#!/usr/bin/env bash
## fpm-parity-check.sh — end-to-end proof under a REAL web SAPI.
##
## WHY NOT .phpt: the CLI SAPI overwrites DOCUMENT_ROOT / SCRIPT_FILENAME /
## PATH_TRANSLATED after importing the environment, and the cli-server SAPI does
## not process .user.ini at all — so neither can exercise the two things that
## actually matter here.
##
## WHY PHP-FPM: php-fpm takes DOCUMENT_ROOT and SCRIPT_FILENAME as caller-
## supplied FastCGI params and honours .user.ini — structurally the same shape as
## OpenLiteSpeed handing a detached lsphp its LSAPI params. It is the closest
## analogue available without an OLS runtime.
##
## Asserts:
##   1. CONTROL   — no mapping => PHP reports the raw /mnt/users paths, i.e. the
##                  test reproduces the bug before claiming to fix it.
##   2. FIX       — mapping    => both keys read /home/<user>/... .
##   3. WORDFENCE — mapping AND a customer .user.ini auto_prepend_file (the state
##                  7 live shared_ols sites are in): paths are STILL corrected
##                  AND the customer's prepend STILL runs. This is the case the
##                  old auto_prepend_file normaliser silently lost.
##   4. OLD       — for the record: the previous auto_prepend mechanism, with the
##                  same customer .user.ini, does NOT run. This is the evidence
##                  that hardening the prepend hook could not have worked.
##
## Usage:  ./fpm-parity-check.sh [ROOT] [PHP_FPM_BIN] [EXT_SO]
##   ROOT defaults to /mnt/users (falls back to a temp dir if not creatable).
set -uo pipefail

HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROOT="${1:-/mnt/users}"
FPM_BIN="${2:-$(command -v php-fpm8.3 || echo /usr/sbin/php-fpm8.3)}"
EXT_SO="${3:-$HERE/../modules/cac_path_parity.so}"
PORT="${PORT:-9001}"

command -v cgi-fcgi >/dev/null || { echo "SKIP: cgi-fcgi not installed (apt install libfcgi-bin)"; exit 0; }
[ -x "$FPM_BIN" ] || { echo "SKIP: php-fpm not found"; exit 0; }
[ -f "$EXT_SO" ] || { echo "SKIP: $EXT_SO not built (run phpize && ./configure && make)"; exit 0; }

mkdir -p "$ROOT" 2>/dev/null || ROOT="$(mktemp -d)/mnt/users"
USER_NAME=bob
SITE="$ROOT/$USER_NAME/site.com"
DOCROOT="$SITE/public_html"
HOME_PATH="/home/$USER_NAME"
TMP="$(mktemp -d)"
fail=0

mkdir -p "$DOCROOT" || { echo "cannot create $DOCROOT"; exit 1; }
trap 'rm -rf "$TMP"; rm -f "$DOCROOT/.user.ini"' EXIT

cat > "$DOCROOT/probe.php" <<'PHP'
<?php
echo "DOCUMENT_ROOT="   . $_SERVER['DOCUMENT_ROOT']   . "\n";
echo "SCRIPT_FILENAME=" . $_SERVER['SCRIPT_FILENAME'] . "\n";
echo "PREPEND_RAN="     . (defined('CUSTOMER_PREPEND_RAN') ? 'yes' : 'no') . "\n";
PHP

## Stand-in for the customer's wordfence-waf.php.
cat > "$SITE/customer-waf.php" <<'PHP'
<?php
define('CUSTOMER_PREPEND_RAN', 1);
PHP

## Stand-in for the OLD mechanism (scripts/cac-lsphp-normalize.php).
cat > "$TMP/old-normalize.php" <<'PHP'
<?php
foreach (array('DOCUMENT_ROOT', 'SCRIPT_FILENAME') as $k) {
    if (!empty($_SERVER[$k]) && strncmp($_SERVER[$k], '/mnt/users/', 11) === 0) {
        $r = realpath($_SERVER[$k]);
        if ($r !== false) { $_SERVER[$k] = $r; }
    }
}
PHP

cat > "$TMP/fpm.conf" <<EOF
[global]
error_log = $TMP/fpm-error.log
daemonize = no
[www]
listen = 127.0.0.1:$PORT
pm = static
pm.max_children = 2
EOF

run_case() {
	"$FPM_BIN" -n -y "$TMP/fpm.conf" -F -d user_ini.cache_ttl=0 "$@" \
		>"$TMP/fpm.out" 2>&1 &
	local pid=$! out=""
	for _ in $(seq 1 40); do
		sleep 0.15
		out=$(SCRIPT_FILENAME="$DOCROOT/probe.php" DOCUMENT_ROOT="$DOCROOT" \
			SCRIPT_NAME=/probe.php REQUEST_METHOD=GET QUERY_STRING= \
			cgi-fcgi -bind -connect "127.0.0.1:$PORT" 2>/dev/null)
		[ -n "$out" ] && break
	done
	kill "$pid" 2>/dev/null; wait "$pid" 2>/dev/null
	printf '%s' "$out"
}

expect() {
	local label="$1" got="$2" want="$3"
	if [ "$got" = "$want" ]; then
		echo "  PASS  $label"
	else
		echo "  FAIL  $label"
		echo "        want: $want"
		echo "        got:  $got"
		fail=1
	fi
}
field() { printf '%s' "$1" | sed -n "s/^$2=//p"; }

EXT=( -d "extension=$EXT_SO" )
MAP=( -d "cac_path_parity.from=$SITE" -d "cac_path_parity.to=$HOME_PATH" )
USERINI_LINE="auto_prepend_file = $SITE/customer-waf.php"

echo "== 1. CONTROL: extension loaded, no mapping (reproduces the bug) =="
rm -f "$DOCROOT/.user.ini"
out=$(run_case "${EXT[@]}")
expect "DOCUMENT_ROOT is the raw OLS path"   "$(field "$out" DOCUMENT_ROOT)"   "$DOCROOT"
expect "SCRIPT_FILENAME is the raw OLS path" "$(field "$out" SCRIPT_FILENAME)" "$DOCROOT/probe.php"

echo "== 2. FIX: mapping configured =="
out=$(run_case "${EXT[@]}" "${MAP[@]}")
expect "DOCUMENT_ROOT == cac-fpm value"   "$(field "$out" DOCUMENT_ROOT)"   "$HOME_PATH/public_html"
expect "SCRIPT_FILENAME == cac-fpm value" "$(field "$out" SCRIPT_FILENAME)" "$HOME_PATH/public_html/probe.php"

echo "== 3. WORDFENCE: customer .user.ini auto_prepend_file present =="
printf '%s\n' "$USERINI_LINE" > "$DOCROOT/.user.ini"
out=$(run_case "${EXT[@]}" "${MAP[@]}")
expect "DOCUMENT_ROOT still corrected"        "$(field "$out" DOCUMENT_ROOT)"   "$HOME_PATH/public_html"
expect "SCRIPT_FILENAME still corrected"      "$(field "$out" SCRIPT_FILENAME)" "$HOME_PATH/public_html/probe.php"
expect "customer auto_prepend_file still ran" "$(field "$out" PREPEND_RAN)"     "yes"

echo "== 4. OLD MECHANISM (why the prepend hook could not be hardened) =="
out=$(run_case -d "auto_prepend_file=$TMP/old-normalize.php")
expect "auto_prepend normaliser is displaced by the customer's .user.ini" \
	"$(field "$out" DOCUMENT_ROOT)" "$DOCROOT"
expect "customer's prepend is the one that ran" "$(field "$out" PREPEND_RAN)" "yes"

rm -f "$DOCROOT/.user.ini"
if [ "$fail" -eq 0 ]; then echo "ALL PASS"; else echo "FAILURES"; fi
exit "$fail"