#!/usr/bin/env bash
set -euo pipefail

INSTALL_DIR="/opt/logar-server"
CONFIG_DIR="/etc/logar"

# Parse command line options
while [[ $# -gt 0 ]]; do
    case "$1" in
        --config-dir|--data-dir)
            CONFIG_DIR="$2"
            shift 2
            ;;
        *)
            shift
            ;;
    esac
done

echo "============================================================"
echo "  LOGAR Server Enterprise Linux Installer"
echo "============================================================"

# 1. Mutual Exclusion Check: Deny installation if LOGAR Client is present
if [ -f "/opt/logar-client/Linux_Client" ] || [ -f "/etc/systemd/system/logar-client.service" ]; then
    echo "[-] Error: LOGAR Client is already installed on this machine." >&2
    echo "[-] LOGAR Server cannot be installed on a host where LOGAR Client is present (LOGAR Server includes built-in log collection)." >&2
    echo "[-] Please uninstall LOGAR Client first before installing LOGAR Server." >&2
    exit 1
fi

# 2. Existing LOGAR Server Detection for In-Place Update Mode
IS_UPDATE=0
if [ -f "${INSTALL_DIR}/Server" ] || [ -f "/etc/systemd/system/logar-server.service" ]; then
    IS_UPDATE=1
    echo "[*] Existing LOGAR Server installation detected. Performing in-place upgrade..."
fi

# Interactive configuration if running in a terminal without CLI arguments (only for fresh install)
if [ "${IS_UPDATE}" -eq 0 ] && [ -t 0 ]; then
    read -r -p "Enter Data and Configuration Directory [${CONFIG_DIR}]: " USER_CFG
    if [ -n "${USER_CFG}" ]; then
        CONFIG_DIR="${USER_CFG}"
    fi
fi

if [ "${IS_UPDATE}" -eq 1 ] && command -v systemctl >/dev/null 2>&1; then
    echo "[*] Stopping LOGAR Server service for upgrade..."
    systemctl stop logar-server.service || true
fi

mkdir -p "${INSTALL_DIR}" "${CONFIG_DIR}" "/var/log/logar"

if [ -f "dist/Server.bin" ]; then
    cp dist/Server.bin "${INSTALL_DIR}/Server"
elif [ -f "dist/Server" ]; then
    cp dist/Server "${INSTALL_DIR}/Server"
elif [ -f "dist/LOGAR_Server" ]; then
    cp dist/LOGAR_Server "${INSTALL_DIR}/Server"
else
    echo "[!] Warning: dist/Server.bin binary not found in current directory. Continuing with existing binary if present."
fi

if [ -f "${INSTALL_DIR}/Server" ]; then
    chmod +x "${INSTALL_DIR}/Server"
fi

cat <<EOF > /etc/systemd/system/logar-server.service
[Unit]
Description=LOGAR Hub and Aggregator Engine
After=network.target

[Service]
Type=simple
WorkingDirectory=${INSTALL_DIR}
ExecStart=${INSTALL_DIR}/Server --config ${CONFIG_DIR}/server_config.json
Restart=always
RestartSec=5s
User=root
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

if command -v systemctl >/dev/null 2>&1; then
    systemctl daemon-reload
    systemctl enable --now logar-server.service || true
    echo "[+] LOGAR Server service installed and activated."
else
    echo "[+] Systemd service installed at /etc/systemd/system/logar-server.service"
fi