namespace _zeitbild.api
{
	
	/**
	 * @todo zu plankton auslagern?
	 */
	type type_stuff = {
        version: (null | string);
        headers: Record<string, string>;
        path_parameters: Record<string, string>;
        query_parameters: Record<string, string>;
    };
    
    
	/**
	 */
	export async function session_from_stuff(
		stuff : {headers : Record<string, string>;}
	) : Promise<{key : string; value : lib_plankton.session.type_session}>
	{
		const key : string = (stuff.headers["X-Session-Key"] || stuff.headers["X-Session-Key".toLowerCase()]);
		const value : lib_plankton.session.type_session = await lib_plankton.session.get(key);
		return {"key": key, "value": value};
	}
	
	
	/**
	 * @todo outsource?
	 */
	export async function web_auth(
		authorization_string : (null | string)
	) : Promise<(null | _zeitbild.type_user_id)>
	{
		if (authorization_string === null) {
			return Promise.resolve<(null | _zeitbild.type_user_id)>(null);
		}
		else {
			const parts : Array<string> = authorization_string.split(" ");
			const strategy : string = parts[0];
			const data_raw : string = parts.slice(1).join(" ");
			switch (strategy) {
				default: {
					lib_plankton.log.notice(
						"zeitbild.web_auth.unhandled_strategy",
						{
							"strategy": strategy,
						}
					);
					return Promise.resolve<(null | _zeitbild.type_user_id)>(null);
					break;
				}
				case "Basic": {
					const data_raw_decoded : string = lib_plankton.base64.decode(data_raw);
					const parts_ : Array<string> = data_raw_decoded.split(":");
					const username : string = parts_[0];
					const password_is : string = parts_.slice(1).join(":");
					const {"value": user_id, "error": error} = await lib_plankton.call.try_catch_wrap_async<_zeitbild.type_user_id>(
						() => _zeitbild.service.user.identify(username)
					);
					if (error !== null) {
						lib_plankton.log.notice(
							"zeitbild.web_auth.unknown_user",
							{
								"username": username,
							}
						);
						return Promise.resolve<(null | _zeitbild.type_user_id)>(null);
					}
					else {
						const password_shall : string = lib_plankton.sha256.get(
							username,
							_zeitbild.conf.get()["misc"]["auth_salt"]
						);
						if (! (password_is === password_shall)) {
							/**
							 * @todo remove
							 */
							lib_plankton.log.notice(
								"zeitbild.web_auth.wrong_pasword",
								{
									"shall": password_shall,
									"is": password_is,
								}
							);
							return Promise.resolve<(null | _zeitbild.type_user_id)>(null);
						}
						else {
							return Promise.resolve<(null | _zeitbild.type_user_id)>(user_id);
						}
					}
					break;
				}
			}
		}
	}
	
	
	/**
	 */
	export const restriction_logged_in : lib_plankton.rest_caldav.type_restriction<any> = (
		(stuff) => (
			session_from_stuff(stuff)
			.then(() => Promise.resolve<boolean>(true))
			.catch(() => Promise.resolve<boolean>(false))
		)
	);
	
	
	/**
	 */
	export const restriction_basic_auth : lib_plankton.rest_caldav.type_restriction<any> = (
		(stuff) => (
			web_auth(
				stuff.headers["Authorization"]
				??
				stuff.headers["authorization"]
				??
				null
			)
			.then<boolean>(
				(user_id) => Promise.resolve<boolean>(
					(user_id !== null)
				)
			)
		)
	);
	
	
	/**
	 */
	export const restriction_none : lib_plankton.rest_caldav.type_restriction<any> = (
		(stuff) => Promise.resolve<boolean>(true)
	);
	
	
	/**
	 */
	export function register<type_input, type_output>(
		rest_subject : lib_plankton.rest_caldav.type_rest,
		http_method : lib_plankton.caldav.enum_method,
		path : string,
		options : {
			active ?: ((version : string) => boolean);
			restriction ?: (null | lib_plankton.rest_caldav.type_restriction<type_input>);
			execution ?: lib_plankton.rest_caldav.type_execution<type_input, type_output>;
			title ?: (null | string);
			description ?: (null | string);
			query_parameters ?: ((version : (null | string)) => Array<
				{
					name : string;
					description : (null | string);
					required : boolean;
				}
			>);
			input_schema ?: ((version: (null | string)) => lib_plankton.rest_caldav.type_oas_schema);
			output_schema ?: ((version: (null | string)) => lib_plankton.rest_caldav.type_oas_schema);
			request_body_mimetype ?: string;
			request_body_decode ?: ((http_request_body : Buffer, http_request_header_content_type : (null | string)) => any);
			response_body_mimetype ?: string;
			response_body_encode ?: ((output : any) => Buffer);
		} = {}
	) : void
	{
		options = Object.assign(
			{
			},
			options
		);
		lib_plankton.rest_caldav.register<type_input, type_output>(
			rest_subject,
			http_method,
			(_zeitbild.conf.get().server.path_base + path),
			options
		);
	}
	
}