/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * 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 Netscape are
 * Copyright (C) 1998-1999 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): 
 *   Pierre Phaneuf <pp@ludusdesign.com>
 */

#include "DeleteRangeTxn.h"
#include "nsIDOMRange.h"
#include "nsIDOMCharacterData.h"
#include "nsIDOMNodeList.h"
#include "nsISelection.h"
#include "DeleteTextTxn.h"
#include "DeleteElementTxn.h"
#include "TransactionFactory.h"
#include "nsIContentIterator.h"
#include "nsIContent.h"
#include "nsLayoutCID.h"

#ifdef NS_DEBUG
#include "nsIDOMElement.h"
#endif

#ifdef NS_DEBUG
static PRBool gNoisy = PR_FALSE;
#else
static const PRBool gNoisy = PR_FALSE;
#endif

// note that aEditor is not refcounted
DeleteRangeTxn::DeleteRangeTxn()
  : EditAggregateTxn()
{
}

NS_IMETHODIMP DeleteRangeTxn::Init(nsIEditor *aEditor, nsIDOMRange *aRange)
{
  NS_ASSERTION(aEditor && aRange, "bad state");
  if (!aEditor || !aRange) { return NS_ERROR_NOT_INITIALIZED; }

  mEditor = aEditor;
  mRange  = do_QueryInterface(aRange);
  
  nsresult result = aRange->GetStartContainer(getter_AddRefs(mStartParent));
  NS_ASSERTION((NS_SUCCEEDED(result)), "GetStartParent failed.");
  result = aRange->GetEndContainer(getter_AddRefs(mEndParent));
  NS_ASSERTION((NS_SUCCEEDED(result)), "GetEndParent failed.");
  result = aRange->GetStartOffset(&mStartOffset);
  NS_ASSERTION((NS_SUCCEEDED(result)), "GetStartOffset failed.");
  result = aRange->GetEndOffset(&mEndOffset);
  NS_ASSERTION((NS_SUCCEEDED(result)), "GetEndOffset failed.");
  result = aRange->GetCommonAncestorContainer(getter_AddRefs(mCommonParent));
  NS_ASSERTION((NS_SUCCEEDED(result)), "GetCommonParent failed.");

#ifdef NS_DEBUG
  {
    PRUint32 count;
    nsCOMPtr<nsIDOMCharacterData> textNode;
    textNode = do_QueryInterface(mStartParent);
    if (textNode)
      textNode->GetLength(&count);
    else
    {
      nsCOMPtr<nsIDOMNodeList> children;
      result = mStartParent->GetChildNodes(getter_AddRefs(children));
      NS_ASSERTION(((NS_SUCCEEDED(result)) && children), "bad start child list");
      children->GetLength(&count);
    }
    NS_ASSERTION(mStartOffset<=(PRInt32)count, "bad start offset");

    textNode = do_QueryInterface(mEndParent);
    if (textNode)
      textNode->GetLength(&count);
    else
    {
      nsCOMPtr<nsIDOMNodeList> children;
      result = mEndParent->GetChildNodes(getter_AddRefs(children));
      NS_ASSERTION(((NS_SUCCEEDED(result)) && children), "bad end child list");
      children->GetLength(&count);
    }
    NS_ASSERTION(mEndOffset<=(PRInt32)count, "bad end offset");
    if (gNoisy)
    {
      printf ("DeleteRange: %d of %p to %d of %p\n", 
               mStartOffset, (void *)mStartParent, mEndOffset, (void *)mEndParent);
    }         
  }
#endif
  return result;

}

DeleteRangeTxn::~DeleteRangeTxn()
{
}

NS_IMETHODIMP DeleteRangeTxn::DoTransaction(void)
{
  if (gNoisy) { printf("Do Delete Range\n"); }
  if (!mStartParent || !mEndParent || !mCommonParent || !mEditor) 
    return NS_ERROR_NOT_INITIALIZED;

  nsresult result; 
  // build the child transactions

  if (mStartParent==mEndParent)
  { // the selection begins and ends in the same node
    result = CreateTxnsToDeleteBetween(mStartParent, mStartOffset, mEndOffset);
  }
  else
  { // the selection ends in a different node from where it started
    // delete the relevant content in the start node
    result = CreateTxnsToDeleteContent(mStartParent, mStartOffset, nsIEditor::eNext);
    if (NS_SUCCEEDED(result))
    {
      // delete the intervening nodes
      result = CreateTxnsToDeleteNodesBetween();
      if (NS_SUCCEEDED(result))
      {
        // delete the relevant content in the end node
        result = CreateTxnsToDeleteContent(mEndParent, mEndOffset, nsIEditor::ePrevious);
      }
    }
  }

  // if we've successfully built this aggregate transaction, then do it.
  if (NS_SUCCEEDED(result)) {
    result = EditAggregateTxn::DoTransaction();
  }

  if (NS_FAILED(result)) return result;
  
  // only set selection to deletion point if editor gives permission
  PRBool bAdjustSelection;
  mEditor->ShouldTxnSetSelection(&bAdjustSelection);
  if (bAdjustSelection)
  {
    nsCOMPtr<nsISelection> selection;
    result = mEditor->GetSelection(getter_AddRefs(selection));
    if (NS_FAILED(result)) return result;
    if (!selection) return NS_ERROR_NULL_POINTER;
    result = selection->Collapse(mStartParent, mStartOffset);
  }
  else
  {
    // do nothing - dom range gravity will adjust selection
  }

  return result;
}

NS_IMETHODIMP DeleteRangeTxn::UndoTransaction(void)
{
  if (gNoisy) { printf("Undo Delete Range\n"); }
  if (!mStartParent || !mEndParent || !mCommonParent || !mEditor) 
    return NS_ERROR_NOT_INITIALIZED;

  nsresult result = EditAggregateTxn::UndoTransaction();
  return result;
}

NS_IMETHODIMP DeleteRangeTxn::RedoTransaction(void)
{
  if (gNoisy) { printf("Redo Delete Range\n"); }
  if (!mStartParent || !mEndParent || !mCommonParent || !mEditor) 
    return NS_ERROR_NOT_INITIALIZED;

  nsresult result = EditAggregateTxn::RedoTransaction();
  return result;
}

NS_IMETHODIMP DeleteRangeTxn::Merge(nsITransaction *aTransaction, PRBool *aDidMerge)
{
  if (nsnull!=aDidMerge)
    *aDidMerge=PR_FALSE;
  return NS_OK;
}

NS_IMETHODIMP DeleteRangeTxn::GetTxnDescription(nsAWritableString& aString)
{
  aString.Assign(NS_LITERAL_STRING("DeleteRangeTxn"));
  return NS_OK;
}

NS_IMETHODIMP 
DeleteRangeTxn::CreateTxnsToDeleteBetween(nsIDOMNode *aStartParent, 
                                          PRUint32    aStartOffset, 
                                          PRUint32    aEndOffset)
{
  nsresult result;
  // see what kind of node we have
  nsCOMPtr<nsIDOMCharacterData> textNode;
  textNode =  do_QueryInterface(aStartParent);
  if (textNode)
  { // if the node is a text node, then delete text content
    DeleteTextTxn *txn;
    result = TransactionFactory::GetNewTransaction(DeleteTextTxn::GetCID(), (EditTxn **)&txn);
    if (NS_FAILED(result)) return result;
    if (!txn) return NS_ERROR_NULL_POINTER;

    PRInt32 numToDel;
    if (aStartOffset==aEndOffset)
      numToDel = 1;
    else
      numToDel = aEndOffset-aStartOffset;
    txn->Init(mEditor, textNode, aStartOffset, numToDel);
    AppendChild(txn);
    NS_RELEASE(txn);
  }
  else
  {
    PRUint32 childCount;
    nsCOMPtr<nsIDOMNodeList> children;
    result = aStartParent->GetChildNodes(getter_AddRefs(children));
    if (NS_FAILED(result)) return result;
    if (!children) return NS_ERROR_NULL_POINTER;

    children->GetLength(&childCount);
    NS_ASSERTION(aEndOffset<=childCount, "bad aEndOffset");
    PRUint32 i;
    for (i=aStartOffset; i<aEndOffset; i++)
    {
      nsCOMPtr<nsIDOMNode> child;
      result = children->Item(i, getter_AddRefs(child));
      if (NS_FAILED(result)) return result;
      if (!child) return NS_ERROR_NULL_POINTER;

      DeleteElementTxn *txn;
      result = TransactionFactory::GetNewTransaction(DeleteElementTxn::GetCID(), (EditTxn **)&txn);
      if (NS_FAILED(result)) return result;
      if (!txn) return NS_ERROR_NULL_POINTER;

      txn->Init(child);
      AppendChild(txn);
      NS_RELEASE(txn);
    }
  }
  return result;
}

NS_IMETHODIMP DeleteRangeTxn::CreateTxnsToDeleteContent(nsIDOMNode *aParent, 
                                                        PRUint32    aOffset, 
                                                        nsIEditor::EDirection aAction)
{
  nsresult result = NS_OK;
  // see what kind of node we have
  nsCOMPtr<nsIDOMCharacterData> textNode;
  textNode = do_QueryInterface(aParent);
  if (textNode)
  { // if the node is a text node, then delete text content
    PRUint32 start, numToDelete;
    if (nsIEditor::eNext == aAction)
    {
      start=aOffset;
      textNode->GetLength(&numToDelete);
      numToDelete -= aOffset;
    }
    else
    {
      start=0;
      numToDelete=aOffset;
    }
    
    if (numToDelete)
    {
      DeleteTextTxn *txn;
      result = TransactionFactory::GetNewTransaction(DeleteTextTxn::GetCID(), (EditTxn **)&txn);
      if (NS_FAILED(result)) return result;
      if (!txn) return NS_ERROR_NULL_POINTER;

      txn->Init(mEditor, textNode, start, numToDelete);
      AppendChild(txn);
      NS_RELEASE(txn);
    }
  }

  return result;
}

static NS_DEFINE_IID(kSubtreeIteratorCID, NS_SUBTREEITERATOR_CID);
static NS_DEFINE_IID(kRangeCID, NS_RANGE_CID);

NS_IMETHODIMP DeleteRangeTxn::CreateTxnsToDeleteNodesBetween()
{
  nsresult result;

  nsCOMPtr<nsIContentIterator> iter;
  
  result = nsComponentManager::CreateInstance(kSubtreeIteratorCID,
                                        nsnull,
                                        NS_GET_IID(nsIContentIterator), 
                                        getter_AddRefs(iter));
  if (NS_FAILED(result)) return result;
  if (!iter) return NS_ERROR_NULL_POINTER;

  result = iter->Init(mRange);
  if (NS_FAILED(result)) return result;
    
  while (NS_ENUMERATOR_FALSE == iter->IsDone())
  {
    nsCOMPtr<nsIDOMNode> node;
    nsCOMPtr<nsIContent> content;
    result = iter->CurrentNode(getter_AddRefs(content));
    node = do_QueryInterface(content);
    if (NS_FAILED(result)) return result;
    if (!node) return NS_ERROR_NULL_POINTER;

    DeleteElementTxn *txn;
    result = TransactionFactory::GetNewTransaction(DeleteElementTxn::GetCID(), (EditTxn **)&txn);
    if (NS_FAILED(result)) return result;
    if (!txn) return NS_ERROR_NULL_POINTER;

    txn->Init(node);
    AppendChild(txn);
    NS_RELEASE(txn);
    iter->Next();
  }
  return result;
}