{ nglib, nixpkgs }:
let
  logConfig = pkgs: (pkgs.formats.yaml {}).generate "log.yaml"
    {
      version = 1;

      formatters.precise.format = "%(asctime)s - %(name)s - %(lineno)d - %(levelname)s - %(request)s - %(message)s";
      handlers.console =
        {
          class = "logging.StreamHandler";
          formatter = "precise";
        };
      loggers."synapse.storage.SQL" =
        {
          level = "INFO";
        };
      root =
        {
          level = "INFO";
          handlers = [ "console" ];
        };

      disable_existing_loggers = false;
    };

  commonConfig = pkgs: (pkgs.formats.yaml {}).generate "common.yaml"
    {
      server_name = "matrix.redalder.org";
      report_stats = "yes";
      pid_file = "/homeserver.pid";

      log_config = logConfig pkgs;

      trusted_key_servers =
        [
          {
            server_name = "matrix.org";
          }
        ];
      media_store_path = "/var/lib/synapse/media_store";
      signing_key_path = "/var/lib/synapse/signing.key";

      enable_registration = false;
      enable_registration_without_verification = false;

      federation_sender_instances = [
        "worker-federation-sender-0"
      ];
    };

  genericWorker = { listener_resources, name }:
    nglib.makeSystem {
      system = "x86_64-linux";
      name = "synapse-worker-${name}";
      inherit nixpkgs;
      config = ({ pkgs, ... }:
        {
          dumb-init = {
            enable = true;
            type.services = { };
          };

          services.synapse.workers.${name} = {
            settings = {
              worker_app = "synapse.app.generic_worker";

              # The replication listener on the main synapse process.
              worker_replication_host = "127.0.0.1";
              worker_replication_http_port = 9093;

              worker_listeners = [
                {
                  port = 6167;
                  tls = false;
                  type = "http";
                  x_forwarded = true;
                  bind_adrresses = [ "0.0.0.0" ];
                  resources =
                    [
                      {
                        names = listener_resources;
                        compress = false;
                      }
                    ];
                }
              ];

              worker_log_config = logConfig pkgs;
            };
            arguments = {
              config-path = [
                (commonConfig pkgs)
                "/secrets/extra.yaml"
                "/var/lib/registrations/extra.yaml"
              ];
              keys-directory = [
                "/var/lib/synapse/keys"
              ];
            };
          };
        });
    };
in
{
  postgresql = nglib.makeSystem {
    system = "x86_64-linux";
    name = "nixng-synapse-postgresql";
    inherit nixpkgs;
    config = { pkgs, config, ... }:
      {
        config = {
          dumb-init = {
            enable = true;
            type.services = {};
          };
          services.postgresql = {
            enable = true;
            package = pkgs.postgresql_12;

            initialScript = "/secrets/init.sql";
            enableTCPIP = true;

            authentication = "host  all all all          md5";

            ensureDatabases = {
              "synapse" = { ENCODING = "UTF8"; TEMPLATE = "template0"; };
              "mautrix-facebook" = { ENCODING = "UTF8"; TEMPLATE = "template0"; };
              "mautrix-signal" = { ENCODING = "UTF8"; TEMPLATE = "template0"; };
              "mautrix-whatsapp" = { ENCODING = "UTF8"; TEMPLATE = "template0"; };
              "mautrix-discord" = { ENCODING = "UTF8"; TEMPLATE = "template0"; };
            };
            ensureExtensions = {};
            ensureUsers = [
              {
                name = "synapse";
                ensurePermissions."DATABASE \"synapse\"" = "ALL PRIVILEGES";
              }
              {
                name = "mautrix-facebook";
                ensurePermissions."DATABASE \"mautrix-facebook\"" = "ALL PRIVILEGES";
              }
              {
                name = "mautrix-signal";
                ensurePermissions."DATABASE \"mautrix-signal\"" = "ALL PRIVILEGES";
              }
              {
                name = "mautrix-whatsapp";
                ensurePermissions."DATABASE \"mautrix-whatsapp\"" = "ALL PRIVILEGES";
              }
              {
                name = "mautrix-discord";
                ensurePermissions."DATABASE \"mautrix-discord\"" = "ALL PRIVILEGES";
              }
            ];
          };
        };
      };
  };

  redis = nglib.makeSystem {
    system = "x86_64-linux";
    name = "redis";
    inherit nixpkgs;
    config = ({ pkgs, ... }:
      {
        dumb-init = {
          enable = true;
          type.services = { };
        };

        users.users."redis" = {
          home = "/var/empty";
          uid = 9001;
          group = "redis";
        };

        users.groups."redis" = {
          gid = 9001;
        };

        init.services.redis = {
          enabled = true;
          shutdownOnExit = true;
          script =
            pkgs.writeShellScript "redis-run" ''
              cd /var/lib/redis
              chpst -U redis:redis ${pkgs.redis}/bin/redis-server ${./redis.conf}
            '';
        };

        init.services.redis-setup = {
          enabled = true;
          script =
            pkgs.writeShellScript "redis-run" ''
              export PATH="${pkgs.redis}/bin:$PATH"
              nc -z 127.0.0.1 6379 -w 10 -v || exit 1

              redis-cli acl setuser default on '>'"$(cat /secrets/redis_password)" allcommands allkeys
              sleep 86400
            '';
        };
      });
  };

  synapseFederationSender = genericWorker { name = "generic"; listener_resources = [ "health" ]; };
  synapseFederationReceiver = genericWorker { name = "generic"; listener_resources = [ "health" "federation" ]; };
  synapseClient = genericWorker { name = "generic"; listener_resources = [ "client" "health" ]; };
  synapseSync = genericWorker { name = "generic"; listener_resources = [ "client" "health" ]; };

  synapse = nglib.makeSystem {
    system = "x86_64-linux";
    name = "synapse";
    inherit nixpkgs;
    config = ({ pkgs, ... }:
      {
        dumb-init = {
          enable = true;
          type.services = { };
        };

        init.services.synapse = {
          enabled = true;
          shutdownOnExit = true;
          script =
            let
              synapseConfig = (pkgs.formats.yaml {}).generate "synapse.yaml"
                {
                  listeners =
                    [
                      # The HTTP replication port
                      {
                        port = 9093;
                        bind_addresses = [ "0.0.0.0" ];
                        type = "http";
                        resources = [
                          {
                            names = [ "replication" ];
                          }
                        ];
                      }
                      {
                        port = 6167;
                        tls = false;
                        type = "http";
                        x_forwarded = true;
                        bind_adrresses = [ "0.0.0.0" ];
                        resources =
                          [
                            {
                              names = [ "client" "federation" ];
                              compress = false;
                            }
                          ];
                      }
                    ];

                  public_baseurl = "https://matrix.redalder.org/";

                  # Add a random shared secret to authenticate traffic.
                  worker_replication_secret = "";
                };
            in
              pkgs.writeShellScript "synapse"
                ''
                  [ -e /var/lib/synapse/signing.key ] || \
                    ${pkgs.matrix-synapse}/bin/synapse_homeserver \
                      --config-path ${synapseConfig} \
                      --config-path ${commonConfig pkgs} \
                      --config-path /secrets/extra.yaml \
                      --config-path /var/lib/registrations/extra.yaml \
                      --keys-directory /var/lib/synapse/keys \
                      --generate-keys
                  ${pkgs.matrix-synapse}/bin/synapse_homeserver \
                    --config-path ${synapseConfig} \
                    --config-path ${commonConfig pkgs} \
                    --config-path /secrets/extra.yaml \
                    --config-path /var/lib/registrations/extra.yaml \
                    --keys-directory /var/lib/synapse/keys
                '';
        };
      });
  };
}