package org.apache.solr.search.function.distance;

import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.spell.StringDistance;
import org.apache.solr.search.function.DocValues;
import org.apache.solr.search.function.ValueSource;

import java.io.IOException;
import java.util.Map;


/**
 *
 *
 **/
public class StringDistanceFunction extends ValueSource {
  protected ValueSource str1, str2;
  protected StringDistance dist;

  /**
   * @param str1
   * @param str2
   * @param measure
   */
  public StringDistanceFunction(ValueSource str1, ValueSource str2, StringDistance measure) {
    this.str1 = str1;
    this.str2 = str2;
    dist = measure;


  }

  @Override
  public DocValues getValues(Map context, IndexReader reader) throws IOException {
    final DocValues str1DV = str1.getValues(context, reader);
    final DocValues str2DV = str2.getValues(context, reader);
    return new DocValues() {

      public float floatVal(int doc) {
        return (float) dist.getDistance(str1DV.strVal(doc), str2DV.strVal(doc));
      }

      public int intVal(int doc) {
        return (int) doubleVal(doc);
      }

      public long longVal(int doc) {
        return (long) doubleVal(doc);
      }

      public double doubleVal(int doc) {
        return (double) floatVal(doc);
      }

      @Override
      public String toString(int doc) {
        StringBuilder sb = new StringBuilder();
        sb.append("strdist").append('(');
        sb.append(str1DV.toString(doc)).append(',').append(str2DV.toString(doc))
                .append(", dist=").append(dist.getClass().getName());
        sb.append(')');
        return sb.toString();
      }
    };
  }

  public String description() {
    StringBuilder sb = new StringBuilder();
    sb.append("strdist").append('(');
    sb.append(str1).append(',').append(str2).append(", dist=").append(dist.getClass().getName());
    sb.append(')');
    return sb.toString();
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (!(o instanceof StringDistanceFunction)) return false;

    StringDistanceFunction that = (StringDistanceFunction) o;

    if (!dist.equals(that.dist)) return false;
    if (!str1.equals(that.str1)) return false;
    if (!str2.equals(that.str2)) return false;

    return true;
  }

  @Override
  public int hashCode() {
    int result = str1.hashCode();
    result = 31 * result + str2.hashCode();
    result = 31 * result + dist.hashCode();
    return result;
  }
}