#!/bin/bash
set -euo pipefail

[ -r ./env-fip ] && . ./env-fip

if [ -z "${IFACE:-}" ]; then
    echo "ERROR: IFACE not set"
    exit 1
fi

# Support both FLOATING_IPS (space-separated, new) and FLOATING_IP (legacy singular)
if [ -n "${FLOATING_IPS:-}" ]; then
    IPS=($FLOATING_IPS)
elif [ -n "${FLOATING_IP:-}" ]; then
    IPS=($FLOATING_IP)
else
    echo "ERROR: neither FLOATING_IPS nor FLOATING_IP set — check taskserv params"
    exit 1
fi

IFACES_FILE="/etc/network/interfaces.d/60-floating-ip"

# Build expected file content for all IPs
build_content() {
    echo "# Floating IPs managed by provisioning — do not edit manually"
    local idx=0
    for ip in "${IPS[@]}"; do
        echo ""
        echo "auto ${IFACE}:fip${idx}"
        echo "iface ${IFACE}:fip${idx} inet static"
        echo "    address ${ip}"
        echo "    netmask 255.255.255.255"
        idx=$((idx + 1))
    done
}

EXPECTED=$(build_content)

# Check if all IPs are already configured and active
all_configured=true
for ip in "${IPS[@]}"; do
    if ! grep -qF "address ${ip}" "$IFACES_FILE" 2>/dev/null; then
        all_configured=false
        break
    fi
done

if $all_configured; then
    echo "All floating IPs already configured in ${IFACES_FILE}"
    # Ensure each is active (re-apply after reboot if missing)
    idx=0
    for ip in "${IPS[@]}"; do
        if ! ip addr show "$IFACE" | grep -qF "${ip}"; then
            ip addr add "${ip}/32" dev "$IFACE" 2>/dev/null || true
            echo "Re-applied ${ip} on ${IFACE}:fip${idx}"
        fi
        idx=$((idx + 1))
    done
    exit 0
fi

echo "$EXPECTED" > "$IFACES_FILE"
echo "Written ${IFACES_FILE}"

# Activate all IPs immediately
idx=0
for ip in "${IPS[@]}"; do
    ip addr add "${ip}/32" dev "$IFACE" 2>/dev/null || true
    sleep 0.5
    if ip addr show "$IFACE" | grep -qF "${ip}"; then
        echo "Floating IP ${ip} active on ${IFACE}:fip${idx}"
    else
        echo "ERROR: ${ip} not visible on ${IFACE} after ip addr add"
        exit 1
    fi
    idx=$((idx + 1))
done