#!/usr/bin/env bash

# setup-keyboard-remap-poller.sh
# =============================
# Installs a systemd user service that polls for keyboard plug-in / KVM switch events
# and runs ~/sh/keymaps.sh (your xmodmap stuff) when it detects a change.
#
# Why polling? Udev is too early / env broken for X11 tools in most cases.

set -euo pipefail

SERVICE_NAME="keyboard-remap-poller"
SERVICE_FILE="$HOME/.config/systemd/user/$SERVICE_NAME.service"
POLLER_SCRIPT="$HOME/.local/bin/keyboard-remap-poller.sh"
KEYMAPS_SCRIPT="$HOME/sh/keymaps.sh"

if [[ ! -x "$KEYMAPS_SCRIPT" ]]; then
    echo "Error: $KEYMAPS_SCRIPT not found or not executable."
    echo "Make sure it exists and chmod +x it."
    exit 1
fi

echo "Creating poller script: $POLLER_SCRIPT"

mkdir -p "$(dirname "$POLLER_SCRIPT")"

cat > "$POLLER_SCRIPT" << 'EOP'
#!/usr/bin/env bash
# keyboard-remap-poller.sh - checks for keyboard/input changes and runs keymaps.sh

KEYMAPS_SCRIPT="$HOME/sh/keymaps.sh"
LOG_FILE="$HOME/.local/share/keyboard-remap.log"
LAST_COUNT_FILE="$HOME/.cache/keyboard-event-count"

# Initial count of input devices (rough way to detect plug/unplug/KVM)
get_input_count() {
    ls /dev/input/event* 2>/dev/null | wc -l
}

last_count=$(cat "$LAST_COUNT_FILE" 2>/dev/null || echo "0")

while true; do
    current_count=$(get_input_count)

    if [[ "$current_count" != "$last_count" ]]; then
        echo "$(date '+%Y-%m-%d %H:%M:%S') - Input device count changed ($last_count → $current_count). Running keymaps.sh" >> "$LOG_FILE"

        # Run your script in X session context
        if [[ -n "${DISPLAY:-}" ]]; then
            "$KEYMAPS_SCRIPT" >> "$LOG_FILE" 2>&1
        else
            # Fallback: try common display :0 or :0.0
            DISPLAY=:0 XAUTHORITY="$HOME/.Xauthority" "$KEYMAPS_SCRIPT" >> "$LOG_FILE" 2>&1 || \
            DISPLAY=:0.0 XAUTHORITY="$HOME/.Xauthority" "$KEYMAPS_SCRIPT" >> "$LOG_FILE" 2>&1
        fi

        echo "$(date '+%Y-%m-%d %H:%M:%S') - keymaps.sh finished (exit code $?)" >> "$LOG_FILE"
        echo "$current_count" > "$LAST_COUNT_FILE"
    fi

    last_count="$current_count"
    sleep 8   # Check every 8 seconds - low overhead
done
EOP

chmod +x "$POLLER_SCRIPT"
echo "Poller script created."

echo "Creating systemd user service: $SERVICE_FILE"

mkdir -p "$(dirname "$SERVICE_FILE")"

cat > "$SERVICE_FILE" << EOF
[Unit]
Description=Poll for keyboard plug-in / KVM events and run keymaps.sh
After=graphical-session.target

[Service]
Type=simple
ExecStart=$POLLER_SCRIPT
Restart=always
RestartSec=5

[Install]
WantedBy=graphical-session.target
EOF

echo "Service file created."

echo "Enabling and starting the service (user level)..."
systemctl --user daemon-reload
systemctl --user enable --now "$SERVICE_NAME.service"

echo ""
echo "=== Setup Done ==="
echo "The service is now running as your user."
echo ""
echo "Test it:"
echo "  1. Switch KVM or plug/unplug a keyboard"
echo "  2. Wait 10–20 seconds"
echo "  3. Check if your xmodmap changes applied (e.g. press your remapped keys)"
echo "  4. Look at log:"
echo "     tail -f $HOME/.local/share/keyboard-remap.log"
echo ""
echo "If it doesn't trigger reliably:"
echo "  - Increase sleep 8 → sleep 5 in $POLLER_SCRIPT"
echo "  - Or if DISPLAY is wrong, edit the DISPLAY/XAUTHORITY lines"
echo ""
echo "To stop/disable:"
echo "  systemctl --user stop $SERVICE_NAME.service"
echo "  systemctl --user disable $SERVICE_NAME.service"
echo ""
echo "Enjoy your remaps without F10 every time!"