{
  lib,
  config,
  pkgs,
  ...
}: let
  lokiConfig = import ./loki.nix;
  blackboxConfig = import ./blackbox.nix;
  inherit (import <niveum/lib>) restic;
in {
  services.grafana = {
    enable = true;
    settings.server = {
      domain = "grafana.kmein.r";
      http_port = 9444;
      http_addr = "127.0.0.1";
    };
  };

  services.nginx.virtualHosts = {
    ${config.services.grafana.settings.server.domain} = {
      locations."/" = {
        proxyPass = "http://127.0.0.1:${toString config.services.grafana.settings.server.http_port}";
        proxyWebsockets = true;
      };
    };
    "alertmanager.kmein.r" = {
      locations."/" = {
        proxyPass = "http://127.0.0.1:${toString config.services.prometheus.alertmanager.port}";
        proxyWebsockets = true;
      };
    };
  };

  niveum.passport.services = [
    {
      title = "Prometheus";
      description = "collects metrics from devices in the <i>niveum</i> network, blackbox monitors some websites.";
    }
    {
      title = "Loki";
      description = "aggregates logs of the <i>niveum</i> network.";
    }
    {
      title = "Grafana";
      link = "http://${config.services.grafana.domain}";
      description = "displays metrics from devices in the <i>niveum</i> network.";
    }
    {
      title = "Alertmanager bot";
      description = "notifies me when something goes wrong.";
    }
  ];

  services.prometheus.rules = let
    diskFreeThreshold = 10;
  in [
    (builtins.toJSON {
      groups = [
        {
          name = "niveum";
          rules = [
            {
              alert = "ServiceDown";
              expr = ''node_systemd_unit_state{state="failed"} == 1'';
              annotations = {
                summary = "{{$labels.name}} failed on {{$labels.job}}";
              };
            }
            {
              alert = "RootPartitionFull";
              for = "10m";
              expr = ''(node_filesystem_free_bytes{mountpoint="/"} * 100) / node_filesystem_size_bytes{mountpoint="/"} < ${toString diskFreeThreshold}'';
              annotations = {
                summary = ''{{ $labels.job }} running out of space: {{ $value | printf "%.2f" }}% < ${toString diskFreeThreshold}%'';
              };
            }
            {
              alert = "RootPartitionFullWeek";
              for = "1h";
              expr =
                ''node_filesystem_free_bytes{mountpoint="/"} ''
                + ''and predict_linear(node_filesystem_free_bytes{mountpoint="/"}[2d], 7*24*3600) <= 0'';
              annotations = {
                summary = "{{$labels.job}} running out of space in 7 days";
              };
            }
            {
              alert = "HighLoad";
              expr = ''node_load15 / on(job) count(node_cpu_seconds_total{mode="system"}) by (job) >= 1.0'';
              for = "10m";
              annotations = {
                summary = "{{$labels.job}} running on high load: {{$value}}";
              };
            }
            {
              alert = "HighRAM";
              expr = "node_memory_MemFree_bytes + node_memory_Buffers_bytes + node_memory_Cached_bytes < node_memory_MemTotal_bytes * 0.1";
              for = "1h";
              annotations.summary = "{{$labels.job}} using lots of RAM";
            }
            {
              alert = "UptimeMonster";
              expr = "time() - node_boot_time_seconds > 2592000";
              annotations.summary = "uptime monster {{$labels.job}} up for more than 30 days";
            }
            {
              alert = "HostDown";
              expr = ''up == 0'';
              for = "5m";
              annotations = {
                summary = "{{ $labels.job }} seeming down since 5 minutes";
              };
            }
            {
              alert = "Reboot";
              expr = "time() - node_boot_time_seconds < 300";
              annotations.summary = "{{$labels.job}} rebooted";
            }
            {
              alert = "ProbeFailed";
              expr = "probe_success == 0";
              for = "5m";
              annotations.summary = "HTTP probe failed for {{$labels.instance}}";
            }
            {
              alert = "SlowProbe";
              expr = "avg_over_time(probe_http_duration_seconds[1m]) > 1";
              for = "5m";
              annotations.summary = "HTTP probe slow for {{$labels.instance}}";
            }
            {
              alert = "HttpStatusCode";
              expr = "probe_http_status_code != 0 AND (probe_http_status_code <= 199 OR probe_http_status_code >= 400)";
              for = "5m";
              annotations.summary = "status code {{$value}} for {{$labels.instance}}";
            }
            {
              alert = "SslExpirySoon";
              expr = "probe_ssl_earliest_cert_expiry - time() < 86400 * 30";
              for = "5m";
              annotations.summary = "SSL certificate for {{$labels.instance}} expires in 30 days";
            }
            {
              alert = "SslExpiry";
              expr = "probe_ssl_earliest_cert_expiry - time()  <= 0";
              for = "5m";
              annotations.summary = "SSL certificate for {{$labels.instance}} has expired";
            }
          ];
        }
      ];
    })
  ];

  services.prometheus.alertmanager = {
    enable = true;
    listenAddress = "localhost";
    configuration = {
      route = {
        group_wait = "30s";
        repeat_interval = "24h";
        receiver = "email";
      };
      receivers = [
        {
          name = "email";
          email_configs = let
            inherit (import <niveum/lib>) kieran;
            inherit (import <niveum/lib/email.nix> {inherit lib;}) cock;
          in [
            {
              send_resolved = true;
              to = kieran.email;
              from = cock.user;
              smarthost = "${cock.smtp}:587";
              auth_username = cock.user;
              auth_identity = cock.user;
              auth_password = cock.password;
            }
          ];
        }
      ];
    };
  };

  services.prometheus.alertmanagers = [
    {
      scheme = "http";
      path_prefix = "/";
      static_configs = [{targets = ["localhost:${toString config.services.prometheus.alertmanager.port}"];}];
    }
  ];

  services.prometheus.scrapeConfigs = [
    {
      job_name = "makanek";
      static_configs = [
        {
          targets = [
            "127.0.0.1:${toString config.services.prometheus.exporters.node.port}"
          ];
        }
      ];
    }
    {
      scrape_interval = "5m";
      job_name = "blackbox";
      metrics_path = "/probe";
      params.module = ["http_2xx"];
      relabel_configs = [
        {
          source_labels = ["__address__"];
          target_label = "__param_target";
        }
        {
          source_labels = ["__param_target"];
          target_label = "instance";
        }
        {
          replacement = "127.0.0.1:${toString config.services.prometheus.exporters.blackbox.port}";
          target_label = "__address__";
        }
      ];
      static_configs = [
        {
          targets = [
            "alew.hu-berlin.de"
            "pad.kmein.de"
            "code.kmein.de"
            "radio.kmein.de"
            "tarot.kmein.de"
            "cloud.xn--kiern-0qa.de"
            "grafana.kmein.r"
            # "names.kmein.r"
            "rrm.r"
            "graph.r"
          ];
        }
      ];
    }
    {
      job_name = "zaatar";
      static_configs = [
        {
          targets = [
            "zaatar.r:${toString config.services.prometheus.exporters.node.port}"
            "zaatar.r:${toString restic.port}"
          ];
        }
      ];
    }
    {
      job_name = "ful";
      static_configs = [
        {
          targets = [
            "ful.r:${toString config.services.prometheus.exporters.node.port}"
          ];
        }
      ];
    }
  ];

  services.prometheus.exporters.blackbox = {
    enable = true;
    configFile = (pkgs.formats.yaml {}).generate "blackbox.yaml" blackboxConfig;
  };

  networking.firewall.allowedTCPPorts = [
    lokiConfig.server.http_listen_port
  ];

  services.loki = {
    enable = true;
    configFile = (pkgs.formats.yaml {}).generate "loki.yaml" lokiConfig;
  };
}