#!/bin/bash

# Arch Linux MATE Xscreensaver full-replace & configuration script
# 	Version 0.1		Author: Ben @ LostGeek.NET
# 	Description: 	Run as your regular user; uses sudo/doas internally
# 		(must have one of these installed & configured for that user)
#

set -euo pipefail

### CONFIG
PACMAN_CONF="/etc/pacman.conf"
AUTOSTART_FILE="$HOME/.config/autostart/xscreensaver.desktop"
USER_NAME="$USER"
USER_HOME="$HOME"

# Detect available privilege escalation command
if command -v sudo &> /dev/null; then
  ELEVATE="sudo"
elif command -v doas &> /dev/null; then
  ELEVATE="doas"
else
  echo "❌ Error: Neither 'sudo' nor 'doas' is installed. Please install one to proceed... Configure it, add yourself to 'wheel' or 'sudo'..."
  exit 1
fi

echo "==> Running xscreensaver setup for MATE on Arch (user: $USER_NAME)"

### Step 1: Ask once about sonar SUID
read -p "Enable sonar hack with ping SUID capability? [y/N]: " ENABLE_SONAR

### Step 2: System-level tasks (via sudo/doas)

# 2.1 Remove mate-screensaver if installed
if pacman -Qs mate-screensaver &> /dev/null; then
  echo "==> Removing mate-screensaver..."
  $ELEVATE pacman -Rns --noconfirm mate-screensaver
else
  echo "✓ mate-screensaver already removed"
fi

# 2.2 Add IgnorePkg to pacman.conf
if $ELEVATE grep -q '^IgnorePkg.*mate-screensaver' "$PACMAN_CONF"; then
  echo "✓ mate-screensaver already pinned in $PACMAN_CONF"
else
  echo "==> Pinning mate-screensaver in $PACMAN_CONF"
  $ELEVATE sed -i '/^\[options\]/a IgnorePkg = mate-screensaver' "$PACMAN_CONF"
fi

# 2.3 Install xscreensaver if missing
if pacman -Q xscreensaver &> /dev/null; then
  echo "✓ xscreensaver already installed"
else
  echo "==> Installing xscreensaver..."
  $ELEVATE pacman -Sy --noconfirm xscreensaver
fi

# 2.4 Symlinks for lock compatibility
declare -A SYMLINKS=(
  [/usr/local/bin/gnome-screensaver-command]=/usr/bin/xscreensaver-command
  [/usr/local/bin/mate-screensaver-command]=/usr/bin/xscreensaver-command
)

for LINK in "${!SYMLINKS[@]}"; do
  TARGET="${SYMLINKS[$LINK]}"
  if $ELEVATE test -L "$LINK" && [[ "$($ELEVATE readlink "$LINK")" == "$TARGET" ]]; then
    echo "✓ $LINK already symlinked to $TARGET"
  else
    echo "==> Creating symlink: $LINK -> $TARGET"
    $ELEVATE ln -sf "$TARGET" "$LINK"
  fi
done

# 2.5 SUID on ping for sonar
if [[ "$ENABLE_SONAR" =~ ^[Yy]$ ]]; then
  if [[ -u /usr/bin/ping ]]; then
    echo "✓ /usr/bin/ping already has setuid bit"
  else
    echo "==> Enabling setuid on /usr/bin/ping"
    $ELEVATE chmod u+s /usr/bin/ping
  fi
else
  echo "✓ Skipping sonar SUID setup"
fi

### Step 3: User-level tasks

# 3.1 Create autostart entry
mkdir -p "$(dirname "$AUTOSTART_FILE")"
AUTOSTART_CONTENT="[Desktop Entry]
Name=XScreenSaver
Exec=xscreensaver -nosplash
StartupNotify=false
Terminal=false
Type=Application
X-GNOME-Autostart-enabled=true"

if [[ -f "$AUTOSTART_FILE" ]] && grep -q "Exec=xscreensaver -nosplash" "$AUTOSTART_FILE"; then
  echo "✓ Autostart already configured"
else
  echo "==> Creating xscreensaver autostart entry"
  echo "$AUTOSTART_CONTENT" > "$AUTOSTART_FILE"
fi

# 3.2 Set MATE lock command via dconf
if command -v dconf &> /dev/null; then
  CURRENT_CMD=$(dconf read /org/mate/desktop/screensaver/lock-command 2>/dev/null || echo "")
  if [[ "$CURRENT_CMD" == "'xscreensaver-command -lock'" ]]; then
    echo "✓ MATE lock command already set to xscreensaver"
  else
    echo "==> Setting MATE lock command to xscreensaver"
    dconf write /org/mate/desktop/screensaver/lock-enabled true
    dconf write /org/mate/desktop/screensaver/lock-command "'xscreensaver-command -lock'"
  fi
else
  echo "⚠ dconf not found — skipping MATE lock command config"
fi

echo "Complete."
echo "Log out & back in, XSS will auto-start."