text: /*
   * Copyright (C) 2005 Frerich Raabe <raabe@kde.org>
   * Copyright (C) 2006, 2009 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 THE AUTHOR ``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 THE AUTHOR 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/xml/XPathResult.h"
  
  #include "bindings/core/v8/ExceptionState.h"
  #include "core/dom/Document.h"
  #include "core/dom/ExceptionCode.h"
  #include "core/xml/XPathEvaluator.h"
  #include "core/xml/XPathExpressionNode.h"
  
  namespace blink {
  
  using namespace XPath;
  
  XPathResult::XPathResult(EvaluationContext& context, const Value& value)
      : value_(value), node_set_position_(0), dom_tree_version_(0) {
    switch (value_.GetType()) {
      case Value::kBooleanValue:
        result_type_ = kBooleanType;
        return;
      case Value::kNumberValue:
        result_type_ = kNumberType;
        return;
      case Value::kStringValue:
        result_type_ = kStringType;
        return;
      case Value::kNodeSetValue:
        result_type_ = kUnorderedNodeIteratorType;
        node_set_position_ = 0;
        node_set_ = NodeSet::Create(value_.ToNodeSet(&context));
        document_ = &context.node->GetDocument();
        dom_tree_version_ = document_->DomTreeVersion();
        return;
    }
    NOTREACHED();
  }
  
  DEFINE_TRACE(XPathResult) {
    visitor->Trace(value_);
    visitor->Trace(node_set_);
    visitor->Trace(document_);
  }
  
  void XPathResult::ConvertTo(unsigned short type,
                              ExceptionState& exception_state) {
    switch (type) {
      case kAnyType:
        break;
      case kNumberType:
        result_type_ = type;
        value_ = value_.ToNumber();
        break;
      case kStringType:
        result_type_ = type;
        value_ = value_.ToString();
        break;
      case kBooleanType:
        result_type_ = type;
        value_ = value_.ToBoolean();
        break;
      case kUnorderedNodeIteratorType:
      case kUnorderedNodeSnapshotType:
      case kAnyUnorderedNodeType:
      // This is correct - singleNodeValue() will take care of ordering.
      case kFirstOrderedNodeType:
        if (!value_.IsNodeSet()) {
          exception_state.ThrowTypeError(
              "The result is not a node set, and therefore cannot be converted "
              "to the desired type.");
          return;
        }
        result_type_ = type;
        break;
      case kOrderedNodeIteratorType:
        if (!value_.IsNodeSet()) {
          exception_state.ThrowTypeError(
              "The result is not a node set, and therefore cannot be converted "
              "to the desired type.");
          return;
        }
        GetNodeSet().Sort();
        result_type_ = type;
        break;
      case kOrderedNodeSnapshotType:
        if (!value_.IsNodeSet()) {
          exception_state.ThrowTypeError(
              "The result is not a node set, and therefore cannot be converted "
              "to the desired type.");
          return;
        }
        value_.ToNodeSet(0).Sort();
        result_type_ = type;
        break;
    }
  }
  
  unsigned short XPathResult::resultType() const {
    return result_type_;
  }
  
  double XPathResult::numberValue(ExceptionState& exception_state) const {
    if (resultType() != kNumberType) {
      exception_state.ThrowTypeError("The result type is not a number.");
      return 0.0;
    }
    return value_.ToNumber();
  }
  
  String XPathResult::stringValue(ExceptionState& exception_state) const {
    if (resultType() != kStringType) {
      exception_state.ThrowTypeError("The result type is not a string.");
      return String();
    }
    return value_.ToString();
  }
  
  bool XPathResult::booleanValue(ExceptionState& exception_state) const {
    if (resultType() != kBooleanType) {
      exception_state.ThrowTypeError("The result type is not a boolean.");
      return false;
    }
    return value_.ToBoolean();
  }
  
  Node* XPathResult::singleNodeValue(ExceptionState& exception_state) const {
    if (resultType() != kAnyUnorderedNodeType &&
        resultType() != kFirstOrderedNodeType) {
      exception_state.ThrowTypeError("The result type is not a single node.");
      return nullptr;
    }
  
    const NodeSet& nodes = value_.ToNodeSet(0);
    if (resultType() == kFirstOrderedNodeType)
      return nodes.FirstNode();
    return nodes.AnyNode();
  }
  
  bool XPathResult::invalidIteratorState() const {
    if (resultType() != kUnorderedNodeIteratorType &&
        resultType() != kOrderedNodeIteratorType)
      return false;
  
    DCHECK(document_);
    return document_->DomTreeVersion() != dom_tree_version_;
  }
  
  unsigned XPathResult::snapshotLength(ExceptionState& exception_state) const {
    if (resultType() != kUnorderedNodeSnapshotType &&
        resultType() != kOrderedNodeSnapshotType) {
      exception_state.ThrowTypeError("The result type is not a snapshot.");
      return 0;
    }
  
    return value_.ToNodeSet(0).size();
  }
  
  Node* XPathResult::iterateNext(ExceptionState& exception_state) {
    if (resultType() != kUnorderedNodeIteratorType &&
        resultType() != kOrderedNodeIteratorType) {
      exception_state.ThrowTypeError("The result type is not an iterator.");
      return nullptr;
    }
  
    if (invalidIteratorState()) {
      exception_state.ThrowDOMException(
          kInvalidStateError,
          "The document has mutated since the result was returned.");
      return nullptr;
    }
  
    if (node_set_position_ + 1 > GetNodeSet().size())
      return nullptr;
  
    Node* node = GetNodeSet()[node_set_position_];
  
    node_set_position_++;
  
    return node;
  }
  
  Node* XPathResult::snapshotItem(unsigned index,
                                  ExceptionState& exception_state) {
    if (resultType() != kUnorderedNodeSnapshotType &&
        resultType() != kOrderedNodeSnapshotType) {
      exception_state.ThrowTypeError("The result type is not a snapshot.");
      return nullptr;
    }
  
    const NodeSet& nodes = value_.ToNodeSet(0);
    if (index >= nodes.size())
      return nullptr;
  
    return nodes[index];
  }
  
  }  // namespace blink
  