#!/usr/bin/env bash
# ~/bin/synergy-client-connect - Dynamic Synergy Client Launcher
# Automatically probes and connects to t520 whether on Ethernet, WiFi, or VPN.

set -euo pipefail

CLIENT_NAME="${1:-$(hostname -s 2>/dev/null || uname -n)}"
CANDIDATE_SERVERS=(
    "192.168.1.100:24800" # t520 Ethernet
    "192.168.1.102:24800" # t520 WiFi
    "10.0.0.18:24800"     # t520 Legacy LAN
    "10.39.9.100:24800"   # t520 WireGuard VPN
)

find_active_server() {
    for target in "${CANDIDATE_SERVERS[@]}"; do
        local host="${target%%:*}"
        local port="${target##*:}"
        if (echo > /dev/tcp/"$host"/"$port") >/dev/null 2>&1; then
            echo "$target"
            return 0
        fi
    done
    return 1
}

# Ensure DISPLAY is set for graphical/XWayland environments (e.g. Crostini or systemd user services)
export DISPLAY="${DISPLAY:-:0}"

# Locate synergyc / barrierc / deskflow-client binary across standard paths
SYNERGYC="$(command -v synergyc 2>/dev/null || command -v barrierc 2>/dev/null || command -v deskflow-client 2>/dev/null || true)"
if [ -z "$SYNERGYC" ]; then
    for candidate in \
        "/usr/local/bin/synergyc" "/usr/bin/synergyc" "$HOME/.local/bin/synergyc" \
        "/usr/local/bin/barrierc" "/usr/bin/barrierc" \
        "/usr/local/bin/deskflow-client" "/usr/bin/deskflow-client"; do
        if [ -x "$candidate" ]; then
            SYNERGYC="$candidate"
            break
        fi
    done
fi

if [ -z "$SYNERGYC" ]; then
    echo "[synergy-connect] Error: Neither synergyc, barrierc, nor deskflow-client found in PATH or standard locations." >&2
    echo "[synergy-connect] Please install barrier or deskflow: 'sudo apt install barrier' or 'sudo apt install deskflow'" >&2
    exit 1
fi

# Determine crypto flag based on synergyc build (note: synergyc --help exits with code 3)
CRYPTO_FLAG=""
if ("$SYNERGYC" --help 2>&1 || true) | grep -q -- '--disable-crypto'; then
    CRYPTO_FLAG="--disable-crypto"
fi

echo "[synergy-connect] Starting dynamic Synergy client for '$CLIENT_NAME' using $SYNERGYC..."

while true; do
    if ACTIVE_SERVER=$(find_active_server); then
        echo "[synergy-connect] Found active server at $ACTIVE_SERVER. Connecting..."
        "$SYNERGYC" -f $CRYPTO_FLAG --name "$CLIENT_NAME" "$ACTIVE_SERVER" || true
        echo "[synergy-connect] Synergy client exited or disconnected. Probing again in 2s..."
    else
        echo "[synergy-connect] No reachable t520 server on Ethernet/WiFi/VPN. Retrying in 3s..."
    fi
    sleep 2
done