#!/bin/sh
#
# CrowdSec Firewall Bouncer - UCI Defaults Script
# Automatically configures and registers the firewall bouncer on first install
#

BOUNCER_NAME="crowdsec-firewall-bouncer"
CONFIG_FILE="/etc/config/crowdsec"
BOUNCER_CONFIG="/etc/config/crowdsec-bouncer"

# Function to check if CrowdSec is installed and running
check_crowdsec() {
	if ! command -v cscli >/dev/null 2>&1; then
		echo "CrowdSec (cscli) not found. Please install crowdsec first."
		return 1
	fi

	# Check if LAPI is reachable
	if ! cscli lapi status >/dev/null 2>&1; then
		echo "CrowdSec LAPI not running. Start crowdsec service first."
		return 1
	fi

	return 0
}

# Function to register bouncer and get API key
register_bouncer() {
	local api_key

	# Check if bouncer already registered
	if cscli bouncers list | grep -q "$BOUNCER_NAME"; then
		echo "Bouncer '$BOUNCER_NAME' already registered"
		# Try to get existing key (note: cscli doesn't show keys after creation)
		return 0
	fi

	# Register new bouncer
	echo "Registering bouncer '$BOUNCER_NAME' with CrowdSec LAPI..."
	api_key=$(cscli bouncers add "$BOUNCER_NAME" -o raw 2>/dev/null)

	if [ -n "$api_key" ] && [ "$api_key" != "null" ]; then
		echo "Bouncer registered successfully"
		# Update UCI config with API key
		uci set crowdsec.bouncer.api_key="$api_key"
		uci commit crowdsec
		return 0
	else
		echo "Failed to register bouncer"
		return 1
	fi
}

# Function to detect network interfaces
detect_interfaces() {
	local interfaces=""
	local lan_iface
	local wan_iface

	# Get LAN interface
	lan_iface=$(uci -q get network.lan.device)
	[ -z "$lan_iface" ] && lan_iface=$(uci -q get network.lan.ifname)
	[ -z "$lan_iface" ] && lan_iface="br-lan"

	# Get WAN interface
	wan_iface=$(uci -q get network.wan.device)
	[ -z "$wan_iface" ] && wan_iface=$(uci -q get network.wan.ifname)
	[ -z "$wan_iface" ] && wan_iface="eth1"

	interfaces="$lan_iface $wan_iface"

	echo "$interfaces"
}

# Function to merge bouncer config into main crowdsec config
merge_config() {
	# Check if bouncer section already exists in main config
	if ! uci -q get crowdsec.bouncer >/dev/null 2>&1; then
		echo "Creating bouncer section in /etc/config/crowdsec..."

		# Copy from template if it exists
		if [ -f "$BOUNCER_CONFIG" ]; then
			# Read values from bouncer config template
			uci -q import crowdsec < "$BOUNCER_CONFIG"
		else
			# Create basic bouncer section
			uci set crowdsec.bouncer=bouncer
			uci set crowdsec.bouncer.enabled='0'
			uci set crowdsec.bouncer.ipv4='1'
			uci set crowdsec.bouncer.ipv6='1'
			uci set crowdsec.bouncer.api_url='http://127.0.0.1:8180/'
			uci set crowdsec.bouncer.update_frequency='10s'
			uci set crowdsec.bouncer.deny_action='drop'
			uci set crowdsec.bouncer.deny_log='1'
			uci set crowdsec.bouncer.log_prefix='CrowdSec: '
			uci set crowdsec.bouncer.log_level='info'
			uci set crowdsec.bouncer.filter_input='1'
			uci set crowdsec.bouncer.filter_forward='1'
		fi

		# Auto-detect and set interfaces
		local ifaces
		ifaces=$(detect_interfaces)
		uci delete crowdsec.bouncer.interface 2>/dev/null
		for iface in $ifaces; do
			uci add_list crowdsec.bouncer.interface="$iface"
		done

		uci commit crowdsec
	fi
}

# Function to load nftables kernel modules
load_nftables_modules() {
	modprobe nf_tables 2>/dev/null
	modprobe nft_chain_nat 2>/dev/null
	modprobe nf_nat 2>/dev/null
}

# Main execution
main() {
	echo "Configuring CrowdSec Firewall Bouncer..."

	# Merge configuration
	merge_config

	# Load required kernel modules
	load_nftables_modules

	# Check if CrowdSec is available
	if ! check_crowdsec; then
		echo "CrowdSec not ready. Bouncer registration skipped."
		echo "Run 'cscli bouncers add $BOUNCER_NAME' manually after starting crowdsec."
		exit 0
	fi

	# Register bouncer
	if register_bouncer; then
		echo "Bouncer configuration complete"
		echo "Enable the bouncer with: uci set crowdsec.bouncer.enabled='1'; uci commit crowdsec"
		echo "Start the service with: /etc/init.d/crowdsec-firewall-bouncer enable && /etc/init.d/crowdsec-firewall-bouncer start"
	else
		echo "Bouncer registration failed. You may need to register manually:"
		echo "  cscli bouncers add $BOUNCER_NAME"
	fi
}

# Run main function
main

# Cleanup: remove this script after execution
rm -f /etc/uci-defaults/99_crowdsec-bouncer

exit 0