#!/bin/sh
#
# run-local.sh - build and run latd in place for VT1200 experiments.
#
# Nothing is installed system-wide: binaries, unix sockets, logs and pcaps all
# live under lat/.  latd advertises the VT1200 login services through
# tools/osc-filter.py (strips OSC strings that crash the terminal emulator).
#
# Usage:  run-local.sh {build|start|stop|restart|status|capture}
#
#   build     bootstrap + configure + make into lat/local/build[-debug]
#   start     start latd (root) + apply multicast/group/service config
#   stop      stop latd
#   restart   stop then start
#   status    show latd configuration and advertised services
#   capture   tcpdump LAT frames (ethetype 0x6004) to lat/local/capture-*.pcap
#
# Environment overrides:
#   IFACE=enp197s0f3u1     interface latd uses (VT1200's segment)
#   VARIANT=debug|release  which build tree (default: debug)
#
set -eu

SELF_DIR=$(cd "$(dirname "$0")" && pwd)
SRC="$SELF_DIR/code/latd"
LOCAL="$SELF_DIR/local"
FILTER="$SELF_DIR/tools/osc-filter.py"
IFACE="${IFACE:-enp197s0f3u1}"
VARIANT="${VARIANT:-debug}"

case "$VARIANT" in
    debug)   BUILDDIR="$LOCAL/build-debug"; CONFOPTS="--enable-debug" ;;
    release) BUILDDIR="$LOCAL/build";       CONFOPTS="" ;;
    *) echo "VARIANT must be 'release' or 'debug'" >&2; exit 2 ;;
esac

LATCP="$BUILDDIR/latcp"
SOCK_LATCP="$LOCAL/run/latcp"
SOCK_LLOGIN="$LOCAL/run/latlogin"
LOG="$LOCAL/latd.log"

need_root() {
    [ "$(id -u)" = 0 ] || { echo "must run as root (use sudo)" >&2; exit 1; }
}

do_build() {
    mkdir -p "$LOCAL/run" "$BUILDDIR"
    [ -x "$SRC/configure" ] || ( cd "$SRC" && ./bootstrap.sh )
    if ! ( cd "$BUILDDIR" && "$SRC/configure" $CONFOPTS \
            --with-latcp-socket="$SOCK_LATCP" \
            --with-llogin-socket="$SOCK_LLOGIN" \
            && make -j"$(nproc)" ) >"$LOCAL/build.log" 2>&1; then
        echo "build failed - see $LOCAL/build.log" >&2
        exit 1
    fi
    echo "built: $BUILDDIR/{latd,latcp,llogin,moprc}   (log: $LOCAL/build.log)"
}

do_stop() {
    [ -x "$LATCP" ] || return 0
    "$LATCP" -h 2>/dev/null || true
}

do_start() {
    need_root
    [ -x "$LATCP" ] || { echo "not built yet: run '$0 build'" >&2; exit 1; }
    do_stop; sleep 1

    # -d: do not fork (foreground); setsid detaches it from this shell.
    setsid "$LATCP" -s -d -v -v -i "$IFACE" >"$LOG" 2>&1 </dev/null &

    i=0
    while [ ! -S "$SOCK_LATCP" ] && [ "$i" -lt 10 ]; do sleep 1; i=$((i+1)); done
    [ -S "$SOCK_LATCP" ] || { echo "latd did not start; see $LOG" >&2; exit 1; }

    "$LATCP" -m 10                 # advertise every 10s (default 60)
    "$LATCP" -G 1                  # group 1: match the VT1200's group code

    # latd creates a default service named after the node (SID) that runs
    # /bin/login UNFILTERED.  Replace it (and add a VT1200 alias) with the
    # OSC-filtered login, so the terminal never sees control strings.
    "$LATCP" -D -a SID    2>/dev/null || true
    "$LATCP" -D -a VT1200 2>/dev/null || true
    "$LATCP" -A -a SID    -i 'filtered login (node name)' -r 100 -C "$FILTER"
    "$LATCP" -A -a VT1200 -i 'filtered login'             -r 100 -C "$FILTER"

    echo "latd up on $IFACE (variant=$VARIANT)"
    echo "services: SID, VT1200 -> login through $FILTER"
    echo "log: $LOG   stop with: sudo $0 stop"
}

do_status() {
    need_root
    "$LATCP" -d
}

do_capture() {
    need_root
    out="$LOCAL/capture-$(date +%H%M%S).pcap"
    echo "capturing LAT (0x6004) on $IFACE -> $out   (Ctrl-C to stop)"
    exec tcpdump -i "$IFACE" -w "$out" 'ether proto 0x6004'
}

case "${1:-}" in
    build)   do_build ;;
    start)   do_start ;;
    stop)    need_root; do_stop; echo "latd stopped" ;;
    restart) need_root; do_stop; sleep 1; do_start ;;
    status)  do_status ;;
    capture) do_capture ;;
    *) echo "usage: $0 {build|start|stop|restart|status|capture}" >&2; exit 2 ;;
esac