#!/usr/bin/env bash

set -euo pipefail

umask 022

export LC_ALL="POSIX"

export TARGET="x86_64-axe-linux-gnu"

export MAKEFLAGS="-j$(nproc)"

export SYSROOT="$PWD/sysroot"

export PROJDIR="$PWD"

export SOURCES="$SYSROOT/sources"

export CROSS="$SYSROOT/cross"

export PATH="$CROSS/bin:/usr/bin:/usr/sbin"

export CONFIG_SITE="$SYSROOT/usr/share/config.site"

BINUTILS_VERSION=2.45.1
BINUTILS_URL=https://mirror.ufs.ac.za/gnu/binutils/binutils-$BINUTILS_VERSION.tar.xz

GCC_VERSION=15.2.0
GCC_URL=https://mirror.ufs.ac.za/gnu/gcc/gcc-$GCC_VERSION/gcc-$GCC_VERSION.tar.xz

GMP_VERSION=6.3.0
GMP_URL=https://mirror.ufs.ac.za/gnu/gmp/gmp-$GMP_VERSION.tar.xz

MPC_VERSION=1.3.1
MPC_URL=https://mirror.ufs.ac.za/gnu/mpc/mpc-$MPC_VERSION.tar.gz

MPFR_VERSION=4.2.2
MPFR_URL=https://mirror.ufs.ac.za/gnu/mpfr/mpfr-$MPFR_VERSION.tar.xz

ISL_VERSION=0.27
ISL_URL=https://libisl.sourceforge.io/isl-$ISL_VERSION.tar.xz

GLIBC_VERSION=2.43
GLIBC_URL=https://mirror.ufs.ac.za/gnu/glibc/glibc-$GLIBC_VERSION.tar.xz

LINUX_VERSION=6.18.7
IFS='.' read -r LINUX_VERSION_MAJOR LINUX_VERSION_MINOR LINUX_VERSION_PATCH <<< $LINUX_VERSION
LINUX_URL=https://cdn.kernel.org/pub/linux/kernel/v$LINUX_VERSION_MAJOR.x/linux-$LINUX_VERSION.tar.xz


if [ ! -d "$SYSROOT" ]; then
    mkdir -p "$SYSROOT"/{etc,cross,sources,usr,dev,proc,sys,run}
	mkdir -p "$SYSROOT"/usr/{bin,sbin,lib,include}

	for directory in bin sbin lib; do
		ln -fs "usr/$directory" "$SYSROOT/$directory"
	done
fi

fetch() {
    wget -N -c --show-progress -q -P "$SOURCES" $1
}


bootstrap_binutils() {
    fetch $BINUTILS_URL

    cd "$SOURCES" && tar xf binutils-$BINUTILS_VERSION.tar.xz && cd binutils-$BINUTILS_VERSION

    mkdir -p build && cd build

	../configure \
		--prefix="$CROSS" \
		--with-sysroot="$SYSROOT" \
		--target=$TARGET \
		--disable-nls \
		--enable-gprofng=no \
		--disable-werror \
		--enable-new-dtags \
		--enable-default-hash-style=gnu
	
	make && make install

    cd "$SOURCES"
    rm -rf binutils-$BINUTILS_VERSION
}

bootstap_gcc() {
    fetch $GCC_URL
    fetch $GMP_URL
    fetch $ISL_URL
    fetch $MPC_URL
    fetch $MPFR_URL

    cd "$SOURCES" && tar xf gcc-$GCC_VERSION.tar.xz && cd gcc-$GCC_VERSION

    tar xf ../gmp-$GMP_VERSION.tar.xz && mv gmp-$GMP_VERSION gmp
	tar xf ../isl-$ISL_VERSION.tar.xz && mv isl-$ISL_VERSION isl
	tar xf ../mpc-$MPC_VERSION.tar.gz && mv mpc-$MPC_VERSION mpc
	tar xf ../mpfr-$MPFR_VERSION.tar.xz && mv mpfr-$MPFR_VERSION mpfr

	sed -e '/m64=/s/lib64/lib/' -i.orig gcc/config/i386/t-linux64

	mkdir -p build && cd build

	../configure \
		--target=$TARGET \
		--prefix="$CROSS" \
		--with-glibc-version=$GLIBC_VERSION \
		--with-sysroot="$SYSROOT" \
		--with-newlib \
		--without-headers \
		--enable-default-pie \
		--enable-default-ssp \
		--disable-nls \
		--disable-shared \
		--disable-multilib \
		--disable-threads \
		--disable-libatomic \
		--disable-libgomp \
		--disable-libquadmath \
		--disable-libssp \
		--disable-libvtv \
		--disable-libstdcxx \
		--enable-languages=c,c++

	make && make install

	cd ..
	cat gcc/limitx.h gcc/glimits.h gcc/limity.h > "`dirname $($TARGET-gcc -print-libgcc-file-name)`/include/limits.h"

    cd "$SOURCES" && rm -rf gcc-$GCC_VERSION
}

bootstap_linux() {
    fetch $LINUX_URL

    cd "$SOURCES" && tar xf linux-$LINUX_VERSION.tar.xz && cd linux-$LINUX_VERSION

    make mrproper
    make headers
    find usr/include -type f ! -name '*.h' -delete
    cp -r usr/include "$SYSROOT"/usr

    cd "$SOURCES" && rm -rf linux-$LINUX_VERSION
}

bootstap_glibc() {
    fetch $GLIBC_URL
    fetch https://www.linuxfromscratch.org/patches/lfs/development/glibc-fhs-1.patch

    cd "$SOURCES" && tar xf glibc-$GLIBC_VERSION.tar.xz && cd glibc-$GLIBC_VERSION

    ln -sf ld-linux-x86-64.so.2 "$SYSROOT"/lib/ld-lsb-x86-64.so.3

	patch -Np1 -i "$SOURCES"/glibc-fhs-1.patch

	mkdir -p build && cd build

	echo "rootsbindir=/usr/sbin" > configparms

	../configure \
		--prefix=/usr \
		--host=$TARGET \
		--build=$(../scripts/config.guess) \
		--disable-nscd \
        --disable-nls \
		libc_cv_slibdir=/usr/lib \
		--enable-kernel=$LINUX_VERSION

	make && make DESTDIR="$SYSROOT" install

	sed '/RTLDLIST=/s@/usr@@g' -i "$SYSROOT"/usr/bin/ldd

    cd "$SOURCES" && rm -rf gcc-$GLIBC_VERSION
}

#bootstrap_binutils
#bootstap_gcc
#bootstap_linux
bootstap_glibc