#!/bin/sh
set -e

#DEBHELPER#

case "$1" in
    configure)
        # Set narrow capabilities for packet capture and eBPF support without requiring root/sudo.
        # If eBPF capabilities are unavailable, fall back to packet capture only;
        # rustnet will degrade to procfs process detection rather than auto-grant CAP_SYS_ADMIN.
        if command -v setcap >/dev/null 2>&1; then
            # CAP_NET_RAW: read-only packet capture (non-promiscuous mode)
            # CAP_BPF, CAP_PERFMON: eBPF support for enhanced process tracking
            setcap 'cap_net_raw,cap_bpf,cap_perfmon+eip' /usr/bin/rustnet 2>/dev/null || \
                setcap 'cap_net_raw+eip' /usr/bin/rustnet || true
        fi

        cat <<EOF

================================================================================
RustNet has been installed with eBPF support!

NETWORK PACKET CAPTURE PERMISSIONS:
  RustNet requires specific Linux capabilities for packet capture and eBPF
  process detection. These have been automatically set if setcap is available.

  To verify permissions are set correctly:
    getcap /usr/bin/rustnet

  Expected output (Linux 5.8+ with eBPF support):
    /usr/bin/rustnet cap_net_raw,cap_bpf,cap_perfmon=eip

  Or, if eBPF capabilities were unavailable during install:
    /usr/bin/rustnet cap_net_raw=eip

  If capabilities are not set, you can manually set them:
    # For modern Linux 5.8+ with eBPF support
    sudo setcap 'cap_net_raw,cap_bpf,cap_perfmon+eip' /usr/bin/rustnet

    # Packet capture only (eBPF falls back to procfs)
    sudo setcap 'cap_net_raw+eip' /usr/bin/rustnet

  Note: RustNet uses read-only packet capture (no promiscuous mode).
        CAP_NET_ADMIN is NOT required.

  Alternatively, run rustnet with sudo:
    sudo rustnet

  eBPF FALLBACK:
    If eBPF fails to load, rustnet will automatically fall back to procfs-based
    process detection. Check the TUI Statistics panel to see which detection
    method is active.

GEOIP (OPTIONAL):
  To show country codes for remote IPs, install GeoLite2 databases:
    sudo apt-get install geoipupdate
  Edit /etc/GeoIP.conf with your free MaxMind credentials, then run:
    sudo geoipupdate
  See: https://github.com/domcyrus/rustnet/blob/main/INSTALL.md#geoip-databases-optional

USAGE:
  rustnet              # Start network monitoring
  rustnet --help       # Show all options

For more information, visit: https://github.com/domcyrus/rustnet
================================================================================

EOF
        ;;
esac

exit 0