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

{
  networking.firewall.allowedTCPPorts = [ 80 443 ];

  nixpkgs.overlays = [ (import ./../pkgs/matrix) ];


  services.postgresql.enable = true;
  services.postgresql.initialScript = pkgs.writeText "synapse-init.sql" ''
    CREATE ROLE "matrix-synapse" WITH LOGIN PASSWORD 'synapse';
    CREATE DATABASE "matrix-synapse" WITH OWNER "matrix-synapse"
      TEMPLATE template0
      LC_COLLATE = "C"
      LC_CTYPE = "C";
  '';

  services.nginx = {
    enable = true;
    # only recommendedProxySettings and recommendedGzipSettings are strictly required,
    # but the rest make sense as well (according to the broken example from the manual)
    recommendedTlsSettings = true;
    recommendedOptimisation = true;
    recommendedGzipSettings = true;
    recommendedProxySettings = true;

    virtualHosts = {

      # This host section can be placed on a different host than the rest,
      # i.e. to delegate from the host on which matrix / synapse actually run.
      # This may make migration easier; in our case it's mostly added complexity.
      "hacc.space" = {
        # see https://matrix.org/docs/spec/client_server/latest#get-well-known-matrix-client
        # for documentation on what should be returned at these endpoints.
        locations."= /.well-known/matrix/server".extraConfig = ''
          add_header Content-Type application/json;
          return 200 '${builtins.toJSON  { "m.server" = "matrix.hacc.space:443"; }}';
        '';
        # this is to configure the nice default homeserver setting for our element web.
        locations."= /.well-known/matrix/client".extraConfig =
          let client = {
            "m.homeserver" =  { "base_url" = "https://matrix.hacc.space"; };
            "m.identity_server" =  { "base_url" = "https://vector.im"; };
          };
        in ''
          add_header Content-Type application/json;
          add_header Access-Control-Allow-Origin *;
          return 200 '${builtins.toJSON client}';
        '';
      };


      # this serves the actual matrix endpoint
      "matrix.hacc.space" = {
        enableACME = true;
        forceSSL = true;

        # it is not recommended to have the actual element web interface on the same domain,
        # cf. https://github.com/vector-im/element-web#separate-domains on this.
        locations."/".extraConfig = ''
          return 404;
        '';

        locations."/_matrix" = {
          proxyPass = "http://[::1]:8008";
        };
      };


      # the element web client for our matrix server.
      "element.hacc.space" = {
        enableACME = true;
        forceSSL = true;
        root = pkgs.element-web.override {
          conf = {
            # the base_url here must be identical to the one on hacc.space/.well-known above.
            default_server_config."m.homeserver" = {
              "base_url" = "https://matrix.hacc.space";
              "server_name" = "matrix.hacc.space";
            };
          };
        };
      };
    };
  };

  services.matrix-synapse = {
    enable = true;
    server_name = "hacc.space";
    public_baseurl = "https://matrix.hacc.space";
    enable_registration = true;
    allow_guest_access = true;
    max_upload_size = "25M";
    max_image_pixels = "25M";
    dynamic_thumbnails = true;
    extraConfigFiles = [ "/var/lib/matrix-synapse/secrets.yml" ];
    extraConfig = ''
      email:
        smtp_host: mail.hacc.space
        smtp_user: "noreply@infra4future.de"
        smtp_port: 587
        notif_from: "Your Friendly %(app)s homeserver <noreply@hacc.space>"
        require_transport_security: true
        enable_notifs: true
        client_base_url: "https://element.hacc.space"
        invite_client_location: "https://element.hacc.space"

      admin_contact: 'mailto:admin@hacc.space'
      web_client_location: https://element.hacc.space/
      use_presence: false # uses lots of CPU for bacially nothing
      limit_profile_requests_to_users_who_share_rooms: true # limits unoticed stalking/network analysis
      allow_public_rooms_without_auth: true # public rooms should be public. can be changed if too much spam occurs
      default_room_version: "6"

      redaction_retention_period: 3d # ich hab keine Ahnung, was das tut, aber weniger klingt besser
      user_ips_max_age: 1d # ich will das Zeug gar nicht qq

      retention:
        enabled: true
        default_policy:
          min_lifetime: 1d # does nothing
          max_lifetime: 2w
        allowed_lifetime_min: 1h
        allowed_lifetime_max: 15w
        purge_jobs:
          - longest_max_lifetime: 1h
            interval: 15m
          - longest_max_lifetime: 1d
            interval: 1h
          - longest_max_lifetime: 3d
            interval: 12h
          - shortest_max_lifetime: 1w
            interval: 1d
      
      auto_join_rooms:
        - "#lobby:hacc.space"
      auto_join_rooms_for_guests: true

      password_config:
         policy:
            enabled: true
            minimum_length: 16

      push:
        include_content: false
        group_unread_count_by_room: false

      encryption_enabled_by_default_for_room_type: all # invite might be the more sane setting, but like this we never retain any unecrypted messeage from our rooms

      enable_group_creation: true
      group_creation_prefix: "__" # groups created by non-admins start eith this prefix

      user_directory:
          enabled: true
          search_all_users: false
          prefer_local_users: true

      # User Consent configuration
      #
      # for detailed instructions, see
      # https://github.com/matrix-org/synapse/blob/master/docs/consent_tracking.md
      #
      # Parts of this section are required if enabling the 'consent' resource under
      # 'listeners', in particular 'template_dir' and 'version'.
      #
      # 'template_dir' gives the location of the templates for the HTML forms.
      # This directory should contain one subdirectory per language (eg, 'en', 'fr'),
      # and each language directory should contain the policy document (named as
      # '<version>.html') and a success page (success.html).
      #
      # 'version' specifies the 'current' version of the policy document. It defines
      # the version to be served by the consent resource if there is no 'v'
      # parameter.
      #
      # 'server_notice_content', if enabled, will send a user a "Server Notice"
      # asking them to consent to the privacy policy. The 'server_notices' section
      # must also be configured for this to work. Notices will *not* be sent to
      # guest users unless 'send_server_notice_to_guests' is set to true.
      #
      # 'block_events_error', if set, will block any attempts to send events
      # until the user consents to the privacy policy. The value of the setting is
      # used as the text of the error.
      #
      # 'require_at_registration', if enabled, will add a step to the registration
      # process, similar to how captcha works. Users will be required to accept the
      # policy before their account is created.
      #
      # 'policy_name' is the display name of the policy users will see when registering
      # for an account. Has no effect unless `require_at_registration` is enabled.
      # Defaults to "Privacy Policy".
      #
      #user_consent:
      #  template_dir: res/templates/privacy
      #  version: 1.0
      #  server_notice_content:
      #    msgtype: m.text
      #    body: >-
      #      To continue using this homeserver you must review and agree to the
      #      terms and conditions at %(consent_uri)s
      #  send_server_notice_to_guests: true
      #  block_events_error: >-
      #    To continue using this homeserver you must review and agree to the
      #    terms and conditions at %(consent_uri)s
      #  require_at_registration: false
      #  policy_name: Privacy Policy
      #      
    '';
    listeners = [ {
      port = 8008;
      bind_address = "::1";
      type = "http";
      tls = false;
      x_forwarded = true;
      resources = [ {
        names = [ "client" "federation" ];
        compress = false;
      } ];
    } ];
  };
}