#!/bin/sh
# checks/pf.sh
# pf health summary (enabled, state table usage, rule count), plus the
# actual active filter and nat/rdr rules listed as rows below. The rule
# rows use status "info" (a neutral gray square) rather than "ok" -
# they're informational, not a health signal, and a green square there
# would wrongly imply each individual rule was itself being health-
# checked.
set -eu

DIR=$(dirname "$0")
. "$DIR/../lib/common.sh"

# abbreviate_rule RULE
# Best-effort compression of pfctl's verbose rule syntax so rows fit a
# narrow column without wrapping mid-word. Not a semantic parser - just
# strips/replaces the tokens that are near-universal boilerplate on this
# ruleset (quick, flags S/SA, proto/from-to-port verbosity) and swaps
# in/out for arrows. Uses only the Arrows block (confirmed present in
# the scientifica font); avoids Dingbats (✓/✗) since that block isn't
# shipped. A rule shape this doesn't recognize just passes through
# unshortened - still correct, just longer.
abbreviate_rule() {
    printf '%s' "$1" | sed -E \
        -e 's/ in / → /' \
        -e 's/ out / ← /' \
        -e 's/ quick//' \
        -e 's/ on / /' \
        -e 's/ flags [A-Za-z\/]+//' \
        -e 's/ modulate state/ [state]/' \
        -e 's/ keep state/ [state]/' \
        -e 's/ proto (tcp|udp|icmp)/ \1/' \
        -e 's/ from any to any port = ([a-zA-Z0-9]+)/ :\1/' \
        -e 's/ from any to any/ /' \
        -e 's/ from ([^ ]+) to ([^ ]+)/ \1 → \2/' \
        -e 's/ inet / /' \
        -e 's/ round-robin//' \
        -e 's/ -> / → /' \
        -e 's/ all$//' \
        -e 's/ all / /' \
        -e 's/  +/ /g' \
        -e 's/^ +//' -e 's/ +$//'
}

INFO=$(pfctl -si 2>/dev/null) || INFO=""

ENABLED=$(printf '%s\n' "$INFO" | awk -F'[ :]+' '/^Status:/{print $2; exit}')
if [ "$ENABLED" = "Enabled" ]; then
    json_line "pf" "pf" "" "ok"
else
    json_line "pf" "pf" "${ENABLED:-unknown}" "down"
fi

CURRENT=$(printf '%s\n' "$INFO" | awk '/current entries/{print $NF; exit}')
LIMIT=$(pfctl -sm 2>/dev/null | awk '/^states/{print $NF; exit}')

if [ -n "$CURRENT" ] && [ -n "$LIMIT" ] && [ "$LIMIT" -gt 0 ] 2>/dev/null; then
    PCT=$((CURRENT * 100 / LIMIT))
    if [ "$PCT" -ge 90 ]; then
        SSTATUS=down
    elif [ "$PCT" -ge 75 ]; then
        SSTATUS=warn
    else
        SSTATUS=ok
    fi
    json_line "pf" "state table" "${CURRENT}/${LIMIT} (${PCT}%)" "$SSTATUS"
fi

RULE_COUNT=$(pfctl -sr 2>/dev/null | grep -c .) || RULE_COUNT=0
json_line "pf" "filter rules loaded" "$RULE_COUNT" "ok"

# Group rules by interface (then in before out) rather than pfctl's raw
# eval order, which is just how the ruleset happens to be authored and
# reads as arbitrarily interleaved (e.g. an "out" rule sandwiched between
# unrelated "in" rules for the same interface). This is a display-only
# reorder - pf's actual evaluation order (and quick/first-match
# semantics) is untouched, only pfctl -sr's raw output is re-sorted here.
TAB=$(printf '\t')
pfctl -sr 2>/dev/null | awk -v OFS="$TAB" '
{
    iface = ""
    n = split($0, w, " ")
    for (i = 1; i <= n; i++) {
        if (w[i] == "on" && i < n) { iface = w[i + 1]; break }
    }
    dir = "2"
    if ($0 ~ / in /) dir = "0"
    else if ($0 ~ / out /) dir = "1"
    print iface, dir, $0
}' | sort -t "$TAB" -k1,1 -k2,2 -k3 | cut -f3- | while IFS= read -r rule; do
    [ -n "$rule" ] || continue
    json_line "pf" "  $(abbreviate_rule "$rule")" "" "info"
done

pfctl -sn 2>/dev/null | while IFS= read -r rule; do
    [ -n "$rule" ] || continue
    json_line "pf" "  $(abbreviate_rule "$rule")" "" "info"
done