// Copyright (c) 2009 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// A GoogleServiceAuthError is immutable, plain old data representing an
// error from an attempt to authenticate with a Google service.
// It could be from Google Accounts itself, or any service using Google
// Accounts (e.g expired credentials).  It may contain additional data such as
// captcha challenges.

// A GoogleServiceAuthError without additional data is just a State, defined
// below. A case could be made to have this relation implicit, to allow raising
// error events concisely by doing OnAuthError(GoogleServiceAuthError::NONE),
// for example. But the truth is this class is ever so slightly more than a
// transparent wrapper around 'State' due to additional Captcha data
// (e.g consider operator=), and this would violate the style guide. Thus,
// you must explicitly use the constructor when all you have is a State.
// The good news is the implementation nests the enum inside a class, so you
// may forward declare and typedef GoogleServiceAuthError to something shorter
// in the comfort of your own translation unit.

#ifndef CHROME_BROWSER_GOOGLE_SERVICE_AUTH_ERROR_H_
#define CHROME_BROWSER_GOOGLE_SERVICE_AUTH_ERROR_H_

#include <string>
#include "googleurl/src/gurl.h"

class GoogleServiceAuthError {
 public:
  enum State {
    // The user is authenticated.
    NONE = 0,

    // The credentials supplied to GAIA were either invalid, or the locally
    // cached credentials have expired.
    INVALID_GAIA_CREDENTIALS,

    // The GAIA user is not authorized to use the service.
    USER_NOT_SIGNED_UP,

    // Could not connect to server to verify credentials. This could be in
    // response to either failure to connect to GAIA or failure to connect to
    // the service needing GAIA tokens during authentication.
    CONNECTION_FAILED,

    // The user needs to satisfy a CAPTCHA challenge to unlock their account.
    // If no other information is available, this can be resolved by visiting
    // https://www.google.com/accounts/DisplayUnlockCaptcha. Otherwise,
    // captcha() will provide details about the associated challenge.
    CAPTCHA_REQUIRED,
  };

  // Additional data for CAPTCHA_REQUIRED errors.
  struct Captcha {
    Captcha() {}
    Captcha(const std::string& t, const GURL& img, const GURL& unlock)
        : token(t), image_url(img), unlock_url(unlock) {}
    std::string token;  // Globally identifies the specific CAPTCHA challenge.
    GURL image_url;     // The CAPTCHA image to show the user.
    GURL unlock_url;    // Pretty unlock page containing above captcha.
  };

  // Construct a GoogleServiceAuthError from a State with no additional data.
  explicit GoogleServiceAuthError(State s) : state_(s) {}

  // Construct a CAPTCHA_REQUIRED error with CAPTCHA challenge data.
  static GoogleServiceAuthError FromCaptchaChallenge(
      const std::string& captcha_token,
      const GURL& captcha_image_url,
      const GURL& captcha_unlock_url) {
    return GoogleServiceAuthError(CAPTCHA_REQUIRED, captcha_token,
                                  captcha_image_url, captcha_unlock_url);
  }

  // Provided for convenience for clients needing to reset an instance to NONE.
  // (avoids err_ = GoogleServiceAuthError(GoogleServiceAuthError::NONE), due
  // to explicit class and State enum relation. Note: shouldn't be inlined!
  static const GoogleServiceAuthError None() {
    static const GoogleServiceAuthError e(NONE);
    return e;
  }

  // The error information.
  const State& state() const { return state_; }
  const Captcha& captcha() const { return captcha_; }

 private:
  GoogleServiceAuthError(State s, const std::string& captcha_token,
                         const GURL& captcha_image_url,
                         const GURL& captcha_unlock_url)
      : state_(s),
        captcha_(captcha_token, captcha_image_url, captcha_unlock_url) {
  }

  State state_;
  Captcha captcha_;
};

#endif  // CHROME_BROWSER_GOOGLE_SERVICE_AUTH_ERROR_H_