import type { JWTPayload } from '../types';
import isObject from '../utils/is_object';
import secs, { epoch } from '../utils/secs';

/** Generic class for JWT producing. */
export class ProduceJWT {
  protected _payload: JWTPayload = {};

  /** @param payload The JWT Claims Set object. */
  setPayload(payload: JWTPayload) {
    if (!isObject(payload)) {
      throw new TypeError('JWT Claims Set MUST be an object');
    }
    this._payload = { ...this._payload, ...payload };
    return this;
  }

  /**
   * Set "iss" (Issuer) Claim.
   *
   * @param issuer "Issuer" Claim value to set on the JWT Claims Set.
   */
  setIssuer(issuer: string) {
    this._payload = { ...this._payload, iss: issuer };
    return this;
  }

  /**
   * Set "sub" (Subject) Claim.
   *
   * @param subject "sub" (Subject) Claim value to set on the JWT Claims Set.
   */
  setSubject(subject: string) {
    this._payload = { ...this._payload, sub: subject };
    return this;
  }

  /**
   * Set "aud" (Audience) Claim.
   *
   * @param audience "aud" (Audience) Claim value to set on the JWT Claims Set.
   */
  setAudience(audience: string | string[]) {
    this._payload = { ...this._payload, aud: audience };
    return this;
  }

  /**
   * Set "jti" (JWT ID) Claim.
   *
   * @param jwtId "jti" (JWT ID) Claim value to set on the JWT Claims Set.
   */
  setJti(jwtId: string) {
    this._payload = { ...this._payload, jti: jwtId };
    return this;
  }

  /**
   * Set "nbf" (Not Before) Claim.
   *
   * @param input "nbf" (Not Before) Claim value to set on the JWT Claims Set. When number is passed
   *   that is used as a value, when string is passed it is resolved to a time span and added to the
   *   current timestamp.
   */
  setNotBefore(input: number | string) {
    if (typeof input === 'number') {
      this._payload = { ...this._payload, nbf: input };
    } else {
      this._payload = {
        ...this._payload,
        nbf: epoch(new Date()) + secs(input),
      };
    }
    return this;
  }

  /**
   * Set "exp" (Expiration Time) Claim.
   *
   * @param input "exp" (Expiration Time) Claim value to set on the JWT Claims Set. When number is
   *   passed that is used as a value, when string is passed it is resolved to a time span and added
   *   to the current timestamp.
   */
  setExpirationTime(input: number | string) {
    if (typeof input === 'number') {
      this._payload = { ...this._payload, exp: input };
    } else {
      this._payload = {
        ...this._payload,
        exp: epoch(new Date()) + secs(input),
      };
    }
    return this;
  }

  /**
   * Set "iat" (Issued At) Claim.
   *
   * @param input "iat" (Issued At) Claim value to set on the JWT Claims Set. Default is current
   *   timestamp.
   */
  setIssuedAt(input?: number) {
    if (typeof input === 'undefined') {
      this._payload = { ...this._payload, iat: epoch(new Date()) };
    } else {
      this._payload = { ...this._payload, iat: input };
    }
    return this;
  }
}