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/**
 * Copyright 2012 Twitter, Inc.
 *
 * Licensed 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.
 */
package parquet.filter;

import parquet.Preconditions;
import parquet.column.ColumnReader;
import parquet.io.api.Binary;

/**
 * ColumnPredicates class provides checks for column values. Factory methods
 * are provided for standard predicates which wrap the job of getting the
 * correct value from the column.
 */
public class ColumnPredicates {

  public static interface Predicate {
    boolean apply(ColumnReader input);
  }

  public static interface PredicateFunction  {
    boolean functionToApply(T input);
  }

  /* provide the following to avoid boxing primitives */

  public static interface IntegerPredicateFunction {
    boolean functionToApply(int input);
  }

  public static interface LongPredicateFunction {
    boolean functionToApply(long input);
  }

  public static interface FloatPredicateFunction {
    boolean functionToApply(float input);
  }

  public static interface DoublePredicateFunction {
    boolean functionToApply(double input);
  }

  public static interface BooleanPredicateFunction {
    boolean functionToApply(boolean input);
  }

  public static Predicate equalTo(final String target) {
    Preconditions.checkNotNull(target,"target");
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return target.equals(input.getBinary().toStringUsingUTF8());
      }
    };
  }

  public static Predicate applyFunctionToString(final PredicateFunction fn) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
          return fn.functionToApply(input.getBinary().toStringUsingUTF8());
      }
    };
  }

  public static Predicate equalTo(final int target) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return input.getInteger() == target;
      }
    };
  }

  public static Predicate applyFunctionToInteger(final IntegerPredicateFunction fn) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return fn.functionToApply(input.getInteger());
      }
    };
  }

  public static Predicate equalTo(final long target) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return input.getLong() == target;
      }
    };
  }

  public static Predicate applyFunctionToLong(final LongPredicateFunction fn) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return fn.functionToApply(input.getLong());
      }
    };
  }

  public static Predicate equalTo(final float target) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return input.getFloat() == target;
      }
    };
  }

  public static Predicate applyFunctionToFloat(final FloatPredicateFunction fn) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return fn.functionToApply(input.getFloat());
      }
    };
  }

  public static Predicate equalTo(final double target) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return input.getDouble() == target;
      }
    };
  }

  public static Predicate applyFunctionToDouble(final DoublePredicateFunction fn) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return fn.functionToApply(input.getDouble());
      }
    };
  }

  public static Predicate equalTo(final boolean target) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return input.getBoolean() == target;
      }
    };
  }

  public static Predicate applyFunctionToBoolean (final BooleanPredicateFunction fn) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return fn.functionToApply(input.getBoolean());
      }
    };
  }

  public static  Predicate equalTo(final E target) {
    Preconditions.checkNotNull(target,"target");
    final String targetAsString = target.name();
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
        return targetAsString.equals(input.getBinary().toStringUsingUTF8());
      }
    };
  }

  public static Predicate applyFunctionToBinary (final PredicateFunction fn) {
    return new Predicate() {
      @Override
      public boolean apply(ColumnReader input) {
	  return fn.functionToApply(input.getBinary());
      }
    };
  }
}