#!/bin/sh
# CVE Triage - Recommender Module
# Generates actionable recommendations from CVE analysis

RECOMMENDATIONS_FILE="/var/lib/cve-triage/recommendations.json"
ALERTS_FILE="/var/lib/cve-triage/alerts.json"

# Generate recommendation from analyzed CVE
generate_recommendation() {
	local cve_id="$1"
	local cvss="$2"
	local severity="$3"
	local affected_pkg="$4"
	local analysis="$5"

	local action=$(echo "$analysis" | jsonfilter -e '@.action' 2>/dev/null)
	local urgency=$(echo "$analysis" | jsonfilter -e '@.urgency' 2>/dev/null)
	local mitigation=$(echo "$analysis" | jsonfilter -e '@.mitigation' 2>/dev/null)
	local impact=$(echo "$analysis" | jsonfilter -e '@.impact_level' 2>/dev/null)

	action="${action:-monitor}"
	urgency="${urgency:-scheduled}"
	mitigation="${mitigation:-Update to latest version}"
	impact="${impact:-$severity}"

	local rec_id="rec_$(date +%s)_${cve_id}"

	# Generate specific command based on action
	local command=""
	case "$action" in
		patch)
			if [ -n "$affected_pkg" ]; then
				command="opkg update && opkg upgrade $affected_pkg"
			else
				command="opkg update && opkg list-upgradable"
			fi
			;;
		mitigate)
			command="# Manual mitigation required: $mitigation"
			;;
		monitor)
			command="# No immediate action - continue monitoring"
			;;
	esac

	# Escape strings for JSON
	mitigation=$(echo "$mitigation" | sed 's/\\/\\\\/g; s/"/\\"/g')
	command=$(echo "$command" | sed 's/\\/\\\\/g; s/"/\\"/g')

	cat <<EOF
{
  "id": "$rec_id",
  "cve": "$cve_id",
  "cvss": $cvss,
  "severity": "$severity",
  "impact": "$impact",
  "affected_package": "$affected_pkg",
  "action": "$action",
  "urgency": "$urgency",
  "mitigation": "$mitigation",
  "command": "$command",
  "status": "pending",
  "created": "$(date -Iseconds)"
}
EOF
}

# Process analyzed CVEs and create recommendations
create_recommendations() {
	local analyzed_cves="$1"
	local max_recs="${max_recommendations:-10}"

	mkdir -p "$(dirname "$RECOMMENDATIONS_FILE")"

	local count=0
	local recs='[]'

	echo "$analyzed_cves" | jsonfilter -e '@[*]' 2>/dev/null | while read -r cve_data; do
		[ $count -ge $max_recs ] && break

		local cve_id=$(echo "$cve_data" | jsonfilter -e '@.cve' 2>/dev/null)
		local cvss=$(echo "$cve_data" | jsonfilter -e '@.cvss' 2>/dev/null)
		local severity=$(echo "$cve_data" | jsonfilter -e '@.severity' 2>/dev/null)
		local affected_pkg=$(echo "$cve_data" | jsonfilter -e '@.affected_package' 2>/dev/null)
		local analysis=$(echo "$cve_data" | jsonfilter -e '@.analysis' 2>/dev/null)

		# Skip CVEs that don't affect OpenWrt (if analysis says so)
		local affects_openwrt=$(echo "$analysis" | jsonfilter -e '@.affects_openwrt' 2>/dev/null)
		[ "$affects_openwrt" = "false" ] && continue

		# Skip CVEs with action=ignore
		local action=$(echo "$analysis" | jsonfilter -e '@.action' 2>/dev/null)
		[ "$action" = "ignore" ] && continue

		generate_recommendation "$cve_id" "${cvss:-0}" "$severity" "$affected_pkg" "$analysis"
		count=$((count + 1))
	done | json_slurp
}

# Save recommendations to file
save_recommendations() {
	local new_recs="$1"

	# Load existing recommendations
	local existing='[]'
	[ -f "$RECOMMENDATIONS_FILE" ] && existing=$(cat "$RECOMMENDATIONS_FILE" 2>/dev/null)

	# Merge (keep existing, add new if CVE not already present)
	{
		echo '['
		local first=1

		# Keep existing non-completed recommendations
		echo "$existing" | jsonfilter -e '@[*]' 2>/dev/null | while read -r rec; do
			local status=$(echo "$rec" | jsonfilter -e '@.status' 2>/dev/null)
			[ "$status" = "completed" ] || [ "$status" = "rejected" ] && continue
			[ $first -eq 0 ] && printf ','
			first=0
			printf '%s' "$rec"
		done

		# Add new recommendations (skip duplicates)
		echo "$new_recs" | jsonfilter -e '@[*]' 2>/dev/null | while read -r rec; do
			local cve=$(echo "$rec" | jsonfilter -e '@.cve' 2>/dev/null)
			# Check if CVE already in existing
			if ! echo "$existing" | grep -q "\"cve\":\"$cve\""; then
				[ $first -eq 0 ] && printf ','
				first=0
				printf '%s' "$rec"
			fi
		done

		echo ']'
	} > "${RECOMMENDATIONS_FILE}.tmp"

	mv "${RECOMMENDATIONS_FILE}.tmp" "$RECOMMENDATIONS_FILE"
}

# Create alert for immediate attention CVEs
create_alert() {
	local cve_id="$1"
	local severity="$2"
	local message="$3"

	mkdir -p "$(dirname "$ALERTS_FILE")"

	local alert=$(cat <<EOF
{
  "id": "alert_$(date +%s)_$cve_id",
  "cve": "$cve_id",
  "severity": "$severity",
  "message": "$message",
  "created": "$(date -Iseconds)",
  "acknowledged": false
}
EOF
)

	# Append to alerts file
	if [ -f "$ALERTS_FILE" ]; then
		local existing=$(cat "$ALERTS_FILE")
		# Check if alert for this CVE already exists
		if ! echo "$existing" | grep -q "\"cve\":\"$cve_id\""; then
			echo "$existing" | sed "s/\]$/,$alert]/" > "${ALERTS_FILE}.tmp"
			mv "${ALERTS_FILE}.tmp" "$ALERTS_FILE"
		fi
	else
		echo "[$alert]" > "$ALERTS_FILE"
	fi

	log_warn "ALERT: $cve_id ($severity) - $message"
}

# Process recommendations and create alerts for critical/immediate items
process_recommendations() {
	local recs="$1"

	echo "$recs" | jsonfilter -e '@[*]' 2>/dev/null | while read -r rec; do
		local cve=$(echo "$rec" | jsonfilter -e '@.cve' 2>/dev/null)
		local severity=$(echo "$rec" | jsonfilter -e '@.severity' 2>/dev/null)
		local urgency=$(echo "$rec" | jsonfilter -e '@.urgency' 2>/dev/null)
		local affected=$(echo "$rec" | jsonfilter -e '@.affected_package' 2>/dev/null)

		# Create alert for critical CVEs or immediate urgency
		if [ "$severity" = "critical" ] || [ "$urgency" = "immediate" ]; then
			create_alert "$cve" "$severity" "Critical vulnerability affecting ${affected:-system}. Immediate action required."
		fi
	done
}

# Get pending recommendations
get_pending_recommendations() {
	[ -f "$RECOMMENDATIONS_FILE" ] || { echo '[]'; return; }

	echo '['
	local first=1
	jsonfilter -i "$RECOMMENDATIONS_FILE" -e '@[*]' 2>/dev/null | while read -r rec; do
		local status=$(echo "$rec" | jsonfilter -e '@.status' 2>/dev/null)
		[ "$status" = "pending" ] || continue
		[ $first -eq 0 ] && printf ','
		first=0
		printf '%s' "$rec"
	done
	echo ']'
}

# Get active alerts
get_active_alerts() {
	[ -f "$ALERTS_FILE" ] || { echo '[]'; return; }

	echo '['
	local first=1
	jsonfilter -i "$ALERTS_FILE" -e '@[*]' 2>/dev/null | while read -r alert; do
		local ack=$(echo "$alert" | jsonfilter -e '@.acknowledged' 2>/dev/null)
		[ "$ack" = "true" ] && continue
		[ $first -eq 0 ] && printf ','
		first=0
		printf '%s' "$alert"
	done
	echo ']'
}