/*------------------------------------------------------------------------------
* Copyright (C) 2003-2006 Ben van Klinken and the CLucene Team
* 
* Distributable under the terms of either the Apache License (Version 2.0) or 
* the GNU Lesser General Public License, as specified in the COPYING file.
------------------------------------------------------------------------------*/
#ifndef MultiFieldQueryParser_H
#define MultiFieldQueryParser_H

#if defined(_LUCENE_PRAGMA_ONCE)
# pragma once
#endif

#include "CLucene/analysis/AnalysisHeader.h"
#include "CLucene/search/SearchHeader.h"
#include "QueryParser.h"


CL_NS_DEF(queryParser)

typedef CL_NS(util)::CLHashMap<const TCHAR*,
                               float_t,
                               CL_NS(util)::Compare::TChar,
                               CL_NS(util)::Equals::TChar,
                               CL_NS(util)::Deletor::tcArray,
                               CL_NS(util)::Deletor::DummyFloat
                              > BoostMap;

    /**
     * A QueryParser which constructs queries to search multiple fields.
     *
     */
    class MultiFieldQueryParser: public QueryParser
    {
	protected:
		const TCHAR** fields;
        BoostMap* boosts;
    public:
    	LUCENE_STATIC_CONSTANT(uint8_t, NORMAL_FIELD=0);
		LUCENE_STATIC_CONSTANT(uint8_t, REQUIRED_FIELD=1);
		LUCENE_STATIC_CONSTANT(uint8_t, PROHIBITED_FIELD=2);
    
        /**
        * Creates a MultiFieldQueryParser.
        *
        * <p>It will, when parse(String query)
        * is called, construct a query like this (assuming the query consists of
        * two terms and you specify the two fields <code>title</code> and <code>body</code>):</p>
        * 
        * <code>
        * (title:term1 body:term1) (title:term2 body:term2)
        * </code>
        *
        * <p>When setDefaultOperator(AND_OPERATOR) is set, the result will be:</p>
        *  
        * <code>
        * +(title:term1 body:term1) +(title:term2 body:term2)
        * </code>
        * 
        * <p>In other words, all the query's terms must appear, but it doesn't matter in
        * what fields they appear.</p>
        */
		MultiFieldQueryParser(const TCHAR** fields, CL_NS(analysis)::Analyzer* a, BoostMap* boosts = NULL);
		virtual ~MultiFieldQueryParser();
    
        /**
         * <p>
         * Parses a query which searches on the fields specified.
         * <p>
         * If x fields are specified, this effectively constructs:
         * <pre>
         * <code>
         * (field1:query) (field2:query) (field3:query)...(fieldx:query)
         * </code>
         * </pre>
         *
         * @param query Query string to parse
         * @param fields Fields to search on
         * @param analyzer Analyzer to use
         * @throws ParserException if query parsing fails
         * @throws TokenMgrError if query parsing fails
         */
		static CL_NS(search)::Query* parse(const TCHAR* query, const TCHAR** fields, CL_NS(analysis)::Analyzer* analyzer);
    
        /**
         * <p>
         * Parses a query, searching on the fields specified.
         * Use this if you need to specify certain fields as required,
         * and others as prohibited.
         * <p><pre>
         * Usage:
         * <code>
         * String[] fields = {"filename", "contents", "description"};
         * int32_t[] flags = {MultiFieldQueryParser.NORMAL FIELD,
         *                MultiFieldQueryParser.REQUIRED FIELD,
         *                MultiFieldQueryParser.PROHIBITED FIELD,};
         * parse(query, fields, flags, analyzer);
         * </code>
         * </pre>
         *<p>
         * The code above would construct a query:
         * <pre>
         * <code>
         * (filename:query) +(contents:query) -(description:query)
         * </code>
         * </pre>
         *
         * @param query Query string to parse
         * @param fields Fields to search on
         * @param flags Flags describing the fields
         * @param analyzer Analyzer to use
         * @throws ParserException if query parsing fails
         * @throws TokenMgrError if query parsing fails
         */
		static CL_NS(search)::Query* parse(const TCHAR* query, const TCHAR** fields, const uint8_t* flags, CL_NS(analysis)::Analyzer* analyzer);



	protected:
		CL_NS(search)::Query* GetFieldQuery(const TCHAR* field, TCHAR* queryText);
		CL_NS(search)::Query* GetFieldQuery(const TCHAR* field, TCHAR* queryText, int32_t slop);
        CL_NS(search)::Query* GetFuzzyQuery(const TCHAR* field, TCHAR* termStr);
		CL_NS(search)::Query* GetRangeQuery(const TCHAR* field, TCHAR* part1, TCHAR* part2, bool inclusive);
	    CL_NS(search)::Query* GetPrefixQuery(const TCHAR* field, TCHAR* termStr);
	    CL_NS(search)::Query* GetWildcardQuery(const TCHAR* field, TCHAR* termStr);

		/**
		* A special virtual function for the MultiFieldQueryParser which can be used
		* to clean up queries. Once the field name is known and the query has been
		* created, its passed to this function. 
		* An example of this usage is to set boosts.
		*/
		virtual CL_NS(search)::Query* QueryAddedCallback(const TCHAR* field, CL_NS(search)::Query* query){ return query; }
    };
CL_NS_END
#endif
