browser/search/search.h

// Copyright 2012 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.

#ifndef CHROME_BROWSER_SEARCH_SEARCH_H_
#define CHROME_BROWSER_SEARCH_SEARCH_H_

#include <string>
#include <utility>
#include <vector>

#include "base/basictypes.h"
#include "base/strings/string16.h"
#include "chrome/browser/ui/search/search_model.h"

class GURL;
class Profile;
class TemplateURL;
class TemplateURLRef;

namespace content {
class BrowserContext;
class NavigationEntry;
class WebContents;
}

namespace user_prefs {
class PrefRegistrySyncable;
}

namespace chrome {

enum OptInState {
  // The user has not manually opted in/out of InstantExtended.
  INSTANT_EXTENDED_NOT_SET,
  // The user has opted-in to InstantExtended.
  INSTANT_EXTENDED_OPT_IN,
  // The user has opted-out of InstantExtended.
  INSTANT_EXTENDED_OPT_OUT,
  INSTANT_EXTENDED_OPT_IN_STATE_ENUM_COUNT,
};

// Use this value for "start margin" to prevent the "es_sm" parameter from
// being used.
extern const int kDisableStartMargin;

// Returns whether the Instant Extended API is enabled.
bool IsInstantExtendedAPIEnabled();

// Returns whether the suggest is enabled for the given |profile|.
bool IsSuggestPrefEnabled(Profile* profile);

// Returns the value to pass to the &espv CGI parameter when loading the
// embedded search page from the user's default search provider. Returns 0 if
// the Instant Extended API is not enabled.
uint64 EmbeddedSearchPageVersion();

// Returns whether query extraction is enabled.
bool IsQueryExtractionEnabled();

// Extracts and returns search terms from |url|. Returns empty string if the URL
// is not secure or doesn't have a search term replacement key.  Does not
// consider IsQueryExtractionEnabled() and Instant support state of the page and
// does not check for a privileged process, so most callers should use
// GetSearchTerms() below instead.
string16 GetSearchTermsFromURL(Profile* profile, const GURL& url);

// Returns the search terms attached to a specific NavigationEntry, or empty
// string otherwise. Does not consider IsQueryExtractionEnabled() and does not
// check Instant support, so most callers should use GetSearchTerms() below
// instead.
string16 GetSearchTermsFromNavigationEntry(
    const content::NavigationEntry* entry);

// Returns search terms if this WebContents is a search results page. It looks
// in the visible NavigationEntry first, to see if search terms have already
// been extracted. Failing that, it tries to extract search terms from the URL.
//
// Returns a blank string if search terms were not found, or if search terms
// extraction is disabled for this WebContents or profile, or if |contents|
// does not support Instant.
string16 GetSearchTerms(const content::WebContents* contents);

// Returns true if |url| should be rendered in the Instant renderer process.
bool ShouldAssignURLToInstantRenderer(const GURL& url, Profile* profile);

// Returns true if the Instant |url| should use process per site.
bool ShouldUseProcessPerSiteForInstantURL(const GURL& url, Profile* profile);

// Returns true if |url| corresponds to a New Tab page (it can be either an
// Instant Extended NTP or a non-extended NTP).
bool IsNTPURL(const GURL& url, Profile* profile);

// Returns true if the visible entry of |contents| is a New Tab Page rendered
// by Instant. A page that matches the search or Instant URL of the default
// search provider but does not have any search terms is considered an Instant
// New Tab Page.
bool IsInstantNTP(const content::WebContents* contents);

// Same as IsInstantNTP but uses |nav_entry| to determine the URL for the page
// instead of using the visible entry.
bool NavEntryIsInstantNTP(const content::WebContents* contents,
                          const content::NavigationEntry* nav_entry);

// Returns the Instant URL of the default search engine. Returns an empty GURL
// if the engine doesn't have an Instant URL, or if it shouldn't be used (say
// because it doesn't satisfy the requirements for extended mode or if Instant
// is disabled through preferences). Callers must check that the returned URL is
// valid before using it. The value of |start_margin| is used for the "es_sm"
// parameter in the URL.
// NOTE: This method expands the default search engine's instant_url template,
// so it shouldn't be called from SearchTermsData or other such code that would
// lead to an infinite recursion.
GURL GetInstantURL(Profile* profile, int start_margin);

// Returns the Local Instant URL of the New Tab Page.
// TODO(kmadhusu): Remove this function and update the call sites.
GURL GetLocalInstantURL(Profile* profile);

// Returns true if 'hide_verbatim' flag is enabled in field trials
// to hide the top match in the native suggestions dropdown if it is a verbatim
// match.  See comments on ShouldHideTopMatch in autocomplete_result.h.
bool ShouldHideTopVerbatimMatch();

// Returns true if 'use_remote_ntp_on_startup' flag is enabled in field trials
// to always show the remote NTP on browser startup.
bool ShouldPreferRemoteNTPOnStartup();

// Returns true if the cacheable NTP should be shown and false if not.
// Exposed for testing.
bool ShouldUseCacheableNTP();

// Returns true if the Instant NTP should be shown and false if not.
bool ShouldShowInstantNTP();

// Returns true if the recent tabs link should be shown on the local NTP in
// field trials.
bool ShouldShowRecentTabsOnNTP();

// Returns true if Instant Extended should be disabled on the search results
// page.
bool ShouldSuppressInstantExtendedOnSRP();

// Returns true if |my_url| matches |other_url|.
bool MatchesOriginAndPath(const GURL& my_url, const GURL& other_url);

// Transforms the input |url| into its "effective URL". The returned URL
// facilitates grouping process-per-site. The |url| is transformed, for
// example, from
//
//   https://www.google.com/search?espv=1&q=tractors
//
// to the privileged URL
//
//   chrome-search://www.google.com/search?espv=1&q=tractors
//
// Notice the scheme change.
//
// If the input is already a privileged URL then that same URL is returned.
//
// If |url| is that of the online NTP, its host is replaced with "online-ntp".
// This forces the NTP and search results pages to have different SiteIntances,
// and hence different processes.
GURL GetEffectiveURLForInstant(const GURL& url, Profile* profile);

// Returns the staleness timeout (in seconds) that should be used to refresh the
// InstantLoader.
int GetInstantLoaderStalenessTimeoutSec();

// Returns true if |contents| corresponds to a preloaded instant extended NTP.
bool IsPreloadedInstantExtendedNTP(const content::WebContents* contents);

// Rewrites |url| if
//   1. |url| is kChromeUINewTabURL,
//   2. InstantExtended is enabled, and
//   3. The --instant-new-tab-url switch is set to a valid URL.
// |url| is rewritten to the value of --instant-new-tab-url.
bool HandleNewTabURLRewrite(GURL* url,
                            content::BrowserContext* browser_context);
// Reverses the operation from HandleNewTabURLRewrite.
bool HandleNewTabURLReverseRewrite(GURL* url,
                                   content::BrowserContext* browser_context);

// Sets the Instant support |state| in the navigation |entry|.
void SetInstantSupportStateInNavigationEntry(InstantSupportState state,
                                             content::NavigationEntry* entry);

// Returns the Instant support state attached to the NavigationEntry, or
// INSTANT_SUPPORT_UNKNOWN otherwise.
InstantSupportState GetInstantSupportStateFromNavigationEntry(
    const content::NavigationEntry& entry);

// Returns true if the field trial flag is enabled to prefetch results on SRP.
bool ShouldPrefetchSearchResultsOnSRP();

// -----------------------------------------------------
// The following APIs are exposed for use in tests only.
// -----------------------------------------------------

// Forces the Instant Extended API to be enabled for tests.
void EnableInstantExtendedAPIForTesting();

// Forces the Instant Extended API to be disabled for tests.
void DisableInstantExtendedAPIForTesting();

// Type for a collection of experiment configuration parameters.
typedef std::vector<std::pair<std::string, std::string> > FieldTrialFlags;

// Given a field trial group name, parses out the group number and configuration
// flags. On success, |flags| will be filled with the field trial flags. |flags|
// must not be NULL. If not NULL, |group_number| will receive the experiment
// group number.
// Returns true iff |group_name| is successfully parsed and not disabled.
// Note that |flags| may be successfully populated in some cases when false is
// returned - in these cases it should not be used.
// Exposed for testing only.
bool GetFieldTrialInfo(const std::string& group_name,
                       FieldTrialFlags* flags,
                       uint64* group_number);

// Given a FieldTrialFlags object, returns the string value of the provided
// flag.
// Exposed for testing only.
std::string GetStringValueForFlagWithDefault(const std::string& flag,
                                             const std::string& default_value,
                                             const FieldTrialFlags& flags);

// Given a FieldTrialFlags object, returns the uint64 value of the provided
// flag.
// Exposed for testing only.
uint64 GetUInt64ValueForFlagWithDefault(const std::string& flag,
                                        uint64 default_value,
                                        const FieldTrialFlags& flags);

// Given a FieldTrialFlags object, returns the bool value of the provided flag.
// Exposed for testing only.
bool GetBoolValueForFlagWithDefault(const std::string& flag,
                                    bool default_value,
                                    const FieldTrialFlags& flags);

// Returns the Cacheable New Tab Page URL for the given |profile|.
// Exposed for testing only.
GURL GetNewTabPageURL(Profile* profile);

// Let tests reset the gate that prevents metrics from being sent more than
// once.
void ResetInstantExtendedOptInStateGateForTest();

}  // namespace chrome

#endif  // CHROME_BROWSER_SEARCH_SEARCH_H_