package org.apache.blur.analysis.type;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.lang.reflect.Constructor;
import java.util.Map;

import org.apache.blur.analysis.FieldTypeDefinition;
import org.apache.blur.analysis.NoStopWordStandardAnalyzer;
import org.apache.blur.log.Log;
import org.apache.blur.log.LogFactory;
import org.apache.blur.lucene.LuceneVersionConstant;
import org.apache.blur.thrift.generated.Column;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.FieldType;
import org.apache.lucene.document.TextField;
import org.apache.lucene.search.SortField;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.Version;

public class TextFieldTypeDefinition extends FieldTypeDefinition {

  private static final Log LOG = LogFactory.getLog(TextFieldTypeDefinition.class);

  public static final String ANALYZER_CLASS = "analyzerClass";
  public static final String STOP_WORD_PATH = "stopWordPath";
  public static final String NAME = "text";
  public static final FieldType TYPE_NOT_STORED;
  public static final FieldType TYPE_STORED;

  private Analyzer _analyzer;

  static {
    TYPE_STORED = new FieldType(TextField.TYPE_STORED);
    TYPE_STORED.setOmitNorms(true);
    TYPE_STORED.freeze();

    TYPE_NOT_STORED = new FieldType(TextField.TYPE_NOT_STORED);
    TYPE_NOT_STORED.setOmitNorms(true);
    TYPE_NOT_STORED.freeze();
  }

  @Override
  public String getName() {
    return NAME;
  }

  @Override
  public void configure(String fieldNameForThisInstance, Map<String, String> properties, Configuration configuration) {
    String stopWordUri = properties.get(STOP_WORD_PATH);
    String className = properties.get(ANALYZER_CLASS);
    if (stopWordUri == null) {
      if (className == null) {
        _analyzer = new NoStopWordStandardAnalyzer();
      } else {
        _analyzer = instance(className);
      }
    } else {
      if (className != null) {
        LOG.warn("Class name [{0}] ignored do due to the [{1}] property being set.", className, STOP_WORD_PATH);
      }
      try {
        Path path = new Path(stopWordUri);
        FileSystem fileSystem = path.getFileSystem(configuration);
        Reader reader = new InputStreamReader(fileSystem.open(path));
        // Reader closed by analyzer
        _analyzer = new StandardAnalyzer(LuceneVersionConstant.LUCENE_VERSION, reader);
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }
  }
  
  private static Analyzer instance(String name) {
    try {

      Class<?> clazz = Class.forName(name);
      Constructor<?>[] constructors = clazz.getConstructors();
      for (Constructor<?> constructor : constructors) {
        Class<?>[] parameterTypes = constructor.getParameterTypes();
        if (parameterTypes.length == 0) {
          return (Analyzer) constructor.newInstance(new Object[] {});
        }
      }

      for (Constructor<?> constructor : constructors) {
        Class<?>[] parameterTypes = constructor.getParameterTypes();
        if (parameterTypes.length == 1) {
          Class<?> type = parameterTypes[0];
          if (type.equals(Version.class)) {
            return (Analyzer) constructor.newInstance(new Object[] { LuceneVersionConstant.LUCENE_VERSION });
          }
        }
      }
      throw new RuntimeException("Cannot find a default constructor or a constructor that takes a ["
          + Version.class.getName() + "]");
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  @Override
  public Iterable<? extends Field> getFieldsForColumn(String family, Column column) {
    String name = getName(family, column.getName());
    Field field = new Field(name, column.getValue(), TYPE_STORED);
    return makeIterable(field);
  }

  @Override
  public Iterable<? extends Field> getFieldsForSubColumn(String family, Column column, String subName) {
    String name = getName(family, column.getName(), subName);
    Field field = new Field(name, column.getValue(), TYPE_NOT_STORED);
    return makeIterable(field);
  }

  @Override
  public Analyzer getAnalyzerForIndex(String fieldName) {
    return _analyzer;
  }

  @Override
  public Analyzer getAnalyzerForQuery(String fieldName) {
    return _analyzer;
  }

  @Override
  public boolean checkSupportForFuzzyQuery() {
    return true;
  }

  @Override
  public boolean checkSupportForWildcardQuery() {
    return true;
  }

  @Override
  public boolean checkSupportForPrefixQuery() {
    return true;
  }

  @Override
  public boolean checkSupportForRegexQuery() {
    return true;
  }

  @Override
  public boolean isNumeric() {
    return false;
  }

  @Override
  public boolean checkSupportForCustomQuery() {
    return false;
  }
  
  @Override
  public boolean checkSupportForSorting() {
    return false;
  }
  
  @Override
  public SortField getSortField(boolean reverse) {
    throw new RuntimeException("Sort not supported.");
  }
  
  @Override
  public String readTerm(BytesRef byteRef) {
	return byteRef.utf8ToString();
  }
}