{ pkgs, config, ... }:

let
  mkWorker =
    name: tasks:
    import ../../../../modules/software-templates/synapse-workers/generic.nix {
      workerName = name;
      tasks = tasks;
    };
in
{
  # Worker plumbing examples: https://github.com/element-hq/synapse/blob/master/docker/configure_workers_and_start.py
  # Documentation: https://github.com/element-hq/synapse/blob/develop/docs/workers.md
  imports = [
    ../../../../modules/software-templates/synapse-workers/module.nix
    ./postgres.nix

    (mkWorker "sync" [ "sync" ])
  ];

  services.matrix-synapse = {
    enable = true;
    withJemalloc = true;

    nginxVirtualHostName = "matrix.rory.gay";
    enableWorkers = true;

    federationSenders = 16; # 16
    pushers = 1;
    mediaRepoWorkers = 2; # 4
    clientReaders = 2; # 4
    syncWorkers = 2; # 4
    authWorkers = 0;

    eventCreators = 16;

    federationReaders = 8; # 8
    federationInboundWorkers = 16; # 8

    enableAppserviceWorker = true;
    enableBackgroundWorker = true;
    enableUserDirWorker = true;

    accountDataStreamWriters = 1;
    eventStreamWriters = 2; # 8
    presenceStreamWriters = 1;
    pushRuleStreamWriters = 1;
    receiptStreamWriters = 1;
    toDeviceStreamWriters = 1;
    typingStreamWriters = 1;

    # https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html
    settings = {
      server_name = "rory.gay";

      dummy_devents_treshold = 2;
      cleanup_extremities_with_dummy_events = true;

      enable_registration = true;
      registration_requires_token = true;

      require_membership_for_aliases = false;
      redaction_retention_period = null;
      user_ips_max_age = null;
      allow_device_name_lookup_over_federation = true;

      federation = {
        client_timeout = "30s"; # default=60s
        max_short_retries = 12;
        max_short_retry_delay = "5s";
        max_long_retries = 5;
        max_long_retry_delay = "30s";

        # rapid retry, small increments
        destination_min_retry_interval = "5m"; # default=10m
        destination_max_retry_interval = "12h"; # default=7d
        destination_retry_multiplier = 1.2; # default=2
      };

      registration_shared_secret_path = pkgs.writeText "registration_shared_secret.txt" ''
        sometext
      '';

      listeners = [
        {
          port = 8008;
          bind_addresses = [ "127.0.0.1" ];
          type = "http";
          tls = false;
          x_forwarded = true;
          resources = [
            {
              names = [
                "client"
                "federation"
              ];
              compress = false;
            }
          ];
        }
        {
          type = "http";
          path = "/run/matrix-synapse/main.sock";
          resources = [
            {
              names = [ "replication" ];
              compress = false;
            }
          ];
        }
      ];
      presence = {
        enablee = true;
        update_interval = 60;
      };
      database = {
        name = "psycopg2";
        args = {
          user = "matrix-synapse-rory-gay";
          password = "somepassword";
          database = "matrix-synapse-rory-gay";
          host = "/run/postgresql";
          application_name = "matrix-synapse (rory.gay) - main";
          cp_min = 2;
          cp_max = 5;

          # cp_reconnect - default=True - https://github.com/element-hq/synapse/blob/develop/synapse/storage/database.py#L129
          # cp_noisy - default=False - https://docs.twisted.org/en/stable/api/twisted.enterprise.adbapi.ConnectionPool.html#__init__ - info logs during operation
          # check_same_thread - default=False - https://github.com/element-hq/synapse/blob/develop/synapse/config/database.py#L65 - can this even be set?
        };

        # synchronous_commit - default=True - https://github.com/element-hq/synapse/blob/develop/synapse/storage/engines/postgres.py#L56
        # statement_timeout - default=60 * 60 * 1000 ms - https://github.com/element-hq/synapse/blob/develop/synapse/storage/engines/postgres.py#L63
        # allow_unsafe_locale - default=False - https://github.com/element-hq/synapse/blob/develop/synapse/storage/engines/postgres.py#L99
        # allow_outdated_version - default=False - https://github.com/element-hq/synapse/blob/develop/synapse/storage/engines/postgres.py#L92 - needs source link
        # txn_limit - default=0 - https://github.com/element-hq/synapse/blob/develop/synapse/storage/database.py#L564

        statement_timeout = 24 * 60 * 60 * 1000; # 24 hours, good for bg jobs
        txn_limit = 500; # maybe dropping old data from pg caches helps?
      };

      ui_auth = {
        session_timeout = "1m";
      };

      login_via_existing_session = {
        enabled = true;
        require_ui_auth = true;
        token_timeout = "1y";
      };

      report_stats = false;

      user_directory = {
        enabled = true;
        search_all_users = true;
        prefer_local_users = true;
      };

      # https://github.com/element-hq/synapse/blob/master/synapse/config/experimental.py
      experimental_features = {
        "msc2815_enabled" = true; # Redacted event content
        "msc3026_enabled" = true; # Busy presence
        "msc3266_enabled" = true; # Room summary API
        "msc3916_authenticated_media_enabled" = true; # Authenticated media
        "msc3823_account_suspension" = true; # Account suspension
        "msc4151_enabled" = true; # Report room API (CS-API)
      };

      redis = {
        enabled = true;
        path = "/run/redis-matrix-synapse/redis.sock";
      };

      instance_map = {
        main = {
          # replication listener
          path = "/run/matrix-synapse/main.sock";
        };
      };
    };
    #      // import ./ratelimits.nix
    #      // import ./caches.nix;
  };

  services.redis = {
    package = pkgs.keydb;
    servers.matrix-synapse = {
      enable = true;
      user = "matrix-synapse";
    };
  };

  services.postgresql = {
    initialScript = pkgs.writeText "synapse-init.sql" ''
      CREATE USER "${config.services.matrix-synapse.settings.database.args.user}" WITH PASSWORD '${config.services.matrix-synapse.settings.database.args.password}';
      CREATE DATABASE "${config.services.matrix-synapse.settings.database.args.database}" OWNER '${config.services.matrix-synapse.settings.database.args.user}' LOCALE 'C' ENCODING 'UTF8' TEMPLATE "template0";
    '';
  };

  systemd.tmpfiles.rules = [ "D /run/redis-matrix-synapse 0755 matrix-synapse matrix-synapse" ];
}