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package tech.tablesaw.columns.strings;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import tech.tablesaw.api.BooleanColumn;
import tech.tablesaw.api.Table;
import tech.tablesaw.selection.BitmapBackedSelection;
import tech.tablesaw.selection.Selection;

/**
 * Interface implemented by the objects that perform the dictionary encoding of the Strings in
 * StringColumn, as well as the primitive values that represent the individual instances of the
 * String in the column.
 */
public interface DictionaryMap {

  void sortDescending();

  void sortAscending();

  /** Returns the int that represents the string at rowNumber */
  int getKeyAtIndex(int rowNumber);

  String getValueForKey(int key);

  int size();

  String getValueForIndex(int rowIndex);

  int countOccurrences(String value);

  Set asSet();

  /** Returns the number of unique values at or before the given index */
  default int uniqueValuesAt(int index) {
    int result = 0;
    List uniqueValues = new ArrayList<>();
    for (int i = 0; i <= index; i++) {
      String value = getValueForIndex(i);
      int uniqueIndex = uniqueValues.indexOf(value);
      if (uniqueIndex < 0) {
        uniqueValues.add(value);
        result++;
      }
    }
    return result;
  }

  default int[] asIntArray() {
    int[] result = new int[size()];
    List uniqueValues = new ArrayList<>();
    for (int i = 0; i < size(); i++) {
      String value = getValueForIndex(i);
      int uniqueIndex = uniqueValues.indexOf(value);
      if (uniqueIndex < 0) {
        uniqueValues.add(value);
        uniqueIndex = uniqueValues.size() - 1;
      }
      result[i] = uniqueIndex;
    }
    return result;
  }

  int getKeyForIndex(int i);

  int firstIndexOf(String string);

  String[] asObjectArray();

  Selection selectIsIn(String... strings);

  Selection selectIsIn(Collection strings);

  void append(String value) throws NoKeysAvailableException;

  void set(int rowIndex, String stringValue) throws NoKeysAvailableException;

  void clear();

  int countUnique();

  Table countByCategory(String columnName);

  Selection isEqualTo(String string);

  default Selection isNotEqualTo(String string) {
    Selection selection = new BitmapBackedSelection();
    selection.addRange(0, size());
    selection.andNot(isEqualTo(string));
    return selection;
  }

  List getDummies();

  /** Returns the contents of the cell at rowNumber as a byte[] */
  public byte[] asBytes(int rowNumber);

  /** Returns the count of missing values in this column */
  int countMissing();

  Iterator iterator();

  void appendMissing();

  boolean isMissing(int rowNumber);

  DictionaryMap promoteYourself();

  int nextKeyWithoutIncrementing();
}