/* -*- 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 txKey_h__
#define txKey_h__

#include "nsTHashtable.h"
#include "txNodeSet.h"
#include "txList.h"
#include "txXSLTPatterns.h"
#include "txXMLUtils.h"

class txPattern;
class Expr;
class txExecutionState;

class txKeyValueHashKey
{
public:
    txKeyValueHashKey(const txExpandedName& aKeyName,
                      int32_t aRootIdentifier,
                      const nsAString& aKeyValue)
        : mKeyName(aKeyName),
          mKeyValue(aKeyValue),
          mRootIdentifier(aRootIdentifier)
    {
    }

    txExpandedName mKeyName;
    nsString mKeyValue;
    int32_t mRootIdentifier;
};

struct txKeyValueHashEntry : public PLDHashEntryHdr
{
public:
    typedef const txKeyValueHashKey& KeyType;
    typedef const txKeyValueHashKey* KeyTypePointer;

    explicit txKeyValueHashEntry(KeyTypePointer aKey)
        : mKey(*aKey),
          mNodeSet(new txNodeSet(nullptr)) { }

    txKeyValueHashEntry(const txKeyValueHashEntry& entry)
        : mKey(entry.mKey),
          mNodeSet(entry.mNodeSet) { }

    bool KeyEquals(KeyTypePointer aKey) const;

    static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }

    static PLDHashNumber HashKey(KeyTypePointer aKey);

    enum { ALLOW_MEMMOVE = true };
    
    txKeyValueHashKey mKey;
    nsRefPtr<txNodeSet> mNodeSet;
};

typedef nsTHashtable<txKeyValueHashEntry> txKeyValueHash;

class txIndexedKeyHashKey
{
public:
    txIndexedKeyHashKey(txExpandedName aKeyName,
                        int32_t aRootIdentifier)
        : mKeyName(aKeyName),
          mRootIdentifier(aRootIdentifier)
    {
    }

    txExpandedName mKeyName;
    int32_t mRootIdentifier;
};

struct txIndexedKeyHashEntry : public PLDHashEntryHdr
{
public:
    typedef const txIndexedKeyHashKey& KeyType;
    typedef const txIndexedKeyHashKey* KeyTypePointer;

    explicit txIndexedKeyHashEntry(KeyTypePointer aKey)
        : mKey(*aKey),
          mIndexed(false) { }

    txIndexedKeyHashEntry(const txIndexedKeyHashEntry& entry)
        : mKey(entry.mKey),
          mIndexed(entry.mIndexed) { }

    bool KeyEquals(KeyTypePointer aKey) const;

    static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }

    static PLDHashNumber HashKey(KeyTypePointer aKey);

    enum { ALLOW_MEMMOVE = true };

    txIndexedKeyHashKey mKey;
    bool mIndexed;
};

typedef nsTHashtable<txIndexedKeyHashEntry> txIndexedKeyHash;

/**
 * Class holding all <xsl:key>s of a particular expanded name in the
 * stylesheet.
 */
class txXSLKey {
    
public:
    explicit txXSLKey(const txExpandedName& aName) : mName(aName)
    {
    }
    
    /**
     * Adds a match/use pair.
     * @param aMatch  match-pattern
     * @param aUse    use-expression
     * @return false if an error occurred, true otherwise
     */
    bool addKey(nsAutoPtr<txPattern>&& aMatch, nsAutoPtr<Expr>&& aUse);

    /**
     * Indexes a subtree and adds it to the hash of key values
     * @param aRoot         Subtree root to index and add
     * @param aKeyValueHash Hash to add values to
     * @param aEs           txExecutionState to use for XPath evaluation
     */
    nsresult indexSubtreeRoot(const txXPathNode& aRoot,
                              txKeyValueHash& aKeyValueHash,
                              txExecutionState& aEs);

private:
    /**
     * Recursively searches a node, its attributes and its subtree for
     * nodes matching any of the keys match-patterns.
     * @param aNode         Node to search
     * @param aKey          Key to use when adding into the hash
     * @param aKeyValueHash Hash to add values to
     * @param aEs           txExecutionState to use for XPath evaluation
     */
    nsresult indexTree(const txXPathNode& aNode, txKeyValueHashKey& aKey,
                       txKeyValueHash& aKeyValueHash, txExecutionState& aEs);

    /**
     * Tests one node if it matches any of the keys match-patterns. If
     * the node matches its values are added to the index.
     * @param aNode         Node to test
     * @param aKey          Key to use when adding into the hash
     * @param aKeyValueHash Hash to add values to
     * @param aEs           txExecutionState to use for XPath evaluation
     */
    nsresult testNode(const txXPathNode& aNode, txKeyValueHashKey& aKey,
                      txKeyValueHash& aKeyValueHash, txExecutionState& aEs);

    /**
     * represents one match/use pair
     */
    struct Key {
        nsAutoPtr<txPattern> matchPattern;
        nsAutoPtr<Expr> useExpr;
    };

    /**
     * List of all match/use pairs. The items as |Key|s
     */
    nsTArray<Key> mKeys;
    
    /**
     * Name of this key
     */
    txExpandedName mName;
};


class txKeyHash
{
public:
    explicit txKeyHash(const txOwningExpandedNameMap<txXSLKey>& aKeys)
        : mKeyValues(4)
        , mIndexedKeys(1)
        , mKeys(aKeys)
    {
    }
    
    nsresult init();

    nsresult getKeyNodes(const txExpandedName& aKeyName,
                         const txXPathNode& aRoot,
                         const nsAString& aKeyValue,
                         bool aIndexIfNotFound,
                         txExecutionState& aEs,
                         txNodeSet** aResult);

private:
    // Hash of all indexed key-values
    txKeyValueHash mKeyValues;

    // Hash showing which keys+roots has been indexed
    txIndexedKeyHash mIndexedKeys;
    
    // Map of txXSLKeys
    const txOwningExpandedNameMap<txXSLKey>& mKeys;
    
    // Empty nodeset returned if no key is found
    nsRefPtr<txNodeSet> mEmptyNodeSet;
};


#endif //txKey_h__