// 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.

#include "webkit/glue/plugins/pepper_url_loader.h"

#include "base/logging.h"
#include "third_party/ppapi/c/pp_completion_callback.h"
#include "third_party/ppapi/c/pp_errors.h"
#include "third_party/ppapi/c/dev/ppb_url_loader_dev.h"
#include "third_party/ppapi/c/dev/ppb_url_loader_trusted_dev.h"
#include "third_party/WebKit/WebKit/chromium/public/WebDocument.h"
#include "third_party/WebKit/WebKit/chromium/public/WebElement.h"
#include "third_party/WebKit/WebKit/chromium/public/WebFrame.h"
#include "third_party/WebKit/WebKit/chromium/public/WebKit.h"
#include "third_party/WebKit/WebKit/chromium/public/WebKitClient.h"
#include "third_party/WebKit/WebKit/chromium/public/WebPluginContainer.h"
#include "third_party/WebKit/WebKit/chromium/public/WebSecurityOrigin.h"
#include "third_party/WebKit/WebKit/chromium/public/WebURLRequest.h"
#include "third_party/WebKit/WebKit/chromium/public/WebURLResponse.h"
#include "webkit/glue/plugins/pepper_plugin_instance.h"
#include "webkit/glue/plugins/pepper_url_request_info.h"
#include "webkit/glue/plugins/pepper_url_response_info.h"

using WebKit::WebFrame;
using WebKit::WebString;
using WebKit::WebURL;
using WebKit::WebURLError;
using WebKit::WebURLLoader;
using WebKit::WebURLRequest;
using WebKit::WebURLResponse;

#ifdef _MSC_VER
// Do not warn about use of std::copy with raw pointers.
#pragma warning(disable : 4996)
#endif

namespace pepper {

namespace {

PP_Resource Create(PP_Instance instance_id) {
  PluginInstance* instance = ResourceTracker::Get()->GetInstance(instance_id);
  if (!instance)
    return 0;

  URLLoader* loader = new URLLoader(instance, false);
  return loader->GetReference();
}

bool IsURLLoader(PP_Resource resource) {
  return !!Resource::GetAs<URLLoader>(resource);
}

int32_t Open(PP_Resource loader_id,
             PP_Resource request_id,
             PP_CompletionCallback callback) {
  scoped_refptr<URLLoader> loader(Resource::GetAs<URLLoader>(loader_id));
  if (!loader)
    return PP_ERROR_BADRESOURCE;

  scoped_refptr<URLRequestInfo> request(
      Resource::GetAs<URLRequestInfo>(request_id));
  if (!request)
    return PP_ERROR_BADRESOURCE;

  return loader->Open(request, callback);
}

int32_t FollowRedirect(PP_Resource loader_id,
                       PP_CompletionCallback callback) {
  scoped_refptr<URLLoader> loader(Resource::GetAs<URLLoader>(loader_id));
  if (!loader)
    return PP_ERROR_BADRESOURCE;

  return loader->FollowRedirect(callback);
}

bool GetUploadProgress(PP_Resource loader_id,
                       int64_t* bytes_sent,
                       int64_t* total_bytes_to_be_sent) {
  scoped_refptr<URLLoader> loader(Resource::GetAs<URLLoader>(loader_id));
  if (!loader)
    return false;

  *bytes_sent = loader->bytes_sent();
  *total_bytes_to_be_sent = loader->total_bytes_to_be_sent();
  return true;
}

bool GetDownloadProgress(PP_Resource loader_id,
                         int64_t* bytes_received,
                         int64_t* total_bytes_to_be_received) {
  scoped_refptr<URLLoader> loader(Resource::GetAs<URLLoader>(loader_id));
  if (!loader)
    return false;

  *bytes_received = loader->bytes_received();
  *total_bytes_to_be_received = loader->total_bytes_to_be_received();
  return true;
}

PP_Resource GetResponseInfo(PP_Resource loader_id) {
  scoped_refptr<URLLoader> loader(Resource::GetAs<URLLoader>(loader_id));
  if (!loader)
    return 0;

  URLResponseInfo* response_info = loader->response_info();
  if (!response_info)
    return 0;

  return response_info->GetReference();
}

int32_t ReadResponseBody(PP_Resource loader_id,
                         char* buffer,
                         int32_t bytes_to_read,
                         PP_CompletionCallback callback) {
  scoped_refptr<URLLoader> loader(Resource::GetAs<URLLoader>(loader_id));
  if (!loader)
    return PP_ERROR_BADRESOURCE;

  return loader->ReadResponseBody(buffer, bytes_to_read, callback);
}

int32_t FinishStreamingToFile(PP_Resource loader_id,
                              PP_CompletionCallback callback) {
  scoped_refptr<URLLoader> loader(Resource::GetAs<URLLoader>(loader_id));
  if (!loader)
    return PP_ERROR_BADRESOURCE;

  return loader->FinishStreamingToFile(callback);
}

void Close(PP_Resource loader_id) {
  scoped_refptr<URLLoader> loader(Resource::GetAs<URLLoader>(loader_id));
  if (!loader)
    return;

  loader->Close();
}

const PPB_URLLoader_Dev ppb_urlloader = {
  &Create,
  &IsURLLoader,
  &Open,
  &FollowRedirect,
  &GetUploadProgress,
  &GetDownloadProgress,
  &GetResponseInfo,
  &ReadResponseBody,
  &FinishStreamingToFile,
  &Close
};

void GrantUniversalAccess(PP_Resource loader_id) {
  scoped_refptr<URLLoader> loader(Resource::GetAs<URLLoader>(loader_id));
  if (!loader)
    return;

  loader->GrantUniversalAccess();
}

const PPB_URLLoaderTrusted_Dev ppb_urlloadertrusted = {
  &GrantUniversalAccess
};

}  // namespace

URLLoader::URLLoader(PluginInstance* instance, bool main_document_loader)
    : Resource(instance->module()),
      instance_(instance),
      main_document_loader_(main_document_loader),
      pending_callback_(),
      bytes_sent_(0),
      total_bytes_to_be_sent_(-1),
      bytes_received_(0),
      total_bytes_to_be_received_(-1),
      user_buffer_(NULL),
      user_buffer_size_(0),
      done_status_(PP_ERROR_WOULDBLOCK),
      has_universal_access_(false) {
}

URLLoader::~URLLoader() {
}

// static
const PPB_URLLoader_Dev* URLLoader::GetInterface() {
  return &ppb_urlloader;
}

// static
const PPB_URLLoaderTrusted_Dev* URLLoader::GetTrustedInterface() {
  return &ppb_urlloadertrusted;
}

int32_t URLLoader::Open(URLRequestInfo* request,
                        PP_CompletionCallback callback) {
  if (loader_.get())
    return PP_ERROR_INPROGRESS;

  // We only support non-blocking calls.
  if (!callback.func)
    return PP_ERROR_BADARGUMENT;

  WebFrame* frame = instance_->container()->element().document().frame();
  if (!frame)
    return PP_ERROR_FAILED;
  WebURLRequest web_request(request->ToWebURLRequest(frame));

  // Check if we are allowed to access this URL.
  if (!has_universal_access_ &&
      !frame->securityOrigin().canRequest(web_request.url()))
    return PP_ERROR_NOACCESS;

  frame->dispatchWillSendRequest(web_request);

  loader_.reset(WebKit::webKitClient()->createURLLoader());
  if (!loader_.get())
    return PP_ERROR_FAILED;
  loader_->loadAsynchronously(web_request, this);

  pending_callback_ = callback;

  // Notify completion when we receive a redirect or response headers.
  return PP_ERROR_WOULDBLOCK;
}

int32_t URLLoader::FollowRedirect(PP_CompletionCallback callback) {
  NOTIMPLEMENTED();  // TODO(darin): Implement me.
  return PP_ERROR_FAILED;
}

int32_t URLLoader::ReadResponseBody(char* buffer, int32_t bytes_to_read,
                                    PP_CompletionCallback callback) {
  if (!response_info_ || response_info_->body())
    return PP_ERROR_FAILED;
  if (bytes_to_read <= 0 || !buffer)
    return PP_ERROR_BADARGUMENT;
  if (pending_callback_.func)
    return PP_ERROR_INPROGRESS;

  // We only support non-blocking calls.
  if (!callback.func)
    return PP_ERROR_BADARGUMENT;

  user_buffer_ = buffer;
  user_buffer_size_ = bytes_to_read;

  if (!buffer_.empty())
    return FillUserBuffer();

  // We may have already reached EOF.
  if (done_status_ != PP_ERROR_WOULDBLOCK) {
    user_buffer_ = NULL;
    user_buffer_size_ = 0;
    return done_status_;
  }

  pending_callback_ = callback;
  return PP_ERROR_WOULDBLOCK;
}

int32_t URLLoader::FinishStreamingToFile(PP_CompletionCallback callback) {
  if (!response_info_ || !response_info_->body())
    return PP_ERROR_FAILED;
  if (pending_callback_.func)
    return PP_ERROR_INPROGRESS;

  // We may have already reached EOF.
  if (done_status_ != PP_ERROR_WOULDBLOCK)
    return done_status_;

  // Wait for didFinishLoading / didFail.
  pending_callback_ = callback;
  return PP_ERROR_WOULDBLOCK;
}

void URLLoader::Close() {
  if (loader_.get()) {
    loader_->cancel();
  } else if (main_document_loader_) {
    WebFrame* frame = instance_->container()->element().document().frame();
    frame->stopLoading();
  }
}

void URLLoader::GrantUniversalAccess() {
  has_universal_access_ = true;
}

void URLLoader::willSendRequest(WebURLLoader* loader,
                                WebURLRequest& new_request,
                                const WebURLResponse& redirect_response) {
  NOTIMPLEMENTED();  // TODO(darin): Allow the plugin to inspect redirects.
}

void URLLoader::didSendData(WebURLLoader* loader,
                            unsigned long long bytes_sent,
                            unsigned long long total_bytes_to_be_sent) {
  // TODO(darin): Bounds check input?
  bytes_sent_ = static_cast<int64_t>(bytes_sent);
  total_bytes_to_be_sent_ = static_cast<int64_t>(total_bytes_to_be_sent);
}

void URLLoader::didReceiveResponse(WebURLLoader* loader,
                                   const WebURLResponse& response) {
  scoped_refptr<URLResponseInfo> response_info(new URLResponseInfo(module()));
  if (response_info->Initialize(response))
    response_info_ = response_info;

  // Sets -1 if the content length is unknown.
  total_bytes_to_be_received_ = response.expectedContentLength();

  RunCallback(PP_OK);
}

void URLLoader::didDownloadData(WebURLLoader* loader,
                                int data_length) {
  bytes_received_ += data_length;
}

void URLLoader::didReceiveData(WebURLLoader* loader,
                               const char* data,
                               int data_length) {
  bytes_received_ += data_length;

  buffer_.insert(buffer_.end(), data, data + data_length);
  if (user_buffer_) {
    RunCallback(FillUserBuffer());
  } else {
    DCHECK(!pending_callback_.func);
  }
}

void URLLoader::didFinishLoading(WebURLLoader* loader, double finish_time) {
  done_status_ = PP_OK;
  RunCallback(done_status_);
}

void URLLoader::didFail(WebURLLoader* loader, const WebURLError& error) {
  // TODO(darin): Provide more detailed error information.
  done_status_ = PP_ERROR_FAILED;
  RunCallback(done_status_);
}

void URLLoader::RunCallback(int32_t result) {
  if (!pending_callback_.func)
    return;

  PP_CompletionCallback callback = {0};
  std::swap(callback, pending_callback_);
  PP_RunCompletionCallback(&callback, result);
}

size_t URLLoader::FillUserBuffer() {
  DCHECK(user_buffer_);
  DCHECK(user_buffer_size_);

  size_t bytes_to_copy = std::min(buffer_.size(), user_buffer_size_);
  std::copy(buffer_.begin(), buffer_.begin() + bytes_to_copy, user_buffer_);
  buffer_.erase(buffer_.begin(), buffer_.begin() + bytes_to_copy);

  // Reset for next time.
  user_buffer_ = NULL;
  user_buffer_size_ = 0;
  return bytes_to_copy;
}

}  // namespace pepper