#!/bin/sh
# uninstall-synology.sh — remove the exact Synology DSM installation that
# contains this script. DSM Task Scheduler entries remain a manual cleanup.
set -u

YES=0
for arg in "$@"; do
	case "$arg" in
	--yes) YES=1 ;;
	--help | -h) echo "Usage: sudo sh $0 [--yes]"; exit 0 ;;
	*) echo "!! 未知参数:$arg" >&2; exit 2 ;;
	esac
done

ROOT_PREFIX="${MYVPN_UNINSTALL_ROOT:-}"
case "$ROOT_PREFIX" in
"" | /) ROOT_PREFIX="" ;;
/*) ROOT_PREFIX="${ROOT_PREFIX%/}" ;;
*) echo "!! MYVPN_UNINSTALL_ROOT 必须是绝对路径" >&2; exit 2 ;;
esac
root_path() { printf '%s%s\n' "$ROOT_PREFIX" "$1"; }

effective_uid="$(id -u)"
if [ -n "$ROOT_PREFIX" ]; then
	effective_uid="${MYVPN_UNINSTALL_TEST_UID:-$effective_uid}"
fi
[ "$effective_uid" -eq 0 ] || {
	echo "!! 卸载需要 root。请用:sudo sh $0" >&2
	exit 1
}

SCRIPT_DIR="$(CDPATH= cd "$(dirname "$0")" && pwd -P)"
if [ -n "${MYVPN_APP:-}" ]; then
	APP="$MYVPN_APP"
elif [ -n "$ROOT_PREFIX" ]; then
	case "$SCRIPT_DIR" in
	"$ROOT_PREFIX"/*) APP="${SCRIPT_DIR#"$ROOT_PREFIX"}" ;;
	*) APP="/volume1/myvpn" ;;
	esac
else
	APP="$SCRIPT_DIR"
fi
case "$APP" in
/*) ;;
*) echo "!! MYVPN_APP 必须是绝对路径" >&2; exit 2 ;;
esac
REAL_APP="$(root_path "$APP")"
case "$REAL_APP" in "" | / | "$ROOT_PREFIX") echo "!! 拒绝删除不安全的安装路径:$REAL_APP" >&2; exit 1 ;; esac
[ -d "$REAL_APP" ] || {
	echo "myvpn 已不在 ${APP}，视为卸载完成。"
	echo "提醒：控制台中的设备记录仍需管理员另行删除；DSM 任务计划也请手工检查。"
	exit 0
}
APP_DIR="$(CDPATH= cd "$REAL_APP" && pwd -P)"
[ "$APP_DIR" = "$SCRIPT_DIR" ] || {
	echo "!! 拒绝卸载:$0 不在目标安装目录 $APP 内。" >&2
	exit 1
}
TARGET_APP="$APP_DIR"
case "$TARGET_APP" in "" | / | "$ROOT_PREFIX") echo "!! 拒绝删除不安全的物理安装路径:$TARGET_APP" >&2; exit 1 ;; esac
logical_app_is_link=0
[ -L "$REAL_APP" ] && logical_app_is_link=1
LOGICAL_SUPERVISOR="$REAL_APP/myvpn-run.sh"

echo "即将完整卸载 $APP 下的 myvpn 程序、登录状态、凭据和日志。"
echo "本地卸载不会删除控制台中的设备记录；如需删除，请让管理员在控制台另行操作。"
if [ "$YES" -ne 1 ]; then
	printf "继续卸载？输入 y 确认 [y/N]: "
	answer=""
	IFS= read -r answer || true
	case "$answer" in y | Y | yes | YES | Yes) ;; *) echo "已取消，未做任何更改。"; exit 0 ;; esac
fi

SOCK="$TARGET_APP/agent.sock"
CLI="$TARGET_APP/myvpn"
if [ -x "$CLI" ]; then
	MYVPN_SOCKET="$SOCK" "$CLI" down >/dev/null 2>&1 || true
fi

# Match argv structurally rather than flattening cmdline and doing a substring
# search. The agent must be argv[0]. The supervisor is either argv[0] itself or
# argv[1] of a known shell (the normal #!/bin/sh representation). This avoids
# killing an editor/logger merely because one of its arguments mentions a path
# beginning with "$TARGET_APP/myvpn-agent".
PROC_DIR="${MYVPN_PROC:-$(root_path /proc)}"
cmdline_is_myvpn() {
	cmdline="$1"
	argv0="$(tr '\0' '\n' <"$cmdline" 2>/dev/null | sed -n '1p')"
	argv1="$(tr '\0' '\n' <"$cmdline" 2>/dev/null | sed -n '2p')"
	[ "$argv0" = "$TARGET_APP/myvpn-agent" ] && return 0
	{ [ "$argv0" = "$TARGET_APP/myvpn-run.sh" ] || [ "$argv0" = "$LOGICAL_SUPERVISOR" ]; } && return 0
	case "$argv0" in
	sh | ash | bash | dash | */sh | */ash | */bash | */dash)
		{ [ "$argv1" = "$TARGET_APP/myvpn-run.sh" ] || [ "$argv1" = "$LOGICAL_SUPERVISOR" ]; } && return 0
		;;
	esac
	return 1
}
matching_pids() {
	[ -d "$PROC_DIR" ] || return 0
	for d in "$PROC_DIR"/[0-9]*; do
		[ -d "$d" ] || continue
		[ -r "$d/cmdline" ] || continue
		p="${d##*/}"
		[ "$p" = "$$" ] && continue
		cmdline_is_myvpn "$d/cmdline" && echo "$p"
	done
}

pids="$(matching_pids)"
if [ -n "$pids" ]; then
	for p in $pids; do kill -TERM "$p" 2>/dev/null || true; done
	i=0
	while [ "$i" -lt 20 ] && [ -n "$(matching_pids)" ]; do
		sleep 1
		i=$((i + 1))
	done
	for p in $(matching_pids); do kill -KILL "$p" 2>/dev/null || true; done
	sleep 1
fi
left="$(matching_pids)"
[ -z "$left" ] || {
	echo "!! 无法停止 $APP 的 myvpn 进程:$left；未删除安装目录。" >&2
	exit 1
}

if ! rm -rf "$TARGET_APP"; then
	echo "!! 删除安装目录失败:$TARGET_APP；凭据或程序可能仍然存在。" >&2
	exit 1
fi
[ ! -e "$TARGET_APP" ] && [ ! -L "$TARGET_APP" ] || {
	echo "!! 删除后安装目录仍然存在:$TARGET_APP；卸载不完整。" >&2
	exit 1
}

echo "myvpn 已从 $APP 完整卸载。"
[ "$logical_app_is_link" -eq 0 ] || echo "提醒:$REAL_APP 是用户提供的符号链接，物理安装内容已删除，但该失效链接已保留。"
echo "⚠️ 请到 DSM「控制面板 → 任务计划」手工删除指向 $APP/myvpn-run.sh 的启动任务。"
echo "提醒：控制台中的设备记录仍然保留，需要管理员另行删除。"