{ config, lib, ... }:
let
  cfg = config.services.matrix-synapse;
  dbGroup = "solo";
  federationSenders = lib.range 0 (cfg.federationSenders - 1);
  workerName = "federation_sender";
  workerRoutes = {
    client = [ ];
    federation = [ ];
    media = [ ];
  };
in
{
  config = lib.mkIf (cfg.federationSenders > 0) {
    services.matrix-synapse = {
      settings = {
        instance_map = lib.listToAttrs (
          lib.map (index: {
            name = "${workerName}-${toString index}";
            value = {
              path = "/run/matrix-synapse/${workerName}-${toString index}.sock";
            };
          }) federationSenders
        );
        send_federation = false;
        federation_sender_instances = lib.map (index: "${workerName}-${toString index}") federationSenders;
        outbound_federation_restricted_to = lib.map (index: "${workerName}-${toString index}") federationSenders;
        worker_replication_secret = "${workerName}_secret";
      };

      workers = lib.listToAttrs (
        lib.map (index: {
          name = "${workerName}-${toString index}";
          value = {
            worker_app = "synapse.app.generic_worker";
            worker_listeners = [
              {
                type = "http";
                path = "/run/matrix-synapse/${workerName}-${toString index}.sock";
                resources = [
                  {
                    names = [ "replication" ];
                    compress = false;
                  }
                ];
              }
            ];
            database = (
              import ../db.nix {
                inherit dbGroup;
                workerName = "${workerName}-${toString index}";
              }
            );
          };
        }) federationSenders
      );
    };
    services.nginx = {
      virtualHosts."${cfg.nginxVirtualHostName}".locations = lib.listToAttrs (
        lib.flatten (
          lib.forEach
            [
              "client"
              "federation"
              "media"
            ]
            (
              type:
              lib.map (route: {
                name = route;
                value = {
                  proxyPass = "http://unix:/run/matrix-synapse/${workerName}-${type}.sock";
                };
              }) workerRoutes.${type}
            )
        )
      );
    };
  };
}