{pkgs}: {applicationName, application}:
	with pkgs.stdenv.lib;

	let
		serviceName = "node-${applicationName}-error-reporter";
		cfg = config.services."${serviceName}";
		# FIXME: report-errors NPM package!
	in {
		options.services."${serviceName}" = {
			enable = mkEnableOption "${name} Error Reporter";

			stackFilter = mkOption {
				description = ''
					What modules to filter out of the simplified stacktraces
					shown in the e-mail report. This can either be the
					string "*" (to filter out every third-party module), or
					an array of module names to filter.

					Note that the e-mail will always include a JSON
					attachment containing the full stacktrace - this setting
					purely affects the e-mail body.
				'';
				default = "*";
				type = types.either types.str (types.listOf types.str);
			};

			subjectFormat = mkOption {
				description = ''
					The format for the subject line of the report e-mail. In
					this string, `$type` will be replaced with the error
					type/name, and `$message` will be replaced with the
					error message.
				'';
				default = "UNHANDLED ERROR: $type - $message";
				type = types.str;
			};

			metadata = {
				from = mkOption {
					description = ''
						 The sender address displayed on the e-mail report.
					'';
					type = types.str;
				};

				to = mkOption {
					description = ''
						 The address to e-mail reports to.
					'';
					type = types.str;
				};
			};

			smtp = {
				hostname = mkOption {
					description = ''
						 The hostname on which the SMTP server can be
						 reached.
					'';
					default = null;
					type = types.nullOr types.str;
				};

				port = mkOption {
					description = ''
						 The port number that the SMTP server is accessible
						 on.
					'';
					default = null;
					type = types.nullOr types.str;
				};

				username = mkOption {
					description = ''
						 Your username for the SMTP server.
					'';
					default = null;
					type = types.nullOr types.str;
				};

				password = mkOption {
					description = ''
						 Your password for the SMTP server.
					'';
					default = null;
					type = types.nullOr types.str;
				};

			};
		};

		config = {
			services."${serviceName}" = mkIf cfg.enabled {
				wantedBy = [ "multi-user.target" ];
				after = [ "network.target" ];
				serviceConfig = {
					ExecStart = "${pkgs.nodejs_6_x}/bin/node ${application}/node_modules/report-errors/lib/daemon/index.js";
					User = systemd.services."node-${applicationName}".serviceConfig.User; # MARKER
				};
			};
		};
	}