/*
 * Linearize.java
 * Copyright (C) 2004-2005, Bjorn Bringert (bringert@cs.chalmers.se)
 * 
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package se.chalmers.cs.gf.oaa;

import se.gu.ling.trindikit.oaa.common.*;
import com.sri.oaa2.icl.*;

import se.chalmers.cs.gf.GFException;
import se.chalmers.cs.gf.abssyn.*;
import se.chalmers.cs.gf.translate.*;
import se.chalmers.cs.gf.util.Pair;
import static se.chalmers.cs.gf.util.Pair.pair;

import java.util.*;

/**
 *  Implements the linearization solvable.
 */
public class Linearize extends OAASolver {

        private static String solvableString = "linearize(Grammar,Lang,Tree,Text)";

        private Translators translators;

        public Linearize(Translators translators) {
                super(solvableString);
                this.translators = translators;
        }

        public boolean solve(IclTerm goal, IclList params, IclList answers) {
                String grammar;
                IclTerm langTerm;
                IclTerm treeTerm;
                IclTerm result;

                try {
                        grammar = ((IclStr)goal.getTerm(0)).toUnquotedString();
                        langTerm = goal.getTerm(1);
                        treeTerm = goal.getTerm(2);
                        result = goal.getTerm(3);
                } catch (ClassCastException e){
                        return false;
                }

                Tree tree = IclTermToTree.iclTermToTree(treeTerm);

                Translator translator = translators.getTranslator(grammar);
                if (translator == null) {
                        System.err.println("Unknown grammar " + grammar);
                        return false;
                }

                Collection<Pair<String,String>> ps = linearize(translator, langTerm, tree);

                boolean success = false;
                for (Pair<String,String> p : ps) {
                        String lang = p.fst;
                        String resultStr = p.snd;
                        IclTerm linResult = new IclStr(resultStr);
                        IclTerm r = Unifier.getInstance().unify(result, linResult);
                        if (r != null) {
                                System.err.println("Success: " + r);
                                IclTerm ans = new IclStruct("linearize", new IclStr(grammar),
                                                            new IclStr(lang), treeTerm, r);
                                System.err.println("Adding answer " + ans);
                                answers.add(ans);
                                success = true;
                        }
                }

                return success;
        }

        public static Collection<Pair<String,String>> linearize(Translator translator,
                                                                IclTerm langTerm,
                                                                Tree tree) {
                try {
                        if (langTerm.isStr()) {
                                String lang = ((IclStr)langTerm).toUnquotedString();
                                System.err.println("Linearizing '" + tree + "' as " + lang);
                                return Arrays.asList(pair(lang,translator.linearize(lang, tree)));
                        } else if (langTerm.isVar()) {
                                System.err.println("Linearizing '" + tree + "' as any language");
                                return translator.linearizeWithAll(tree);
                        } else {
                                System.err.println("Bad language " + langTerm);
                                return new LinkedList<Pair<String,String>>();
                        }
                } catch (GFException ex) {
                        ex.printStackTrace();
                        return new LinkedList<Pair<String,String>>();
                }
        }
    
}