// Copyright 2013 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.

#include "chrome/browser/ui/sync/profile_signin_confirmation_helper.h"

#include "base/bind.h"
#include "base/memory/ref_counted.h"
#include "base/prefs/pref_service.h"
#include "base/strings/string16.h"
#include "base/task/cancelable_task_tracker.h"
#include "chrome/browser/bookmarks/bookmark_model_factory.h"
#include "chrome/browser/history/history_backend.h"
#include "chrome/browser/history/history_service.h"
#include "chrome/browser/history/history_service_factory.h"
#include "chrome/browser/profiles/profile.h"
#include "components/bookmarks/browser/bookmark_model.h"
#include "components/history/core/browser/history_db_task.h"
#include "components/history/core/browser/history_types.h"
#include "content/public/browser/browser_thread.h"
#include "ui/gfx/color_utils.h"
#include "ui/native_theme/native_theme.h"

#if defined(ENABLE_EXTENSIONS)
#include "chrome/common/extensions/extension_constants.h"
#include "chrome/common/extensions/sync_helper.h"
#include "extensions/browser/extension_registry.h"
#include "extensions/common/constants.h"
#include "extensions/common/extension.h"
#include "extensions/common/extension_set.h"
#endif

namespace {

const int kHistoryEntriesBeforeNewProfilePrompt = 10;

// Determines whether a profile has any typed URLs in its history.
class HasTypedURLsTask : public history::HistoryDBTask {
 public:
  explicit HasTypedURLsTask(const base::Callback<void(bool)>& cb)
      : has_typed_urls_(false), cb_(cb) {
  }

  bool RunOnDBThread(history::HistoryBackend* backend,
                     history::HistoryDatabase* db) override {
    history::URLRows rows;
    backend->GetAllTypedURLs(&rows);
    if (!rows.empty()) {
      DVLOG(1) << "ProfileSigninConfirmationHelper: profile contains "
               << rows.size() << " typed URLs";
      has_typed_urls_ = true;
    }
    return true;
  }

  void DoneRunOnMainThread() override { cb_.Run(has_typed_urls_); }

 private:
  ~HasTypedURLsTask() override {}

  bool has_typed_urls_;
  base::Callback<void(bool)> cb_;
};

bool HasBookmarks(Profile* profile) {
  BookmarkModel* bookmarks = BookmarkModelFactory::GetForProfile(profile);
  bool has_bookmarks = bookmarks && bookmarks->HasBookmarks();
  if (has_bookmarks)
    DVLOG(1) << "ProfileSigninConfirmationHelper: profile contains bookmarks";
  return has_bookmarks;
}

// Helper functions for Chrome profile signin.
class ProfileSigninConfirmationHelper {
 public:
  ProfileSigninConfirmationHelper(
      Profile* profile,
      const base::Callback<void(bool)>& return_result);
  void CheckHasHistory(int max_entries);
  void CheckHasTypedURLs();

 private:
  // Deletes itself.
  ~ProfileSigninConfirmationHelper();

  void OnHistoryQueryResults(size_t max_entries,
                             history::QueryResults* results);
  void ReturnResult(bool result);

  // Weak pointer to the profile being signed-in.
  Profile* profile_;

  // Used for async tasks.
  base::CancelableTaskTracker task_tracker_;

  // Keep track of how many async requests are pending.
  int pending_requests_;

  // Callback to pass the result back to the caller.
  const base::Callback<void(bool)> return_result_;

  DISALLOW_COPY_AND_ASSIGN(ProfileSigninConfirmationHelper);
};

ProfileSigninConfirmationHelper::ProfileSigninConfirmationHelper(
    Profile* profile,
    const base::Callback<void(bool)>& return_result)
    : profile_(profile),
      pending_requests_(0),
      return_result_(return_result) {
}

ProfileSigninConfirmationHelper::~ProfileSigninConfirmationHelper() {
  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
}

void ProfileSigninConfirmationHelper::OnHistoryQueryResults(
    size_t max_entries,
    history::QueryResults* results) {
  history::QueryResults owned_results;
  results->Swap(&owned_results);
  bool too_much_history = owned_results.size() >= max_entries;
  if (too_much_history) {
    DVLOG(1) << "ProfileSigninConfirmationHelper: profile contains "
             << owned_results.size() << " history entries";
  }
  ReturnResult(too_much_history);
}

void ProfileSigninConfirmationHelper::CheckHasHistory(int max_entries) {
  HistoryService* service =
      HistoryServiceFactory::GetForProfileWithoutCreating(profile_);
  pending_requests_++;
  if (!service) {
    ReturnResult(false);
    return;
  }
  history::QueryOptions opts;
  opts.max_count = max_entries;
  service->QueryHistory(
      base::string16(),
      opts,
      base::Bind(&ProfileSigninConfirmationHelper::OnHistoryQueryResults,
                 base::Unretained(this),
                 max_entries),
      &task_tracker_);
}

void ProfileSigninConfirmationHelper::CheckHasTypedURLs() {
  HistoryService* service =
      HistoryServiceFactory::GetForProfileWithoutCreating(profile_);
  pending_requests_++;
  if (!service) {
    ReturnResult(false);
    return;
  }
  service->ScheduleDBTask(
      scoped_ptr<history::HistoryDBTask>(new HasTypedURLsTask(
          base::Bind(&ProfileSigninConfirmationHelper::ReturnResult,
                     base::Unretained(this)))),
      &task_tracker_);
}

void ProfileSigninConfirmationHelper::ReturnResult(bool result) {
  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  // Pass |true| into the callback as soon as one of the tasks passes a
  // result of |true|, otherwise pass the last returned result.
  if (--pending_requests_ == 0 || result) {
    return_result_.Run(result);

    // This leaks at shutdown if the HistoryService is destroyed, but
    // the process is going to die anyway.
    delete this;
  }
}

}  // namespace

namespace ui {

SkColor GetSigninConfirmationPromptBarColor(SkAlpha alpha) {
  static const SkColor kBackgroundColor =
      ui::NativeTheme::instance()->GetSystemColor(
          ui::NativeTheme::kColorId_DialogBackground);
  return color_utils::BlendTowardOppositeLuminance(kBackgroundColor, alpha);
}

bool HasBeenShutdown(Profile* profile) {
#if defined(OS_IOS)
  // This check is not useful on iOS: the browser can be shut down without
  // explicit user action (for example, in response to memory pressure), and
  // this should be invisible to the user. The desktop assumption that the
  // profile going through a restart indicates something about user intention
  // does not hold. We rely on the other profile dirtiness checks.
  return false;
#else
  bool has_been_shutdown = !profile->IsNewProfile();
  if (has_been_shutdown)
    DVLOG(1) << "ProfileSigninConfirmationHelper: profile is not new";
  return has_been_shutdown;
#endif
}

bool HasSyncedExtensions(Profile* profile) {
#if defined(ENABLE_EXTENSIONS)
  extensions::ExtensionRegistry* registry =
      extensions::ExtensionRegistry::Get(profile);
  if (registry) {
    for (const scoped_refptr<const extensions::Extension>& extension :
         registry->enabled_extensions()) {
      // The webstore is synced so that it stays put on the new tab
      // page, but since it's installed by default we don't want to
      // consider it when determining if the profile is dirty.
      if (extensions::sync_helper::IsSyncable(extension.get()) &&
          extension->id() != extensions::kWebStoreAppId &&
          extension->id() != extension_misc::kChromeAppId) {
        DVLOG(1) << "ProfileSigninConfirmationHelper: "
                 << "profile contains a synced extension: " << extension->id();
        return true;
      }
    }
  }
#endif
  return false;
}

void CheckShouldPromptForNewProfile(
    Profile* profile,
    const base::Callback<void(bool)>& return_result) {
  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));

  if (HasBeenShutdown(profile) ||
      HasBookmarks(profile) ||
      HasSyncedExtensions(profile)) {
    return_result.Run(true);
    return;
  }
  // Fire asynchronous queries for profile data.
  ProfileSigninConfirmationHelper* helper =
      new ProfileSigninConfirmationHelper(profile, return_result);
  helper->CheckHasHistory(kHistoryEntriesBeforeNewProfilePrompt);
  helper->CheckHasTypedURLs();
}

}  // namespace ui