/*
 * Copyright 2008 Google 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 com.google.template.soy.data.restricted;

import javax.annotation.concurrent.Immutable;


/**
 * Float data.
 *
 * <p> Important: This class may only be used in implementing plugins (e.g. functions, directives).
 *
 */
@Immutable
public final class FloatData extends NumberData {


  /** The float value. */
  private final double value;


  /**
   * @param value The float value.
   * @deprecated Use {@link FloatData#forValue}.
   */
  @Deprecated
  public FloatData(double value) {
    this.value = value;
  }


  /**
   * Gets a FloatData instance for the given value.
   * @param value The desired value.
   * @return A FloatData instance with the given value.
   */
  @SuppressWarnings("deprecation")
  public static FloatData forValue(double value) {
    return new FloatData(value);
  }


  /** Returns the float value. */
  public double getValue() {
    return value;
  }


  @Override public double floatValue() {
    return value;
  }


  @Override public String toString() {
    return toString(value);
  }

  /**
   * Returns Soy's idea of a double as a string.
   */
  public static String toString(double value) {
    // This approximately consistent with Javascript for important cases.
    // Reference: http://www.ecma-international.org/ecma-262/5.1/#sec-9.8.1
    if (value % 1 == 0 && Math.abs(value) < Long.MAX_VALUE) {
      // The value is non-fractional and within the magnitude of a long, so print as an integer
      // instead of scientific notation.  Note that Javascript uses 1.0e19 as the cutoff, but
      // Long.MAX_VALUE is not that far off (9.2e18), and it is both easy and efficient to coerce
      // to a long.
      return String.valueOf((long) value);
    } else {
      // Note: This differs from JS in how it rendered values that have a zero fractional component
      // and in how it renders the value -0.0.
      // JavaScript specifies that the string form of -0 is signless, and that the string form of
      // fractionless numeric values has no decimal point.
      return Double.toString(value).replace('E', 'e');
    }
  }

  /**
   * {@inheritDoc}
   *
   * <p> 0.0 is falsy as is NaN.
   */
  @Deprecated
  @Override public boolean toBoolean() {
    return value != 0.0 && !Double.isNaN(value);
  }


  @Override public double toFloat() {
    return value;
  }

}