#!/usr/bin/env sh
set -eu

INSTALL_DIR="${PLATFORM_AGENT_DIR:-/opt/platform-agent}"
SERVICE_NAME="${PLATFORM_AGENT_SERVICE:-platform-agent}"
SERVICE_FILE="/etc/systemd/system/${SERVICE_NAME}.service"

log() {
  printf '%s\n' "$*"
}

need_cmd() {
  command -v "$1" >/dev/null 2>&1
}

as_root() {
  if [ "$(id -u)" -eq 0 ]; then
    "$@"
  elif need_cmd sudo; then
    sudo "$@"
  else
    log "Root privileges are required: $*"
    exit 1
  fi
}

prompt_yes_no() {
  label="$1"
  default="${2:-no}"
  suffix="[y/N]"
  [ "$default" = "yes" ] && suffix="[Y/n]"
  printf '%s %s ' "$label" "$suffix"
  IFS= read -r answer || answer=""
  answer="$(printf '%s' "$answer" | tr '[:upper:]' '[:lower:]')"
  if [ -z "$answer" ]; then
    [ "$default" = "yes" ]
    return
  fi
  [ "$answer" = "y" ] || [ "$answer" = "yes" ]
}

read_config_value() {
  key_path="$1"
  config_path="${INSTALL_DIR}/agent.config.json"
  if [ ! -f "$config_path" ] || ! need_cmd python3; then
    return
  fi
  python3 - "$config_path" "$key_path" <<'PY'
import json
import sys

with open(sys.argv[1], "r", encoding="utf-8") as fp:
    data = json.load(fp)

value = data
for key in sys.argv[2].split("."):
    if not isinstance(value, dict):
        value = None
        break
    value = value.get(key)

if isinstance(value, str):
    print(value)
PY
}

expand_path_for_user() {
  path="$1"
  run_user="$2"
  case "$path" in
    "~")
      if [ "$run_user" = "root" ]; then
        printf '/root'
      else
        printf '/home/%s' "$run_user"
      fi
      ;;
    "~/"*)
      if [ "$run_user" = "root" ]; then
        printf '/root/%s' "${path#~/}"
      else
        printf '/home/%s/%s' "$run_user" "${path#~/}"
      fi
      ;;
    *)
      printf '%s' "$path"
      ;;
  esac
}

service_user() {
  if [ -f "$SERVICE_FILE" ]; then
    user_line="$(sed -n 's/^User=//p' "$SERVICE_FILE" | head -n 1)"
    [ -n "$user_line" ] && {
      printf '%s' "$user_line"
      return
    }
  fi
  id -un
}

remove_packages() {
  packages="$1"
  if [ -z "$packages" ]; then
    return
  fi
  if need_cmd apt-get; then
    as_root apt-get remove -y $packages || true
    as_root apt-get autoremove -y || true
  elif need_cmd dnf; then
    as_root dnf remove -y $packages || true
  elif need_cmd yum; then
    as_root yum remove -y $packages || true
  elif need_cmd pacman; then
    as_root pacman -Rns --noconfirm $packages || true
  elif need_cmd zypper; then
    as_root zypper --non-interactive remove $packages || true
  else
    log "No supported package manager found. Skipping package removal."
  fi
}

clear
log "Autonomy Studio Platform Agent Uninstall"
log "========================================"
log "Service     : ${SERVICE_NAME}"
log "Install dir : ${INSTALL_DIR}"
log ""

RUN_USER="$(service_user)"
WORKSPACE_ROOT="$(read_config_value workspace.root || true)"
[ -n "${WORKSPACE_ROOT:-}" ] || WORKSPACE_ROOT="~/autonomy-studio/workspaces"
WORKSPACE_PATH="$(expand_path_for_user "$WORKSPACE_ROOT" "$RUN_USER")"

log "Detected user      : ${RUN_USER}"
log "Workspace root     : ${WORKSPACE_ROOT}"
log "Resolved workspace : ${WORKSPACE_PATH}"
log ""

if ! prompt_yes_no "Uninstall the platform agent now?" "no"; then
  log "Canceled."
  exit 0
fi

if need_cmd systemctl; then
  log "Stopping systemd service."
  as_root systemctl stop "$SERVICE_NAME" 2>/dev/null || true
  as_root systemctl disable "$SERVICE_NAME" 2>/dev/null || true
  if [ -f "$SERVICE_FILE" ]; then
    as_root rm -f "$SERVICE_FILE"
    as_root systemctl daemon-reload
  fi
elif need_cmd service; then
  as_root service "$SERVICE_NAME" stop 2>/dev/null || true
fi

if prompt_yes_no "Remove install directory ${INSTALL_DIR}?" "yes"; then
  case "$INSTALL_DIR" in
    "/"|"/root"|"/home"|"/usr"|"/opt"|"/var"|"/etc")
      log "Refusing to remove broad system directory: ${INSTALL_DIR}"
      ;;
    *)
      as_root rm -rf "$INSTALL_DIR"
      ;;
  esac
fi

if prompt_yes_no "Delete workspace ${WORKSPACE_PATH}? This removes cloned modules and user files." "no"; then
  case "$WORKSPACE_PATH" in
    "/home/$RUN_USER"|"/home/$RUN_USER/")
      log "Refusing to remove user home directory: ${WORKSPACE_PATH}"
      ;;
    "/"|"/root"|"/home"|"/usr"|"/opt"|"/var"|"/etc"|"/home/"*)
      as_root rm -rf "$WORKSPACE_PATH"
      ;;
    *)
      as_root rm -rf "$WORKSPACE_PATH"
      ;;
  esac
fi

if need_cmd tailscale && prompt_yes_no "Logout this device from Tailscale/Headscale?" "no"; then
  as_root tailscale logout || true
fi

if prompt_yes_no "Remove packages installed by install.sh if present? (tailscale openssh-server git)" "no"; then
  remove_packages "tailscale openssh-server git"
fi

log ""
log "Uninstall complete."