/**
 *******************************************************************************
 * Copyright (C) 2006, International Business Machines Corporation and others. *
 * All Rights Reserved.                                                        *
 *******************************************************************************
 */

#ifndef TRIEDICT_H
#define TRIEDICT_H

#include "unicode/utypes.h"
#include "unicode/uobject.h"
#include "unicode/utext.h"

struct UEnumeration;
struct UDataSwapper;
struct UDataMemory;

/**
 * <p>UDataSwapFn function for use in swapping a compact dictionary.</p>
 *
 * @param ds Pointer to UDataSwapper containing global data about the
 *           transformation and function pointers for handling primitive
 *           types.
 * @param inData Pointer to the input data to be transformed or examined.
 * @param length Length of the data, counting bytes. May be -1 for preflighting.
 *               If length>=0, then transform the data.
 *               If length==-1, then only determine the length of the data.
 *               The length cannot be determined from the data itself for all
 *               types of data (e.g., not for simple arrays of integers).
 * @param outData Pointer to the output data buffer.
 *                If length>=0 (transformation), then the output buffer must
 *                have a capacity of at least length.
 *                If length==-1, then outData will not be used and can be NULL.
 * @param pErrorCode ICU UErrorCode parameter, must not be NULL and must
 *                   fulfill U_SUCCESS on input.
 * @return The actual length of the data.
 *
 * @see UDataSwapper
 */

U_CAPI int32_t U_EXPORT2
triedict_swap(const UDataSwapper *ds,
        const void *inData, int32_t length, void *outData,
        UErrorCode *pErrorCode);

U_NAMESPACE_BEGIN

class StringEnumeration;

/*******************************************************************
 * TrieWordDictionary
 */

/**
 * <p>TrieWordDictionary is an abstract class that represents a word
 * dictionary based on a trie. The base protocol is read-only.
 * Subclasses may allow writing.</p>
 */
class U_COMMON_API TrieWordDictionary : public UMemory {
public:

    /**
     * <p>Default constructor.</p>
     *
     */
    TrieWordDictionary();

    /**
     * <p>Virtual destructor.</p>
     */
    virtual ~TrieWordDictionary();

    /**
     * <p>Returns true if the dictionary contains values associated with each word.</p>
     */
    virtual UBool getValued() const = 0;

    /**
     * <p>Find dictionary words that match the text.</p>
     *
     * @param text A UText representing the text. The
     * iterator is left after the longest prefix match in the dictionary.
     * @param maxLength The maximum number of code units to match.
     * @param lengths An array that is filled with the lengths of words that matched.
     * @param count Filled with the number of elements output in lengths.
     * @param limit The size of the lengths array; this limits the number of words output.
     * @param values An array that is filled with the values associated with the matched words.
     * @return The number of characters in text that were matched.
     */
    virtual int32_t matches( UText *text,
            int32_t maxLength,
            int32_t *lengths,
            int &count,
            int limit,
            uint16_t *values = NULL) const = 0;

    /**
     * <p>Return a StringEnumeration for iterating all the words in the dictionary.</p>
     *
     * @param status A status code recording the success of the call.
     * @return A StringEnumeration that will iterate through the whole dictionary.
     * The caller is responsible for closing it. The order is unspecified.
     */
    virtual StringEnumeration *openWords( UErrorCode &status ) const = 0;

};

/*******************************************************************
 * MutableTrieDictionary
 */

/**
 * <p>MutableTrieDictionary is a TrieWordDictionary that allows words to be
 * added.</p>
 */

struct TernaryNode;             // Forwards declaration

class U_COMMON_API MutableTrieDictionary : public TrieWordDictionary {
private:
    /**
     * The root node of the trie
     * @internal
     */

    TernaryNode               *fTrie;

    /**
     * A UText for internal use
     * @internal
     */
    UText    *fIter;

    /**
     * A UText for internal use
     * @internal
     */
    UBool fValued;

    friend class CompactTrieDictionary;   // For fast conversion

public:

    /**
     * <p>Constructor.</p>
     *
     * @param median A UChar around which to balance the trie. Ideally, it should
     * begin at least one word that is near the median of the set in the dictionary
     * @param status A status code recording the success of the call.
     * @param containsValue True if the dictionary stores values associated with each word.
     */
    MutableTrieDictionary( UChar median, UErrorCode &status, UBool containsValue = FALSE );

    /**
     * <p>Virtual destructor.</p>
     */
    virtual ~MutableTrieDictionary();

    /**
     * Indicate whether the MutableTrieDictionary stores values associated with each word
     */
    void setValued(UBool valued){
        fValued = valued;
    }

    /**
     * <p>Returns true if the dictionary contains values associated with each word.</p>
     */
    virtual UBool getValued() const {
        return fValued;
    }

    /**
     * <p>Find dictionary words that match the text.</p>
     *
     * @param text A UText representing the text. The
     * iterator is left after the longest prefix match in the dictionary.
     * @param maxLength The maximum number of code units to match.
     * @param lengths An array that is filled with the lengths of words that matched.
     * @param count Filled with the number of elements output in lengths.
     * @param limit The size of the lengths array; this limits the number of words output.
     * @param values An array that is filled with the values associated with the matched words.
     * @return The number of characters in text that were matched.
     */
    virtual int32_t matches( UText *text,
            int32_t maxLength,
            int32_t *lengths,
            int &count,
            int limit,
            uint16_t *values = NULL) const;

    /**
     * <p>Return a StringEnumeration for iterating all the words in the dictionary.</p>
     *
     * @param status A status code recording the success of the call.
     * @return A StringEnumeration that will iterate through the whole dictionary.
     * The caller is responsible for closing it. The order is unspecified.
     */
    virtual StringEnumeration *openWords( UErrorCode &status ) const;

    /**
     * <p>Add one word to the dictionary with an optional associated value.</p>
     *
     * @param word A UChar buffer containing the word.
     * @param length The length of the word.
     * @param status The resultant status.
     * @param value The nonzero value associated with this word.
     */
    virtual void addWord( const UChar *word,
            int32_t length,
            UErrorCode &status,
            uint16_t value = 0);

#if 0
    /**
     * <p>Add all strings from a UEnumeration to the dictionary.</p>
     *
     * @param words A UEnumeration that will return the desired words.
     * @param status The resultant status
     */
    virtual void addWords( UEnumeration *words, UErrorCode &status );
#endif

protected:
    /**
     * <p>Search the dictionary for matches.</p>
     *
     * @param text A UText representing the text. The
     * iterator is left after the longest prefix match in the dictionary.
     * @param maxLength The maximum number of code units to match.
     * @param lengths An array that is filled with the lengths of words that matched.
     * @param count Filled with the number of elements output in lengths.
     * @param limit The size of the lengths array; this limits the number of words output.
     * @param parent The parent of the current node.
     * @param pMatched The returned parent node matched the input/
     * @param values An array that is filled with the values associated with the matched words.
     * @return The number of characters in text that were matched.
     */
    virtual int32_t search( UText *text,
            int32_t maxLength,
            int32_t *lengths,
            int &count,
            int limit,
            TernaryNode *&parent,
            UBool &pMatched,
            uint16_t *values = NULL) const;

private:
    /**
     * <p>Private constructor. The root node it not allocated.</p>
     *
     * @param status A status code recording the success of the call.
     * @param containsValues True if the dictionary will store a value associated 
     * with each word added.
     */
    MutableTrieDictionary( UErrorCode &status, UBool containsValues = false );
};

/*******************************************************************
 * CompactTrieDictionary
 */

//forward declarations
struct CompactTrieHeader;
struct CompactTrieInfo;

/**
 * <p>CompactTrieDictionary is a TrieWordDictionary that has been compacted
 * to save space.</p>
 */
class U_COMMON_API CompactTrieDictionary : public TrieWordDictionary {
private:
    /**
     * The header of the CompactTrieDictionary which contains all info
     */

    CompactTrieInfo                 *fInfo; 

    /**
     * A UBool indicating whether or not we own the fData.
     */
    UBool                     fOwnData;

    UDataMemory              *fUData;
public:
    /**
     * <p>Construct a dictionary from a UDataMemory.</p>
     *
     * @param data A pointer to a UDataMemory, which is adopted
     * @param status A status code giving the result of the constructor
     */
    CompactTrieDictionary(UDataMemory *dataObj, UErrorCode &status);

    /**
     * <p>Construct a dictionary from raw saved data.</p>
     *
     * @param data A pointer to the raw data, which is still owned by the caller
     * @param status A status code giving the result of the constructor
     */
    CompactTrieDictionary(const void *dataObj, UErrorCode &status);

    /**
     * <p>Construct a dictionary from a MutableTrieDictionary.</p>
     *
     * @param dict The dictionary to use as input.
     * @param status A status code recording the success of the call.
     */
    CompactTrieDictionary( const MutableTrieDictionary &dict, UErrorCode &status );

    /**
     * <p>Virtual destructor.</p>
     */
    virtual ~CompactTrieDictionary();

    /**
     * <p>Returns true if the dictionary contains values associated with each word.</p>
     */
    virtual UBool getValued() const;

    /**
     * <p>Find dictionary words that match the text.</p>
     *
     * @param text A UText representing the text. The
     * iterator is left after the longest prefix match in the dictionary.
     * @param maxLength The maximum number of code units to match.
     * @param lengths An array that is filled with the lengths of words that matched.
     * @param count Filled with the number of elements output in lengths.
     * @param limit The size of the lengths array; this limits the number of words output.
     * @param values An array that is filled with the values associated with the matched words.
     * @return The number of characters in text that were matched.
     */
    virtual int32_t matches( UText *text,
            int32_t maxLength,
            int32_t *lengths,
            int &count,
            int limit,
            uint16_t *values = NULL) const;

    /**
     * <p>Return a StringEnumeration for iterating all the words in the dictionary.</p>
     *
     * @param status A status code recording the success of the call.
     * @return A StringEnumeration that will iterate through the whole dictionary.
     * The caller is responsible for closing it. The order is unspecified.
     */
    virtual StringEnumeration *openWords( UErrorCode &status ) const;

    /**
     * <p>Return the size of the compact data.</p>
     *
     * @return The size of the dictionary's compact data.
     */
    virtual uint32_t dataSize() const;

    /**
     * <p>Return a void * pointer to the (unmanaged) compact data, platform-endian.</p>
     *
     * @return The data for the compact dictionary, suitable for passing to the
     * constructor.
     */
    virtual const void *data() const;

    /**
     * <p>Return a MutableTrieDictionary clone of this dictionary.</p>
     *
     * @param status A status code recording the success of the call.
     * @return A MutableTrieDictionary with the same data as this dictionary
     */
    virtual MutableTrieDictionary *cloneMutable( UErrorCode &status ) const;

private:

    /**
     * <p>Convert a MutableTrieDictionary into a compact data blob.</p>
     *
     * @param dict The dictionary to convert.
     * @param status A status code recording the success of the call.
     * @return A single data blob starting with a CompactTrieHeader.
     */
    static CompactTrieHeader *compactMutableTrieDictionary( const MutableTrieDictionary &dict,
            UErrorCode &status );

};

U_NAMESPACE_END

/* TRIEDICT_H */
#endif