/**
 * DataCleaner (community edition)
 * Copyright (C) 2014 Neopost - Customer Information Management
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program 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 distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.datacleaner.reference;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.util.List;
import java.util.Objects;

import org.datacleaner.beans.stringpattern.DefaultTokenizer;
import org.datacleaner.beans.stringpattern.Token;
import org.datacleaner.beans.stringpattern.TokenPattern;
import org.datacleaner.beans.stringpattern.TokenPatternImpl;
import org.datacleaner.beans.stringpattern.Tokenizer;
import org.datacleaner.beans.stringpattern.TokenizerConfiguration;
import org.datacleaner.configuration.DataCleanerConfiguration;
import org.datacleaner.util.LabelUtils;
import org.datacleaner.util.ReadObjectBuilder;

/**
 * Represents a string pattern that is based on a sequence of token types. The
 * pattern format is similar to the one used by the Pattern finder analyzer,
 * which makes it ideal for reusing discovered patterns.
 *
 * @see TokenPattern
 *
 *
 */
public final class SimpleStringPattern extends AbstractReferenceData implements StringPattern {

    private static final long serialVersionUID = 1L;

    private final String _expression;
    private transient TokenPattern _tokenPattern;
    private transient DefaultTokenizer _tokenizer;
    private transient TokenizerConfiguration _configuration;

    public SimpleStringPattern(final String name, final String expression) {
        this(name, expression, new TokenizerConfiguration());
    }

    public SimpleStringPattern(final String name, final String expression, final TokenizerConfiguration configuration) {
        super(name);
        _expression = expression;
        _configuration = configuration;
    }

    private void readObject(final ObjectInputStream stream) throws IOException, ClassNotFoundException {
        ReadObjectBuilder.create(this, SimpleStringPattern.class).readObject(stream);
    }

    @Override
    public boolean equals(final Object obj) {
        if (super.equals(obj)) {
            final SimpleStringPattern other = (SimpleStringPattern) obj;
            return Objects.equals(_expression, other._expression);
        }
        return false;
    }

    public boolean matches(final String string) {
        final List<Token> tokens = getTokenizer().tokenize(string);
        return getTokenPattern().match(tokens);
    }

    @Override
    public StringPatternConnection openConnection(final DataCleanerConfiguration configuration) {
        return new StringPatternConnection() {

            @Override
            public boolean matches(final String string) {
                return SimpleStringPattern.this.matches(string);
            }

            @Override
            public void close() {
            }
        };
    }

    private Tokenizer getTokenizer() {
        if (_tokenizer == null) {
            _tokenizer = new DefaultTokenizer(getConfiguration());
        }
        return _tokenizer;
    }

    private TokenizerConfiguration getConfiguration() {
        if (_configuration == null) {
            // TODO: Ideally we should provide all the configuration options in
            // the constructor
            _configuration = new TokenizerConfiguration();
        }
        return _configuration;
    }

    private TokenPattern getTokenPattern() {
        if (_tokenPattern == null) {
            final String expression;
            if (LabelUtils.NULL_LABEL.equals(_expression)) {
                expression = null;
            } else if (LabelUtils.BLANK_LABEL.equals(_expression)) {
                expression = "";
            } else {
                expression = _expression;
            }

            final List<Token> tokens = getTokenizer().tokenize(expression);
            _tokenPattern = new TokenPatternImpl(expression, tokens, getConfiguration());
        }
        return _tokenPattern;
    }

    public String getExpression() {
        return _expression;
    }

    @Override
    public String toString() {
        return "SimpleStringPattern[name=" + getName() + ", expression=" + _expression + "]";
    }
}