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

# ─────────────────────────────────────────────
# VPSmon - Quick Install Script (Run on VPS)
# Usage:
# curl -sL https://raw.githubusercontent.com/leodeim/vpsmon/main/install.sh | sudo bash
# ─────────────────────────────────────────────

REPO="leodeim/vpsmon"
APP_NAME="vpsmon"
REMOTE_DIR="/opt/vpsmon"
SERVICE_USER="vpsmon"
SERVICE_GROUP="vpsmon"

if [ "$EUID" -ne 0 ]; then
  echo "Please run this script as root or with sudo."
  exit 1
fi

echo "═══════════════════════════════════════"
echo "  VPSmon - VPS Installer"
echo "═══════════════════════════════════════"
echo ""

# Determine architecture
ARCH=$(uname -m)
case $ARCH in
    x86_64) GOARCH="amd64" ;;
    aarch64) GOARCH="arm64" ;;
    armv8l) GOARCH="arm64" ;;
    *) echo "Unsupported architecture: $ARCH"; exit 1 ;;
esac

echo "==> Fetching latest release info for ${REPO}..."
LATEST_RELEASE_URL=$(curl -s "https://api.github.com/repos/${REPO}/releases/latest" | grep '"browser_download_url":' | grep "linux-${GOARCH}" | cut -d '"' -f 4 | head -n 1 || true)

if [ -z "$LATEST_RELEASE_URL" ]; then
    echo "Error: Could not find a binary for linux-${GOARCH} in the latest release."
    echo "Make sure you have created a release on GitHub with attached binaries."
    exit 1
fi

echo "── Configuration ──────────────────────"
read -rp "Monitor port [8088]: " MON_PORT </dev/tty
MON_PORT="${MON_PORT:-8088}"

read -rp "Monitor username [admin]: " MON_USER </dev/tty
MON_USER="${MON_USER:-admin}"
while true; do
    read -rsp "Monitor password: " MON_PASS </dev/tty
    echo "" >/dev/tty
    if [ -z "$MON_PASS" ]; then
        echo "Password cannot be empty. Try again." >/dev/tty
        continue
    fi
    read -rsp "Confirm password: " MON_PASS2 </dev/tty
    echo "" >/dev/tty
    if [ "$MON_PASS" != "$MON_PASS2" ]; then
        echo "Passwords do not match. Try again." >/dev/tty
        continue
    fi
    break
done

echo ""
echo "==> Setting up directories and users..."
mkdir -p "${REMOTE_DIR}"

if ! getent group "${SERVICE_GROUP}" > /dev/null 2>&1; then
    groupadd --system "${SERVICE_GROUP}"
    echo "    Created group: ${SERVICE_GROUP}"
fi
if ! id "${SERVICE_USER}" > /dev/null 2>&1; then
    adduser --system --no-create-home --ingroup "${SERVICE_GROUP}" --shell /usr/sbin/nologin "${SERVICE_USER}" 2>/dev/null
    echo "    Created user: ${SERVICE_USER}"
fi

echo "==> Downloading VPSmon..."
curl -sL "$LATEST_RELEASE_URL" -o "${REMOTE_DIR}/${APP_NAME}.tmp"
mv -f "${REMOTE_DIR}/${APP_NAME}.tmp" "${REMOTE_DIR}/${APP_NAME}"
chmod 755 "${REMOTE_DIR}/${APP_NAME}"
chown "${SERVICE_USER}:${SERVICE_GROUP}" "${REMOTE_DIR}/${APP_NAME}"

echo "==> Generating credentials..."
# Run the binary to generate password hash
PASS_HASH=$("${REMOTE_DIR}/${APP_NAME}" -hash "${MON_PASS}")

cat > "${REMOTE_DIR}/.env" <<ENVEOF
MONITOR_ADDR=:${MON_PORT}
MONITOR_USER=${MON_USER}
MONITOR_PASS_HASH=${PASS_HASH}
ENVEOF
chmod 600 "${REMOTE_DIR}/.env"
chown "${SERVICE_USER}:${SERVICE_GROUP}" "${REMOTE_DIR}/.env"

echo "==> Installing systemd service..."
cat > "/etc/systemd/system/${APP_NAME}.service" <<SVCEOF
[Unit]
Description=VPSmon
After=network.target

[Service]
Type=simple
User=${SERVICE_USER}
Group=${SERVICE_GROUP}
WorkingDirectory=${REMOTE_DIR}
EnvironmentFile=${REMOTE_DIR}/.env
ExecStart=${REMOTE_DIR}/${APP_NAME}
Restart=on-failure
RestartSec=5
NoNewPrivileges=true
ProtectSystem=strict
ProtectHome=true
ReadOnlyPaths=/proc /sys

[Install]
WantedBy=multi-user.target
SVCEOF

systemctl daemon-reload
systemctl enable "${APP_NAME}" --quiet
systemctl restart "${APP_NAME}"

echo "==> Verifying service..."
sleep 2
STATUS=$(systemctl is-active ${APP_NAME} 2>/dev/null || true)
if [ "$STATUS" = "active" ]; then
    echo "    Service is running!"
else
    echo "    WARNING: Service is not running (status: ${STATUS})"
    echo "    Check logs: journalctl -u ${APP_NAME} -n 20"
    exit 1
fi

echo ""
echo "═══════════════════════════════════════"
echo "  VPSmon installed successfully!"
echo ""
echo "  URL:     http://<your-vps-ip>:${MON_PORT}"
echo "  Login:   ${MON_USER}"
echo ""
echo "  Useful commands:"
echo "    systemctl status ${APP_NAME}"
echo "    journalctl -u ${APP_NAME} -f"
echo "    systemctl restart ${APP_NAME}"
echo "═══════════════════════════════════════"