{ config, pkgs, lib, ... }:

with lib;

let
  hosts = (import ../../lib/hosts.nix { inherit pkgs; }).hosts;

  monitoringHosts = filterAttrs (name: host:
    attrByPath ["clerie" "monitoring" "enable"] false host.config)
    hosts;

  monitoringHostsNames = mapAttrs' (name: host:
    nameValuePair "fd00:327:327:327::${host.config.clerie.monitoring.id}"  ["${host.config.networking.hostName}.mon.clerie.de"])
    monitoringHosts;

  monitoringPeers = mapAttrsToList (name: host: {
      allowedIPs = [ "fd00:327:327:327::${host.config.clerie.monitoring.id}/128" ];
      publicKey = host.config.clerie.monitoring.pubkey;
    })
    monitoringHosts;

  monitoringTargets = mapAttrsToList (name: host:
    "${host.config.networking.hostName}.mon.clerie.de:9100")
    monitoringHosts;

in {
  imports =
    [
      ./hardware-configuration.nix
      ../../configuration/common
      ../../configuration/proxmox-vm
    ];

  boot.loader.grub.enable = true;
  boot.loader.grub.version = 2;
  boot.loader.grub.device = "/dev/sda";

  networking.hostName = "monitoring-3";

  networking.useDHCP = false;
  networking.interfaces.ens18.ipv4.addresses = [ { address = "192.168.10.32"; prefixLength = 24; } ];
  networking.interfaces.ens19.ipv6.addresses = [ { address = "2001:638:904:ffca::7"; prefixLength = 64; } ];
  networking.defaultGateway = { address = "192.168.10.1"; interface = "ens18"; };
  networking.defaultGateway6 = { address = "2001:638:904:ffca::1"; interface = "ens19"; };
  networking.nameservers = [ "2001:638:904:ffcc::3" "2001:638:904:ffcc::4" "141.24.40.3" "141.24.40.4" ];

  networking.hosts = {
    "fd00:327:327:327::1" = [ "monitoring-3.mon.clerie.de" ];
  }
  // monitoringHostsNames;

  networking.wireguard.enable = true;
  networking.wireguard.interfaces = {
    wg-monitoring = {
      ips = [ "fd00:327:327:327::1/64" ];
      listenPort = 54523;
      peers = monitoringPeers;
      privateKeyFile = "/var/src/secrets/wireguard/wg-monitoring";
    };
  };

  networking.firewall.allowedUDPPorts = [ 54523 ];

  services.prometheus.exporters.node.enable = true;

  services.prometheus = {
    enable = true;
    listenAddress = "[::1]";
    scrapeConfigs = [
      {
        job_name = "prometheus";
        scrape_interval = "20s";
        scheme = "http";
        static_configs = [
          {
            targets = [
              "monitoring-3.mon.clerie.de:9090"
            ];
          }
        ];
      }
      {
        job_name = "node-exporter";
        scrape_interval = "20s";
        static_configs = [
          {
            targets = [
              "monitoring-3.mon.clerie.de:9100"
            ]
            ++ monitoringTargets;
          }
        ];
      }
    ];
  };

  services.grafana = {
    enable  = true;
    domain  = "grafana.monitoring.clerie.de";
    rootUrl = "https://grafana.monitoring.clerie.de";
    port    = 3001;
    addr = "::1";
    auth.anonymous.enable = true;

    provision = {
      enable = true;
      datasources = [
        {
          type = "prometheus";
          name = "Prometheus";
          url = "http://[::1]:9090";
          isDefault = true;
        }
      ];
      dashboards = [
        {
          options.path = ./dashboards;
        }
      ];
    };
  };

  users.users.uptimestatus = {
    description = "Uptime Status Service";
    group = "uptimestatus";
    home = "/var/lib/uptimestatus/";
    useDefaultShell = true;
    isSystemUser = true;
  };
  users.groups.uptimestatus = {};

  systemd.services.uptimestatus = {
    wantedBy = [ "multi-user.target" ];
    serviceConfig = {
      RuntimeDirectory = "uptimestatus";
      StateDirectory = "uptimestatus";
      User = "uptimestatus";
      Group = "uptimestatus";
    };
    script = "gunicorn -w 4 -b [::1]:8235 uptimestatus:app";
    path = with pkgs; [ (python38.withPackages (ps: [ ps.gunicorn uptimestatus ])) ];
  };

  services.nginx = {
    enable = true;

    virtualHosts = {
      "prometheus.monitoring.clerie.de" = {
        enableACME = true;
        forceSSL   = true;
        locations."/".proxyPass = "http://[::1]:9090/";
      };
      "grafana.monitoring.clerie.de" = {
        enableACME = true;
        forceSSL   = true;
        locations."/".proxyPass = "http://[::1]:3001/";
      };
      "status.monitoring.clerie.de" = {
        enableACME = true;
        forceSSL   = true;
        locations."/".proxyPass = "http://[::1]:8235/";
      };
    };
  };

  networking.firewall.allowedTCPPorts = [ 80 443 ];

  system.stateVersion = "21.03";
}