/*
   Copyright (c) 2017 James Ahlborn
   
   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.healthmarketscience.jackcess.impl.expr;
  
  import java.math.BigDecimal;
  import java.time.LocalDateTime;
  
  import com.healthmarketscience.jackcess.expr.LocaleContext;
  import com.healthmarketscience.jackcess.expr.Value;
  
  /**
   *
   * @author James Ahlborn
   */
  public abstract class BaseDelayedValue implements Value
  {
    private Value _val;
  
    protected BaseDelayedValue() {
    }
  
    private Value getDelegate() {
      if(_val == null) {
        _val = eval();
      }
      return _val;
    }
  
    @Override
    public boolean isNull() {
      return(getType() == Type.NULL);
    }
  
    @Override
    public Value.Type getType() {
      return getDelegate().getType();
    }
  
    @Override
    public Object get() {
      return getDelegate().get();
    }
  
    @Override
    public boolean getAsBoolean(LocaleContext ctx) {
      return getDelegate().getAsBoolean(ctx);
    }
  
    @Override
    public String getAsString(LocaleContext ctx) {
      return getDelegate().getAsString(ctx);
    }
  
    @Override
    public LocalDateTime getAsLocalDateTime(LocaleContext ctx) {
      return getDelegate().getAsLocalDateTime(ctx);
    }
  
    @Override
    public Value getAsDateTimeValue(LocaleContext ctx) {
      return getDelegate().getAsDateTimeValue(ctx);
    }
  
    @Override
    public Integer getAsLongInt(LocaleContext ctx) {
      return getDelegate().getAsLongInt(ctx);
    }
  
    @Override
    public Double getAsDouble(LocaleContext ctx) {
      return getDelegate().getAsDouble(ctx);
    }
  
    @Override
    public BigDecimal getAsBigDecimal(LocaleContext ctx) {
      return getDelegate().getAsBigDecimal(ctx);
    }
  
    protected abstract Value eval();
  }