/*
 * Copyright 2003,2004 The Apache Software Foundation.
 * 
 * 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.
 */
 
#include <log4cxx/ndc.h>

using namespace log4cxx;
using namespace log4cxx::helpers;

NDC::DiagnosticContext::DiagnosticContext(const String& message, 
	const DiagnosticContext * parent)
	: message(message)
{
	if (parent != 0)
	{
		fullMessage = parent->fullMessage + _T(' ') + message;
	} 
	else
	{
		fullMessage = message;
	}
}

// static member instanciation
ThreadSpecificData NDC::threadSpecificData;

NDC::NDC(const String& message)
{
	push(message);
}

NDC::~NDC()
{
	pop();
}

NDC::Stack * NDC::getCurrentThreadStack()
{
	return (Stack *)threadSpecificData.GetData();
}

void NDC::setCurrentThreadStack(NDC::Stack * stack)
{
	threadSpecificData.SetData((void *)stack); 
}

void NDC::clear()
{
	Stack * stack = getCurrentThreadStack();    
	if(stack != 0)
	{
		delete stack;
		setCurrentThreadStack(0);
	} 
}

NDC::Stack * NDC::cloneStack()
{
	Stack * stack = getCurrentThreadStack();
	if(stack != 0)
	{
		return new Stack(*stack);
	}
	else
	{
		return new Stack();
	}
}

void NDC::inherit(NDC::Stack * stack)
{
	if(stack != 0)
	{
		Stack * oldStack = getCurrentThreadStack();
		if(oldStack != 0)
		{
			delete oldStack;
		}
	
		setCurrentThreadStack(stack);
	}
}

String NDC::get()
{
	Stack * stack = getCurrentThreadStack();
	if(stack != 0 && !stack->empty())
	{
		return stack->top().fullMessage;
	}
	else
	{
		return String();
	}
}

int NDC::getDepth()
{
	Stack * stack = getCurrentThreadStack();
	if(stack == 0)
	{
		return 0;
	}
	else
	{
		return stack->size();
	}
}

String NDC::pop()
{
	Stack * stack = getCurrentThreadStack();
	if(stack != 0 && !stack->empty())
	{
		String message = stack->top().message;
		stack->pop();
		if (stack->empty())
		{
			delete stack;
			setCurrentThreadStack(0);
		}
		return message;
	}
	else
	{
		return String();
	}
}

String NDC::peek()
{
	Stack * stack = getCurrentThreadStack();
	if(stack != 0 && !stack->empty())
	{
		return stack->top().message;
	}
	else
	{
		return String();
	}
}

void NDC::push(const String& message)
{
	Stack * stack = getCurrentThreadStack();

	if (stack == 0)
	{
		stack = new Stack;
		setCurrentThreadStack(stack);
		stack->push(DiagnosticContext(message, 0));
	}
	else if (stack->empty())
	{
		stack->push(DiagnosticContext(message, 0));
	}
	else
	{
		DiagnosticContext& parent = stack->top();
		stack->push(DiagnosticContext(message, &parent));
	}
}

void NDC::remove()
{
	Stack * stack = getCurrentThreadStack();
	if(stack != 0)
	{
		delete stack;
		setCurrentThreadStack(0);
	}
}