#!/usr/bin/env bash
set -Eeuo pipefail

ETC_DIR=${PLUGIN_ETC_DIR:-/etc/sub2api-add}
VAR_DIR=${PLUGIN_VAR_DIR:-/var/lib/sub2api-add}
PREFIX=${PLUGIN_INSTALL_PREFIX:-/opt/sub2api-add}
SOURCE_DIR=${PLUGIN_SOURCE_DIR:-/opt/sub2api-add}
RUN_USER=${PLUGIN_SYSTEM_USER:-sub2api-plugin}
SELECTION=all
PURGE=false
YES=false

validate_managed_root() {
  local value=$1 label=$2 component current=""
  [[ -n "$value" && "$value" = /* ]] || die "$label 必须是绝对路径"
  [[ "$value" != *$'\n'* && "$value" != *$'\r'* ]] || die "$label 包含非法换行"
  [[ "$value" != "/" ]] || die "$label 不允许指向根目录"
  local parts=()
  IFS='/' read -r -a parts <<< "${value#/}"
  for component in "${parts[@]}"; do
    [[ -z "$component" ]] && continue
    [[ "$component" != "." && "$component" != ".." ]] || die "$label 不能包含 . 或 .. 路径组件"
    current="$current/$component"
    [[ ! -L "$current" ]] || die "$label 的路径组件不能是符号链接：$current"
    [[ ! -e "$current" || -d "$current" ]] || die "$label 的路径组件不是目录：$current"
  done
  if [[ "$value" != */sub2api-add && "${PLUGIN_ALLOW_CUSTOM_PATHS:-false}" != "true" ]]; then
    die "$label 必须位于受管的 sub2api-add 目录；如确需自定义路径请显式设置 PLUGIN_ALLOW_CUSTOM_PATHS=true"
  fi
}

ensure_real_parent() {
  local path=$1 label=$2 parent component current="" parts=()
  parent=$(dirname -- "$path")
  IFS='/' read -r -a parts <<< "${parent#/}"
  for component in "${parts[@]}"; do
    [[ -z "$component" ]] && continue
    current="$current/$component"
    [[ -d "$current" && ! -L "$current" ]] || die "$label 的父目录必须是已存在的真实目录：$current"
  done
}

ensure_real_dir() {
  local path=$1 label=$2 component current="" parts=()
  [[ -n "$path" && "$path" = /* ]] || die "$label 路径无效"
  IFS='/' read -r -a parts <<< "${path#/}"
  for component in "${parts[@]}"; do
    [[ -z "$component" ]] && continue
    current="$current/$component"
    [[ -d "$current" && ! -L "$current" ]] || die "$label 必须是已存在的真实目录：$current"
  done
}

ensure_regular_target() {
  local path=$1 label=$2
  [[ ! -L "$path" ]] || die "$label 不能是符号链接：$path"
}

die() { printf '错误：%s\n' "$*" >&2; exit 1; }
[[ $EUID -eq 0 ]] || die "请使用 root 或 sudo 运行"
command -v systemctl >/dev/null 2>&1 || die "缺少 systemd/systemctl"

while (($#)); do
  case "$1" in
    --plugin) (($# >= 2)) || die "--plugin 需要参数"; SELECTION=$2; shift 2 ;;
    --purge) PURGE=true; shift ;;
    --yes) YES=true; shift ;;
    -h|--help) printf '%s\n' '用法：deploy/uninstall.sh [--plugin all|plugin-admin|subscription-admin] [--purge --yes]'; exit 0 ;;
    *) die "未知参数：$1" ;;
  esac
done

case "$SELECTION" in
  all) PLUGINS=(plugin-admin subscription-admin) ;;
  plugin-admin|subscription-admin) PLUGINS=("$SELECTION") ;;
  *) die "插件必须是 all、plugin-admin 或 subscription-admin" ;;
esac

validate_managed_root "$ETC_DIR" PLUGIN_ETC_DIR
validate_managed_root "$VAR_DIR" PLUGIN_VAR_DIR
validate_managed_root "$PREFIX" PLUGIN_INSTALL_PREFIX
validate_managed_root "$SOURCE_DIR" PLUGIN_SOURCE_DIR
ensure_real_parent "$ETC_DIR" PLUGIN_ETC_DIR
ensure_real_parent "$VAR_DIR" PLUGIN_VAR_DIR
ensure_real_parent "$PREFIX" PLUGIN_INSTALL_PREFIX
ensure_real_parent "$SOURCE_DIR" PLUGIN_SOURCE_DIR
ensure_real_dir /etc/systemd/system SYSTEMD_UNIT_DIR
if $PURGE && [[ "${PLUGIN_PURGE_SOURCE:-true}" == "true" && "$SOURCE_DIR" != "$PREFIX" && "${PLUGIN_ALLOW_CUSTOM_PATHS:-false}" != "true" ]]; then
  die "为避免误删，--purge 默认要求 PLUGIN_SOURCE_DIR 与 PLUGIN_INSTALL_PREFIX 相同"
fi

if $PURGE && ! $YES; then
  [[ -t 0 ]] || die "非交互环境执行 --purge 时必须同时提供 --yes"
  read -r -p "将删除插件配置和数据，继续？[y/N] " answer
  [[ "$answer" == [yY] ]] || { printf '%s\n' '已取消'; exit 0; }
fi

for plugin in "${PLUGINS[@]}"; do
  unit="sub2api-$plugin.service"
  unit_path="/etc/systemd/system/$unit"
  if [[ -e "$unit_path" || -L "$unit_path" ]]; then
    ensure_regular_target "$unit_path" SYSTEMD_UNIT
  fi
  systemctl disable --now "$unit" 2>/dev/null || true
  rm -f -- "$unit_path"
  # Keep the checked-out source clean so a later install can fast-forward it.
  # Only generated binaries are removed unless --purge is explicitly used.
  if [[ -e "$PREFIX/$plugin/bin/$plugin" || -L "$PREFIX/$plugin/bin/$plugin" ]]; then
    ensure_real_parent "$PREFIX/$plugin/bin/$plugin" PLUGIN_INSTALL_PREFIX
    rm -f -- "$PREFIX/$plugin/bin/$plugin"
  fi
  if $PURGE; then
    plugin_root="$PREFIX/$plugin"
    if [[ -d "$plugin_root" && ! -L "$plugin_root" ]]; then
      ensure_real_parent "$plugin_root" PLUGIN_INSTALL_PREFIX
      rm -rf -- "${plugin_root:?}"
    fi
    rm -f -- "$ETC_DIR/$plugin.env"
    plugin_data="$VAR_DIR/$plugin"
    if [[ -d "$plugin_data" && ! -L "$plugin_data" ]]; then
      ensure_real_parent "$plugin_data" PLUGIN_VAR_DIR
      rm -rf -- "${plugin_data:?}"
    fi
  fi
done

systemctl daemon-reload
if $PURGE && [[ -d "$ETC_DIR" && ! -L "$ETC_DIR" ]]; then rmdir "$ETC_DIR" 2>/dev/null || true; fi
if $PURGE && [[ -d "$VAR_DIR" && ! -L "$VAR_DIR" ]]; then rmdir "$VAR_DIR" 2>/dev/null || true; fi
if $PURGE && [[ "${PLUGIN_PURGE_SOURCE:-true}" == "true" && "$SOURCE_DIR" == "$PREFIX" && -d "$SOURCE_DIR" && ! -L "$SOURCE_DIR" ]]; then ensure_real_parent "$SOURCE_DIR" PLUGIN_SOURCE_DIR; rm -rf -- "$SOURCE_DIR"; fi

if $PURGE; then
  userdel "$RUN_USER" 2>/dev/null || true
  printf '%s\n' '插件、配置、数据和源码已删除；Core 数据库未被触碰。'
else
  printf '%s\n' "插件服务已卸载；配置和数据仍保留在 $ETC_DIR 与 $VAR_DIR。"
fi