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

# Vigilar — NUT (Network UPS Tools) configuration helper
# Detects USB UPS devices and configures NUT for standalone monitoring.

info()  { printf '\033[1;34m[INFO]\033[0m  %s\n' "$*"; }
ok()    { printf '\033[1;32m[ OK ]\033[0m  %s\n' "$*"; }
warn()  { printf '\033[1;33m[WARN]\033[0m  %s\n' "$*"; }
fail()  { printf '\033[1;31m[FAIL]\033[0m  %s\n' "$*" >&2; exit 1; }

detect_pkg_manager() {
    if command -v apt-get &>/dev/null; then
        echo "apt"
    elif command -v pacman &>/dev/null; then
        echo "pacman"
    else
        fail "Unsupported package manager."
    fi
}

install_nut() {
    if command -v upsc &>/dev/null; then
        ok "NUT already installed"
        return
    fi

    info "Installing NUT"
    local pkg_mgr
    pkg_mgr="$(detect_pkg_manager)"

    case "$pkg_mgr" in
        apt)
            sudo apt-get update -qq
            sudo apt-get install -y -qq nut nut-client nut-server
            ;;
        pacman)
            sudo pacman -Sy --needed --noconfirm nut
            ;;
    esac
    ok "NUT installed"
}

detect_ups() {
    info "Scanning for USB UPS devices..."

    local driver=""
    local port=""
    local desc=""

    # Try nut-scanner first
    if command -v nut-scanner &>/dev/null; then
        local scan_output
        scan_output="$(sudo nut-scanner -U 2>/dev/null)" || true
        if [[ -n "$scan_output" ]]; then
            driver="$(echo "$scan_output" | grep -oP 'driver\s*=\s*"\K[^"]+' | head -1)" || true
            port="$(echo "$scan_output" | grep -oP 'port\s*=\s*"\K[^"]+' | head -1)" || true
            desc="$(echo "$scan_output" | grep -oP 'desc\s*=\s*"\K[^"]+' | head -1)" || true
        fi
    fi

    # Fallback: check for common USB UPS vendor IDs
    if [[ -z "$driver" ]]; then
        if lsusb 2>/dev/null | grep -qi "051d"; then
            driver="usbhid-ups"
            port="auto"
            desc="APC UPS (auto-detected via lsusb)"
        elif lsusb 2>/dev/null | grep -qi "0764"; then
            driver="usbhid-ups"
            port="auto"
            desc="CyberPower UPS (auto-detected via lsusb)"
        elif lsusb 2>/dev/null | grep -qi "0463"; then
            driver="usbhid-ups"
            port="auto"
            desc="Eaton UPS (auto-detected via lsusb)"
        elif lsusb 2>/dev/null | grep -qi "06da"; then
            driver="usbhid-ups"
            port="auto"
            desc="Phoenixtec/Tripp Lite UPS (auto-detected via lsusb)"
        fi
    fi

    if [[ -z "$driver" ]]; then
        warn "No USB UPS detected. Using generic usbhid-ups driver with auto port."
        warn "You may need to edit /etc/nut/ups.conf manually."
        driver="usbhid-ups"
        port="auto"
        desc="UPS (not auto-detected)"
    else
        ok "Detected UPS: ${desc:-unknown}"
    fi

    # Export for use in config generation
    UPS_DRIVER="$driver"
    UPS_PORT="$port"
    UPS_DESC="${desc:-UPS}"
}

generate_configs() {
    info "Generating NUT configuration"

    # /etc/nut/nut.conf — standalone mode
    sudo tee /etc/nut/nut.conf > /dev/null <<'NUTCONF'
# Vigilar NUT configuration — standalone mode
MODE=standalone
NUTCONF

    # /etc/nut/ups.conf — UPS definition
    sudo tee /etc/nut/ups.conf > /dev/null <<UPSCONF
# Vigilar UPS configuration
# Generated by setup_nut.sh

[ups]
    driver = ${UPS_DRIVER}
    port = ${UPS_PORT}
    desc = "${UPS_DESC}"
    pollinterval = 15
UPSCONF

    # /etc/nut/upsd.conf — daemon config (localhost only)
    sudo tee /etc/nut/upsd.conf > /dev/null <<'UPSDCONF'
# Vigilar upsd configuration
LISTEN 127.0.0.1 3493
UPSDCONF

    # /etc/nut/upsd.users — local monitoring user
    sudo tee /etc/nut/upsd.users > /dev/null <<'USERSCONF'
[vigilar]
    password = vigilar_local
    upsmon master
USERSCONF

    # /etc/nut/upsmon.conf — monitoring config
    sudo tee /etc/nut/upsmon.conf > /dev/null <<'MONCONF'
# Vigilar upsmon configuration
MONITOR ups@localhost 1 vigilar vigilar_local master
MINSUPPLIES 1
SHUTDOWNCMD "/sbin/shutdown -h +0"
POLLFREQ 15
POLLFREQALERT 5
HOSTSYNC 15
DEADTIME 45
RBWARNTIME 43200
NOCOMMWARNTIME 600
FINALDELAY 5
MONCONF

    # Secure the config files
    sudo chmod 0640 /etc/nut/ups.conf /etc/nut/upsd.conf /etc/nut/upsd.users /etc/nut/upsmon.conf
    sudo chown root:nut /etc/nut/ups.conf /etc/nut/upsd.conf /etc/nut/upsd.users /etc/nut/upsmon.conf 2>/dev/null || true

    ok "NUT configuration files written"
}

enable_services() {
    info "Enabling and starting NUT services"

    # Service names vary by distro
    local driver_svc="nut-driver"
    local server_svc="nut-server"
    local monitor_svc="nut-monitor"

    # On Arch, the services may be named differently
    if ! systemctl list-unit-files "${server_svc}.service" &>/dev/null; then
        if systemctl list-unit-files "upsd.service" &>/dev/null; then
            server_svc="upsd"
            monitor_svc="upsmon"
            driver_svc="nut-driver-enumerator"
        fi
    fi

    # Enable and start
    for svc in "$driver_svc" "$server_svc" "$monitor_svc"; do
        if systemctl list-unit-files "${svc}.service" &>/dev/null; then
            sudo systemctl enable "${svc}.service" 2>/dev/null || true
            sudo systemctl restart "${svc}.service" 2>/dev/null || warn "Could not start ${svc}.service — check UPS connection"
        fi
    done

    ok "NUT services enabled"
}

main() {
    info "=== Vigilar NUT Setup ==="
    echo

    install_nut

    UPS_DRIVER=""
    UPS_PORT=""
    UPS_DESC=""
    detect_ups

    generate_configs
    enable_services

    echo
    ok "=== NUT setup complete ==="
    info "Test with: upsc ups@localhost"
    info "Vigilar will monitor UPS at 127.0.0.1:3493 (ups name: 'ups')"
}

main "$@"