export interface ISessionBroker {

    // TODO: change in init()
    createTable(): void
    createSessionFromUserID(userID: number): Session
    getSessionFromUserID(userID: number): Session | null
    getSessionFromToken(token: string): Session | null

}

export class Session {

    public sessionID: number
    public userID: number
    public sessionToken: string

    constructor(
        sessionID: number,
        userID: number,
        sessionToken: string
    ) {
        this.sessionID = sessionID
        this.userID = userID
        this.sessionToken = sessionToken
    }

    public toString() {
        return this.sessionToken
    }

}

export class SessionApp {

    private static broker: ISessionBroker
    private static initialized: boolean = false

    public static init(broker: ISessionBroker) {
        if (SessionApp.initialized) {
            // UGLY: make this Error more specific
            throw Error("SessionApp has already been initialized")
        }

        SessionApp.initialized = true
        SessionApp.broker = broker
        SessionApp.broker.createTable()

    }

    public static createSessionFromUserID(userID: number): Session {
        SessionApp.assertInitialized()
        return SessionApp.broker.createSessionFromUserID(userID)
    }

    public static getSessionFromUserID(userID: number): Session | null {
        SessionApp.assertInitialized()
        return SessionApp.broker.getSessionFromUserID(userID)
    }

    public static getSessionFromToken(token: string): Session | null {
        SessionApp.assertInitialized()
        return SessionApp.broker.getSessionFromToken(token)
    }

    private static assertInitialized() {

        if (!SessionApp.initialized) {
            // UGLY: make more specific
            throw Error("SessionApp has't been Initialized yet!")
        }

    }


}