namespace _espe.conf
{
	
	/**
	 */
	export type type_conf = {
		general : {
			verbosity : (
				"none"
				|
				"debug"
				|
				"notice"
				|
				"info"
				|
				"warning"
				|
				"error"
			);
			verification_secret : (null | string);
		};
		server : {
			port : int;
		};
		database : (
			{
				kind : "sqlite";
				data : {
					path : string;
				};
			}
			|
			{
				kind : "postgresql";
				data : {
					host : string;
					port ?: int;
					username : string;
					password : string;
					schema : string;
				};
			}
		);
		email_sending : {
			mode : (
				"regular"
				|
				"redirect"
				|
				"console"
				|
				"drop"
			);
			smtp_credentials : (
				null
				|
				{
					host : string;
					port : int;
					username : string;
					password : string;
				}
			);
		};
		session_management : {
			lifetime : int;
			drop_all_at_start : boolean;
		};
		settings : {
			target_domain : string;
			prefix_for_numberbased_email_addresses : string;
		};
		// TODO: evtl. in Datenbank verlagern
		admins : Array<
			{
				name : string;
				password_image : string;
			}
		>;
	};
	
	
	/**
	 */
	var _data : (null | type_conf) = null;
	
	
	/**
	 * @todo mandatory fields
	 */
	export async function load(
		path : (null | string)
	) : Promise<void>
	{
		const conf_raw : any = (
			(path !== null)
			? (lib_plankton.json.decode(await lib_plankton.file.read(path)) as type_conf)
			: {}
		);
		_data = {
			"general": (
				((node_general) => ({
					"verbosity": (node_general["verbosity"] ?? "notice"),
					"verification_secret": (node_general["verification_secret"] ?? null),
				})) (conf_raw["general"] ?? {})
			),
			"server": (
				((node_server) => ({
					"port": (node_server["port"] ?? 7979),
				})) (conf_raw["server"] ?? {})
			),
			"database": (
				((node_database) => {
					const kind : string = (node_database["kind"] ?? "sqlite");
					const node_database_data_raw = (node_database["data"] ?? {});
					switch (kind) {
						case "sqlite": {
							return {
								"kind": kind,
								"data": {
									"path": (node_database_data_raw["path"] ?? "data.sqlite"),
								}
							};
						}
						case "postgresql": {
							return {
								"kind": kind,
								"data": node_database_data_raw,
							};
						}
						default: {
							throw (new Error("unhandled"));
							break;
						}
					}
				}) (conf_raw["database"] ?? {})
			),
			"email_sending": (
				((node_email_sending) => ({
					"mode": (node_email_sending["mode"] ?? "regular"),
					"smtp_credentials": (node_email_sending["smtp_credentials"] ?? null),
				})) (conf_raw["email_sending"] ?? {})
			),
			"session_management": (
				((node_session_management) => ({
					"lifetime": (node_session_management["lifetime"] ?? 900),
					"drop_all_at_start": (node_session_management["drop_all_at_start"] ?? true),
				})) (conf_raw["session_management"] ?? {})
			),
			"settings": (
				((node_settings) => ({
					"target_domain": (node_settings["target_domain"] ?? "example.org"),
					"prefix_for_numberbased_email_addresses": (node_settings["prefix_for_numberbased_email_addresses"] ?? "member-"),
				})) (conf_raw["settings"] ?? {})
			),
			"admins": (conf_raw["admins"] ?? []),
		};
		// process.stderr.write(JSON.stringify(_data, undefined, "\t"));
		return Promise.resolve<void>(undefined);
	}
	
	
	/**
	 */
	export function get(
	) : type_conf
	{
		if (_data === null) {
			throw (new Error("conf not loaded yet"));
		}
		else {
			return _data;
		}
	}
	
}