/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * 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 org.apache.wicket.ajax.json;

class JSON
{
	/**
	 * Returns the input if it is a JSON-permissible value; throws otherwise.
	 */
	static double checkDouble(double d) throws JSONException
	{
		if (Double.isInfinite(d) || Double.isNaN(d))
		{
			throw new JSONException("Forbidden numeric value: " + d);
		}
		return d;
	}

	static Boolean toBoolean(Object value)
	{
		if (value instanceof Boolean)
		{
			return (Boolean)value;
		}
		else if (value instanceof String)
		{
			String stringValue = (String)value;
			if ("true".equalsIgnoreCase(stringValue))
			{
				return true;
			}
			else if ("false".equalsIgnoreCase(stringValue))
			{
				return false;
			}
		}
		return null;
	}

	static Double toDouble(Object value)
	{
		if (value instanceof Double)
		{
			return (Double)value;
		}
		else if (value instanceof Number)
		{
			return ((Number)value).doubleValue();
		}
		else if (value instanceof String)
		{
			try
			{
				return Double.valueOf((String)value);
			}
			catch (NumberFormatException ignored)
			{
			}
		}
		return null;
	}

	static Integer toInteger(Object value)
	{
		if (value instanceof Integer)
		{
			return (Integer)value;
		}
		else if (value instanceof Number)
		{
			return ((Number)value).intValue();
		}
		else if (value instanceof String)
		{
			try
			{
				return (int)Double.parseDouble((String)value);
			}
			catch (NumberFormatException ignored)
			{
			}
		}
		return null;
	}

	static Long toLong(Object value)
	{
		if (value instanceof Long)
		{
			return (Long)value;
		}
		else if (value instanceof Number)
		{
			return ((Number)value).longValue();
		}
		else if (value instanceof String)
		{
			try
			{
				return (long)Double.parseDouble((String)value);
			}
			catch (NumberFormatException ignored)
			{
			}
		}
		return null;
	}

	static String toString(Object value)
	{
		if (value instanceof String)
		{
			return (String)value;
		}
		else if (value != null)
		{
			return String.valueOf(value);
		}
		return null;
	}

	public static JSONException typeMismatch(Object indexOrName, Object actual, String requiredType)
		throws JSONException
	{
		if (actual == null)
		{
			throw new JSONException("Value at " + indexOrName + " is null.");
		}
		else
		{
			throw new JSONException("Value " + actual + " at " + indexOrName + " of type "
				+ actual.getClass().getName() + " cannot be converted to " + requiredType);
		}
	}

	public static JSONException typeMismatch(Object actual, String requiredType)
		throws JSONException
	{
		if (actual == null)
		{
			throw new JSONException("Value is null.");
		}
		else
		{
			throw new JSONException("Value " + actual + " of type " + actual.getClass().getName()
				+ " cannot be converted to " + requiredType);
		}
	}
}
