#!/bin/bash

set -e

update_notes() {
  local vmid="$1"
  local type="$2"

  echo "[INFO] Procesando $type $vmid..."

  # Detectar OS
  os=$(pct exec "$vmid" -- cat /etc/os-release 2>/dev/null | grep '^ID=' | cut -d= -f2 | tr -d '"')
  [ -z "$os" ] && echo "[WARN] No se pudo detectar OS para $type $vmid. Saltando." && return

  echo "[INFO] Sistema operativo detectado: $os"

  # Comandos por OS
  case "$os" in
    alpine)
      update_cmd="tries=5; for i in \$(seq 1 \$tries); do if apk update; then ok=1; break; else echo \"[WARN] apk update failed (\$i/\$tries). Retrying in \$((i*2))s...\"; sleep \$((i*2)); fi; done; [ \"\${ok:-0}\" = \"1\" ] || echo \"[WARN] Proceeding with stale indexes\"; apk upgrade --no-cache || echo \"[WARN] apk upgrade failed; continuing\""
      install_base_pkgs="apk add --no-cache docker openssh jq"
      
      # Comprobar si tailscale está instalado
      check_tailscale_installed=$(pct exec "$vmid" -- sh -c "which tailscale 2>/dev/null || echo notfound")
      if [[ "$check_tailscale_installed" == "notfound" ]]; then
        install_tailscale="apk add --no-cache tailscale"
      else
        install_tailscale="echo '[INFO] tailscale ya está instalado'"
      fi

      enable_docker="rc-update add docker && rc-service docker start"
      enable_ssh="rc-update add sshd && rc-service sshd start"
      enable_tailscale_check='if [ -e /etc/init.d/tailscaled ]; then rc-update add tailscaled; rc-service tailscaled start; fi'
      check_tailscale_status='if [ -e /etc/init.d/tailscaled ]; then rc-service tailscaled status; else echo notinstalled; fi'
      ;;
    ubuntu)
      update_cmd="apt-get update && DEBIAN_FRONTEND=noninteractive apt-get upgrade -y"
      install_base_pkgs="apt-get install -y docker.io openssh-server jq"

      check_tailscale_installed=$(pct exec "$vmid" -- sh -c "which tailscale 2>/dev/null || echo notfound")
      if [[ "$check_tailscale_installed" == "notfound" ]]; then
        install_tailscale="apt-get install -y tailscale"
      else
        install_tailscale="echo '[INFO] tailscale ya está instalado'"
      fi

      enable_docker="systemctl enable docker && systemctl start docker"
      enable_ssh="systemctl enable ssh && systemctl start ssh"
      enable_tailscale_check="systemctl enable tailscaled && systemctl start tailscaled"
      check_tailscale_status="systemctl is-active tailscaled"
      ;;
    *)
      echo "[WARN] OS no soportado: $os. Saltando $vmid."
      return
      ;;
  esac

  # Ejecutar comandos
  pct exec "$vmid" -- sh -c "$update_cmd"
  pct exec "$vmid" -- sh -c "$install_base_pkgs || true"
  pct exec "$vmid" -- sh -c "$install_tailscale || true"
  pct exec "$vmid" -- sh -c "$enable_docker"
  pct exec "$vmid" -- sh -c "$enable_ssh"
  pct exec "$vmid" -- sh -c "$enable_tailscale_check"

  echo "[INFO] Verificando configuración del Docker API y métricas en $type $vmid..."
  pct exec "$vmid" -- sh -c '
    set -e
    mkdir -p /etc/docker
    DAEMON_JSON="/etc/docker/daemon.json"
    TMP_JSON="/etc/docker/daemon.json.tmp"

    ensure_json() {
      if [ -f "$DAEMON_JSON" ]; then
        echo "[INFO] daemon.json existente encontrado. Verificando llaves requeridas..."
        if ! command -v jq >/dev/null 2>&1; then
          echo "[ERROR] jq no está instalado; no se puede actualizar JSON de Docker." >&2
          exit 1
        fi
        JQF="/tmp/daemon_filter.jq"
        cat > "$JQF" <<\JQ
(.hosts = ((.hosts // []) + ["unix:///var/run/docker.sock","tcp://0.0.0.0:2375"]) | .hosts |= unique)
| .["metrics-addr"] = "0.0.0.0:9023"
| .experimental = true
JQ
        jq -f "$JQF" "$DAEMON_JSON" > "$TMP_JSON"
        rm -f "$JQF"
      else
        echo "[INFO] Creando daemon.json con configuración por defecto (API TCP + métricas)."
        cat > "$TMP_JSON" <<\JSON
{
  "hosts": ["unix:///var/run/docker.sock", "tcp://0.0.0.0:2375"],
  "metrics-addr": "0.0.0.0:9023",
  "experimental": true
}
JSON
      fi

      if [ ! -f "$DAEMON_JSON" ] || ! cmp -s "$DAEMON_JSON" "$TMP_JSON"; then
        echo "[INFO] Aplicando cambios a daemon.json"
        cp "$TMP_JSON" "$DAEMON_JSON"
        JSON_CHANGED=1
      else
        echo "[INFO] daemon.json ya contiene la configuración requerida."
        JSON_CHANGED=0
      fi
      rm -f "$TMP_JSON"
    }

    apply_systemd_override_if_needed() {
      # Sólo para sistemas con systemd (Ubuntu)
      if command -v systemctl >/dev/null 2>&1; then
        echo "[INFO] Detectado systemd. Verificando override de servicio Docker..."
        mkdir -p /etc/systemd/system/docker.service.d
        OVERRIDE="/etc/systemd/system/docker.service.d/override.conf"
        NEED_OVERRIDE=0
        if systemctl cat docker 2>/dev/null | grep -qE "ExecStart=.*-H fd://"; then
          NEED_OVERRIDE=1
        fi

        if [ $NEED_OVERRIDE -eq 1 ]; then
          echo "[INFO] Creando override de systemd para remover -H fd:// y permitir hosts desde daemon.json"
          cat > "$OVERRIDE" <<\OVR
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd
OVR
          systemctl daemon-reload
          OVERRIDE_APPLIED=1
        else
          echo "[INFO] No se requiere override de systemd."
          OVERRIDE_APPLIED=0
        fi
      else
        OVERRIDE_APPLIED=0
      fi
    }

    restart_docker() {
      if command -v systemctl >/dev/null 2>&1; then
        systemctl restart docker || true
        if systemctl is-active --quiet docker; then
          echo "[INFO] Docker reiniciado (systemd)."
        else
          echo "[WARN] Docker no está activo tras reinicio (systemd)."
        fi
      elif command -v rc-service >/dev/null 2>&1; then
        rc-service docker restart || true
        rc-service docker status || true
        echo "[INFO] Docker reiniciado (OpenRC)."
      else
        echo "[WARN] No se pudo detectar gestor de servicios para reiniciar Docker."
      fi
    }

    check_listeners() {
      echo "[INFO] Comprobando puertos en escucha para Docker..."
      if command -v ss >/dev/null 2>&1; then
        ss -lnt | awk "{print}"
      elif command -v netstat >/dev/null 2>&1; then
        netstat -lnt || true
      fi
      if ss -lnt 2>/dev/null | grep -q ":2375 "; then
        echo "[INFO] API Docker TCP escuchando en 0.0.0.0:2375"
      else
        echo "[WARN] API Docker TCP NO detectada en 0.0.0.0:2375"
      fi
      if ss -lnt 2>/dev/null | grep -q ":9023 "; then
        echo "[INFO] Métricas Docker escuchando en 0.0.0.0:9023"
      else
        echo "[WARN] Métricas Docker NO detectadas en 0.0.0.0:9023"
      fi
    }

    ensure_json
    apply_systemd_override_if_needed
    if [ ${JSON_CHANGED:-0} -eq 1 ] || [ ${OVERRIDE_APPLIED:-0} -eq 1 ]; then
      restart_docker
    else
      echo "[INFO] Configuración de Docker ya presente; no se requiere reinicio."
    fi
    check_listeners
  '

  # Estado tailscale
  tailscale_status=$(pct exec "$vmid" -- sh -c "$check_tailscale_status" 2>&1)
  if echo "$tailscale_status" | grep -q "running"; then
    tailscale_note="tailscale UP"
  elif echo "$tailscale_status" | grep -q "notinstalled"; then
    tailscale_note="tailscale NOT INSTALLED"
  else
    tailscale_note="tailscale DOWN"
  fi

  # Obtener contenedores Docker
  docker_info=$(pct exec "$vmid" -- sh -c "docker ps --format '{{.Names}} : {{.Image}}'" 2>/dev/null || echo "Sin contenedores")
  if [[ -z "$docker_info" ]]; then
    docker_info="Sin contenedores"
  fi

  # Formar nota
  full_note=$(printf "# Notes:\n%s\n%s\n" "$tailscale_note" "$docker_info")

  # Añadir al archivo de configuración del contenedor
  conf_path="/etc/pve/lxc/${vmid}.conf"

  # Eliminar notas anteriores si existen
  sed -i '/^# Notes:/,$d' "$conf_path"
  echo -e "$full_note" >> "$conf_path"

  echo "[INFO] Notas actualizadas en $conf_path:"
  echo "$full_note"
}

echo "[INFO] Iniciando gestión automática de LXC..."

# Iterar sobre LXC activos
for vmid in $(pct list | awk 'NR>1 {print $1}'); do
  update_notes "$vmid" "LXC"
done

# VMs (sin integración por ahora)
for vmid in $(qm list | awk 'NR>1 && $2 == "running" {print $1}'); do
  echo "[INFO] Saltando VM $vmid (se requiere integración SSH para gestionar desde el host)"
done

echo "[INFO] Script completado."