/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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/. */

#ifndef mozilla_dom_XPathResult_h
#define mozilla_dom_XPathResult_h

#include "nsStubMutationObserver.h"
#include "nsAutoPtr.h"
#include "nsCOMPtr.h"
#include "nsCOMArray.h"
#include "nsWeakPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "mozilla/Attributes.h"
#include "mozilla/ErrorResult.h"
#include "nsString.h"
#include "nsWrapperCache.h"
#include "nsINode.h"

class nsIDocument;
class txAExprResult;

// {662f2c9a-c7cd-4cab-9349-e733df5a838c}
#define NS_IXPATHRESULT_IID \
{ 0x662f2c9a, 0xc7cd, 0x4cab, {0x93, 0x49, 0xe7, 0x33, 0xdf, 0x5a, 0x83, 0x8c }}

class nsIXPathResult : public nsISupports
{
public:
    NS_DECLARE_STATIC_IID_ACCESSOR(NS_IXPATHRESULT_IID)
    virtual nsresult SetExprResult(txAExprResult *aExprResult,
                                   uint16_t aResultType,
                                   nsINode* aContextNode) = 0;
    virtual nsresult GetExprResult(txAExprResult **aExprResult) = 0;
    virtual nsresult Clone(nsIXPathResult **aResult) = 0;
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsIXPathResult, NS_IXPATHRESULT_IID)

namespace mozilla {
namespace dom {

/**
 * A class for evaluating an XPath expression string
 */
class XPathResult final : public nsIXPathResult,
                              public nsStubMutationObserver,
                              public nsWrapperCache
{
    ~XPathResult();

public:
    explicit XPathResult(nsINode* aParent);
    XPathResult(const XPathResult &aResult);

    enum {
        ANY_TYPE = 0U,
        NUMBER_TYPE = 1U,
        STRING_TYPE = 2U,
        BOOLEAN_TYPE = 3U,
        UNORDERED_NODE_ITERATOR_TYPE = 4U,
        ORDERED_NODE_ITERATOR_TYPE = 5U,
        UNORDERED_NODE_SNAPSHOT_TYPE = 6U,
        ORDERED_NODE_SNAPSHOT_TYPE = 7U,
        ANY_UNORDERED_NODE_TYPE = 8U,
        FIRST_ORDERED_NODE_TYPE = 9U
    };

    // nsISupports interface
    NS_DECL_CYCLE_COLLECTING_ISUPPORTS
    NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(XPathResult,
                                                           nsIXPathResult)

    static XPathResult* FromSupports(nsISupports* aSupports)
    {
        return static_cast<XPathResult*>(static_cast<nsIXPathResult*>(aSupports));
    }

    virtual JSObject* WrapObject(JSContext* aCx) override;
    nsINode* GetParentObject() const
    {
        return mParent;
    }
    uint16_t ResultType() const
    {
        return mResultType;
    }
    double GetNumberValue(ErrorResult& aRv) const
    {
        if (mResultType != NUMBER_TYPE) {
            aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
            return 0;
        }

        return mNumberResult;
    }
    void GetStringValue(nsAString &aStringValue, ErrorResult& aRv) const
    {
        if (mResultType != STRING_TYPE) {
            aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
            return;
        }

        aStringValue = mStringResult;
    }
    bool GetBooleanValue(ErrorResult& aRv) const
    {
        if (mResultType != BOOLEAN_TYPE) {
            aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
            return false;
        }

        return mBooleanResult;
    }
    nsINode* GetSingleNodeValue(ErrorResult& aRv) const
    {
        if (!isNode()) {
            aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
            return nullptr;
       }

        return mResultNodes.SafeObjectAt(0);
    }
    bool InvalidIteratorState() const
    {
        return isIterator() && mInvalidIteratorState;
    }
    uint32_t GetSnapshotLength(ErrorResult& aRv) const
    {
        if (!isSnapshot()) {
            aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
            return 0;
        }

        return (uint32_t)mResultNodes.Count();
    }
    nsINode* IterateNext(ErrorResult& aRv);
    nsINode* SnapshotItem(uint32_t aIndex, ErrorResult& aRv) const
    {
        if (!isSnapshot()) {
            aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
            return nullptr;
        }

        return mResultNodes.SafeObjectAt(aIndex);
    }

    // nsIMutationObserver interface
    NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATACHANGED
    NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
    NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
    NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
    NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
    NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED

    nsresult SetExprResult(txAExprResult *aExprResult, uint16_t aResultType,
                           nsINode* aContextNode) override;
    nsresult GetExprResult(txAExprResult **aExprResult) override;
    nsresult Clone(nsIXPathResult **aResult) override;
    void RemoveObserver();
private:
    static bool isSnapshot(uint16_t aResultType)
    {
        return aResultType == UNORDERED_NODE_SNAPSHOT_TYPE ||
               aResultType == ORDERED_NODE_SNAPSHOT_TYPE;
    }
    static bool isIterator(uint16_t aResultType)
    {
        return aResultType == UNORDERED_NODE_ITERATOR_TYPE ||
               aResultType == ORDERED_NODE_ITERATOR_TYPE;
    }
    static bool isNode(uint16_t aResultType)
    {
        return aResultType == FIRST_ORDERED_NODE_TYPE ||
               aResultType == ANY_UNORDERED_NODE_TYPE;
    }
    bool isSnapshot() const
    {
        return isSnapshot(mResultType);
    }
    bool isIterator() const
    {
        return isIterator(mResultType);
    }
    bool isNode() const
    {
        return isNode(mResultType);
    }

    void Invalidate(const nsIContent* aChangeRoot);

    nsCOMPtr<nsINode> mParent;
    nsRefPtr<txAExprResult> mResult;
    nsCOMArray<nsINode> mResultNodes;
    nsCOMPtr<nsIDocument> mDocument;
    nsWeakPtr mContextNode;
    uint32_t mCurrentPos;
    uint16_t mResultType;
    bool mInvalidIteratorState;
    bool mBooleanResult;
    double mNumberResult;
    nsString mStringResult;
};

} // namespace dom
} // namespace mozilla

#endif /* mozilla_dom_XPathResult_h */
