// Copyright (c) 2010 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.

// This class represents contextual information (cookies, cache, etc.)
// that's useful when processing resource requests.
// The class is reference-counted so that it can be cleaned up after any
// requests that are using it have been completed.

#ifndef NET_URL_REQUEST_URL_REQUEST_CONTEXT_H_
#define NET_URL_REQUEST_URL_REQUEST_CONTEXT_H_

#include "base/ref_counted.h"
#include "base/string_util.h"
#include "net/base/cookie_store.h"
#include "net/base/host_resolver.h"
#include "net/base/ssl_config_service.h"
#include "net/base/transport_security_state.h"
#include "net/ftp/ftp_auth_cache.h"
#include "net/proxy/proxy_service.h"
#include "net/url_request/request_tracker.h"

namespace net {
class CookiePolicy;
class FtpTransactionFactory;
class HttpTransactionFactory;
class SocketStream;
}
class URLRequest;

// Subclass to provide application-specific context for URLRequest instances.
class URLRequestContext :
    public base::RefCountedThreadSafe<URLRequestContext> {
 public:
  URLRequestContext()
      : http_transaction_factory_(NULL),
        ftp_transaction_factory_(NULL),
        cookie_policy_(NULL),
        transport_security_state_(NULL) {
  }

  net::HostResolver* host_resolver() const {
    return host_resolver_;
  }

  // Get the proxy service for this context.
  net::ProxyService* proxy_service() const {
    return proxy_service_;
  }

  // Get the ssl config service for this context.
  net::SSLConfigService* ssl_config_service() const {
    return ssl_config_service_;
  }

  // Gets the http transaction factory for this context.
  net::HttpTransactionFactory* http_transaction_factory() const {
    return http_transaction_factory_;
  }

  // Gets the ftp transaction factory for this context.
  net::FtpTransactionFactory* ftp_transaction_factory() {
    return ftp_transaction_factory_;
  }

  // Gets the cookie store for this context (may be null, in which case
  // cookies are not stored).
  net::CookieStore* cookie_store() { return cookie_store_.get(); }

  // Gets the cookie policy for this context (may be null, in which case
  // cookies are allowed).
  net::CookiePolicy* cookie_policy() { return cookie_policy_; }

  net::TransportSecurityState* transport_security_state() {
      return transport_security_state_; }

  // Gets the FTP authentication cache for this context.
  net::FtpAuthCache* ftp_auth_cache() { return &ftp_auth_cache_; }

  // Gets the value of 'Accept-Charset' header field.
  const std::string& accept_charset() const { return accept_charset_; }

  // Gets the value of 'Accept-Language' header field.
  const std::string& accept_language() const { return accept_language_; }

  // Gets the tracker for URLRequests associated with this context.
  RequestTracker<URLRequest>* url_request_tracker() {
    return &url_request_tracker_;
  }

  // Gets the tracker for SocketStreams associated with this context.
  RequestTracker<net::SocketStream>* socket_stream_tracker() {
    return &socket_stream_tracker_;
  }

  // Gets the UA string to use for the given URL.  Pass an invalid URL (such as
  // GURL()) to get the default UA string.  Subclasses should override this
  // method to provide a UA string.
  virtual const std::string& GetUserAgent(const GURL& url) const {
    return EmptyString();
  }

  // In general, referrer_charset is not known when URLRequestContext is
  // constructed. So, we need a setter.
  const std::string& referrer_charset() const { return referrer_charset_; }
  void set_referrer_charset(const std::string& charset) {
    referrer_charset_ = charset;
  }

  // Called before adding cookies to requests. Returns true if cookie can
  // be added to the request. The cookie might still be modified though.
  virtual bool InterceptRequestCookies(const URLRequest* request,
                                       const std::string& cookies) const {
    return true;
  }

  // Called before adding cookies from respones to the cookie monster. Returns
  // true if the cookie can be added. The cookie might still be modified though.
  virtual bool InterceptResponseCookie(const URLRequest* request,
                                       const std::string& cookie) const {
    return true;
  }

 protected:
  friend class base::RefCountedThreadSafe<URLRequestContext>;

  virtual ~URLRequestContext() {}

  // The following members are expected to be initialized and owned by
  // subclasses.
  scoped_refptr<net::HostResolver> host_resolver_;
  scoped_refptr<net::ProxyService> proxy_service_;
  scoped_refptr<net::SSLConfigService> ssl_config_service_;
  net::HttpTransactionFactory* http_transaction_factory_;
  net::FtpTransactionFactory* ftp_transaction_factory_;
  scoped_refptr<net::CookieStore> cookie_store_;
  net::CookiePolicy* cookie_policy_;
  scoped_refptr<net::TransportSecurityState> transport_security_state_;
  net::FtpAuthCache ftp_auth_cache_;
  std::string accept_language_;
  std::string accept_charset_;
  // The charset of the referrer where this request comes from. It's not
  // used in communication with a server but is used to construct a suggested
  // filename for file download.
  std::string referrer_charset_;

  // Tracks the requests associated with this context.
  RequestTracker<URLRequest> url_request_tracker_;

  // Trakcs the socket streams associated with this context.
  RequestTracker<net::SocketStream> socket_stream_tracker_;

 private:
  DISALLOW_COPY_AND_ASSIGN(URLRequestContext);
};

#endif  // NET_URL_REQUEST_URL_REQUEST_CONTEXT_H_