// Copyright (C) 2008  Lukas Lalinsky
//
// 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.
//
// This program 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 this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

#include <QGraphicsScene>
#include <QDebug>
#include "diagramdocument.h"
#include "column.h"
#include "columnlist.h"
#include "databasetable.h"
#include "line.h"
#include "databaserelationship.h"
#include "databaserelationshipproperties.h"
#include "utils/range.h"
#include "domutils.h"
#include "hub.h"

class DatabaseRelationship::PrivateData
{
public:
	PrivateData() :
		cardinality(OneToMany),
		childOptional(true),
		parentOptional(true),
		onUpdateAction(NoAction),
		onDeleteAction(NoAction),
		childColumn(0),
		parentColumn(0)
	{
		if (!pathsInitialized) {
			pathsInitialized = true;

			paths[1].moveTo(-5, 0);
			paths[1].lineTo(0, 8);
			paths[1].lineTo(5, 0);
			paths[1].moveTo(-4, 10);
			paths[1].lineTo(4, 10);

			paths[3].moveTo(-4, 5);
			paths[3].lineTo(4, 5);
			paths[3].moveTo(-4, 8);
			paths[3].lineTo(4, 8);

			paths[2].moveTo(-4, 5);
			paths[2].lineTo(4, 5);
			paths[2].addEllipse(-3.5, 8, 7, 7);

			paths[0].moveTo(-5, 0);
			paths[0].lineTo(0, 8);
			paths[0].lineTo(5, 0);
			paths[0].addEllipse(-3.5, 8, 7, 7);

			paths[4].moveTo(-4.5, 9);
			paths[4].lineTo(0, 0);
			paths[4].lineTo(4.5, 9);
			paths[4].lineTo(-4.5, 9);
		}
	}

	Cardinality cardinality;
	bool childOptional;
	bool parentOptional;
	Action onUpdateAction;
	Action onDeleteAction;
	Column *childColumn;
	Column *parentColumn;

	QPainterPath crowsFootPath(bool toMany, bool optional)
	{
		if (toMany) {
			if (optional) // 0..*
				return paths[0];
			else // 1..*
				return paths[1];
		}
		else {
			if (optional) // 0..1
				return paths[2];
			else // 1..1
				return paths[3];
		}
	}

	QPainterPath arrowHeadPath()
	{
		return paths[4];
	}

	static bool pathsInitialized;
	static QPainterPath paths[5];
};

bool DatabaseRelationship::PrivateData::pathsInitialized = false;
QPainterPath DatabaseRelationship::PrivateData::paths[5];

DatabaseRelationship::DatabaseRelationship(DiagramItem *parent)
	: Line(parent), d(new PrivateData)
{
	setFlag(ItemIsSelectable);
}

DatabaseRelationship::~DatabaseRelationship()
{
	delete d;
}

DatabaseRelationship::Cardinality
DatabaseRelationship::cardinality() const
{
	return d->cardinality;
}

void
DatabaseRelationship::setCardinality(Cardinality cardinality)
{
	if (d->cardinality != cardinality) {
		d->cardinality = cardinality;
		emit propertyChanged("cardinality", cardinality);
		updateEnds();
		update();
	}
}

bool
DatabaseRelationship::isChildOptional() const
{
	return d->childOptional;
}

void
DatabaseRelationship::setChildOptional(bool optional)
{
	if (d->childOptional != optional) {
		d->childOptional = optional;
		emit propertyChanged("childOptional", optional);
		updateEnds();
		update();
	}
}

bool
DatabaseRelationship::isParentOptional() const
{
	return d->parentOptional;
}

void
DatabaseRelationship::setParentOptional(bool optional)
{
	if (d->parentOptional != optional) {
		d->parentOptional = optional;
		emit propertyChanged("parentOptional", optional);
		updateEnds();
		update();
	}
}

Column *
DatabaseRelationship::childColumn() const
{
	return d->childColumn;
}

void
DatabaseRelationship::setChildColumn(Column *column)
{
	if (d->childColumn != column) {
		d->childColumn = column;
		emit propertyChanged("childColumn", qVariantFromValue<Column*>(column));
		static_cast<DatabaseTable *>(connector(0)->hub()->owner())->updateLayout();
		updateLayout();
		update();
	}
}

Column *
DatabaseRelationship::parentColumn() const
{
	return d->parentColumn;
}

void
DatabaseRelationship::setParentColumn(Column *column)
{
	if (d->parentColumn != column) {
		d->parentColumn = column;
		emit propertyChanged("parentColumn", qVariantFromValue<Column*>(column));
		updateLayout();
		update();
	}
}

bool
DatabaseRelationship::isIdentifying() const
{
	DatabaseTable *table = childTable();
	if (table) {
		Column *column = childColumn();
		if (column) {
			return column->isPrimaryKey();
		}
	}
	return false;
}

QVariant
DatabaseRelationship::itemChange(GraphicsItemChange change, const QVariant &value)
{
	if (change == ItemSceneHasChanged) {
		updateLayout();
	}
	return QGraphicsItem::itemChange(change, value);
}

void
DatabaseRelationship::updateEnds()
{
	if (!document())
		return;

	switch (document()->notation()) {
		case DiagramDocument::Relational:
			setFillStartArrow(false);
			setFillEndArrow(true);
			setStartArrow(QPainterPath());
			setEndArrow(d->arrowHeadPath());
			setLineStyle(Qt::SolidLine);
			break;
		case DiagramDocument::CrowsFoot:
			setFillStartArrow(false);
			setFillEndArrow(false);
			setStartArrow(d->crowsFootPath(d->cardinality != OneToOne, isChildOptional()));
			setEndArrow(d->crowsFootPath(d->cardinality == ManyToMany, isParentOptional()));
			setLineStyle(isIdentifying() ? Qt::SolidLine : Qt::DashLine);
			break;
	}
}

void
DatabaseRelationship::updateLayout()
{
	prepareGeometryChange();

    Connector *connector1 = connector(0);
    Connector *connector2 = connector(1);

	bool haveLine = false;

	QPolygonF line;

	// Orthogonal line
	if (!haveLine) {
		QPointF p1 = connector1->pos();
		QPointF p2 = connector2->pos();
		qreal a1 = connector1->angle();
		qreal a2 = connector2->angle();

		QLineF line1 = QLineF::fromPolar(1, a1).translated(p1);
		QLineF line2 = QLineF::fromPolar(1, a2).translated(p2);
		QPointF intersection;
		line << p1;
		if (line1.intersect(line2, &intersection) != QLineF::NoIntersection) {
			// 2-segment line
			line << intersection;
		}
		else {
			if (line1.intersect(line2.normalVector(), &intersection) != QLineF::NoIntersection) {
				// 3-segment line
				qreal len = QLineF(p1, intersection).length() * 0.5;
				line << QLineF::fromPolar(len, a1).translated(p1).p2();
				line << QLineF::fromPolar(len, a2).translated(p2).p2();
			}
			else {
				qFatal("No line?");
			}
		}
		line << p2;
		haveLine = true;
	}

	// Simple center<->center line
	if (!haveLine) {
		QPointF p1 = connector1->pos();
		QPointF p2 = connector2->pos();
		line << p1 << p2;
		haveLine = true;
	}

	setLinePoints(line);
	updateEnds();
}

void
DatabaseRelationship::loadFromXml(QDomElement element, DiagramDocument *document)
{
	Line::loadFromXml(element, document);
	QDomElement relationshipeElement = element.firstChildElement("relationship");
	if (!relationshipeElement.isNull()) {
		setCardinality(readEnumElement(relationshipeElement, "cardinality", OneToMany, this, "Cardinality"));
		QDomElement modalityElement = relationshipeElement.firstChildElement("modality");
		if (!modalityElement.isNull()) {
			setChildOptional(readBoolElement(modalityElement, "child", true, "Optional", "Mandatory"));
			setParentOptional(readBoolElement(modalityElement, "parent", true, "Optional", "Mandatory"));
		}
		QDomElement columnsElement = relationshipeElement.firstChildElement("columns");
		if (!columnsElement.isNull()) {
			int index = readIntElement(columnsElement, "child", -1);
			if (index != -1 && childTable())
				setChildColumn(childTable()->columnList()->column(index));
			index = readIntElement(columnsElement, "parent", -1);
			if (index != -1 && parentTable())
				setParentColumn(parentTable()->columnList()->column(index));
		}
	}
}

void
DatabaseRelationship::saveToXml(QDomDocument doc, QDomElement element)
{
	Line::saveToXml(doc, element);
	QDomElement relationshipeElement = doc.createElement("relationship");
	element.appendChild(relationshipeElement);
	appendEnumElement(doc, relationshipeElement, "cardinality", d->cardinality, this, "Cardinality");
	QDomElement modalityElement = doc.createElement("modality");
	relationshipeElement.appendChild(modalityElement);
	appendBoolElement(doc, modalityElement, "child", d->childOptional, "Optional", "Mandatory");
	appendBoolElement(doc, modalityElement, "parent", d->parentOptional, "Optional", "Mandatory");
	if (d->childColumn || d->parentColumn) {
		QDomElement columnsElement = doc.createElement("columns");
		relationshipeElement.appendChild(columnsElement);
		if (d->childColumn)
			appendIntElement(doc, columnsElement, "child", childTable()->columnList()->indexOf(d->childColumn));
		if (d->parentColumn)
			appendIntElement(doc, columnsElement, "parent", parentTable()->columnList()->indexOf(d->parentColumn));
	}
}

DiagramItemProperties *
DatabaseRelationship::createPropertiesEditor(QWidget *parent)
{
	return new DatabaseRelationshipProperties(parent);
}