#!/bin/bash
set -Eeuo pipefail

HOST="$(hostname)"
LOG="/opt/pingu/logs/update.log"

TELEGRAM_TOKEN="${TELEGRAM_TOKEN:-8101319618:AAHboFVVgmLPccJB0MDr_R2g0K90hkGqkRw}"
TELEGRAM_CHAT_ID="${TELEGRAM_CHAT_ID:-581059353}"

REBOOT=0
DOCKER_UPDATES=0
DOCKER_UPDATE_LIST=""
DOCKER_MSG=""

PIHOLE_INSTALLED=0
PIHOLE_UPDATED=0
PIHOLE_MSG=""

log() {
    echo "[$(date '+%F %T')] $1" | tee -a "$LOG"
}

send_telegram() {
    local text="$1"

    curl -sS -X POST "https://api.telegram.org/bot${TELEGRAM_TOKEN}/sendMessage" \
        --data-urlencode "chat_id=${TELEGRAM_CHAT_ID}" \
        --data-urlencode "text=${text}" \
        >> "$LOG" 2>&1 || true
}

cleanup_on_error() {
    local exit_code=$?
    log "❌ Fehler in Zeile ${1:-unknown} (Exit ${exit_code})"

    send_telegram "❌ ${HOST}: Update fehlgeschlagen (Zeile ${1:-?}, Exit ${exit_code})"
    exit "$exit_code"
}

trap 'cleanup_on_error ${LINENO}' ERR

check_docker_updates() {

    if ! command -v docker >/dev/null 2>&1; then
        DOCKER_MSG="🚫 Docker: nicht installiert"
        return
    fi

    if ! docker info >/dev/null 2>&1; then
        DOCKER_MSG="⚠️ Docker: Daemon nicht erreichbar"
        return
    fi

    local containers
    mapfile -t containers < <(docker ps -q)

    if [ "${#containers[@]}" -eq 0 ]; then
        DOCKER_MSG="🐳 Docker: keine Container aktiv"
        return
    fi

    for cid in "${containers[@]}"; do
        local name image running_id latest_id

        name="$(docker inspect --format '{{.Name}}' "$cid" | sed 's#^/##')"
        image="$(docker inspect --format '{{.Config.Image}}' "$cid")"
        running_id="$(docker inspect --format '{{.Image}}' "$cid")"

        docker pull "$image" >/dev/null 2>&1 || continue
        latest_id="$(docker image inspect --format '{{.Id}}' "$image" 2>/dev/null || true)"

        if [[ -n "$latest_id" && "$running_id" != "$latest_id" ]]; then
            DOCKER_UPDATES=$((DOCKER_UPDATES + 1))
            DOCKER_UPDATE_LIST+=$'\n'"🐳 ${name} (${image})"
        fi
    done

    if [ "$DOCKER_UPDATES" -gt 0 ]; then
        DOCKER_MSG="🐳 Docker Updates: ${DOCKER_UPDATES}${DOCKER_UPDATE_LIST}"
    else
        DOCKER_MSG="🐳 Docker: aktuell"
    fi
}

check_pihole_update() {

    if ! command -v pihole >/dev/null 2>&1; then
        PIHOLE_MSG=""
        return
    fi

    PIHOLE_INSTALLED=1

    log "Pi-hole detected → checking update"

    local output
    if output="$(pihole -up 2>&1)"; then
        if echo "$output" | grep -q "Everything is up to date"; then
            PIHOLE_MSG="🧱 Pi-hole: aktuell"
        else
            PIHOLE_UPDATED=1
            PIHOLE_MSG="🧱 Pi-hole: Update durchgeführt"
        fi
    else
        PIHOLE_MSG="❌ Pi-hole: Update fehlgeschlagen"
        log "$output"
    fi
}

# Pihole Check 
if [ "$PIHOLE_INSTALLED" -eq 1 ]; then
    if ! pihole status | grep -q "enabled"; then
        PIHOLE_MSG="❌ Pi-hole: läuft nicht korrekt"
    fi
fi

main() {

    mkdir -p "$(dirname "$LOG")"
    touch "$LOG"

    log "=== Update Start ${HOST} ==="

    export DEBIAN_FRONTEND=noninteractive

    log "APT Update"
    apt-get update 2>&1 | tee -a "$LOG"

    log "APT Upgrade"
    apt-get -y upgrade 2>&1 | tee -a "$LOG"

    if [ -f /var/run/reboot-required ]; then
        REBOOT=1
        log "Reboot erforderlich"
    fi

    check_docker_updates
    check_pihole_update

    local msg
    msg=$(cat <<EOF
🐧 System Update Report
━━━━━━━━━━━━━━━
🖥 Host: ${HOST}

$( [ "$REBOOT" -eq 1 ] && echo "🔄 Reboot: erforderlich" || echo "✔ Reboot: nicht nötig" )

${DOCKER_MSG}
$( [ "$PIHOLE_INSTALLED" -eq 1 ] && echo "" )
${PIHOLE_MSG}

━━━━━━━━━━━━━━━
📅 $(date '+%F %T')
EOF
)

    log "Sende Telegram"
    send_telegram "$msg"

    log "=== Update Ende ${HOST} ==="

    if [ "$REBOOT" -eq 1 ]; then
        reboot
    fi
}

main "$@"