/***************************************************************************
 *   Copyright (C) 2003-2005 by David Saxton                               *
 *   david@bluehaze.org                                                    *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 ***************************************************************************/

#include <vector>
#include "circuit.h"
#include "circuitdocument.h"
#include "element.h"
#include "elementset.h"
#include "logic.h"
#include "matrix.h"
#include "nonlinear.h"
#include "pin.h"
#include "reactive.h"
#include "wire.h"


#include <cmath>
#include <map>

typedef std::multimap<int, PinList> PinListMap;

//BEGIN class Circuit
Circuit::Circuit()
{
	m_bCanAddChanged = true;
	m_pNextChanged[0] = m_pNextChanged[1] = 0l;
	m_logicOutCount = 0;
	m_bCanCache = false;
	m_pLogicOut = 0l;
	m_elementSet = new ElementSet( this, 0, 0 );
	m_cnodeCount = m_branchCount = -1;
	m_prepNLCount = 0;
	m_pLogicCacheBase = new LogicCacheNode;
}

Circuit::~Circuit()
{
	delete m_elementSet;
	delete m_pLogicCacheBase;
	delete[] m_pLogicOut;
}


void Circuit::addPin( Pin *node )
{
	if ( m_pinList.contains(node) ) return;
	m_pinList.append(node);
}

void Circuit::addElement( Element *element )
{
	if ( m_elementList.contains(element) ) return;
	m_elementList.append(element);
}

bool Circuit::contains( Pin *node )
{
	return m_pinList.contains(node);
}


// static function
int Circuit::identifyGround( PinList nodeList, int *highest )
{
	// What this function does:
	// We are given a list of pins. First, we divide them into groups of pins
	// that are directly connected to each other (e.g. through wires or
	// switches). Then, each group of connected pins is looked at to find the
	// pin with the highest "ground priority", and this is taken to be
	// the priority of the group. The highest ground priority from all the
	// groups is recorded. If the highest ground priority found is the maximum,
	// then all the pins in groups with this priority are marked as ground
	// (their eq-id is set to -1). Otherwise, the first group of pins with the
	// highest ground priority found is marked as ground, and all others are
	// marked as non ground (their eq-id is set to 0).
	
	int temp_highest;
	if (!highest)
		highest = &temp_highest;
	
	// Now to give all the Pins ids
	PinListMap eqs;
	while ( !nodeList.isEmpty() )
	{
		PinList associated;
		PinList nodes;
		Pin *node = *nodeList.begin();
		recursivePinAdd( node, &nodeList, &associated, &nodes );
		if ( nodes.size() > 0 )
		{
			eqs.insert( std::make_pair( associated.size(), nodes ) );
		}
	}
	
	
	// Now, we want to look through the associated Pins, 
	// to find the ones with the highest "Ground Priority". Anything with a lower
	// priority than Pin::gt_never will not be considered
	*highest = Pin::gt_never; // The highest priority found so far
	int numGround = 0; // The number of node groups found with that priority
	const PinListMap::iterator eqsEnd = eqs.end();
	for ( PinListMap::iterator it = eqs.begin(); it != eqsEnd; ++it )
	{
		int highPri = Pin::gt_never; // The highest priority found in these group of nodes
		const PinList::iterator send = it->second.end();
		for ( PinList::iterator sit = it->second.begin(); sit != send; ++sit )
		{
			if ( (*sit)->groundType() < highPri )
				highPri = (*sit)->groundType();
		}
		
		if ( highPri == *highest )
			numGround++;
		
		else if ( highPri < *highest ) 
		{
			numGround = 1;
			*highest = highPri;
		}
	}
	
	if ( *highest == Pin::gt_never )
	{
		(*highest)--;
		numGround=0;
	}
	// If there are no Always Ground nodes, then we only want to set one of the nodes as ground
	else if ( *highest > Pin::gt_always )
		numGround = 1;
	
	
	// Now, we can give the nodes their cnode ids, or tell them they are ground
	bool foundGround = false; // This is only used when we don't have a Always ground node
	for ( PinListMap::iterator it = eqs.begin(); it != eqsEnd; ++it )
	{
		bool ground = false;
		const PinList::iterator send = it->second.end();
		for ( PinList::iterator sit = it->second.begin(); sit != send; ++sit )
		{
			ground |= (*sit)->groundType() <= (*highest);
		}
		if ( ground && (!foundGround || *highest == Pin::gt_always ) )
		{
			for ( PinList::iterator sit = it->second.begin(); sit != send; ++sit )
			{
				(*sit)->setEqId(-1);
			}
			foundGround = true;
		}
		else
		{
			for ( PinList::iterator sit = it->second.begin(); sit != send; ++sit )
			{
				(*sit)->setEqId(0);
			}
		}
	}
	
	return numGround;
}


void Circuit::init()
{
	m_branchCount = 0;
	
	const ElementList::iterator listEnd = m_elementList.end();
	for ( ElementList::iterator it = m_elementList.begin(); it != listEnd; ++it )
	{
		m_branchCount += (*it)->numCBranches();
	}
	
	// Now to give all the Pins ids
	int groundCount = 0;
	PinListMap eqs;
	PinList unassignedNodes = m_pinList;
	while ( !unassignedNodes.isEmpty() )
	{
		PinList associated;
		PinList nodes;
		Pin *node = *unassignedNodes.begin();
		if ( recursivePinAdd( node, &unassignedNodes, &associated, &nodes ) ) {
			groundCount++;
		}
		if ( nodes.size() > 0 ) {
			eqs.insert( std::make_pair( associated.size(), nodes ) );
		}
	}
	
	m_cnodeCount = eqs.size() - groundCount;
	
	delete m_pLogicCacheBase;
	m_pLogicCacheBase = 0l;
	
	delete m_elementSet;
	m_elementSet = new ElementSet( this, m_cnodeCount, m_branchCount );
	
	// Now, we can give the nodes their cnode ids, or tell them they are ground
	Vector *x = m_elementSet->x();
	int i=0;
	const PinListMap::iterator eqsEnd = eqs.end();
	for ( PinListMap::iterator it = eqs.begin(); it != eqsEnd; ++it )
	{
		bool foundGround = false;
		
		const PinList::iterator sEnd = it->second.end();
		for ( PinList::iterator sit = it->second.begin(); sit != sEnd; ++sit )
			foundGround |= (*sit)->eqId() == -1;
			
		if ( foundGround )
			continue;
		
		bool foundEnergyStoragePin = false;
		
		for ( PinList::iterator sit = it->second.begin(); sit != sEnd; ++sit )
		{
			(*sit)->setEqId(i);
			
			bool energyStorage = false;
			const ElementList elements = (*sit)->elements();
			ElementList::const_iterator elementsEnd = elements.end();
			for ( ElementList::const_iterator it = elements.begin(); it != elementsEnd; ++it )
			{
				if ( !*it )
					continue;
				
				if ( ((*it)->type() == Element::Element_Capacitance)
									|| ((*it)->type() == Element::Element_Inductance) )
				{
					energyStorage = true;
					break;
				}
			}
			
			// A pin attached to an energy storage pin overrides one that doesn't.
			// If the two pins have equal status with in this regard, we pick the
			// one with the highest absolute voltage on it.
			
			if ( foundEnergyStoragePin && !energyStorage )
				continue;
			
			double v = (*sit)->voltage();
			
			if ( energyStorage && !foundEnergyStoragePin )
			{
				foundEnergyStoragePin = true;
				(*x)[i] = v;
				continue;
			}
			
			if ( std::abs(v) > std::abs( (*x)[i] ) )
				(*x)[i] = v;
		}
		i++;
	}
	
	
	// And add the elements to the elementSet
	for ( ElementList::iterator it = m_elementList.begin(); it != listEnd; ++it )
	{
		// We don't want the element to prematurely try to do anything,
		// as it doesn't know its actual cnode ids yet
		(*it)->setCNodes();
		(*it)->setCBranches();
		m_elementSet->addElement(*it);
	}	
	// And give the branch ids to the elements
	i=0;
	for ( ElementList::iterator it = m_elementList.begin(); it != listEnd; ++it )
	{
		switch ( (*it)->numCBranches() )
		{
			case 0:
				break;
			case 1:
				(*it)->setCBranches( i );
				i += 1;
				break;
			case 2:
				(*it)->setCBranches( i, i+1 );
				i += 2;
				break;
			case 3:
				(*it)->setCBranches( i, i+1, i+2 );
				i += 3;
				break;
			default:
				// What the?!
				break;
		}
	}
}


void Circuit::initCache()
{
	m_elementSet->updateInfo();
	
	m_bCanCache = true;
	m_logicOutCount = 0;
	
	delete[] m_pLogicOut;
	m_pLogicOut = 0l;
	
	delete m_pLogicCacheBase;
	m_pLogicCacheBase = 0l;
	
	const ElementList::iterator end = m_elementList.end();
	for ( ElementList::iterator it = m_elementList.begin(); it != end && m_bCanCache; ++it )
	{
		switch ( (*it)->type() )
		{
			case Element::Element_BJT:
			case Element::Element_CCCS:
			case Element::Element_CCVS:
			case Element::Element_CurrentSource:
			case Element::Element_Diode:
			case Element::Element_LogicIn:
			case Element::Element_OpAmp:
			case Element::Element_Resistance:
			case Element::Element_VCCS:
			case Element::Element_VCVS:
			case Element::Element_VoltagePoint:
			case Element::Element_VoltageSource:
			{
				break;
			}
				
			case Element::Element_LogicOut:
			{
				m_logicOutCount++;
				break;
			}
				
			case Element::Element_CurrentSignal:
			case Element::Element_VoltageSignal:
			case Element::Element_Capacitance:
			case Element::Element_Inductance:
			{
				m_bCanCache = false;
				break;
			}
		}
	}
	
	if ( !m_bCanCache )
		return;
	
	m_pLogicOut = new LogicOut*[m_logicOutCount];
	unsigned i = 0;
	for ( ElementList::iterator it = m_elementList.begin(); it != end && m_bCanCache; ++it )
	{
		if ( (*it)->type() == Element::Element_LogicOut )
			m_pLogicOut[i++] = static_cast<LogicOut*>(*it);
	}
	
	m_pLogicCacheBase = new LogicCacheNode;
}


void Circuit::setCacheInvalidated()
{
	if (m_pLogicCacheBase)
	{
		delete m_pLogicCacheBase->high;
		m_pLogicCacheBase->high = 0l;
	
		delete m_pLogicCacheBase->low;
		m_pLogicCacheBase->low = 0l;
	
		delete m_pLogicCacheBase->data;
		m_pLogicCacheBase->data = 0l;
	}
}


void Circuit::cacheAndUpdate()
{
	LogicCacheNode * node = m_pLogicCacheBase;
	for ( unsigned i = 0; i < m_logicOutCount; i++ )
	{
		if ( m_pLogicOut[i]->outputState() )
		{
			if (!node->high)
				node->high = new LogicCacheNode;
			
			node = node->high;
		}
		else
		{
			if (!node->low)
				node->low = new LogicCacheNode;
			
			node = node->low;
		}
	}
	
	if ( node->data )
	{
		(*m_elementSet->x()) = *node->data;
		m_elementSet->updateInfo();
		return;
	}
	
	if ( m_elementSet->containsNonLinear() )
		m_elementSet->doNonLinear( 150, 1e-10, 1e-13 );
	else
		m_elementSet->doLinear(true);
	
	node->data = new Vector( m_elementSet->x()->size() );
	*node->data = *m_elementSet->x();
}


void Circuit::createMatrixMap()
{
	m_elementSet->createMatrixMap();
}


bool Circuit::recursivePinAdd( Pin *node, PinList *unassignedNodes, PinList *associated, PinList *nodes )
{
	if ( !unassignedNodes->contains(node) )
		return false;
	unassignedNodes->remove(node);
	
	bool foundGround = node->eqId() == -1;
	
	const PinList circuitDependentPins = node->circuitDependentPins();
	const PinList::const_iterator dEnd = circuitDependentPins.end();
	for ( PinList::const_iterator it = circuitDependentPins.begin(); it != dEnd; ++it )
	{
		if ( !associated->contains(*it) )
			associated->append(*it);
	}
	
	nodes->append(node);
	
	const PinList localConnectedPins = node->localConnectedPins();
	const PinList::const_iterator end = localConnectedPins.end();
	for ( PinList::const_iterator it = localConnectedPins.begin(); it != end; ++it )
		foundGround |= recursivePinAdd( *it, unassignedNodes, associated, nodes );
	
	return foundGround;
}


void Circuit::doNonLogic()
{
	if ( !m_elementSet || m_cnodeCount+m_branchCount <= 0 )
		return;
	
	if (m_bCanCache)
	{
		if ( !m_elementSet->b()->isChanged() && !m_elementSet->matrix()->isChanged() )
			return;
		cacheAndUpdate();
		updateNodalVoltages();
		m_elementSet->b()->setUnchanged();
		return;
	}
	
	stepReactive();
	if ( m_elementSet->containsNonLinear() )
	{
		m_elementSet->doNonLinear( 10, 1e-9, 1e-12 );
		updateNodalVoltages();
	}
	else
	{
		if ( m_elementSet->doLinear(true) )
			updateNodalVoltages();
	}
}


void Circuit::stepReactive()
{
	ElementList::iterator listEnd = m_elementList.end();
	for ( ElementList::iterator it = m_elementList.begin(); it != listEnd; ++it )
	{
		Element * const e = *it;
		if ( e && e->isReactive() )
			(static_cast<Reactive*>(e))->time_step();
	}
}


void Circuit::updateNodalVoltages()
{
	CNode **_cnodes = m_elementSet->cnodes();
	
	const PinList::iterator endIt = m_pinList.end();
	for ( PinList::iterator it = m_pinList.begin(); it != endIt; ++it )
	{
		Pin * const node = *it;
		int i = node->eqId();
		if ( i == -1 )
			node->setVoltage(0.);
		else
		{
			const double v = _cnodes[i]->v;
			node->setVoltage( std::isfinite(v)?v:0. );
		}
	}
}


void Circuit::updateCurrents()
{
	ElementList::iterator listEnd = m_elementList.end();
	for ( ElementList::iterator it = m_elementList.begin(); it != listEnd; ++it )
	{
		(*it)->updateCurrents();
	}
}

void Circuit::displayEquations()
{
	m_elementSet->displayEquations();
}
//END class Circuit



//BEGIN class LogicCacheNode
LogicCacheNode::LogicCacheNode()
{
	low = 0l;
	high = 0l;
	data = 0l;
}


LogicCacheNode::~LogicCacheNode()
{
	delete low;
	delete high;
	delete data;
}
//END class LogicCacheNode


