &>/dev/null; then
        echo "ERROR: Required host autotools component '${tool}' not found" >&2
        exit 1
    fi
done

# Out-of-tree build (GRUB requires this for some configurations)
mkdir -p "${COOKBOOK_BUILD}/grub-build" || exit 1
cd "${COOKBOOK_BUILD}/grub-build" || exit 1

# GRUB release tarballs miss extra_deps.lst (normally generated by autogen.sh)
touch "${COOKBOOK_SOURCE}/grub-core/extra_deps.lst" || exit 1

# Inject local RedoxFS GRUB module source from sibling tree: ../grub-redoxfs
RBOS_ROOT="$(cd "${COOKBOOK_RECIPE}/../../../.." && pwd)"
GRUB_REDOXFS_ROOT="${RBOS_ROOT}/../grub-redoxfs"
GRUB_REDOXFS_SRC="${GRUB_REDOXFS_ROOT}/src"

for f in redoxfs.c redoxfs.h seahash.c; do
    if [ ! -f "${GRUB_REDOXFS_SRC}/${f}" ]; then
        echo "ERROR: missing ${GRUB_REDOXFS_SRC}/${f}" >&2
        echo "grub-redoxfs source tree must exist at: ${GRUB_REDOXFS_ROOT}" >&2
        exit 1
    fi
done

cp "${GRUB_REDOXFS_SRC}/redoxfs.c" "${COOKBOOK_SOURCE}/grub-core/fs/redoxfs.c"
cp "${GRUB_REDOXFS_SRC}/seahash.c" "${COOKBOOK_SOURCE}/grub-core/fs/seahash.c"
cp "${GRUB_REDOXFS_SRC}/redoxfs.h" "${COOKBOOK_SOURCE}/grub-core/fs/redoxfs.h"
mkdir -p "${COOKBOOK_SOURCE}/include/grub"
cp "${GRUB_REDOXFS_SRC}/redoxfs.h" "${COOKBOOK_SOURCE}/include/grub/redoxfs.h"
echo "Injected GRUB RedoxFS sources from ${GRUB_REDOXFS_SRC}"

MAKEFILE_CORE_DEF="${COOKBOOK_SOURCE}/grub-core/Makefile.core.def"
if ! grep -q "name = redoxfs;" "${MAKEFILE_CORE_DEF}"; then
    cat >> "${MAKEFILE_CORE_DEF}" <<'EOF'

module = {
  name = redoxfs;
  common = fs/redoxfs.c;
  cflags = '-DGRUB_BUILD';
};
EOF
    echo "Registered redoxfs module in Makefile.core.def"
fi

(
    cd "${COOKBOOK_SOURCE}"
    autoreconf -fiv
)

# Configure for host, targeting x86_64 EFI platform output.
# --target=x86_64 means "produce boot images for x86_64"
# --with-platform=efi means "EFI platform output"
# We intentionally do NOT set --host (it should be the build machine).
echo "Configuring GRUB for x86_64 EFI..."
"${COOKBOOK_SOURCE}/configure" \
    --target=x86_64 \
    --with-platform=efi \
    --disable-werror \
    --disable-nls \
    --disable-grub-mkfont \
    --disable-grub-themes \
    --disable-grub-mount \
    --disable-device-mapper \
    --disable-libzfs \
    --prefix="${COOKBOOK_STAGE}/usr" || exit 1

echo "Building GRUB..."
make -j "${COOKBOOK_MAKE_JOBS}" || exit 1

# Create output directory
mkdir -p "${COOKBOOK_STAGE}/usr/lib/boot"

# Locate GRUB modules directory.
# In an out-of-tree build, modules are in grub-core/ under the build dir.
MOD_DIR=""
for d in grub-core .; do
    if [ -f "${d}/part_gpt.mod" ]; then
        MOD_DIR="${d}"
        break
    fi
done

if [ -z "${MOD_DIR}" ]; then
    echo "ERROR: Cannot find GRUB modules directory" >&2
    echo "Looked in: grub-core/ ." >&2
    find . -name "part_gpt.mod" 2>/dev/null || true
    exit 1
fi

echo "Found GRUB modules in: ${MOD_DIR}"

# Build standalone EFI image with a broad module set.
# -O x86_64-efi: output format
# -d MOD_DIR: module search directory
# -p /EFI/BOOT: prefix for GRUB config search path
# The resulting image is self-contained (no external module files needed).

has_mod() {
    local name="$1"
    [ -f "${MOD_DIR}/${name}.mod" ]
}

add_mod() {
    local name="$1"
    if has_mod "${name}"; then
        SELECTED_MODULES+=("${name}")
    else
        echo "WARN: GRUB module not found, skipping: ${name}" >&2
    fi
}

# Keep this list broad for first-class multi-filesystem support.
# Missing modules are skipped with a warning so builds stay resilient.
SELECTED_MODULES=()
for m in \
    part_gpt part_msdos \
    normal configfile search search_fs_uuid search_label \
    echo test ls cat halt reboot chain \
    fat ext2 btrfs xfs jfs reiserfs udf iso9660 ntfs ntfscomp hfs hfsplus zfs \
    gzio xzio lzopio lzma; do
    add_mod "${m}"
done

if has_mod "redoxfs"; then
    SELECTED_MODULES+=("redoxfs")
else
    echo "ERROR: redoxfs.mod was not produced by GRUB build" >&2
    echo "Expected at: ${MOD_DIR}/redoxfs.mod" >&2
    exit 1
fi

if [ "${#SELECTED_MODULES[@]}" -eq 0 ]; then
    echo "ERROR: No GRUB modules selected for grub-mkimage" >&2
    exit 1
fi

echo "Creating standalone GRUB EFI image..."
./grub-mkimage \
    -O x86_64-efi \
    -d "${MOD_DIR}" \
    -o "${COOKBOOK_STAGE}/usr/lib/boot/grub.efi" \
    -p /EFI/BOOT \
    "${SELECTED_MODULES[@]}" || exit 1

# Verify output
if [ ! -f "${COOKBOOK_STAGE}/usr/lib/boot/grub.efi" ]; then
    echo "ERROR: grub.efi was not created" >&2
    exit 1
fi

GRUB_SIZE=$(stat -c%s "${COOKBOOK_STAGE}/usr/lib/boot/grub.efi" 2>/dev/null || echo "unknown")
echo "GRUB EFI image size: ${GRUB_SIZE} bytes"

# Copy default GRUB configuration from recipe directory.
# grub.cfg lives alongside recipe.toml, not in the extracted source tarball.
if [ -f "${COOKBOOK_RECIPE}/grub.cfg" ]; then
    cp "${COOKBOOK_RECIPE}/grub.cfg" "${COOKBOOK_STAGE}/usr/lib/boot/grub.cfg"
    echo "Installed grub.cfg"
else
    echo "ERROR: grub.cfg not found in ${COOKBOOK_RECIPE}" >&2
    echo "The grub.cfg file must exist alongside recipe.toml." >&2
    exit 1
fi

echo "GRUB recipe complete."
echo "Install with: ./local/scripts/install-grub.sh build/x86_64/harddrive.img"
"""