#!/bin/bash -e
DIR="$(dirname "${BASH_SOURCE[0]}")"

BRIDGE=virbr0

function ask_yn() {
    local ans

    printf '%s (Y/n) ' "$1" >&2
    read -r ans
    case "${ans,,}" in
        y*|'') return 0 ;;
            *) return 1 ;;
    esac
}

function _getmaxram() {
    local ram; ram="$(free -g | awk '/^Mem:/{print $2 - 2}')"

    if   [ "$ram" -le  2 ]; then  ram=2
    elif [ "$ram" -gt 32 ]; then ram=32; fi
    echo "${ram}G"
}

function _getnet() {
    local net=user

    if ! ip link show "$BRIDGE" | grep -q UP; then
        ask_yn 'create bridge?' && sudo "$DIR/startnat.sh" "$BRIDGE" > /dev/null
    fi
    if ip link show "$BRIDGE" | grep -q UP; then
        net="bridge,br=$BRIDGE"
    fi
    echo "$net"
}

# TODO: -bios /usr/share/OVMF/OVMF_CODE.fd
function qemu() {
    local maxram; maxram="$(_getmaxram)"
    local net; net="$(_getnet)"

    (set -x
        qemu-system-x86_64 -accel kvm \
            -M q35 \
            -bios /usr/share/ovmf/x64/OVMF.fd \
            -cpu host \
            -m "2G,maxmem=$maxram" \
            -vga virtio \
            -drive if=virtio,file=hda.qcow2 \
            -audio pipewire,model=hda \
            -nic "model=virtio-net-pci,type=$net" \
            -device qemu-xhci \
            -object memory-backend-ram,id=mem,size=2G,share=on \
            -numa node,memdev=mem \
            "$@"
    )
}