/**
 *
 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either 
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 * 
 **/
/**
 * Implements the CFML Function querysetcell
 */
package lucee.runtime.functions.query;

import java.util.Arrays;
import java.util.Comparator;

import lucee.commons.lang.StringUtil;
import lucee.runtime.PageContext;
import lucee.runtime.config.NullSupportHelper;
import lucee.runtime.exp.DatabaseException;
import lucee.runtime.exp.PageException;
import lucee.runtime.exp.PageRuntimeException;
import lucee.runtime.ext.function.BIF;
import lucee.runtime.op.Caster;
import lucee.runtime.op.Decision;
import lucee.runtime.type.Collection.Key;
import lucee.runtime.type.KeyImpl;
import lucee.runtime.type.Query;
import lucee.runtime.type.QueryImpl;
import lucee.runtime.type.Struct;
import lucee.runtime.type.StructImpl;
import lucee.runtime.type.UDF;
import lucee.runtime.type.util.ListUtil;



public final class QuerySort extends BIF {



	private static final long serialVersionUID = -6566120440638749819L;

	public static boolean call(PageContext pc , Query query, Object columnNameOrSortFunc) throws PageException {
		if(Decision.isSimpleValue(columnNameOrSortFunc))
			return _call(pc,query,Caster.toString(columnNameOrSortFunc),null);
		
		return _call(pc,query,Caster.toFunction(columnNameOrSortFunc));
	}
	

	public static boolean call(PageContext pc , Query query, Object columnNameOrSortFunc, String directions) throws PageException {
		if(Decision.isSimpleValue(columnNameOrSortFunc))
			return _call(pc,query,Caster.toString(columnNameOrSortFunc),directions);
		return _call(pc,query,Caster.toFunction(columnNameOrSortFunc));
	}
	
	public static boolean _call(PageContext pc , Query query, UDF udf) throws PageException {
		int recordcount=query.getRecordcount();
		Key[] columns = query.getColumnNames();
		QueryRow[] rows=new QueryRow[recordcount];
		Struct sct;
		Object empty=NullSupportHelper.full()?null:"";
		for(int row=1;row<=recordcount;row++) {
			sct=new StructImpl();
			for(int col=0;col<columns.length;col++) {
				sct.setEL(columns[col], query.getAt(columns[col],row,empty));
			}
			rows[row-1]=new QueryRow(query,row,sct);
		}
		
		Arrays.sort(rows,new QueryRowComparator(pc,udf));
		((QueryImpl)query).sort(toInt(rows));
		return true;		
	}
	
	
	private static int[] toInt(QueryRow[] rows) {
		int[] ints=new int[rows.length];
		for(int i=0;i<rows.length;i++) {
			ints[i]=rows[i].rowNbr;
		}
		return ints;
	}


	private static boolean _call(PageContext pc , Query query, String columnNames, String directions) throws PageException {
		// column names
		String[] arrColumnNames = ListUtil.trimItems(ListUtil.listToStringArray(columnNames, ','));
		int[] dirs = new int[arrColumnNames.length];
		
		// directions
		if(!StringUtil.isEmpty(directions)) {
			String[] arrDirections = ListUtil.trimItems(ListUtil.listToStringArray(directions, ','));
			if(arrColumnNames.length!=arrDirections.length)throw new DatabaseException("column names and directions has not the same count",null,null,null);
			
			String direction;
			for(int i=0;i<dirs.length;i++){
				direction=arrDirections[i].toLowerCase();
				dirs[i]=0;
				if(direction.equals("asc"))dirs[i]=Query.ORDER_ASC;
				else if(direction.equals("desc"))dirs[i]=Query.ORDER_DESC;
				else {		
					throw new DatabaseException("argument direction of function querySort must be \"asc\" or \"desc\", now \""+direction+"\"",null,null,null);
				}
			}
		}
		else {
			for(int i=0;i<dirs.length;i++){
				dirs[i]=Query.ORDER_ASC;
			}
		}
		
		
		for(int i=arrColumnNames.length-1;i>=0;i--)
			query.sort(KeyImpl.init(arrColumnNames[i]),dirs[i]);
		
		
		
		return true;		
	}
	
	@Override
	public Object invoke(PageContext pc, Object[] args) throws PageException {
		if(args.length==2)return call(pc,Caster.toQuery(args[0]),args[1]);
		return call(pc,Caster.toQuery(args[0]),args[1],Caster.toString(args[2]));
	}
	
	public static class QueryRow {

		public final Query query;
		public final int rowNbr;
		public final Struct row;

		public QueryRow(Query query, int rowNbr, Struct row) {
			this.query=query;
			this.rowNbr=rowNbr;
			this.row=row;
		}

	}
	
	public static class QueryRowComparator implements Comparator<QueryRow> {

		private PageContext pc;
		private final UDF udf;

		public QueryRowComparator(PageContext pc,UDF udf) {
			this.pc=pc;
			this.udf=udf;
		}

		@Override
		public int compare(QueryRow left, QueryRow right) {
			try {
				return Caster.toIntValue(udf.call(pc, new Object[]{left.row,right.row}, true));
			}
			catch (PageException pe) {
				throw new PageRuntimeException(pe);
			}
		}

	}
}