/*
 * Copyright (C) 2010 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "core/dom/DatasetDOMStringMap.h"

#include "bindings/core/v8/ExceptionState.h"
#include "core/dom/Attribute.h"
#include "core/dom/Element.h"
#include "core/dom/ExceptionCode.h"
#include "wtf/ASCIICType.h"
#include "wtf/text/StringBuilder.h"

namespace blink {

static bool isValidAttributeName(const String& name) {
  if (!name.startsWith("data-"))
    return false;

  unsigned length = name.length();
  for (unsigned i = 5; i < length; ++i) {
    if (isASCIIUpper(name[i]))
      return false;
  }

  return true;
}

static String convertAttributeNameToPropertyName(const String& name) {
  StringBuilder stringBuilder;

  unsigned length = name.length();
  for (unsigned i = 5; i < length; ++i) {
    UChar character = name[i];
    if (character != '-') {
      stringBuilder.append(character);
    } else {
      if ((i + 1 < length) && isASCIILower(name[i + 1])) {
        stringBuilder.append(toASCIIUpper(name[i + 1]));
        ++i;
      } else {
        stringBuilder.append(character);
      }
    }
  }

  return stringBuilder.toString();
}

template <typename CharType1, typename CharType2>
static bool propertyNameMatchesAttributeName(const CharType1* propertyName,
                                             const CharType2* attributeName,
                                             unsigned propertyLength,
                                             unsigned attributeLength) {
  unsigned a = 5;
  unsigned p = 0;
  bool wordBoundary = false;
  while (a < attributeLength && p < propertyLength) {
    if (attributeName[a] == '-' && a + 1 < attributeLength &&
        isASCIILower(attributeName[a + 1])) {
      wordBoundary = true;
    } else {
      if ((wordBoundary ? toASCIIUpper(attributeName[a]) : attributeName[a]) !=
          propertyName[p])
        return false;
      p++;
      wordBoundary = false;
    }
    a++;
  }

  return (a == attributeLength && p == propertyLength);
}

static bool propertyNameMatchesAttributeName(const String& propertyName,
                                             const String& attributeName) {
  if (!attributeName.startsWith("data-"))
    return false;

  unsigned propertyLength = propertyName.length();
  unsigned attributeLength = attributeName.length();

  if (propertyName.is8Bit()) {
    if (attributeName.is8Bit())
      return propertyNameMatchesAttributeName(propertyName.characters8(),
                                              attributeName.characters8(),
                                              propertyLength, attributeLength);
    return propertyNameMatchesAttributeName(propertyName.characters8(),
                                            attributeName.characters16(),
                                            propertyLength, attributeLength);
  }

  if (attributeName.is8Bit())
    return propertyNameMatchesAttributeName(propertyName.characters16(),
                                            attributeName.characters8(),
                                            propertyLength, attributeLength);
  return propertyNameMatchesAttributeName(propertyName.characters16(),
                                          attributeName.characters16(),
                                          propertyLength, attributeLength);
}

static bool isValidPropertyName(const String& name) {
  unsigned length = name.length();
  for (unsigned i = 0; i < length; ++i) {
    if (name[i] == '-' && (i + 1 < length) && isASCIILower(name[i + 1]))
      return false;
  }
  return true;
}

// This returns an AtomicString because attribute names are always stored
// as AtomicString types in Element (see setAttribute()).
static AtomicString convertPropertyNameToAttributeName(const String& name) {
  StringBuilder builder;
  builder.append("data-");

  unsigned length = name.length();
  for (unsigned i = 0; i < length; ++i) {
    UChar character = name[i];
    if (isASCIIUpper(character)) {
      builder.append('-');
      builder.append(toASCIILower(character));
    } else {
      builder.append(character);
    }
  }

  return builder.toAtomicString();
}

void DatasetDOMStringMap::getNames(Vector<String>& names) {
  AttributeCollection attributes = m_element->attributes();
  for (const Attribute& attr : attributes) {
    if (isValidAttributeName(attr.localName()))
      names.push_back(convertAttributeNameToPropertyName(attr.localName()));
  }
}

String DatasetDOMStringMap::item(const String& name) {
  AttributeCollection attributes = m_element->attributes();
  for (const Attribute& attr : attributes) {
    if (propertyNameMatchesAttributeName(name, attr.localName()))
      return attr.value();
  }

  return String();
}

bool DatasetDOMStringMap::contains(const String& name) {
  AttributeCollection attributes = m_element->attributes();
  for (const Attribute& attr : attributes) {
    if (propertyNameMatchesAttributeName(name, attr.localName()))
      return true;
  }
  return false;
}

void DatasetDOMStringMap::setItem(const String& name,
                                  const String& value,
                                  ExceptionState& exceptionState) {
  if (!isValidPropertyName(name)) {
    exceptionState.throwDOMException(
        SyntaxError, "'" + name + "' is not a valid property name.");
    return;
  }

  m_element->setAttribute(convertPropertyNameToAttributeName(name),
                          AtomicString(value), exceptionState);
}

bool DatasetDOMStringMap::deleteItem(const String& name) {
  if (isValidPropertyName(name)) {
    AtomicString attributeName = convertPropertyNameToAttributeName(name);
    if (m_element->hasAttribute(attributeName)) {
      m_element->removeAttribute(attributeName);
      return true;
    }
  }
  return false;
}

DEFINE_TRACE(DatasetDOMStringMap) {
  visitor->trace(m_element);
  DOMStringMap::trace(visitor);
}

}  // namespace blink