#!/bin/bash

set -e

cp README Root/Home
cp CHANGELOG Root/Home
cp LICENSE Root/Docs

#!/bin/sh

ROOT="Root"
KERNEL="Kernel/Startup.AC"
TMP="/tmp/Startup.AC.as"
SEED="/tmp/as_seed.txt"

START="/* ANCHORSAND SEED START */"
END="/* ANCHORSAND SEED END */"

esc_file()
{
	awk '
	{
		gsub(/\\/, "\\\\")
		gsub(/"/, "\\\"")
		gsub(/\t/, "\\t")

		if(NR > 1)
			printf "\\n"

		printf "%s", $0
	}
	' "$1"
}

esc_name()
{
	printf '%s' "$1" | sed 's/\\/\\\\/g; s/"/\\"/g'
}

gen_dir()
{
	dir="$1"

	find "$dir" -mindepth 1 -maxdepth 1 -type d | sort | while read d
	do
		name=$(basename "$d")
		cname=$(esc_name "$name")

		echo "	as_mkdir(\"$cname\");"
		echo "	as_cd(\"$cname\");"

		gen_dir "$d"

		echo "	as_cd(\"..\");"
	done

	find "$dir" -mindepth 1 -maxdepth 1 -type f | sort | while read f
	do
		name=$(basename "$f")
		cname=$(esc_name "$name")
		text=$(esc_file "$f")

		echo "	as_touch(\"$cname\");"
		echo "	as_write(\"$cname\", \"$text\");"
	done
}

{
	echo "	$START"
	echo "	as_cd(\"/\");"

	if [ -d "$ROOT" ]; then
		gen_dir "$ROOT"
	fi

	echo "	$END"
} > "$SEED"

build()
{
	echo "[*] Rebuiling AnchorSand seed..."
	awk -v start="$START" -v seed="$SEED" '
		index($0, start) {
			wipe = 1
			next
		}

		wipe && index($0, "print(\"*AnchorSand seed end*\\n\");") {
			while((getline line < seed) > 0)
				print line
			close(seed)

			print $0
			wipe = 0
			next
		}

		wipe {
			next
		}

		index($0, "print(\"*AnchorSand seed end*\\n\");") {
			while((getline line < seed) > 0)
				print line
			close(seed)

			print $0
			next
		}

		{
			print
		}
	' "$KERNEL" > "$TMP"

	mv "$TMP" "$KERNEL"

	echo "[+] AnchorSand seed rebuilt cleanly"

	CC="gcc -m32 -ffreestanding -fno-pie -fno-pic -fno-stack-protector -nostdlib"
	AC="AneoC/AneoC"

	echo "[ASM] Assembling kernel entry point..."
	nasm -f elf32 Kernel/KEntry.ASM -o KEntry.o

	echo "[ASM] Assembling kernel port IO functions..."
        nasm -f elf32 Kernel/PortIO.ASM -o PortIO.o

	echo "[CC] Compiling kernel..."
	$AC Kernel/Kernel.AC -o Kernel.o

	echo "[AC] Compiling AnchorSand..."
	$AC Kernel/AnchorSand.c -o AnchorSand.o

	echo "[ASM] Assembling AnchorSand disk drivers..."
	nasm -f elf32 Kernel/DiskThunk.ASM -o DiskThunk.o

	echo "[CC] Compiling AnchorSand disk save funtions..."
        $CC -c Kernel/FSSave.c -o FSSave.o

	echo "[AC] Compiling PIT functions..."
	$AC Kernel/PIT.AC -o PIT.o

	echo "[AC] Compiling keyboard drivers..."
	$AC Kernel/Keyboard.AC -o Keyboard.o

	echo "[AC] Compiling haltage funtions..."
	$AC Kernel/Haltage.AC -o Haltage.o

	echo "[AC] Compiling startup funtions..."
	$AC Kernel/Startup.AC -o Startup.o

	echo "[ASM/AC] Compiling IDT funtions..."
	nasm -f elf32 Kernel/Fault.ASM -o Fault.o
	nasm -f elf32 Kernel/ISR.ASM -o ISR.o
	$AC Kernel/IDT.AC -o IDT.o

	echo "[AC] Compiling help menu..."
	$AC Cmds/Help/Menu.AC -o HelpMenu.o

	echo "[AC] Compiling 'addr' command..."
	$AC Cmds/Addr.AC -o Addr.o

	echo "[AC] Compiling tune function..."
	$AC Cmds/Tune.AC -o Tune.o

	echo "[AC] Compiling entropy function..."
	$AC Cmds/Entropy.AC -o Entropy.o

	echo "[LD] Creating kernel ELF..."
	ld -m elf_i386 -Ttext 0x10000 --section-start=.bss=0x100000 -e _start \
		KEntry.o \
		PortIO.o \
		Kernel.o \
		DiskThunk.o \
		AnchorSand.o \
		FSSave.o \
		PIT.o \
		Haltage.o \
		Keyboard.o \
		Startup.o \
		Fault.o \
		IDT.o \
		ISR.o \
		HelpMenu.o \
		Addr.o \
		Tune.o \
		Entropy.o \
		-o Kernel.ELF

	BSS_END_HEX=$(nm -n Kernel.ELF | awk '$3 == "_end" { print $1; exit }')
	if [ -z "$BSS_END_HEX" ]; then
		echo "[ERROR] Could not find the kernel .bss end address."
		exit 1
	fi

	BSS_END=$((16#$BSS_END_HEX))
	if [ "$BSS_END" -ge $((0x1F0000)) ]; then
		echo "[ERROR] Kernel .bss is too close to the 0x200000 stack."
		echo "[ERROR] .bss ends at 0x$BSS_END_HEX."
		exit 1
	fi

	echo "[OBJCOPY] Creating kernel binary..."
	objcopy -O binary Kernel.ELF Boot/KERNEL.BIN

	KERNEL_BYTES=$(stat -c %s Boot/KERNEL.BIN)
	KERNEL_SECTORS=$(((KERNEL_BYTES + 511) / 512))

	if [ "$KERNEL_SECTORS" -gt 2879 ]; then
		echo "[ERROR] Kernel no longer fits in the floppy image."
		exit 1
	fi

	echo "[BOOT] Kernel size: $KERNEL_BYTES bytes ($KERNEL_SECTORS sectors)"
	sed -Ei "s/^KERNEL_SECTORS[[:space:]]+EQU[[:space:]]+[0-9]+/KERNEL_SECTORS EQU $KERNEL_SECTORS/" \
		Boot/Boot.ASM Boot/FIBoot.ASM

	echo "[ASM] Assembling CD-ROM bootloader..."
	nasm -f bin Boot/Boot.ASM -o Boot/AEBOOT.BIN

	echo "[ASM] Assembling floppy disk/USB bootloader..."
	nasm -f bin Boot/FIBoot.ASM -o Boot/FIAEBOOT.BIN

	echo "[*] Removing existing disk images..."
	touch Fallback.IMG
	touch Fallback.ISO
	rm *.IMG
	rm *.ISO

	echo "[DD] Initializing AneoEngine floppy disk image..."
	dd if=/dev/zero of=Boot/AneoEngine.IMG bs=512 count=2880

	echo "[DD] Adding bootloader to 'AneoEngine.IMG'..."
	dd if=Boot/AEBOOT.BIN of=Boot/AneoEngine.IMG conv=notrunc

	echo "[DD] Adding kernel to 'AneoEngine.IMG'..."
	dd if=Boot/KERNEL.BIN of=Boot/AneoEngine.IMG bs=512 seek=1 conv=notrunc

	genisoimage \
		-V "AneoEngine Media" \
		-o AneoEngine.ISO \
		-b AneoEngine.IMG \
		-c Boot.CAT \
		Boot

	echo "[DD] Patching floppy disk/USB bootloader boot sector into ISO..."
	dd if=Boot/FIAEBOOT.BIN of=AneoEngine.ISO bs=512 count=1 conv=notrunc

	echo "[*] Removing trash..."
	mv Kernel.ELF Boot
	rm *.o

	echo "[+] Done!"
}

echo "[*] Building image to calculate kernel LBA..."
build
echo "[ISO] Finding KERNEL.BIN LBA..."

FLOPPY_KERNEL_LBA=""

for LBA in $(seq 0 20000); do
	dd if=AneoEngine.ISO of=/tmp/kernel-test.bin \
		bs=512 skip=$LBA count=1 status=none

	if cmp -n 512 Boot/KERNEL.BIN /tmp/kernel-test.bin >/dev/null; then
		FLOPPY_KERNEL_LBA=$LBA
		break
	fi
done

if [ -z "$FLOPPY_KERNEL_LBA" ]; then
	echo "[ERROR] Failed to locate KERNEL.BIN inside ISO!"
	exit 1
fi

echo "[ISO] FLOPPY_KERNEL_LBA = $FLOPPY_KERNEL_LBA"

echo "[ISO] Patching FIBoot.ASM..."

sed -Ei "s/^FLOPPY_KERNEL_LBA[[:space:]]+EQU[[:space:]]+[0-9]+/FLOPPY_KERNEL_LBA EQU $FLOPPY_KERNEL_LBA/" Boot/FIBoot.ASM

echo "[ASM] Assembling floppy disk/USB bootloader..."
nasm -f bin Boot/FIBoot.ASM -o Boot/FIAEBOOT.BIN

dd if=Boot/FIAEBOOT.BIN of=AneoEngine.ISO \
	bs=512 count=1 conv=notrunc

echo "[*] Building final image..."
build

RC1="qemu-system-x86_64 -cdrom AneoEngine.ISO -audiodev pa,id=snd0 -machine pcspk-audiodev=snd0"
RC2="qemu-system-x86_64 -drive file=AneoEngine.ISO,format=raw -audiodev pa,id=snd0 -machine pcspk-audiodev=snd0"

echo "========================"
echo "QEMU run commands:"
echo "$RC1 - use this if you want to boot with a CD-ROM."
echo "$RC2 - use this if you want to boot with a standard drive."
echo " Both commands work with ...-i386 aswell."
echo " "

if [ "$1" = "-RC1" ]; then
	echo "[*] Running 'AneoEngine.ISO'..."
	eval "$RC1"
elif [ "$1" = "-RC2" ]; then
	echo "[*] Running 'AneoEngine.ISO'..."
	eval "$RC2"
fi