# NixOps configuration for the hosts running a Matrix server (synapse)
{
  config,
  pkgs,
  lib,
  ...
}: {
  i18n = {
    extraLocaleSettings = {
      LC_COLLATE = "C.UTF-8"; # Ensure correct locale for postgres
      LC_CTYPE = "C.UTF-8"; # Ensure correct locale for postgres
    };
  };

  services = {
    matrix-synapse = {
      enable = true; # Enable the synapse server
      settings = {
        enable_registration = false; # Toggle user registration
        enable_registration_without_verification = false;
        extraConfig = ''
          enable_group_creation: true   # Allow users to create communities
        '';
        listeners = [
          {
            # federation
            bind_addresses = [];
            port = 8448;
            resources = [
              {
                compress = true;
                names = ["client"];
              }
              {
                compress = false;
                names = ["federation"];
              }
            ];
            tls = true;
            type = "http";
            x_forwarded = false;
          }
          {
            # client
            bind_addresses = ["::1"]; # Listen on localhost only
            port = 8008; # Port to listen on
            resources = [
              {
                compress = true;
                names = ["client"];
              }
              {
                compress = false;
                names = ["federation"];
              }
            ];
            tls = true;
            type = "http";
            x_forwarded = true;
          }
        ];
        max_upload_size = "200M"; # Also set client_max_body_size to at least this
        public_baseurl = "https://synapse.mcwhirter.io:443/"; # Matrix target URL
        server_name = "mcwhirter.io"; # Server's public domain name
        tls_certificate_path = "/var/lib/acme/mcwhirter.io/fullchain.pem";
        tls_private_key_path = "/var/lib/acme/mcwhirter.io/key.pem";
        turn_shared_secret = config.services.coturn.static-auth-secret;
        turn_uris = [
          "turn:turn.mcwhirter.io:5349?transport=udp"
          "turn:turn.mcwhirter.io:5350?transport=udp"
          "turn:turn.mcwhirter.io:5349?transport=tcp"
          "turn:turn.mcwhirter.io:5350?transport=tcp"
        ];
        url_preview_enabled = true;
      };
    };

    nginx = {
      enable = true;
      recommendedTlsSettings = true;
      recommendedOptimisation = true;
      recommendedGzipSettings = true;
      recommendedProxySettings = true;
      virtualHosts = {
        "synapse.mcwhirter.io" = {
          forceSSL = true;
          enableACME = true;
          locations = {
            "/_matrix" = {proxyPass = "https://[::1]:8008";};
            "/.well-known/matrix/server".extraConfig = let
              # use 443 instead of the default 8448 port to unite
              # the client-server and server-server port for simplicity
              server = {"m.server" = "synapse.mcwhirter.io:443";};
            in ''
              add_header Content-Type application/json;
              return 200 '${builtins.toJSON server}';
            '';
            "= /.well-known/matrix/client".extraConfig = let
              client = {
                "m.homeserver" = {
                  "base_url" = "https://synapse.mcwhirter.io";
                };
                "m.identity_server" = {"base_url" = "https://vector.im";};
              };
              # ACAO required to allow element-web on any URL to request this json file
            in ''
              add_header Content-Type application/json;
              add_header Access-Control-Allow-Origin *;
              return 200 '${builtins.toJSON client}';
            '';
          };
          extraConfig = ''
            client_max_body_size 200M;   # Needs to be no less than max_upload_size
          '';
        };
        "chat.mcwhirter.io" = {
          forceSSL = true;
          enableACME = true;
          root = pkgs.element-web; # Install RIOT web in the nginx root
        };
      };
    };

    postgresql = {
      enable = true;
      ensureDatabases = ["matrix-synapse"]; # Ensure the database persists
      ensureUsers = [
        {
          name = "matrix-synapse"; # Ensure the database user persists
          ensureDBOwnership = true;
        }
      ];
      # Initial database creation
      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.UTF-8"
          LC_CTYPE = "C.UTF-8";
      '';
    };
  };

  services.postgresqlBackup = {
    enable = true;
    compression = "zstd";
  };

  services.postgresqlBackup.databases = ["matrix-synapse"];

  security.acme = {
    acceptTerms = true;
    certs = {
      "chat.mcwhirter.io" = {
        postRun = "systemctl reload nginx.service";
        email = "acme@mcwhirter.io";
      };
      "synapse.mcwhirter.io" = {
        group = "matrix-synapse";
        postRun = "systemctl reload nginx.service; systemctl restart matrix-synapse.service";
        email = "acme@mcwhirter.io";
      };
    };
  };

  networking.firewall = {
    enable = true;
    allowedTCPPorts = [
      443 # HTTPS
      8448 # Matrix federation
    ];
  };

  users.groups.matrix-synapse.members = ["nginx"]; # Added for keys permissions
}