// Copyright 2014 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/search/suggestions/image_fetcher_impl.h"

#include <string>

#include "content/public/browser/browser_thread.h"
#include "net/base/load_flags.h"
#include "net/url_request/url_request_context_getter.h"

namespace suggestions {

ImageFetcherImpl::ImageFetcherImpl(
    net::URLRequestContextGetter* url_request_context)
    : delegate_(NULL), url_request_context_(url_request_context) {}

ImageFetcherImpl::~ImageFetcherImpl() {}

ImageFetcherImpl::ImageRequest::ImageRequest() : fetcher(NULL) {}

ImageFetcherImpl::ImageRequest::ImageRequest(chrome::BitmapFetcher* f)
    : fetcher(f) {}

ImageFetcherImpl::ImageRequest::~ImageRequest() { delete fetcher; }

void ImageFetcherImpl::SetImageFetcherDelegate(ImageFetcherDelegate* delegate) {
  DCHECK(delegate);
  delegate_ = delegate;
}

void ImageFetcherImpl::StartOrQueueNetworkRequest(
    const GURL& url, const GURL& image_url,
    base::Callback<void(const GURL&, const SkBitmap*)> callback) {
  // Before starting to fetch the image. Look for a request in progress for
  // |image_url|, and queue if appropriate.
  ImageRequestMap::iterator it = pending_net_requests_.find(image_url);
  if (it == pending_net_requests_.end()) {
    // |image_url| is not being fetched, so create a request and initiate
    // the fetch.
    ImageRequest request(new chrome::BitmapFetcher(image_url, this));
    request.url = url;
    request.callbacks.push_back(callback);
    request.fetcher->Init(
        url_request_context_, std::string(),
        net::URLRequest::CLEAR_REFERRER_ON_TRANSITION_FROM_SECURE_TO_INSECURE,
        net::LOAD_NORMAL);
    request.fetcher->Start();
    pending_net_requests_[image_url].swap(&request);
  } else {
    // Request in progress. Register as an interested callback.
    it->second.callbacks.push_back(callback);
  }
}

void ImageFetcherImpl::OnFetchComplete(const GURL& image_url,
                                       const SkBitmap* bitmap) {
  ImageRequestMap::iterator image_iter = pending_net_requests_.find(image_url);
  DCHECK(image_iter != pending_net_requests_.end());

  ImageRequest* request = &image_iter->second;

  // Here |bitmap| could be NULL or a pointer to a bitmap which is owned by the
  // BitmapFetcher and which ceases to exist after this function. Pass the
  // un-owned pointer to the registered callbacks.
  for (CallbackVector::iterator callback_iter = request->callbacks.begin();
       callback_iter != request->callbacks.end(); ++callback_iter) {
    callback_iter->Run(request->url, bitmap);
  }

  // Inform the ImageFetcherDelegate.
  if (delegate_) {
    delegate_->OnImageFetched(request->url, bitmap);
  }

  // Erase the completed ImageRequest.
  pending_net_requests_.erase(image_iter);
}

}  // namespace suggestions