/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/NPL/
 *
 * 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.org code.
 *
 * The Initial Developer of the Original Code is 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * ***** END LICENSE BLOCK ***** */
#include "nscore.h"
#include "nsINameSpaceManager.h"
#include "nsINameSpace.h"
#include "nsCOMArray.h"
#include "nsIElementFactory.h"
#include "nsIServiceManager.h"
#include "nsDoubleHashtable.h"
#include "nsLayoutAtoms.h"
#include "nsString.h"

static nsINameSpaceManager* gNameSpaceManager = nsnull;

nsresult NS_NewXMLElementFactory(nsIElementFactory** aResult);

#define kXMLNSNameSpaceURI "http://www.w3.org/2000/xmlns/"
#define kXMLNameSpaceURI "http://www.w3.org/XML/1998/namespace"
#define kXHTMLNameSpaceURI "http://www.w3.org/1999/xhtml"
#define kXLinkNameSpaceURI "http://www.w3.org/1999/xlink"
#define kXSLTNameSpaceURI "http://www.w3.org/1999/XSL/Transform"
#define kXBLNameSpaceURI "http://www.mozilla.org/xbl"
#define kMathMLNameSpaceURI "http://www.w3.org/1998/Math/MathML"
#define kRDFNameSpaceURI "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
#define kXULNameSpaceURI "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
#define kSVGNameSpaceURI "http://www.w3.org/2000/svg"

//-----------------------------------------------------------
// Name Space 

class NameSpaceImpl : public nsINameSpace {
public:
  NameSpaceImpl(NameSpaceImpl* aParent, 
                nsIAtom* aPrefix, 
                const nsAString& aURI);
  NameSpaceImpl(NameSpaceImpl* aParent, 
                nsIAtom* aPrefix, 
                PRInt32 aNameSpaceID);
  virtual ~NameSpaceImpl();

  NS_DECL_ISUPPORTS

  NS_IMETHOD GetNameSpaceID(PRInt32* aID) const;
  NS_IMETHOD GetNameSpaceURI(nsAString& aURI) const;
  NS_IMETHOD GetNameSpacePrefix(nsIAtom** aPrefix) const;

  NS_IMETHOD GetParentNameSpace(nsINameSpace** aParent) const;

  NS_IMETHOD FindNameSpace(nsIAtom* aPrefix, nsINameSpace** aNameSpace) const;
  NS_IMETHOD FindNameSpaceID(nsIAtom* aPrefix, PRInt32* aNameSpaceID) const;
  NS_IMETHOD FindNameSpacePrefix(PRInt32 aNameSpaceID, nsIAtom** aPrefix) const;

  NS_IMETHOD CreateChildNameSpace(nsIAtom* aPrefix, const nsAString& aURI,
                                  nsINameSpace** aChildNameSpace);
  NS_IMETHOD CreateChildNameSpace(nsIAtom* aPrefix, PRInt32 aNameSpaceID,
                                  nsINameSpace** aChildNameSpace);

private:
  // These are not supported and are not implemented!
  NameSpaceImpl(const NameSpaceImpl& aCopy);
  NameSpaceImpl& operator=(const NameSpaceImpl& aCopy);

  NameSpaceImpl* mParent;
  nsCOMPtr<nsIAtom> mPrefix;
  PRInt32 mID;
};

NameSpaceImpl::NameSpaceImpl(NameSpaceImpl* aParent, 
                             nsIAtom* aPrefix, 
                             const nsAString& aURI)
  : mParent(aParent),
    mPrefix(aPrefix)
{
  NS_IF_ADDREF(mParent);
  gNameSpaceManager->RegisterNameSpace(aURI, mID);
}

NameSpaceImpl::NameSpaceImpl(NameSpaceImpl* aParent, 
                             nsIAtom* aPrefix, 
                             PRInt32 aNameSpaceID)
  : mParent(aParent),
    mPrefix(aPrefix),
    mID(aNameSpaceID)
{
  NS_IF_ADDREF(mParent);
}

NameSpaceImpl::~NameSpaceImpl()
{
  NS_IF_RELEASE(mParent);
}

NS_IMPL_ISUPPORTS1(NameSpaceImpl, nsINameSpace)

NS_IMETHODIMP
NameSpaceImpl::GetNameSpaceID(PRInt32* aID) const
{
  *aID = mID;

  return NS_OK;
}

NS_IMETHODIMP
NameSpaceImpl::GetNameSpaceURI(nsAString& aURI) const
{
  return gNameSpaceManager->GetNameSpaceURI(mID, aURI);
}

NS_IMETHODIMP
NameSpaceImpl::GetNameSpacePrefix(nsIAtom** aPrefix) const
{
  NS_IF_ADDREF(*aPrefix = mPrefix);

  return NS_OK;
}

NS_IMETHODIMP
NameSpaceImpl::GetParentNameSpace(nsINameSpace** aParent) const
{
  NS_IF_ADDREF(*aParent = mParent);

  return NS_OK;
}

NS_IMETHODIMP
NameSpaceImpl::FindNameSpace(nsIAtom* aPrefix, nsINameSpace** aNameSpace) const
{
  const NameSpaceImpl* nameSpace = this;

  do {
    if (aPrefix == nameSpace->mPrefix) {
      *aNameSpace = (nsINameSpace*)nameSpace;
      NS_ADDREF(*aNameSpace);

      return NS_OK;
    }
    nameSpace = nameSpace->mParent;
  } while (nameSpace);

  *aNameSpace = nsnull;

  return NS_ERROR_ILLEGAL_VALUE;
}

NS_IMETHODIMP
NameSpaceImpl::FindNameSpaceID(nsIAtom* aPrefix, PRInt32* aNameSpaceID) const
{
  const NameSpaceImpl* nameSpace = this;

  do {
    if (aPrefix == nameSpace->mPrefix) {
      *aNameSpaceID = nameSpace->mID;

      return NS_OK;
    }
    nameSpace = nameSpace->mParent;
  } while (nameSpace);

  if (!aPrefix) {
    *aNameSpaceID = kNameSpaceID_None;
  }
  else {
    *aNameSpaceID = kNameSpaceID_Unknown;
  }

  return NS_ERROR_ILLEGAL_VALUE;
}

NS_IMETHODIMP
NameSpaceImpl::FindNameSpacePrefix(PRInt32 aNameSpaceID,
                                   nsIAtom** aPrefix) const
{
  const NameSpaceImpl* nameSpace = this;

  do {
    if (aNameSpaceID == nameSpace->mID) {
      NS_IF_ADDREF(*aPrefix = nameSpace->mPrefix);

      return NS_OK;
    }
    nameSpace = nameSpace->mParent;
  } while (nameSpace);

  *aPrefix = nsnull;

  return NS_ERROR_ILLEGAL_VALUE;
}

NS_IMETHODIMP
NameSpaceImpl::CreateChildNameSpace(nsIAtom* aPrefix, const nsAString& aURI,
                                    nsINameSpace** aChildNameSpace)
{
  NameSpaceImpl* child = new NameSpaceImpl(this, aPrefix, aURI);
  NS_ENSURE_TRUE(child, NS_ERROR_OUT_OF_MEMORY);

  *aChildNameSpace = NS_STATIC_CAST(nsINameSpace*, child);
  NS_ADDREF(*aChildNameSpace);

  return NS_OK;
}

NS_IMETHODIMP
NameSpaceImpl::CreateChildNameSpace(nsIAtom* aPrefix, PRInt32 aNameSpaceID,
                                    nsINameSpace** aChildNameSpace)
{
  PRBool hasNSURI;
  gNameSpaceManager->HasNameSpaceURI(aNameSpaceID, &hasNSURI);
  if (hasNSURI) {
    NameSpaceImpl* child = new NameSpaceImpl(this, aPrefix, aNameSpaceID);
    NS_ENSURE_TRUE(child, NS_ERROR_OUT_OF_MEMORY);

    *aChildNameSpace = NS_STATIC_CAST(nsINameSpace*, child);
    NS_ADDREF(*aChildNameSpace);

    return NS_OK;
  }
  *aChildNameSpace = nsnull;

  return NS_ERROR_ILLEGAL_VALUE;
}

class nsNameSpaceEntry : public PLDHashEntryHdr
{
public:
  nsNameSpaceEntry(const void* aKey) :
    mKey(NS_STATIC_CAST(const nsAString*, aKey))
  {
  }
  ~nsNameSpaceEntry()
  {
  }
  const void* GetKey() const {
    return mKey;
  }
  static PLDHashNumber HashKey(const void* aKey) {
    return HashString(*NS_STATIC_CAST(const nsAString*, aKey));
  }
  PRBool MatchEntry(const void* aKey) const {
    return NS_STATIC_CAST(const nsAString*, aKey)->Equals(*mKey);
  }

  const nsAString* mKey;
  PRInt32 mNameSpaceID;
};

DECL_DHASH_WRAPPER(nsNameSpaceHashBase, nsNameSpaceEntry, nsAString&)
DHASH_WRAPPER(nsNameSpaceHashBase, nsNameSpaceEntry, nsAString&)

class nsNameSpaceHash : public nsNameSpaceHashBase
{
public:
  nsNameSpaceHash()
  {
  }
  ~nsNameSpaceHash()
  {
  }
  nsNameSpaceEntry* LookupEntry(const nsAString& aUri)
  {
    return NS_STATIC_CAST(nsNameSpaceEntry*,
                          PL_DHashTableOperate(&mHashTable, &aUri,
                                               PL_DHASH_LOOKUP));
  }
};

//-----------------------------------------------------------
// Name Space Manager

class NameSpaceManagerImpl : public nsINameSpaceManager {
public:
  NameSpaceManagerImpl();
  virtual ~NameSpaceManagerImpl();

  NS_DECL_ISUPPORTS

  nsresult Init();

  NS_IMETHOD CreateRootNameSpace(nsINameSpace** aRootNameSpace);

  NS_IMETHOD RegisterNameSpace(const nsAString& aURI, 
			                         PRInt32& aNameSpaceID);

  NS_IMETHOD GetNameSpaceURI(PRInt32 aNameSpaceID, nsAString& aURI);
  NS_IMETHOD GetNameSpaceID(const nsAString& aURI,
                            PRInt32* aNameSpaceID);
  NS_IMETHOD GetElementFactory(PRInt32 aNameSpaceID,
                               nsIElementFactory **aElementFactory);
  NS_IMETHOD HasRegisteredFactory(PRInt32 aNameSpaceID,
                                  PRBool* aHasFactory);
  NS_IMETHOD HasNameSpaceURI(PRInt32 aNameSpaceID,
                             PRBool* aHasNameSpaceURI);

private:
  // These are not supported and are not implemented!
  NameSpaceManagerImpl(const NameSpaceManagerImpl& aCopy);
  NameSpaceManagerImpl& operator=(const NameSpaceManagerImpl& aCopy);

  nsresult AddNameSpace(const nsAString& aURI, const PRInt32 aNameSpaceID);

  nsNameSpaceHash mURIToIDTable;
  nsStringArray mURIArray;
  nsCOMArray<nsIElementFactory> mElementFactoryArray;
  nsCOMPtr<nsIElementFactory> mDefaultElementFactory;
};

NameSpaceManagerImpl::NameSpaceManagerImpl()
{
}

NameSpaceManagerImpl::~NameSpaceManagerImpl()
{
}

NS_IMPL_ISUPPORTS1(NameSpaceManagerImpl, nsINameSpaceManager)

nsresult NameSpaceManagerImpl::Init()
{
  nsresult rv = mURIToIDTable.Init(32);
  NS_ENSURE_SUCCESS(rv, rv);

  // Need to be ordered according to ID.
  AddNameSpace(NS_LITERAL_STRING(kXMLNSNameSpaceURI), kNameSpaceID_XMLNS);
  AddNameSpace(NS_LITERAL_STRING(kXMLNameSpaceURI), kNameSpaceID_XML);
  AddNameSpace(NS_LITERAL_STRING(kXHTMLNameSpaceURI), kNameSpaceID_XHTML);
  AddNameSpace(NS_LITERAL_STRING(kXLinkNameSpaceURI), kNameSpaceID_XLink);
  AddNameSpace(NS_LITERAL_STRING(kXSLTNameSpaceURI), kNameSpaceID_XSLT);
  AddNameSpace(NS_LITERAL_STRING(kXBLNameSpaceURI), kNameSpaceID_XBL);
  AddNameSpace(NS_LITERAL_STRING(kMathMLNameSpaceURI), kNameSpaceID_MathML);
  AddNameSpace(NS_LITERAL_STRING(kRDFNameSpaceURI), kNameSpaceID_RDF);
  AddNameSpace(NS_LITERAL_STRING(kXULNameSpaceURI), kNameSpaceID_XUL);
  AddNameSpace(NS_LITERAL_STRING(kSVGNameSpaceURI), kNameSpaceID_SVG);

  return NS_NewXMLElementFactory(getter_AddRefs(mDefaultElementFactory));
}

NS_IMETHODIMP
NameSpaceManagerImpl::CreateRootNameSpace(nsINameSpace** aRootNameSpace)
{
  nsresult  rv = NS_ERROR_OUT_OF_MEMORY;
  *aRootNameSpace = nsnull;

  NameSpaceImpl* xmlns = new NameSpaceImpl(nsnull,
                                           nsLayoutAtoms::xmlnsNameSpace,
                                           kNameSpaceID_XMLNS);
  if (xmlns) {
    NameSpaceImpl* xml = new NameSpaceImpl(xmlns,
                                           nsLayoutAtoms::xmlNameSpace,
                                           kNameSpaceID_XML);
    if (xml) {
      rv = CallQueryInterface(xml, aRootNameSpace);
    }
    else {
      delete xmlns;
    }
  }

  return rv;
}

NS_IMETHODIMP
NameSpaceManagerImpl::RegisterNameSpace(const nsAString& aURI, 
                                        PRInt32& aNameSpaceID)
{
  if (aURI.IsEmpty()) {
    aNameSpaceID = kNameSpaceID_None; // xmlns="", see bug 75700 for details

    return NS_OK;
  }

  nsNameSpaceEntry* entry = mURIToIDTable.GetEntry(aURI);
  if (entry) {
    aNameSpaceID = entry->mNameSpaceID;

    return NS_OK;
  }

  aNameSpaceID = mURIArray.Count() + 1; // id is index + 1

  nsresult rv = AddNameSpace(aURI, aNameSpaceID);
  if (NS_FAILED(rv)) {
    aNameSpaceID = kNameSpaceID_Unknown;
  }

  return rv;
}

NS_IMETHODIMP
NameSpaceManagerImpl::GetNameSpaceURI(PRInt32 aNameSpaceID, nsAString& aURI)
{
  PRInt32 index = aNameSpaceID - 1; // id is index + 1
  if (index < 0 || index >= mURIArray.Count()) {
    aURI.Truncate();

    return NS_ERROR_ILLEGAL_VALUE;
  }

  mURIArray.StringAt(index, aURI);

  return NS_OK;
}

NS_IMETHODIMP
NameSpaceManagerImpl::GetNameSpaceID(const nsAString& aURI, PRInt32* aNameSpaceID)
{
  if (aURI.IsEmpty()) {
    *aNameSpaceID = kNameSpaceID_None; // xmlns="", see bug 75700 for details

    return NS_OK;
  }

  nsNameSpaceEntry* entry = mURIToIDTable.GetEntry(aURI);

  *aNameSpaceID = entry ? entry->mNameSpaceID : kNameSpaceID_Unknown;

  return NS_OK;
}

NS_IMETHODIMP
NameSpaceManagerImpl::GetElementFactory(PRInt32 aNameSpaceID,
                                        nsIElementFactory **aElementFactory)
{
  *aElementFactory = nsnull;

  // Parsing should have aborted before we get here, but for now we'll have to
  // live with returning the default factory. Bugs 184697 and 103255
  if (aNameSpaceID == kNameSpaceID_Unknown) {
    *aElementFactory = mDefaultElementFactory;
    NS_ADDREF(*aElementFactory);

    return NS_OK;
  }

  NS_ENSURE_TRUE(aNameSpaceID >= 0, NS_ERROR_ILLEGAL_VALUE);

  if (aNameSpaceID < mElementFactoryArray.Count()) {
    *aElementFactory = mElementFactoryArray.ObjectAt(aNameSpaceID);
    if (*aElementFactory) {
      NS_ADDREF(*aElementFactory);

      return NS_OK;
    }
  }

  nsAutoString uri;
  GetNameSpaceURI(aNameSpaceID, uri);

  nsCOMPtr<nsIElementFactory> ef;

  if (!uri.IsEmpty()) {
    nsCAutoString contract_id(NS_ELEMENT_FACTORY_CONTRACTID_PREFIX);
    AppendUTF16toUTF8(uri, contract_id);
    ef = do_GetService(contract_id.get());
  }

  if (!ef) {
    ef = mDefaultElementFactory;
  }

  PRInt32 count = mElementFactoryArray.Count();

  if (aNameSpaceID < count) {
    mElementFactoryArray.ReplaceObjectAt(ef, aNameSpaceID);
  } else {
    // This sucks, simply doing an InsertObjectAt() should IMNSHO
    // automatically grow the array and insert null's as needed to
    // fill up the array!?!!
    
    for (PRInt32 i = count; i < aNameSpaceID; ++i) {
      mElementFactoryArray.AppendObject(nsnull);
    }

    mElementFactoryArray.AppendObject(ef);
  }

  *aElementFactory = ef;
  NS_ADDREF(*aElementFactory);

  return NS_OK;
}

NS_IMETHODIMP
NameSpaceManagerImpl::HasRegisteredFactory(PRInt32 aNameSpaceID,
                                           PRBool* aHasFactory)
{
  *aHasFactory = PR_FALSE;
  NS_ENSURE_TRUE(mDefaultElementFactory, NS_ERROR_FAILURE);

  nsCOMPtr<nsIElementFactory> ef;
  GetElementFactory(aNameSpaceID, getter_AddRefs(ef));
  *aHasFactory = ef != mDefaultElementFactory;

  return NS_OK;
}

NS_IMETHODIMP
NameSpaceManagerImpl::HasNameSpaceURI(PRInt32 aNameSpaceID,
                                      PRBool* aHasNameSpaceURI)
{
  *aHasNameSpaceURI = (aNameSpaceID > kNameSpaceID_None ||
                       aNameSpaceID <= mURIArray.Count());

  return NS_OK;
}

nsresult NameSpaceManagerImpl::AddNameSpace(const nsAString& aURI,
                                            const PRInt32 aNameSpaceID)
{
  NS_ASSERTION(aNameSpaceID - 1 == mURIArray.Count(),
               "BAD! AddNameSpace not called in right order!");

  if (!mURIArray.AppendString(aURI)) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  const nsString* uri = mURIArray.StringAt(aNameSpaceID - 1);
  nsNameSpaceEntry* entry = mURIToIDTable.AddEntry(*uri);
  if (!entry) {
    mURIArray.RemoveStringAt(aNameSpaceID - 1);

    return NS_ERROR_OUT_OF_MEMORY;
  }

  entry->mNameSpaceID = aNameSpaceID;

  return NS_OK;
}

nsresult
NS_GetNameSpaceManager(nsINameSpaceManager** aInstancePtrResult)
{
  NS_ENSURE_ARG_POINTER(aInstancePtrResult);

  if (!gNameSpaceManager) {
    nsCOMPtr<NameSpaceManagerImpl> manager = new NameSpaceManagerImpl();
    if (manager) {
      nsresult rv = manager->Init();
      if (NS_SUCCEEDED(rv)) {
        gNameSpaceManager = manager;
        NS_ADDREF(gNameSpaceManager);
      }
    }
  }

  *aInstancePtrResult = gNameSpaceManager;
  NS_ENSURE_TRUE(gNameSpaceManager, NS_ERROR_OUT_OF_MEMORY);

  NS_ADDREF(*aInstancePtrResult);

  return NS_OK;
}

void
NS_NameSpaceManagerShutdown()
{
  NS_IF_RELEASE(gNameSpaceManager);
}