#!/bin/bash
# CI VM IP reporter — called by ci-report-ip.service at boot.
#
# Phase C extension: reads guestinfo.ip-assignment from the VMX (written by the
# host orchestrator before vmrun start).  If present, applies a static IP to
# the primary NIC and reports it back immediately via guestinfo.ci-ip, skipping
# DHCP entirely.  If absent, falls back to the original DHCP-detect behaviour.
#
# The VMCI channel (vmware-rpctool) does not require TCP/IP to be initialised —
# it communicates via the VMware virtual hardware interface.  This means the
# static IP can be configured before network-online.target, so by the time SSH
# starts listening the NIC already has the correct address.
#
# Install:
#   sudo cp ci-report-ip.sh /usr/local/bin/ci-report-ip.sh
#   sudo chmod +x /usr/local/bin/ci-report-ip.sh
#   sudo cp ci-report-ip.service /etc/systemd/system/ci-report-ip.service
#   sudo systemctl daemon-reload
#   sudo systemctl enable ci-report-ip.service

RPCTOOL=/usr/bin/vmware-rpctool
[ -x "$RPCTOOL" ] || exit 0

# ── Check for pre-assigned IP from orchestrator ───────────────────────────────
assigned_ip=$("$RPCTOOL" "info-get guestinfo.ip-assignment" 2>/dev/null | tr -d '[:space:]')

if [[ "$assigned_ip" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
    netmask=$("$RPCTOOL" "info-get guestinfo.netmask" 2>/dev/null | tr -d '[:space:]')
    gateway=$("$RPCTOOL" "info-get guestinfo.gateway" 2>/dev/null | tr -d '[:space:]')

    # Resolve primary NIC (first non-loopback).
    iface=$(ip -o link show | awk -F': ' '$2 != "lo" {print $2; exit}')
    if [ -z "$iface" ]; then
        echo "ci-report-ip: no non-loopback interface found" | systemd-cat -t ci-report-ip
        exit 1
    fi

    # Compute prefix length from netmask (default /24).
    prefix=24
    if [ -n "$netmask" ]; then
        prefix=$(python3 -c \
            "import ipaddress; print(ipaddress.IPv4Network('0.0.0.0/$netmask',strict=False).prefixlen)" \
            2>/dev/null) || prefix=24
    fi

    # Flush any existing config (DHCP or stale static) and apply.
    ip addr flush dev "$iface" 2>/dev/null || true
    ip addr add "${assigned_ip}/${prefix}" dev "$iface"
    ip link set "$iface" up

    if [[ "$gateway" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
        ip route add default via "$gateway" dev "$iface" 2>/dev/null || true
    fi

    # Report IP back to host via guestinfo.ci-ip.
    "$RPCTOOL" "info-set guestinfo.ci-ip $assigned_ip" 2>/dev/null
    echo "ci-report-ip: applied static IP $assigned_ip/$prefix via guestinfo" \
        | systemd-cat -t ci-report-ip
    exit 0
fi

# ── Fallback: DHCP — wait for IP and report ───────────────────────────────────
# Retries for up to 60 s to tolerate open-vm-tools re-init after UUID change
# (linked clones get a new UUID — vmware-rpctool may fail briefly on first boot).
for i in $(seq 1 30); do
    IP=$(ip -4 route get 1.0.0.0 2>/dev/null \
        | awk '{for(i=1;i<=NF;i++) if($i=="src") print $(i+1)}' \
        | head -1)
    if [ -n "$IP" ]; then
        if "$RPCTOOL" "info-set guestinfo.ci-ip $IP" 2>/dev/null; then
            echo "ci-report-ip: set guestinfo.ci-ip=$IP via DHCP (attempt $i)" \
                | systemd-cat -t ci-report-ip
            exit 0
        fi
    fi
    sleep 2
done

echo "ci-report-ip: failed to set guestinfo.ci-ip after 30 attempts" \
    | systemd-cat -t ci-report-ip
exit 1