// Description of the authentication-service
// It is listening on port '9004'
// Routes with a prefix 'secure' are protected routes, that can only accessed with a valid ticket.
// That are routes, that call internally 'authenticate'


// The properties of this interface have to be passed as HTTP-headers in a request. 
Interface Ticket {
    authentication: string,
    cookies: {
        refreshId: string,
        [name: string]: string
    }
}

// This describes, which information is received by requesting `secure/authenticate`.
Interface LoginInformation {
    userId: number;
    sessionId: string;
}

/**
* Describes an http-response, which is sent back to any requesting service.
*/
Interface Response <T> {
    set-authentication-header: string // If an old access-token is expired and refreshed, it is set as authentication-header.
    // This determines if a request was successful.
    success: boolean,
    // This sends back a describing message. For example, the reason of a failured request.
    message: string,
    // Optional data, which is appended, if a request was successful.
    data?: T
}

/**
* The credentials for login/authentication are not valid.
*/
Exception InvalidCredentials {
    success: false,
    message: string
}

/**
* POST to /system/auth/login
*
* A user can login with its credentials for authentication.
* If they are correct, the service answers with a signed Token and sets a cookie, containing the sessionId of the client.
*
* If they aren't correct, the service throws an error.
*
* @throws InvalidCredentials
*/
login (username: string, password: string): Response<void>;

/**
* POST to /internal/auth/authenticate
*
* This will be a library to act as part of the auth-service. The other services have not to 
* request the auth-service for authentication. Instead, they use this library-function in their own
* and receive knowledge about authentication without request.
*
* Throws an exception, if the token is not valid. E.g. if the signature is not valid.
*
* @throws InvalidCredentials
*/
authenticate (ticket: Ticket): Response<LoginInformation>;

/**
* POST to /system/auth/who-am-i
*
* A request to get knowledge about themselves. This information is contained in the payload of 
* a Token. So, this function handles the refreshing of a Token.
* Expects a jwt as string in a cookie (called 'refreshId').
*
* Sends back a new Token (passed as http-header).
*
* Throws an exception, if the cookie is empty, the transmitted sessionId is wrong or the signature is wrong.
*
* @throws InvalidCredentials
*/
who-am-i (refreshId: string): Response<LoginInformation>;

/**
* POST to /system/auth/secure/clear-session-by-id
*
* Function to sign out one specific client from a user by its corresponding session-id.
*/
secure/clear-session-by-id (sessionId: string, ticket: Ticket): Response<void> publishes LogoutSessionEvent;

/**
* POST to /system/auth/secure/clear-all-session-except-themselves
*
* Function to kill all current opened sessions from one user except the one, which is requesting.
*/ 
secure/clear-all-sessions-except-themselves (sessionId: string, ticket: Ticket): Response<void> publishes LogoutSessionEvent;

/**
* POST to /system/auth/secure/logout
*
* The service deletes the session depending on the given Token.
*
* @throws InvalidCredentials
*/
secure/logout (ticket: Ticket): Response<void> publishes LogoutSessionEvent;

/**
* GET to system/auth/secure/list-sessions
*
* Returns all currently active sessions.
*
* @returns an array containing currently active sessions.
*/
secure/list-sessions (ticket: Ticket): Response<{sessions: string[]}>;

/**
* POST to /internal/auth/hash
*
* Hashes a given value. A random salt (64bit) is generated and added to the hashed value.
*
* @returns the hashed value. The hashed value is structured as follows: [salt + hash].
*/
hash (toHash: string): Response<{hash: string}>;

/**
* POST to /internal/auth/is-equals
*
* Compares a given value with an given hash.
*
* @returns a boolean, if the hashed value of the given value is equals to the passed hash.
*/
is-equals (toHash: string, toCompare: string): Response<{isEquals: boolean}>;