#!/bin/bash

platformconfig=$(dirname $0)/platformconfig
#
#
# we need information about the platform
#
if [ ! -e "$platformconfig" ]; then
	echo "error: ${platformconfig} does not exist"
	exit 1
fi

source $platformconfig

if [ -n "${PTXCONF_PLATFORM}" ]; then
	PTXDIST_PLATFORMDIR="./platform-${PTXCONF_PLATFORM}"
else
	PTXDIST_PLATFORMDIR="."
fi

if [ ! -e "${PTXDIST_PLATFORMDIR}/images/linuximage" ]; then
	echo "error: run 'ptxdist go' first"
	exit 1
fi

# the emulator to run
QEMU_EXEC="${PTXDIST_PLATFORMDIR}/sysroot-host/bin/qemu-system-x86_64"

if [ ! -e "${QEMU_EXEC}" ]; then
	echo "error: enable and install 'host-qemu' first"
	exit 1
fi

# the port a 'telned' would connect to (in the emulated sysem)
TELNET_INTERNAL_PORT=23
# port QEMU opens at the host side to give access to the ${TELNET_INTERNAL_PORT}
TELNET_EXTERNAL_PORT=4444

# dito for ssh
SSH_INTERNAL_PORT=22
SSH_EXTERNAL_PORT=4445

# check if vde is available for networking
if [ -z "${VDE_SOCKET}" ]; then
	for dir in $(ls -d /var/run/vde2/*.ctl 2>/dev/null); do
		if [ -r "${dir}" ]; then
			VDE_SOCKET="${dir}"
		fi
	done
fi
if [ -n "${VDE_SOCKET}" ]; then
	# make sure qemu supports vde networking
	if ${QEMU_EXEC} --help | grep -q -- '-net.*vde'; then
		QEMU_NET=( -netdev vde,id=net1,sock=${VDE_SOCKET} )
	fi
fi

# fall back to user network if necessary
if [ -z "${QEMU_NET}" ]; then
	QEMU_NET=(-netdev user,id=net1,hostfwd=tcp:127.0.0.1:${TELNET_EXTERNAL_PORT}-:${TELNET_INTERNAL_PORT},hostfwd=tcp:127.0.0.1:${SSH_EXTERNAL_PORT}-:${SSH_INTERNAL_PORT} )
fi

BASE_CMDLINE="console=ttyS0,115200 loglevel=5 systemd.show_status=auto"

if [ -d "${PTXDIST_PLATFORMDIR}/root/.virtfs_metadata" ]; then
	security_model="mapped-file"
else
	security_model="none"
fi

# Machine to emulate
QEMU_ARGS=( -L ${PTXDIST_PLATFORMDIR}/sysroot-host/share/qemu/ -machine pc-q35-2.12 -smp 2 -cpu host -accel kvm -m 1G -s )
# disable graphics output
QEMU_ARGS[${#QEMU_ARGS[@]}]="-nographic"
# Exit qemu on reboot
QEMU_ARGS[${#QEMU_ARGS[@]}]="-no-reboot"
# Configure networking
QEMU_ARGS=( "${QEMU_ARGS[@]}" -net nic,netdev=net1 "${QEMU_NET[@]}" )
# Set base time to test NTP and time handling
QEMU_ARGS=( "${QEMU_ARGS[@]}" -rtc base=2000-01-01 )

QEMU_LINUX_ARGS=( -kernel ${PTXDIST_PLATFORMDIR}/images/linuximage )

check_hd() {
	if [ ! -e "${PTXDIST_PLATFORMDIR}/images/root.ext2" ]; then
		echo "error: root.ext2 is missing. Run 'ptxdist images' first"
		exit 1
	fi
}

run_qemu_hda() {
	check_hd
	exec ${QEMU_EXEC} \
		"${QEMU_ARGS[@]}" \
		-drive file=${PTXDIST_PLATFORMDIR}/images/root.ext2,if=virtio,format=raw \
		"${QEMU_EXTRA_ARGS[@]}" \
		"${QEMU_LINUX_ARGS[@]}" \
		-append "root=/dev/vda console=ttyS0,115200 rw ${BASE_CMDLINE}"
}

#
# This needs:
# CONFIG_NET_9P_VIRTIO=y
# CONFIG_9P_FS=y
#
run_qemu_9p() {
	exec ${QEMU_EXEC} \
		"${QEMU_ARGS[@]}" \
		-fsdev local,id=rootfs,path=${PTXDIST_PLATFORMDIR}/root,security_model="${security_model}" \
		-device virtio-9p-pci,fsdev=rootfs,mount_tag=/dev/root \
		"${QEMU_EXTRA_ARGS[@]}" \
		"${QEMU_LINUX_ARGS[@]}" \
		-append "root=/dev/root rw rootfstype=9p rootflags=trans=virtio ${BASE_CMDLINE}"
}

# 9p net port
P9_ROOTFS_PORT=99999

run_qemu_9pnet() {
	ROOTPATH=$(realpath ${PTXDIST_PLATFORMDIR}/root)
	# the emulator to run
	DIOD_EXEC="/sbin/diod"

	if [ ! -e "${DIOD_EXEC}" ]; then
		echo "error: apt-get install 'diod' first"
		exit 1
	fi

	${DIOD_EXEC} -f -n -S -l 127.0.0.1:${P9_ROOTFS_PORT} -e ${ROOTPATH} &
	# this is an ugly workaround so diod will be closed after qemu has stopped
	DIOD_PID=$(echo $!)
	(tail --pid $$ -f /dev/null; kill ${DIOD_PID}) &

	exec ${QEMU_EXEC} \
		"${QEMU_ARGS[@]}" \
		"${QEMU_EXTRA_ARGS[@]}" \
		"${QEMU_LINUX_ARGS[@]}" \
		-append "ip=dhcp root=10.0.2.2 rw rootfstype=9p rootflags=trans=tcp,version=9p2000.L,aname=${ROOTPATH},port=${P9_ROOTFS_PORT} ${BASE_CMDLINE} ${EXTRA_CMDLINE}"
}

target="${1:-9p}"

#set -x
run_qemu_${target}