import * as url from "url";
import * as querystring from "querystring";
import * as express from "express";
import {AuthorizationEndpointResponse, OAuthError, Result} from "oauth2-nodejs";

export class Navigation {

  public static redirect(resp: express.Response, uri: string,
                         parameters?: {[key: string]: string | number},
                         fragments?: {[key: string]: string | number}): void {
    const targetUrl = url.parse(uri, true)
    if (parameters) {
      const query = targetUrl.query
      Object.keys(parameters).forEach((key: string): void => {
        const value: string | number = parameters[key]
        query[key] = typeof value === "string" ? value : String(value)
      })
    }
    if (fragments) {
      targetUrl.hash = `#${querystring.stringify(fragments)}`
    }
    resp.redirect(url.format(targetUrl))
  }

  public static backTo(resp: express.Response, result: Result<AuthorizationEndpointResponse>, redirectUri: string): void {
    if (result.isSuccess()) {
      const response = result.value
      this.redirect(resp, redirectUri, response.query, response.fragment)
    } else {
      this.redirect(resp, redirectUri, {"error": result.error.getType()}, {})
    }
  }

  public static sendError(resp: express.Response, error: OAuthError): void {
    resp.set("Content-Type", "application/json; charset=UTF-8")
    resp.status(error.code).send(error.toJson())
  }

}