#!/bin/bash
# Sets up an antiX laptop for the classroom:
#   1. removes Firefox ESR and the other small browsers antiX ships with (first, to free space),
#   2. installs Chromium,
#   3. signs in automatically and opens ZeroAI Studio full screen at start-up,
#   4. reopens Studio if it is closed,
#   5. Shift+Alt+K leaves Studio for the normal browser, after the admin password;
#      Shift+Alt+Z goes back into Studio.
# Run it with:  wget -qO- b.zeroaitech.tech | sudo bash
# Safe to run again: it only changes what is not already set up.
set -uo pipefail

STUDIO_URL="https://studio.zeroaitech.tech"

if [ "$(id -u)" -ne 0 ]; then
  echo "This needs admin rights. Run:  wget -qO- b.zeroaitech.tech | sudo bash"
  exit 1
fi
export DEBIAN_FRONTEND=noninteractive

# The person who ran sudo is the account the laptop signs in to and sets up.
USER_NAME="${SUDO_USER:-}"
if [ -z "$USER_NAME" ] || [ "$USER_NAME" = root ]; then
  USER_NAME=$(getent passwd | awk -F: '$3 >= 1000 && $3 < 60000 {print $1; exit}')
fi
if [ -z "$USER_NAME" ]; then
  echo "Could not find the laptop's user account. Run this from that account with sudo."
  exit 1
fi
USER_HOME=$(getent passwd "$USER_NAME" | cut -d: -f6)
echo "==> Setting up the account: $USER_NAME ($USER_HOME)"

# --- 1. Remove Firefox ESR and other browsers first -------------------------------------------------
echo "==> Removing Firefox ESR and other browsers"
REMOVE=""
for pattern in 'firefox-esr*' 'firefox' 'dillo' 'links' 'links2' 'elinks' 'netsurf*' 'seamonkey*' 'palemoon*' 'midori' 'qutebrowser' 'falkon' 'epiphany-browser' 'luakit' 'surf' 'konqueror'; do
  found=$(dpkg-query -W -f='${binary:Package} ${Status}\n' "$pattern" 2>/dev/null | awk '/ installed$/ {print $1}')
  [ -n "$found" ] && REMOVE="$REMOVE $found"
done
if [ -n "$REMOVE" ]; then
  echo "    Removing:$REMOVE"
  apt-get purge -y $REMOVE
  apt-get autoremove -y
  apt-get clean
else
  echo "    No other browsers installed"
fi

# --- 2. Install Chromium (and yad, for the password box) ------------------------------------------------
echo "==> Installing Chromium"
apt-get update
apt-get install -y chromium yad
if ! command -v chromium >/dev/null; then
  echo "Chromium did not install. Check the internet connection and run this again."
  exit 1
fi
for link in x-www-browser gnome-www-browser; do
  update-alternatives --set "$link" /usr/bin/chromium 2>/dev/null || true
done

# --- 3. The Studio launcher, the way out, and the way back ------------------------------------------------
echo "==> Installing the Studio launcher"
cat > /usr/local/bin/studio-kiosk <<EOF
#!/bin/bash
# Keeps ZeroAI Studio open full screen. If it is closed, it opens again a few seconds later,
# until someone leaves with Shift+Alt+K and the admin password.
OFF="/tmp/studio-kiosk-off-\$(id -u)"
rm -f "\$OFF"
# One launcher per person: a second copy (say, a double start) quietly exits.
exec 9>"/tmp/studio-kiosk-lock-\$(id -u)"
flock -n 9 || exit 0
while [ ! -e "\$OFF" ]; do
  chromium --kiosk --no-first-run --noerrdialogs --disable-session-crashed-bubble \\
    --disable-infobars --password-store=basic --user-data-dir="\$HOME/.config/studio-kiosk" \\
    "$STUDIO_URL"
  [ -e "\$OFF" ] && break
  sleep 3
done
EOF

cat > /usr/local/bin/studio-exit <<'EOF'
#!/bin/bash
# Shift+Alt+K: leave Studio for the normal browser, after the admin (sudo) password.
pass=$(yad --entry --hide-text --center --on-top --width=360 --title="Leave ZeroAI Studio" \
  --text="Enter the admin password to leave ZeroAI Studio." --button=Cancel:1 --button=OK:0) || exit 0
if printf '%s\n' "$pass" | sudo -S -k -p '' true 2>/dev/null; then
  touch "/tmp/studio-kiosk-off-$(id -u)"
  pkill -u "$(id -u)" -f 'user-data-dir=.*studio-kiosk' 2>/dev/null
  sleep 1
  chromium >/dev/null 2>&1 &
else
  yad --error --center --on-top --title="Leave ZeroAI Studio" --text="That password is not right." --button=OK:0
fi
EOF

cat > /usr/local/bin/studio-return <<'EOF'
#!/bin/bash
# Shift+Alt+Z: back into ZeroAI Studio full screen.
setsid /usr/local/bin/studio-kiosk >/dev/null 2>&1 &
EOF
chmod 755 /usr/local/bin/studio-kiosk /usr/local/bin/studio-exit /usr/local/bin/studio-return

# --- 4. Start Studio when the desktop starts, and add the keys ---------------------------------------------
echo "==> Starting Studio with the desktop"
as_user() { sudo -u "$USER_NAME" "$@"; }
add_line() { # file, line: adds the line once, creating the file if needed
  as_user mkdir -p "$(dirname "$1")"
  as_user touch "$1"
  grep -qxF "$2" "$1" || printf '%s\n' "$2" | as_user tee -a "$1" >/dev/null
}

# antiX runs ~/.desktop-session/startup for every desktop (Fluxbox, IceWM, JWM).
add_line "$USER_HOME/.desktop-session/startup" "/usr/local/bin/studio-kiosk &"
as_user chmod +x "$USER_HOME/.desktop-session/startup"
# Fluxbox's own start file too, before its last line, in case the one above is not used.
FB_START="$USER_HOME/.fluxbox/startup"
if [ -f "$FB_START" ] && ! grep -q studio-kiosk "$FB_START"; then
  if grep -q '^exec ' "$FB_START"; then
    sed -i '0,/^exec /s//\/usr\/local\/bin\/studio-kiosk \&\nexec /' "$FB_START"
  else
    printf '%s\n' "/usr/local/bin/studio-kiosk &" >> "$FB_START"
  fi
fi

echo "==> Adding Shift+Alt+K (leave Studio) and Shift+Alt+Z (back to Studio)"
add_line "$USER_HOME/.fluxbox/keys" "Shift Mod1 k :Exec /usr/local/bin/studio-exit"
add_line "$USER_HOME/.fluxbox/keys" "Shift Mod1 z :Exec /usr/local/bin/studio-return"
add_line "$USER_HOME/.icewm/keys" 'key "Shift+Alt+k" /usr/local/bin/studio-exit'
add_line "$USER_HOME/.icewm/keys" 'key "Shift+Alt+z" /usr/local/bin/studio-return'
JWM_KEYS="$USER_HOME/.jwm/keys"
if [ -f "$JWM_KEYS" ] && ! grep -q studio-exit "$JWM_KEYS"; then
  sed -i 's#</JWM>#    <Key mask="SA" key="k">exec:/usr/local/bin/studio-exit</Key>\n    <Key mask="SA" key="z">exec:/usr/local/bin/studio-return</Key>\n</JWM>#' "$JWM_KEYS"
fi

# --- 5. Sign in automatically -----------------------------------------------------------------------
echo "==> Signing in automatically as $USER_NAME"
AUTO=""
# antiX's own login screen. Its settings must start at the first character of a line, and the last
# matching line wins, so old ones are removed and the new ones added in both of its files.
if [ -f /etc/slimski.conf ]; then
  for CONF in /etc/slimski.conf /etc/slimski.local.conf; do
    [ -f "$CONF" ] || continue
    sed -i '/^default_user\([[:space:]]\|$\)/d; /^autologin_enabled\([[:space:]]\|$\)/d' "$CONF"
    printf 'default_user        %s\nautologin_enabled   true\n' "$USER_NAME" >> "$CONF"
  done
  AUTO="slimski"
fi
if [ -f /etc/slim.conf ]; then
  sed -i '/^[[:space:]]*default_user[[:space:]]/d; /^[[:space:]]*auto_login[[:space:]]/d' /etc/slim.conf
  printf 'default_user        %s\nauto_login          yes\n' "$USER_NAME" >> /etc/slim.conf
  AUTO="${AUTO:+$AUTO, }slim"
fi
if [ -d /etc/lightdm ]; then
  mkdir -p /etc/lightdm/lightdm.conf.d
  printf '[Seat:*]\nautologin-user=%s\nautologin-user-timeout=0\n' "$USER_NAME" > /etc/lightdm/lightdm.conf.d/50-studio-autologin.conf
  AUTO="${AUTO:+$AUTO, }lightdm"
fi
[ -n "$AUTO" ] && echo "    Set for: $AUTO" || echo "    No known login screen found; automatic sign-in was NOT set"

echo
echo "Done. $(chromium --version 2>/dev/null)."
echo "Restart the laptop: it should sign in by itself and open ZeroAI Studio."
echo "Shift+Alt+K leaves Studio (admin password). Shift+Alt+Z goes back."