/*
	Copyright 2006-2017 The QElectroTech Team
	This file is part of QElectroTech.

	QElectroTech 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.

	QElectroTech is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with QElectroTech.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "linkelementcommand.h"
#include "element.h"
#include "diagram.h"
#include "conductorautonumerotation.h"
#include "conductor.h"
#include "potentialselectordialog.h"

/**
 * @brief LinkElementCommand::LinkElementCommand
 * Constructor
 * @param element_ : element where we work the link / unlink
 * @param parent : parent undo
 */
LinkElementCommand::LinkElementCommand(Element *element_, QUndoCommand *parent):
	QUndoCommand(parent),
	m_element(element_),
	m_first_redo (true)
{
	m_linked_before = m_linked_after = m_element->linkedElements();
	setText(QObject::tr("Éditer les référence croisé", "edite the cross reference"));
}

/**
 * @brief LinkElementCommand::mergeWith
 * @param other try to merge this command with other
 * @return true if merge with success else false
 */
bool LinkElementCommand::mergeWith(const QUndoCommand *other)
{
	if (id() != other->id() || other->childCount()) return false;
	LinkElementCommand const *undo = static_cast<const LinkElementCommand *> (other);
	if (m_element != undo->m_element) return false;
	m_linked_after = undo->m_linked_after;
	return true;
}

/**
 * @brief LinkElementCommand::isLinkable
 * @param element_a
 * @param element_b
 * @param already_linked
 * @return true if element_a and element_b can be linked between them.
 * There is few condition to be linked :
 * 1- element_a and element_b must be linkable type. (Ex : A is master and B is slave 'OK', A and B is master 'KO')
 * 2- For element type slave and report (no matter if element is 'A' or 'B'), the element must be free (not connected to an element)
 * 3- we can override the section 2 by set already_linked to true. In this case, if slave or report is already
 * linked to the other element ('A' or 'B') return true, but if linked to another element (not 'A' or 'B') return false
 */
bool LinkElementCommand::isLinkable(Element *element_a, Element *element_b, bool already_linked)
{
	switch(element_a->linkType())
	{
		case Element::Simple: return false;

		case Element::NextReport:
		{
				//Type isn't good
			if (element_b->linkType() != Element::PreviousReport) return false;
				//two report is free
			if (element_a->isFree() && element_b->isFree()) return true;
				//Reports aren't free but are already linked between them and and already_linked is true
			if (element_a->linkedElements().contains(element_b) && already_linked) return true;

			return false;
		}

		case Element::PreviousReport:
		{
			//Type isn't good
		if (element_b->linkType() != Element::NextReport) return false;
			//two report is free
		if (element_a->isFree() && element_b->isFree()) return true;
			//Reports aren't free but are already linked between them and and already_linked is true
		if (element_a->linkedElements().contains(element_b) && already_linked) return true;

		return false;
		}

		case Element::Master:
		{
			//Type isn't good
		if (element_b->linkType() != Element::Slave) return false;
			//element_b is free
		if (element_b->isFree()) return true;
			//element_b isn't free but already linked to element_a and already_linked is true
		if (element_a->linkedElements().contains(element_b) && already_linked) return true;

		return false;
		}

		case Element::Slave:
		{
				//Type isn't good
			if (element_b->linkType() != Element::Master) return false;
				//Element_a is free
			if (element_a->isFree()) return true;
				//element_a isn't free but already linked to element_b and already_linked is true;
			if (element_b->linkedElements().contains(element_a) && already_linked) return true;

			return false;
		}

		case Element::Terminale: return false;

		default: return false;
	}
}

/**
 * @brief LinkElementCommand::addLink
 * Add elements from the list to the linked element of edited element
 * This method do several check to know if element can be linked or not.
 * @param element_list
 */
void LinkElementCommand::addLink(QList<Element *> element_list)
{
	setUpNewLink(element_list, false);
}

/**
 * @brief LinkElementCommand::addLink
 * This is an overloaded function
 * @param element_
 */
void LinkElementCommand::addLink(Element *element_)
{
	QList<Element *> list;
	list << element_;
	addLink(list);
}

/**
 * @brief LinkElementCommand::setLink
 * Replace all linked elements of edited element by elements stored in @element_list
 * This method do several check to know if element can be linked or not.
 * @param element_list
 */
void LinkElementCommand::setLink(QList<Element *> element_list)
{
	m_linked_after.clear();
	setUpNewLink(element_list, true);
}

/**
 * @brief LinkElementCommand::setLink
 * This is an overloaded function.
 * @param element_
 */
void LinkElementCommand::setLink(Element *element_)
{
	QList<Element *> list;
	list << element_;
	setLink(list);
}

/**
 * @brief LinkElementCommand::unlink
 * Unlink all elements of element_list from the edited element.
 * @param element_list
 */
void LinkElementCommand::unlink(QList<Element *> element_list)
{
	foreach(Element *elmt, element_list)
		m_linked_after.removeAll(elmt);
}

/**
 * @brief LinkElementCommand::unlinkAll
 * Unlink all element of the edited element
 */
void LinkElementCommand::unlinkAll() {
	m_linked_after.clear();
}

/**
 * @brief LinkElementCommand::undo
 * Undo this command
 */
void LinkElementCommand::undo()
{
	if(m_element->diagram()) m_element->diagram()->showMe();
	makeLink(m_linked_before);
	QUndoCommand::undo();
}

/**
 * @brief LinkElementCommand::redo
 * Redo this command
 */
void LinkElementCommand::redo()
{
	if(m_element->diagram()) m_element->diagram()->showMe();
	makeLink(m_linked_after);

	if (m_first_redo && (m_element->linkType() & Element::AllReport) \
		&& m_element->conductors().size() \
		&& m_linked_after.size() && m_linked_after.first()->conductors().size())
	{
			//fill list of potential
		QSet <Conductor *> c_list = m_element->conductors().first()->relatedPotentialConductors();
		c_list << m_element->conductors().first();
			//fill list of text
		QStringList strl;
		foreach (const Conductor *c, c_list) strl<<(c->properties().text);

			//check text list, isn't same in potential, ask user what to do
		if (!QET::eachStrIsEqual(strl))
		{
			PotentialSelectorDialog psd(m_element, this);
			psd.exec();
		}
		m_first_redo = false;
	}
	QUndoCommand::redo();
}

/**
 * @brief LinkElementCommand::setUpNewLink
 * Update the content of m_link_after with the content of @element_list.
 * Each linkable element (know via the static method isLinkable) is added to m_linked_after
 * @already_link is used for the static method isLinkable.
 * @param element_list
 * @param already_link
 */
void LinkElementCommand::setUpNewLink(const QList<Element *> &element_list, bool already_link)
{
		//m_element is a master we can connect several element to it
		//if m_element isn't master (may be a report or slave) we can connect only one element
	if (m_element->linkType() == Element::Master || element_list.size() == 1)
	{
		foreach(Element *elmt, element_list)
			if (isLinkable(m_element, elmt, already_link))
				m_linked_after << elmt;
	}
	else
	{
		qDebug() << "LinkElementCommand::setUpNewLink : try to link several elements to a report element or slave element,"
					" only the first element of the list will be taken to be linked";
		foreach(Element *elmt, element_list)
			if (isLinkable(m_element, elmt, already_link))
			{
				m_linked_after << elmt;
				return;
			}
	}
}

/**
 * @brief LinkElementCommand::makeLink
 * Make the link between m_element and element_list;
 * This method unlink elements if needed.
 * @param element_list
 */
void LinkElementCommand::makeLink(const QList<Element *> &element_list)
{
		//List is empty, that mean m_element must be free, so we unlink all elements
	if (element_list.isEmpty())
	{
		m_element->unlinkAllElements();
		return;
	}

		//We link all element from element_list
	foreach(Element *elmt, element_list)
		m_element->linkToElement(elmt);

		//At this point may be there are unwanted linked elements to m_element. We must to unlink it.
		//Elements from @element_list are wanted so we compare @element_list to current linked element of @m_element
	QList<Element *> to_unlink = m_element->linkedElements();
	foreach(Element *elmt, element_list)
		to_unlink.removeAll(elmt);

		//All elements stored in to_unlink is unwanted we unlink it from m_element
	if (!to_unlink.isEmpty())
		foreach(Element *elmt, to_unlink)
			m_element->unlinkElement(elmt);
}