/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is 
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 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *
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/*

  Some silly extra stuff that doesn't have anywhere better to go.

 */

#include "nsCOMPtr.h"
#include "nsHTMLUtils.h"
#include "nsIDocument.h"
#include "nsIIOService.h"
#include "nsIServiceManager.h"
#include "nsICharsetConverterManager.h"
#include "nsNetUtil.h"
#include "nsString.h"
#include "nsXPIDLString.h"
#include "prprf.h"
#include "nsEscape.h"

static NS_DEFINE_CID(kIOServiceCID, NS_IOSERVICE_CID);

static PRBool
IsAscii(const PRUnichar* aString)
{
  for (const PRUnichar* p = aString; *p != 0; ++p) {
    if (*p & ~PRUnichar(0x007f))
      return PR_FALSE;
  }
  return PR_TRUE;
}


nsresult
NS_MakeAbsoluteURIWithCharset(char* *aResult,
                              const nsString& aSpec,
                              nsIDocument* aDocument,
                              nsIURI* aBaseURI,
                              nsIIOService* aIOService,
                              nsICharsetConverterManager* aConvMgr)
{
  // Initialize aResult in case of tragedy
  *aResult = nsnull;

  // Sanity
  NS_PRECONDITION(aBaseURI != nsnull, "no base URI");
  if (! aBaseURI)
    return NS_ERROR_FAILURE;

  // This gets the relative spec after gyrating it through all the
  // necessary encodings and escaping.
  nsCAutoString spec;

  if (IsAscii(aSpec.get())) {
    // If it's ASCII, then just copy the characters
    spec.AssignWithConversion(aSpec);
  }
  else {
    // If the scheme is javascript then no charset conversion is needed,
    // escape non ASCII in \uxxxx form.
    PRInt32 pos = aSpec.FindChar(':');
    static const char kJavaScript[] = "javascript";
    nsAutoString scheme;
    if ((pos == (PRInt32)(sizeof kJavaScript - 1)) &&
        (aSpec.Left(scheme, pos) != -1) &&
         scheme.EqualsIgnoreCase(kJavaScript)) {
      char buf[6+1];	// space for \uXXXX plus a NUL at the end
      spec.Truncate(0);
      for (const PRUnichar* uch = aSpec.get(); *uch; ++uch) {
        if (!nsCRT::IsAscii(*uch)) {
          PR_snprintf(buf, sizeof(buf), "\\u%.4x", *uch);
          spec.Append(buf);
        }
        else {
          spec.AppendWithConversion(*uch);
        }
      }
    }
    else {
      // If the scheme is mailtourl then should not convert to a document charset
      // because the charset cannot be passes to mailnews code, 
      // use UTF-8 instead and apply URL escape.
      static const char kMailToURI[] = "mailto";
      if ((pos == (PRInt32)(sizeof kMailToURI - 1)) &&
          (aSpec.Left(scheme, pos) != -1) &&
           scheme.EqualsIgnoreCase(kMailToURI)) {
        spec = NS_ConvertUCS2toUTF8(aSpec.get());
      }
      else {
        // Otherwise, we'll need to use aDocument to cough up a character
        // set converter, and re-encode the relative portion of the URL as
        // 8-bit characters.
        nsCOMPtr<nsIUnicodeEncoder> encoder;

        if (aDocument) {
          nsCOMPtr<nsICharsetConverterManager> convmgr;
          if (aConvMgr) {
            convmgr = aConvMgr;
          }
          else {
            convmgr = do_GetService(NS_CHARSETCONVERTERMANAGER_CONTRACTID);
          }

          if (! convmgr)
            return NS_ERROR_FAILURE;

          nsAutoString charSetID;
          aDocument->GetDocumentCharacterSet(charSetID);

          convmgr->GetUnicodeEncoder(&charSetID, getter_AddRefs(encoder));
        }

        if (encoder) {
          // Got the encoder: let's party.
          PRInt32 len = aSpec.Length();
          PRInt32 maxlen;
          encoder->GetMaxLength(aSpec.get(), len, &maxlen);

          char buf[64], *p = buf;
          if (maxlen > sizeof(buf) - 1)
            p = new char[maxlen + 1];

          if (! p)
            return NS_ERROR_OUT_OF_MEMORY;

          encoder->Convert(aSpec.get(), &len, p, &maxlen);
          p[maxlen] = 0;
          spec = p;
          encoder->Finish(p, &len);
          p[len] = 0;
          spec += p;
          
          if (p != buf)
            delete[] p;
        }
        else {
          // No encoder, but we've got non-ASCII data. Let's UTF-8 encode
          // by default.
          spec = NS_ConvertUCS2toUTF8(aSpec.get());
        }

      }
      // Now we need to URL-escape the string. 
      // XXX andreas.otte has warned that using the nsIIOService::Escape
      // method in this way may be too conservative (e.g., it won't
      // escape a "#" character that appears in a hostname -- does that
      // matter?) But, since there's nothing better, we'll do it...
      static const PRInt32 kEscapeConservatively = esc_Forced - 1;

      // XXX Unfortunately, we can't escape "in place". Maybe the new string
      // APIs will make that better some day.
      nsCAutoString escaped;
      nsresult rv = nsStdEscape(spec.get(), kEscapeConservatively, escaped);
      if (NS_FAILED(rv))
        return rv;
      spec = escaped;
    }
  }

  return aBaseURI->Resolve(spec, aResult);
}


nsIIOService* nsHTMLUtils::IOService;
nsICharsetConverterManager* nsHTMLUtils::CharsetMgr;
PRInt32 nsHTMLUtils::gRefCnt;

void
nsHTMLUtils::AddRef()
{
  if (++gRefCnt == 1) {
    nsServiceManager::GetService(kIOServiceCID, NS_GET_IID(nsIIOService),
                                 NS_REINTERPRET_CAST(nsISupports**, &IOService));

    nsServiceManager::GetService(NS_CHARSETCONVERTERMANAGER_CONTRACTID,
                                 NS_GET_IID(nsICharsetConverterManager),
                                 NS_REINTERPRET_CAST(nsISupports**, &CharsetMgr));
  }
}


void
nsHTMLUtils::Release()
{
  if (--gRefCnt == 0) {
    nsServiceManager::ReleaseService(NS_CHARSETCONVERTERMANAGER_CONTRACTID, CharsetMgr);
    nsServiceManager::ReleaseService(kIOServiceCID, IOService);
  }
}