#!/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=""

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

send_telegram() {
    local text="$1"
    local http_code

    http_code="$(curl -sS --show-error \
        -o /tmp/pingu-telegram-response.txt \
        -w '%{http_code}' \
        -X POST "https://api.telegram.org/bot${TELEGRAM_TOKEN}/sendMessage" \
        --data-urlencode "chat_id=${TELEGRAM_CHAT_ID}" \
        --data-urlencode "text=${text}")"

    cat /tmp/pingu-telegram-response.txt >> "$LOG"
    echo >> "$LOG"

    if [ "$http_code" -ne 200 ]; then
        log "Telegram-API Fehler, HTTP ${http_code}"
        return 1
    fi
}

cleanup_on_error() {
    local exit_code=$?
    local line_no="${1:-unknown}"

    log "FEHLER in Zeile ${line_no}, Exit-Code ${exit_code}"

    curl -sS -X POST "https://api.telegram.org/bot${TELEGRAM_TOKEN}/sendMessage" \
        --data-urlencode "chat_id=${TELEGRAM_CHAT_ID}" \
        --data-urlencode "text=❌ ${HOST}: Update-Script fehlgeschlagen in Zeile ${line_no} (Exit ${exit_code})." \
        >> "$LOG" 2>&1 || true

    exit "$exit_code"
}

trap 'cleanup_on_error ${LINENO}' ERR

check_docker_updates() {
    if ! command -v docker >/dev/null 2>&1; then
        log "Docker nicht installiert - überspringe Container-Prüfung"
        return 0
    fi

    if ! docker info >/dev/null 2>&1; then
        log "Docker-Daemon nicht erreichbar - überspringe Container-Prüfung"
        return 0
    fi

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

    if [ "${#container_ids[@]}" -eq 0 ]; then
        log "Keine laufenden Docker-Container gefunden"
        return 0
    fi

    log "Prüfe ${#container_ids[@]} laufende Docker-Container auf Image-Updates"

    local cid name image running_id latest_id pull_output
    for cid in "${container_ids[@]}"; do
        name="$(docker inspect --format '{{.Name}}' "$cid" | sed 's#^/##')"
        image="$(docker inspect --format '{{.Config.Image}}' "$cid")"
        running_id="$(docker inspect --format '{{.Image}}' "$cid")"

        log "Prüfe Container ${name} mit Image ${image}"

        if pull_output="$(docker pull "$image" 2>&1)"; then
            latest_id="$(docker image inspect --format '{{.Id}}' "$image")"

            if [ "$running_id" != "$latest_id" ]; then
                DOCKER_UPDATES=$((DOCKER_UPDATES + 1))
                DOCKER_UPDATE_LIST+=$'\n'"🐳 ${name} (${image})"
                log "Update verfügbar für ${name}"
            else
                log "Kein Update für ${name}"
            fi
        else
            log "Konnte Image ${image} für ${name} nicht prüfen: ${pull_output}"
        fi
    done
}

main() {
    touch "$LOG"
    chmod 600 "$LOG"

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

    export DEBIAN_FRONTEND=noninteractive

    log "Starte apt-get update"
    apt-get update >> "$LOG" 2>&1

    log "Starte apt-get upgrade"
    apt-get -y upgrade >> "$LOG" 2>&1

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

    check_docker_updates

    local msg="🐧 ${HOST}: Updates installiert."
    if [ "$REBOOT" -eq 1 ]; then
        msg="${msg} REBOOT erforderlich."
    else
        msg="${msg} Kein Reboot nötig."
    fi

    if [ "$DOCKER_UPDATES" -gt 0 ]; then
        msg+=$'\n\n'"🐳 Docker-Updates verfügbar: ${DOCKER_UPDATES}${DOCKER_UPDATE_LIST}"
    else
        msg+=$'\n\n'"🐳 Docker-Container aktuell."
    fi

    log "Sende Telegram-Nachricht"
    send_telegram "$msg"

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

    if [ "$REBOOT" -eq 1 ]; then
        log "System wird neu gestartet"
        reboot
    fi
}

main "$@"