/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/ChangeStyleTransaction.h"

#include "mozilla/dom/Element.h"        // for Element

#include "nsAString.h"                  // for nsAString::Append, etc.

#include "nsCRT.h"                      // for nsCRT::IsAsciiSpace

#include "nsDebug.h"                    // for NS_ENSURE_SUCCESS, etc.

#include "nsError.h"                    // for NS_ERROR_NULL_POINTER, etc.

#include "nsGkAtoms.h"                  // for nsGkAtoms, etc.

#include "nsICSSDeclaration.h"          // for nsICSSDeclaration.

#include "nsLiteralString.h"            // for NS_LITERAL_STRING, etc.

#include "nsReadableUtils.h"            // for ToNewUnicode

#include "nsString.h"                   // for nsAutoString, nsString, etc.

#include "nsStyledElement.h"            // for nsStyledElement.

#include "nsUnicharUtils.h"             // for nsCaseInsensitiveStringComparator

namespace mozilla {

using namespace dom;

// static

already_AddRefed<ChangeStyleTransaction>

ChangeStyleTransaction::Create(Element& aElement,

                               nsAtom& aProperty,

                               const nsAString& aValue)

{

  RefPtr<ChangeStyleTransaction> transaction =

    new ChangeStyleTransaction(aElement, aProperty, aValue, false);

  return transaction.forget();

}

// static

already_AddRefed<ChangeStyleTransaction>

ChangeStyleTransaction::CreateToRemove(Element& aElement,

                                       nsAtom& aProperty,

                                       const nsAString& aValue)

{

  RefPtr<ChangeStyleTransaction> transaction =

    new ChangeStyleTransaction(aElement, aProperty, aValue, true);

  return transaction.forget();

}

ChangeStyleTransaction::ChangeStyleTransaction(Element& aElement,

                                               nsAtom& aProperty,

                                               const nsAString& aValue,

                                               bool aRemove)

  : EditTransactionBase()

  , mElement(&aElement)

  , mProperty(&aProperty)

  , mValue(aValue)

  , mRemoveProperty(aRemove)

  , mUndoValue()

  , mRedoValue()

  , mUndoAttributeWasSet(false)

  , mRedoAttributeWasSet(false)

{

}

#define kNullCh (char16_t('\0'))

NS_IMPL_CYCLE_COLLECTION_INHERITED(ChangeStyleTransaction, EditTransactionBase,

                                   mElement)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ChangeStyleTransaction)

NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)

NS_IMPL_ADDREF_INHERITED(ChangeStyleTransaction, EditTransactionBase)

NS_IMPL_RELEASE_INHERITED(ChangeStyleTransaction, EditTransactionBase)

ChangeStyleTransaction::~ChangeStyleTransaction()

{

}

// Answers true if aValue is in the string list of white-space separated values

// aValueList.

bool

ChangeStyleTransaction::ValueIncludes(const nsAString& aValueList,

                                      const nsAString& aValue)

{

  nsAutoString valueList(aValueList);

  bool result = false;

  // put an extra null at the end

  valueList.Append(kNullCh);

  char16_t* value = ToNewUnicode(aValue);

  char16_t* start = valueList.BeginWriting();

  char16_t* end = start;

  while (kNullCh != *start) {

    while (kNullCh != *start && nsCRT::IsAsciiSpace(*start)) {

      // skip leading space

      start++;

    }

    end = start;

    while (kNullCh != *end && !nsCRT::IsAsciiSpace(*end)) {

      // look for space or end

      end++;

    }

    // end string here

    *end = kNullCh;

    if (start < end) {

      if (nsDependentString(value).Equals(nsDependentString(start),

            nsCaseInsensitiveStringComparator())) {

        result = true;

        break;

      }

    }

    start = ++end;

  }

  free(value);

  return result;

}

// Removes the value aRemoveValue from the string list of white-space separated

// values aValueList

void

ChangeStyleTransaction::RemoveValueFromListOfValues(

                          nsAString& aValues,

                          const nsAString& aRemoveValue)

{

  nsAutoString classStr(aValues);

  nsAutoString outString;

  // put an extra null at the end

  classStr.Append(kNullCh);

  char16_t* start = classStr.BeginWriting();

  char16_t* end = start;

  while (kNullCh != *start) {

    while (kNullCh != *start && nsCRT::IsAsciiSpace(*start)) {

      // skip leading space

      start++;

    }

    end = start;

    while (kNullCh != *end && !nsCRT::IsAsciiSpace(*end)) {

      // look for space or end

      end++;

    }

    // end string here

    *end = kNullCh;

    if (start < end && !aRemoveValue.Equals(start)) {

      outString.Append(start);

      outString.Append(char16_t(' '));

    }

    start = ++end;

  }

  aValues.Assign(outString);

}

NS_IMETHODIMP

ChangeStyleTransaction::DoTransaction()

{

  nsCOMPtr<nsStyledElement> inlineStyles = do_QueryInterface(mElement);

  NS_ENSURE_TRUE(inlineStyles, NS_ERROR_NULL_POINTER);

  nsCOMPtr<nsICSSDeclaration> cssDecl = inlineStyles->Style();

  nsAutoString propertyNameString;

  mProperty->ToString(propertyNameString);

  mUndoAttributeWasSet = mElement->HasAttr(kNameSpaceID_None,

                                           nsGkAtoms::style);

  nsAutoString values;

  nsresult rv = cssDecl->GetPropertyValue(propertyNameString, values);

  NS_ENSURE_SUCCESS(rv, rv);

  mUndoValue.Assign(values);

  // Does this property accept more than one value? (bug 62682)

  bool multiple = AcceptsMoreThanOneValue(*mProperty);

  if (mRemoveProperty) {

    nsAutoString returnString;

    if (multiple) {

      // Let's remove only the value we have to remove and not the others

      RemoveValueFromListOfValues(values, NS_LITERAL_STRING("none"));

      RemoveValueFromListOfValues(values, mValue);

      if (values.IsEmpty()) {

        rv = cssDecl->RemoveProperty(propertyNameString, returnString);

        NS_ENSURE_SUCCESS(rv, rv);

      } else {

        nsAutoString priority;

        cssDecl->GetPropertyPriority(propertyNameString, priority);

        rv = cssDecl->SetProperty(propertyNameString, values, priority);

        NS_ENSURE_SUCCESS(rv, rv);

      }

    } else {

      rv = cssDecl->RemoveProperty(propertyNameString, returnString);

      NS_ENSURE_SUCCESS(rv, rv);

    }

  } else {

    nsAutoString priority;

    cssDecl->GetPropertyPriority(propertyNameString, priority);

    if (multiple) {

      // Let's add the value we have to add to the others

      AddValueToMultivalueProperty(values, mValue);

    } else {

      values.Assign(mValue);

    }

    rv = cssDecl->SetProperty(propertyNameString, values, priority);

    NS_ENSURE_SUCCESS(rv, rv);

  }

  // Let's be sure we don't keep an empty style attribute

  uint32_t length = cssDecl->Length();

  if (!length) {

    rv = mElement->UnsetAttr(kNameSpaceID_None, nsGkAtoms::style, true);

    NS_ENSURE_SUCCESS(rv, rv);

  } else {

    mRedoAttributeWasSet = true;

  }

  return cssDecl->GetPropertyValue(propertyNameString, mRedoValue);

}

nsresult

ChangeStyleTransaction::SetStyle(bool aAttributeWasSet,

                                 nsAString& aValue)

{

  if (aAttributeWasSet) {

    // The style attribute was not empty, let's recreate the declaration

    nsAutoString propertyNameString;

    mProperty->ToString(propertyNameString);

    nsCOMPtr<nsStyledElement> inlineStyles = do_QueryInterface(mElement);

    NS_ENSURE_TRUE(inlineStyles, NS_ERROR_NULL_POINTER);

    nsCOMPtr<nsICSSDeclaration> cssDecl = inlineStyles->Style();

    if (aValue.IsEmpty()) {

      // An empty value means we have to remove the property

      nsAutoString returnString;

      return cssDecl->RemoveProperty(propertyNameString, returnString);

    }

    // Let's recreate the declaration as it was

    nsAutoString priority;

    cssDecl->GetPropertyPriority(propertyNameString, priority);

    return cssDecl->SetProperty(propertyNameString, aValue, priority);

  }

  return mElement->UnsetAttr(kNameSpaceID_None, nsGkAtoms::style, true);

}

NS_IMETHODIMP

ChangeStyleTransaction::UndoTransaction()

{

  return SetStyle(mUndoAttributeWasSet, mUndoValue);

}

NS_IMETHODIMP

ChangeStyleTransaction::RedoTransaction()

{

  return SetStyle(mRedoAttributeWasSet, mRedoValue);

}

// True if the CSS property accepts more than one value

bool

ChangeStyleTransaction::AcceptsMoreThanOneValue(nsAtom& aCSSProperty)

{

  return &aCSSProperty == nsGkAtoms::text_decoration;

}

// Adds the value aNewValue to the list of white-space separated values aValues

void

ChangeStyleTransaction::AddValueToMultivalueProperty(nsAString& aValues,

                                                     const nsAString& aNewValue)

{

  if (aValues.IsEmpty() || aValues.LowerCaseEqualsLiteral("none")) {

    aValues.Assign(aNewValue);

  } else if (!ValueIncludes(aValues, aNewValue)) {

    // We already have another value but not this one; add it

    aValues.Append(char16_t(' '));

    aValues.Append(aNewValue);

  }

}

} // namespace mozilla