nixos-configs/hosts/manatee/modules/home-assistant/default.nix

{
  pkgs,
  lib,
  config,
  ...
}:
let
  nginxEnabled = config.mod.nginx.enable;

  script = pkgs.writeShellScript "bt-reset" ''
    set -euo pipefail
    export PATH="${
      lib.makeBinPath [
        pkgs.bluez
        pkgs.util-linux
        pkgs.kmod
        pkgs.gnugrep
        pkgs.coreutils
      ]
    }"

    logger -t bt-reset "Starting Bluetooth adapter reset..."

    # Exit early if the adapter is already present and running
    if hciconfig hci0 2>/dev/null | grep -q "UP RUNNING"; then
      logger -t bt-reset "hci0 is already UP RUNNING — nothing to do"
      exit 0
    fi

    # If hci0 exists but isn't UP, try bringing it up
    if hciconfig hci0 2>/dev/null; then
      logger -t bt-reset "hci0 exists but not running — bringing it up"
      hciconfig hci0 up || true
      sleep 2

      if hciconfig hci0 2>/dev/null | grep -q "UP RUNNING"; then
        logger -t bt-reset "hci0 is UP now"
        systemctl restart bluetooth.service
        logger -t bt-reset "bluetooth.service restarted — done"
        exit 0
      fi
    fi

    # Hard reset: reload the btusb kernel module (works for USB adapters)
    logger -t bt-reset "hci0 missing — reloading btusb module..."
    modprobe -r btusb 2>/dev/null || true
    sleep 3
    modprobe btusb
    sleep 3

    if hciconfig hci0 2>/dev/null; then
      hciconfig hci0 up
      logger -t bt-reset "hci0 restored after module reload"
    else
      logger -t bt-reset "ERROR: hci0 not found after module reload"
      exit 1
    fi

    # Restart the bluetooth systemd service so bluetoothd picks up the adapter
    systemctl restart bluetooth.service
    logger -t bt-reset "bluetooth.service restarted — done"
  '';
in
{
  hardware.bluetooth.enable = true;

  virtualisation.oci-containers = {
    backend = "podman";

    containers.homeassistant = {
      image = "ghcr.io/home-assistant/home-assistant:stable";

      volumes = [
        "/home/alex/.config/home-assistant:/config"
        # Pass in bluetooth
        "/run/dbus:/run/dbus:ro"
      ];

      environment.TZ = "Europe/Stockholm";

      extraOptions = [
        "--network=host"

        # Allows HA to perform low-level network operations (scan/reset adapter)
        "--cap-add=NET_ADMIN"
        "--cap-add=NET_RAW"

        # Pass in Zigbee antenna
        "--device=/dev/serial/by-id/usb-Nabu_Casa_ZBT-2_9C139EAAD464-if00:/dev/ttyACM0"
      ];
    };
  };

  services = {
    blueman.enable = true;

    nginx = lib.mkIf nginxEnabled {
      recommendedProxySettings = true;

      virtualHosts."ha.ppp.pm" = {
        forceSSL = true;
        useACMEHost = "ha.ppp.pm";

        extraConfig = ''
          proxy_buffering off;
        '';

        locations."/" = {
          proxyPass = "http://127.0.0.1:8123";
          proxyWebsockets = true;
        };
      };
    };

    # Trigger reset via udev when hci0 disappears
    udev.extraRules = ''
      ACTION=="remove", SUBSYSTEM=="bluetooth", KERNEL=="hci0", \
        TAG+="systemd", ENV{SYSTEMD_WANTS}+="bt-reset.service"
    '';
  };

  systemd = {
    services = {
      # Trigger reset on bluetoothd failure
      bluetooth = {
        unitConfig.OnFailure = [ "bt-reset.service" ];
      };

      bt-reset = {
        description = "Reset Bluetooth adapter";
        after = [ "bluetooth.service" ];

        serviceConfig = {
          Type = "oneshot";
          ExecStart = script;

          Restart = "on-failure";
          RestartSec = "10s";
          StartLimitIntervalSec = "120";
          StartLimitBurst = 3;
        };
      };
    };

    timers.bt-reset = {
      description = "Periodically reset Bluetooth adapter";
      wantedBy = [ "timers.target" ];
      timerConfig = {
        OnBootSec = "5min"; # first run 5 min after boot
        OnUnitActiveSec = "4h"; # then every 4 hours
        RandomizedDelaySec = "5min";
      };
    };

    user = {
      timers = {
        "update-hetzner-ha-dns" = {
          unitConfig = {
            Description = "updates Hetzner DNS for home-assistant";
          };

          timerConfig = {
            Unit = "update-hetzner-ha-dns.service";
            OnCalendar = "*-*-* *:00/30:00";
            Persistent = true;
          };

          wantedBy = [ "timers.target" ];
        };
      };

      services = {
        "update-hetzner-ha-dns" = {
          unitConfig = {
            Description = "updates Hetzner DNS for home-assistant";
          };

          serviceConfig = {
            Type = "exec";
            EnvironmentFile = config.age.secrets.hetzner-dns.path;
          };

          path = [
            pkgs.curl
            pkgs.coreutils # For `cat`
            pkgs.jq
          ];

          script = ''
            LAST_IP_FILE="/tmp/hetzner-dns-ha-ip"
            INTERFACE="enp3s0"

            CURRENT_IP=$(curl -s --fail --interface "$INTERFACE" ifconfig.me)

            LAST_IP=""
            if [[ -f "$LAST_IP_FILE" ]]; then
                LAST_IP=$(cat "$LAST_IP_FILE")
            fi

            if [[ "$CURRENT_IP" == "$LAST_IP" ]]; then
                echo "IP unchanged, NOOP update."
                exit 0
            else
                echo "Updating IP"

                JSON_BODY=$(jq -n --arg ip "$CURRENT_IP" '{records: [{value: $ip}]}')

                curl \
                  --fail \
                	-X POST \
                  -H "Authorization: Bearer $HETZNER_API_TOKEN" \
                  -H "Content-Type: application/json" \
                  -d "$JSON_BODY" \
                  "https://api.hetzner.cloud/v1/zones/ppp.pm/rrsets/ha/A/actions/set_records" \
                  && echo $CURRENT_IP > $LAST_IP_FILE
            fi
          '';
        };
      };
    };
  };

  age = {
    secrets = {
      "hetzner-dns" = {
        file = ../../../../secrets/manatee/hetzner-dns.age;
        owner = "alex";
        group = "users";
      };
    };
  };
}