// Copyright (c) 2009 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_frame/http_negotiate.h"

#include <atlbase.h>
#include <atlcom.h>

#include "base/logging.h"
#include "base/scoped_ptr.h"
#include "base/string_util.h"

#include "chrome_frame/html_utils.h"
#include "chrome_frame/urlmon_url_request.h"
#include "chrome_frame/utils.h"
#include "chrome_frame/vtable_patch_manager.h"

static const int kHttpNegotiateBeginningTransactionIndex = 3;
static const int kHttpNegotiateOnResponseTransactionIndex = 4;

BEGIN_VTABLE_PATCHES(IHttpNegotiate)
  VTABLE_PATCH_ENTRY(kHttpNegotiateBeginningTransactionIndex,
                     HttpNegotiatePatch::BeginningTransaction)
  VTABLE_PATCH_ENTRY(kHttpNegotiateOnResponseTransactionIndex,
                     HttpNegotiatePatch::OnResponse)
END_VTABLE_PATCHES()

HttpNegotiatePatch::HttpNegotiatePatch() {
}

HttpNegotiatePatch::~HttpNegotiatePatch() {
}

// static
bool HttpNegotiatePatch::Initialize() {
  if (IS_PATCHED(IHttpNegotiate)) {
    DLOG(WARNING) << __FUNCTION__ << " called more than once.";
    return true;
  }

  // Use our UrlmonUrlRequest class as we need a temporary object that
  // implements IBindStatusCallback.
  CComObjectStackEx<UrlmonUrlRequest> request;
  ScopedComPtr<IBindCtx> bind_ctx;
  HRESULT hr = CreateAsyncBindCtx(0, &request, NULL, bind_ctx.Receive());
  DCHECK(SUCCEEDED(hr)) << "CreateAsyncBindCtx";
  if (bind_ctx) {
    ScopedComPtr<IUnknown> bscb_holder;
    bind_ctx->GetObjectParam(L"_BSCB_Holder_", bscb_holder.Receive());
    if (bscb_holder) {
      hr = PatchHttpNegotiate(bscb_holder);
    } else {
      NOTREACHED() << "Failed to get _BSCB_Holder_";
      hr = E_UNEXPECTED;
    }
    bind_ctx.Release();
  }

  return SUCCEEDED(hr);
}

// static
void HttpNegotiatePatch::Uninitialize() {
  vtable_patch::UnpatchInterfaceMethods(IHttpNegotiate_PatchInfo);
}

// static
HRESULT HttpNegotiatePatch::PatchHttpNegotiate(IUnknown* to_patch) {
  DCHECK(to_patch);
  DCHECK_IS_NOT_PATCHED(IHttpNegotiate);

  ScopedComPtr<IHttpNegotiate> http;
  HRESULT hr = http.QueryFrom(to_patch);
  if (FAILED(hr)) {
    hr = DoQueryService(IID_IHttpNegotiate, to_patch, http.Receive());
  }

  if (http) {
    hr = vtable_patch::PatchInterfaceMethods(http, IHttpNegotiate_PatchInfo);
    DLOG_IF(ERROR, FAILED(hr))
        << StringPrintf("HttpNegotiate patch failed 0x%08X", hr);
  } else {
    DLOG(WARNING)
        << StringPrintf("IHttpNegotiate not supported 0x%08X", hr);
  }

  return hr;
}

// static
HRESULT HttpNegotiatePatch::BeginningTransaction(
    IHttpNegotiate_BeginningTransaction_Fn original, IHttpNegotiate* me,
    LPCWSTR url, LPCWSTR headers, DWORD reserved, LPWSTR* additional_headers) {
  DLOG(INFO) << __FUNCTION__ << " " << url;

  HRESULT hr = original(me, url, headers, reserved, additional_headers);

  if (FAILED(hr)) {
    DLOG(WARNING) << __FUNCTION__ << " Delegate returned an error";
    return hr;
  }

  static const char kLowerCaseUserAgent[] = "user-agent";

  using net::HttpUtil;

  std::string ascii_headers;
  if (*additional_headers)
    ascii_headers = WideToASCII(*additional_headers);

  HttpUtil::HeadersIterator headers_iterator(ascii_headers.begin(),
                                             ascii_headers.end(), "\r\n");
  std::string user_agent_value;
  if (headers_iterator.AdvanceTo(kLowerCaseUserAgent)) {
    user_agent_value = headers_iterator.values();
  } else if (headers != NULL) {
    // See if there's a user-agent header specified in the original headers.
    std::string original_headers(WideToASCII(headers));
    HttpUtil::HeadersIterator original_it(original_headers.begin(),
                                          original_headers.end(), "\r\n");
    if (original_it.AdvanceTo(kLowerCaseUserAgent))
      user_agent_value = original_it.values();
  }

  // Use the default one if none was provided.
  if (user_agent_value.empty())
    user_agent_value = http_utils::GetDefaultUserAgent();

  // Now add chromeframe to it.
  user_agent_value = http_utils::AddChromeFrameToUserAgentValue(
      user_agent_value);

  // Build new headers, skip the existing user agent value from
  // existing headers.
  std::string new_headers;
  headers_iterator.Reset();
  while (headers_iterator.GetNext()) {
    std::string name(headers_iterator.name());
    if (!LowerCaseEqualsASCII(name, kLowerCaseUserAgent)) {
      new_headers += name + ": " + headers_iterator.values() + "\r\n";
    }
  }

  new_headers += "User-Agent: " + user_agent_value;
  new_headers += "\r\n\r\n";

  if (*additional_headers)
    ::CoTaskMemFree(*additional_headers);
  *additional_headers = reinterpret_cast<wchar_t*>(::CoTaskMemAlloc(
      (new_headers.length() + 1) * sizeof(wchar_t)));
  lstrcpyW(*additional_headers, ASCIIToWide(new_headers).c_str());

  return hr;
}

// static
HRESULT HttpNegotiatePatch::OnResponse(IHttpNegotiate_OnResponse_Fn original,
    IHttpNegotiate* me, DWORD response_code, LPCWSTR response_header,
    LPCWSTR request_header, LPWSTR* additional_request_headers) {
  HRESULT hr = original(me, response_code, response_header, request_header,
                        additional_request_headers);
  return hr;
}