import {Awaitable, JSONState, Maybe, Rehydratable} from '../util'

/** Value that can be used to uniquely identify a user. */
export type AuthenticatableIdentifier = string | number

/**
 * Base class for entities that can be authenticated.
 */
export abstract class Authenticatable implements Rehydratable {

    /** Get the globally-unique identifier of the user. */
    abstract getUniqueIdentifier(): AuthenticatableIdentifier

    /** Get the repository-unique identifier of the user. */
    abstract getIdentifier(): AuthenticatableIdentifier

    /** Get the human-readable identifier of the user. */
    abstract getDisplay(): string

    /** Attempt to validate a credential of the user. */
    abstract validateCredential(credential: string): Awaitable<boolean>

    abstract dehydrate(): Promise<JSONState>

    abstract rehydrate(state: JSONState): Awaitable<void>
}

/**
 * Base class for a repository that stores and recalls users.
 */
export abstract class AuthenticatableRepository {
    /** Look up the user by their unique identifier. */
    abstract getByIdentifier(id: AuthenticatableIdentifier): Awaitable<Maybe<Authenticatable>>

    /** Returns true if this repository supports registering users. */
    abstract supportsRegistration(): boolean

    /** Create a user in this repository from an external Authenticatable instance. */
    abstract createFromExternal(user: Authenticatable): Awaitable<Authenticatable>

    /** Create a user in this repository from basic credentials. */
    abstract createFromCredentials(username: string, password: string): Awaitable<Authenticatable>
}