package com.ljs.ootp.extract.html.rating;
   
   import com.fasterxml.jackson.annotation.JsonValue;
   import com.google.common.base.Objects;
   import com.google.common.base.Preconditions;
   import com.google.common.base.Throwables;
   
   /**
    *
   * @author lstephen
   */
  public final class Rating<T, S extends Scale<T>> {
  
      private final T value;
  
      private final S scale;
  
      private Rating(T value, S scale) {
          Preconditions.checkNotNull(value);
          Preconditions.checkNotNull(scale);
  
          // Seems that occaisionally a String gets through here.
          // This fix hides a problem somewhere else.
          // The error occurs when loading from JSON
          this.value = (String.class.isInstance(value)
              ? scale.parse(String.class.cast(value)).value
              : value);
  
          this.scale = scale;
      }
  
      @JsonValue
      public T get() {
          return value;
      }
  
      public Rating<Integer, OneToOneHundred> normalize() {
          try {
              return scale.normalize(value);
          } catch (ClassCastException e) {
              System.out.println(scale + ":" + value);
              throw Throwables.propagate(e);
          }
      }
  
      @Override
      public boolean equals(Object obj) {
          if (obj == null) {
              return false;
          }
          if (obj == this) {
              return true;
          }
          if (obj.getClass() != getClass()) {
              return false;
          }
  
          Rating<?, ?> rhs = Rating.class.cast(obj);
  
          return Objects.equal(value, rhs.value)
              && Objects.equal(scale, rhs.scale);
      }
  
      @Override
      public int hashCode() {
          return Objects.hashCode(value, scale);
      }
  
      @Override
      public String toString() {
          return Objects
              .toStringHelper(this)
              .add("value", value)
              .add("scale", scale)
              .toString();
      }
  
      public static <T, S extends Scale<T>> Rating<T, S> create(
          T value, S scale) {
  
          return new Rating<T, S>(value, scale);
      }
  
  }