#!/bin/bash
set -euo pipefail

# Officer Remote Desktop Setup — Ubuntu GNOME desktop on Xorg, mirrored over VNC.
#
# The platform mirrors the single physical display :0 with x11vnc (see vnc-manager.ts). x11vnc can only
# capture an Xorg server, NOT a Wayland compositor — so we install the full GNOME desktop but force GDM
# onto the Xorg session (WaylandEnable=false). Auto-login is enabled so a user session owns :0 for the
# mirror to attach to. Switching the display manager takes effect on the next reboot.
# Usage: ./scripts/setup/setup-desktop.sh

echo "=== Officer Remote Desktop Setup (Ubuntu GNOME on Xorg) ==="
echo ""

DESKTOP_USER="$(whoami)"

# --- Step 1: Install GNOME desktop + GDM + x11vnc ---
echo "[1/6] Installing ubuntu-desktop, GDM, x11vnc..."
sudo apt update -qq
sudo DEBIAN_FRONTEND=noninteractive apt install -y -qq \
  ubuntu-desktop \
  gdm3 \
  x11vnc \
  dbus-x11
echo "  Done."
# No tigervnc package is needed. The VNC sidecar writes the .vnc/passwd rfbauth file with
# `x11vnc -storepasswd` (see vnc-manager.ts). tigervnc-common was installed here for `vncpasswd`,
# but it does not ship that binary — it only provides tigervncconfig — so the rfbauth file was never
# created and the desktop could not authenticate.

# --- Step 2: Force GDM onto Xorg + enable auto-login (x11vnc cannot mirror Wayland) ---
echo "[2/6] Forcing Xorg session and auto-login in GDM..."
GDM_CONF=/etc/gdm3/custom.conf
sudo mkdir -p /etc/gdm3
[ -f "$GDM_CONF" ] || echo "[daemon]" | sudo tee "$GDM_CONF" > /dev/null
# Ensure a [daemon] section exists to anchor the keys under.
sudo grep -qE '^\[daemon\]' "$GDM_CONF" || echo "[daemon]" | sudo tee -a "$GDM_CONF" > /dev/null

# Set key=value under [daemon]: rewrite an existing (possibly commented) line, else insert after [daemon].
set_gdm_key() {
  local key="$1" val="$2"
  if sudo grep -qE "^[[:space:]]*#?[[:space:]]*${key}=" "$GDM_CONF"; then
    sudo sed -i "s|^[[:space:]]*#\?[[:space:]]*${key}=.*|${key}=${val}|" "$GDM_CONF"
  else
    sudo sed -i "/^\[daemon\]/a ${key}=${val}" "$GDM_CONF"
  fi
}

set_gdm_key WaylandEnable false
set_gdm_key AutomaticLoginEnable true
set_gdm_key AutomaticLogin "$DESKTOP_USER"
echo "  Xorg forced (WaylandEnable=false), auto-login as $DESKTOP_USER."

# --- Step 3: Make GDM the default display manager ---
echo "[3/6] Setting GDM as the default display manager..."
echo "/usr/sbin/gdm3" | sudo tee /etc/X11/default-display-manager > /dev/null
sudo systemctl enable gdm3 >/dev/null 2>&1 || sudo systemctl enable gdm >/dev/null 2>&1 || true
sudo systemctl set-default graphical.target >/dev/null 2>&1 || true
# Disable any prior display manager so it doesn't fight GDM. lightdm is named because earlier versions
# of this script installed XFCE; a host set up back then still has it and it would win the boot race.
sudo systemctl disable lightdm >/dev/null 2>&1 || true
echo "  Done (takes effect on next reboot)."

# --- Step 4: Install Brave browser (native .deb, not snap) ---
echo "[4/6] Installing Brave browser..."
if ! command -v brave-browser-stable > /dev/null 2>&1; then
  sudo curl -fsSLo /usr/share/keyrings/brave-browser-archive-keyring.gpg \
    https://brave-browser-apt-release.s3.brave.com/brave-browser-archive-keyring.gpg
  echo "deb [signed-by=/usr/share/keyrings/brave-browser-archive-keyring.gpg] https://brave-browser-apt-release.s3.brave.com/ stable main" \
    | sudo tee /etc/apt/sources.list.d/brave-browser-release.list > /dev/null
  sudo apt update -qq
  sudo DEBIAN_FRONTEND=noninteractive apt install -y -qq brave-browser
fi
# Fix launcher symlink
if [ -f /opt/brave.com/brave/brave-browser ]; then
  sudo rm -f /usr/bin/brave-browser-stable
  sudo ln -s /opt/brave.com/brave/brave-browser /usr/bin/brave-browser-stable
fi
# Tell Brave to use basic password store (no keyring prompts)
sudo mkdir -p /etc/brave
echo '--password-store=basic' | sudo tee /etc/brave/brave-flags.conf > /dev/null
echo "  Done."

# --- Step 5: Remove GNOME Keyring + set default browser (prevents password prompts on login) ---
echo "[5/6] Removing GNOME Keyring and setting default browser..."
sudo apt remove -y --purge gnome-keyring > /dev/null 2>&1 || true
rm -rf ~/.local/share/keyrings
if command -v brave-browser-stable > /dev/null 2>&1; then
  sudo update-alternatives --set x-www-browser /opt/brave.com/brave/brave 2>/dev/null || true
  echo "  Brave set as default."
else
  echo "  No supported browser found, skipping default."
fi

# --- Step 6: Headless display (keep a desktop when no monitor is attached) ---
echo "[6/6] Configuring the headless display..."

# x11vnc mirrors :0, but with nothing plugged in the connector has no EDID and no CRTC, so GNOME
# renders nothing and the mirror is black. Replaying a real monitor's EDID makes the connector look
# permanently attached. The EDID has to be captured from a screen that is plugged in *now* — there is
# nothing to copy otherwise — so this step is skipped on a headless run and can be re-run later.
EDID_DIR=/lib/firmware/edid
EDID_FILE="$EDID_DIR/officer-screen.bin"
CONNECTED_SYSFS=""
for c in /sys/class/drm/card*-*/status; do
  [ "$(cat "$c" 2>/dev/null)" = "connected" ] || continue
  CONNECTED_SYSFS="$(basename "$(dirname "$c")")"
  break
done

if [ -z "$CONNECTED_SYSFS" ] && [ ! -f "$EDID_FILE" ]; then
  echo "  ! No display connected and no EDID saved — skipping."
  echo "    Plug a monitor in and re-run this script to capture one, otherwise the remote"
  echo "    desktop will be black whenever nothing is attached."
else
  # cardN-HDMI-A-1 -> HDMI-A-1, which is the name the kernel parameters use (card numbering can
  # change between boots; the connector name does not).
  if [ -n "$CONNECTED_SYSFS" ]; then
    CONNECTOR="${CONNECTED_SYSFS#*-}"
    sudo mkdir -p "$EDID_DIR"
    sudo cp "/sys/class/drm/$CONNECTED_SYSFS/edid" "$EDID_FILE"
    echo "  Captured EDID from $CONNECTOR ($(stat -c%s "$EDID_FILE") bytes)."
    echo "$CONNECTOR" | sudo tee "$EDID_DIR/officer-connector" > /dev/null
  else
    CONNECTOR="$(cat "$EDID_DIR/officer-connector" 2>/dev/null || echo HDMI-A-1)"
    echo "  Reusing the saved EDID for $CONNECTOR."
  fi

  # drm.edid_firmware makes the connector report that EDID; the trailing "e" on video= forces it
  # enabled with nothing attached. amdgpu is not in the initramfs, so /lib/firmware is readable by
  # the time the driver loads and no initramfs rebuild is needed.
  KERNEL_ARGS="drm.edid_firmware=$CONNECTOR:edid/officer-screen.bin video=$CONNECTOR:1920x1080e"
  if grep -q "drm.edid_firmware=" /etc/default/grub; then
    echo "  GRUB already carries a forced EDID — leaving it alone."
  else
    sudo cp /etc/default/grub "/etc/default/grub.bak-$(date +%Y%m%d%H%M%S)"
    CURRENT=$(grep "^GRUB_CMDLINE_LINUX_DEFAULT=" /etc/default/grub | sed 's/^[^"]*"//; s/"$//')
    sudo sed -i "s|^GRUB_CMDLINE_LINUX_DEFAULT=.*|GRUB_CMDLINE_LINUX_DEFAULT=\"${CURRENT:+$CURRENT }$KERNEL_ARGS\"|" /etc/default/grub
    sudo update-grub > /dev/null 2>&1
    echo "  Added the forced EDID to the kernel command line (takes effect on reboot)."
  fi

  # The EDID's preferred mode is whatever the captured panel was, which may be small. GNOME picks
  # preferred, so raise it at session start.
  install -d "$HOME/.local/bin" "$HOME/.config/autostart"
  install -m 755 "$(dirname "$0")/officer-set-display.sh" "$HOME/.local/bin/officer-set-display.sh"
  cat > "$HOME/.config/autostart/officer-set-display.desktop" <<AUTOSTART
[Desktop Entry]
Type=Application
Name=Officer display mode
Comment=Raise the headless display to its largest usable mode at login
Exec=$HOME/.local/bin/officer-set-display.sh
X-GNOME-Autostart-enabled=true
NoDisplay=true
AUTOSTART
  echo "  Installed the login-time mode setter."
fi
echo "  Done."

# --- Cleanup old systemd service if it exists ---
if systemctl list-unit-files officer-vnc.service &>/dev/null; then
  echo ""
  echo "Removing old officer-vnc systemd service..."
  sudo systemctl stop officer-vnc 2>/dev/null || true
  sudo systemctl disable officer-vnc 2>/dev/null || true
  sudo rm -f /etc/systemd/system/officer-vnc.service
  sudo systemctl daemon-reload
  echo "  Done."
fi

echo ""
echo "Setup complete. The screen mirror (x11vnc on :0) is managed by the VNC sidecar."
echo "REBOOT to switch into the GNOME-on-Xorg session with auto-login."