namespace _espe.backend
{
	
	/**
	 */
	var _session_key_chest : lib_plankton.storage.type_chest<string, string, void, string, string>;
	
	
	/**
	 * @todo use backend call
	 */
	export async function logged_in(
	) : Promise<boolean>
	{
		let session_key : (null | string);
		try {
			session_key = (await _session_key_chest.read("session_key"));
		}
		catch (error) {
			session_key = null;
		}
		return Promise.resolve<boolean>(session_key !== null);
	}
	
	
	/**
	 */
	export function init(
	) : Promise<void>
	{
		_session_key_chest = lib_plankton.storage.localstorage.implementation_chest(
			{
				"corner": "aum",
			}
		);
		return Promise.resolve<void>(undefined);
	}
	
	
	/**
	 */
	async function abstract_call<type_input, type_output>(
		http_method : string,
		path : string,
		options : {
			data ?: type_input;
		} = {}
	) : Promise<type_output>
	{
		options = Object.assign(
			{
				"data": null,
			},
			options
		);
		
		let session_key : (null | string);
		try {
			session_key = (await _session_key_chest.read("session_key"));
		}
		catch (error) {
			session_key = null;
		}
		
		const without_content : boolean = ["HEAD","OPTIONS","GET"].includes(http_method);
		return (
			fetch(
				lib_plankton.string.coin(
					("{{scheme}}://{{host}}:{{port}}{{path_base}}{{path_action}}"),
					{
						"scheme": _espe.conf.get().backend.scheme,
						"host": _espe.conf.get().backend.host,
						"port": _espe.conf.get().backend.port.toFixed(0),
						"path_base": _espe.conf.get().backend.path_base,
						"path_action": path,
					}
				),
				{
					"method": http_method,
					"headers": Object.assign(
						{},
						((! without_content) ? {"Content-Type": "application/json"} : {}),
						((session_key !== null) ? {"X-Session-Key": session_key} : {})
					),
					"body": (
						without_content
						? null
						: JSON.stringify(options.data)
					),
				}
			)
			.then(
				x => {
					if ((x.status >= 200) && (x.status < 300)) {
						return x.json();
					}
					else {
						return Promise.reject<type_output>(new Error("unexpected response status code"));
					}
				}
			)
		);
	}

	
	/**
	 */
	export async function login(
		name : string,
		password : string
	) : Promise<void>
	{
		const session_key : string = await abstract_call<{name : string; password : string;}, string>(
			"POST",
			"/session/begin",
			{
				"data": {
					"name": name,
					"password": password,
				}
			}
		);
		await _session_key_chest.write("session_key", session_key);
	}
	
	
	/**
	 */
	export async function logout(
	) : Promise<void>
	{
		try {
			await abstract_call<void, null>(
				"DELETE",
				"/session/end"
			);
		}
		catch (error) {
			// do nothing
		}
		await _session_key_chest.delete("session_key");
	}
	
	
	/**
	 */
	export async function email(
		receivers : Array<string>,
		subject : string,
		content : string
	) : Promise<void>
	{
		return (
			abstract_call(
				"POST",
				"/email",
				{
					"data": {
						"receivers": receivers,
						"subject": subject,
						"content": content,
					},
				}
			)
		);
	}
	
	
	/**
	 */
	export async function verification_get(
		data : any
	) : Promise<string>
	{
		return (
			abstract_call(
				"POST",
				"/verification/get",
				{
					"data": {
						"data": data,
					},
				}
			)
		);
	}
	
	
	/**
	 */
	export async function verification_check(
		data : any,
		verification : string
	) : Promise<boolean>
	{
		return (
			abstract_call(
				"POST",
				"/verification/check",
				{
					"data": {
						"data": data,
						"verification": verification,
					}
				}
			)
		);
	}
	
	
	/**
	 */
	export async function member_list(
	) : Promise<Array<any>>
	{
		return (
			abstract_call(
				"GET",
				"/member"
			)
		);
	}
	
	
	/**
	 */
	export async function member_get(
		id : int
	) : Promise<any>
	{
		return abstract_call(
			"GET",
			"/member/" + id.toFixed(0)
		);
	}
	
	
	/**
	 */
	export async function member_add(
		data : Record<string, any>
	) : Promise<int>
	{
		return abstract_call(
			"POST",
			"/member",
			{
				"data": {
					"membership_number": data["membership_number"],
					"enabled": data["enabled"],
					"name_real_value": data["name_real_value"],
					"name_real_extension": data["name_real_extension"],
					"name_display": data["name_display"],
					"name_login": data["name_login"],
					"password_image": null,
					"email_address_private_value": data["email_address_private_value"],
					"email_address_numberbased_use": data["email_address_numberbased_use"],
					"email_address_namebased_use": data["email_address_namebased_use"],
					"email_redirect_to_private": data["email_redirect_to_private"],
					"salutation": data["salutation"],
				}
			}
		);
	}
	
	
	/**
	 */
	export async function member_modify(
		id : int,
		data : Record<string, any>
	) : Promise<void>
	{
		return abstract_call(
			"PATCH",
			"/member/" + id.toFixed(0),
			{
				"data": {
					"membership_number": data["membership_number"],
					"enabled": data["enabled"],
					"name_real_value": data["name_real_value"],
					"name_real_extension": data["name_real_extension"],
					"name_display": data["name_display"],
					"name_login": data["name_login"],
					"password_image": null,
					"email_address_private_value": data["email_address_private_value"],
					"email_address_numberbased_use": data["email_address_numberbased_use"],
					"email_address_namebased_use": data["email_address_namebased_use"],
					"email_redirect_to_private": data["email_redirect_to_private"],
					"salutation": data["salutation"],
				}
			}
		);
	}
	
	
	/**
	 */
	export async function member_urge_for_registration(
		id : int,
		url : string
	) : Promise<null>
	{
		return (
			abstract_call(
				"POST",
				"/member/urge_for_registration",
				{
					"data": {
						"id": id,
						"url": url,
					},
				}
			)
		);
	}
	
	
	/**
	 */
	export async function member_register(
		id : int,
		verification : string,
		data : {
			name_login : string;
			name_display : string;
			salutation : string;
			email_mode : ("none" | "number" | "number_and_name");
			email_redirect : boolean;
			password : string;
		}
	) : Promise<void>
	{
		return (
			abstract_call(
				"POST",
				"/member/register/" + id.toFixed(0) + "?verification=" + verification,
				{
					"data": data,
				}
			)
		);
	}
	
}