// Copyright (c) 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.

#include "chrome/browser/thumbnails/thumbnail_service_impl.h"

#include "base/memory/ref_counted_memory.h"
#include "chrome/browser/history/history.h"

namespace thumbnails {

ThumbnailServiceImpl::ThumbnailServiceImpl(Profile* profile)
    : top_sites_(profile->GetTopSites()) {
}

ThumbnailServiceImpl::~ThumbnailServiceImpl() {
}

bool ThumbnailServiceImpl::SetPageThumbnail(const GURL& url,
                                            const gfx::Image& thumbnail,
                                            const ThumbnailScore& score) {
  scoped_refptr<history::TopSites> local_ptr(top_sites_);
  if (local_ptr == NULL)
    return false;

  return local_ptr->SetPageThumbnail(url, thumbnail, score);
}

bool ThumbnailServiceImpl::GetPageThumbnail(
    const GURL& url,
    scoped_refptr<base::RefCountedMemory>* bytes) {
  scoped_refptr<history::TopSites> local_ptr(top_sites_);
  if (local_ptr == NULL)
    return false;

  return local_ptr->GetPageThumbnail(url, bytes);
}

bool ThumbnailServiceImpl::ShouldAcquirePageThumbnail(const GURL& url) {
  scoped_refptr<history::TopSites> local_ptr(top_sites_);

  if (local_ptr == NULL)
    return false;

  // Skip if the given URL is not appropriate for history.
  if (!HistoryService::CanAddURL(url))
    return false;
  // Skip if the top sites list is full, and the URL is not known.
  if (local_ptr->IsFull() && !local_ptr->IsKnownURL(url))
    return false;
  // Skip if we don't have to udpate the existing thumbnail.
  ThumbnailScore current_score;
  if (local_ptr->GetPageThumbnailScore(url, &current_score) &&
      !current_score.ShouldConsiderUpdating())
    return false;
  // Skip if we don't have to udpate the temporary thumbnail (i.e. the one
  // not yet saved).
  ThumbnailScore temporary_score;
  if (local_ptr->GetTemporaryPageThumbnailScore(url, &temporary_score) &&
      !temporary_score.ShouldConsiderUpdating())
    return false;

  return true;
}

void ThumbnailServiceImpl::ShutdownOnUIThread() {
  // Since each call uses its own scoped_refptr, we can just clear the reference
  // here by assigning null. If another call is completed, it added its own
  // reference.
  top_sites_ = NULL;
}

}