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#include "featuretreemodel.h"

#include "feature.h"

#include <QPalette>

#include <QColor>

#include <QApplication>

#include <QtDebug>

QT_BEGIN_NAMESPACE

class Node

{

public:

    Node(Feature *f, Node *p = 0) : feature(f), parent(p) {}

    ~Node();

    Node* find(const Feature *child) const;

    bool contains(const Feature *child) const { return find(child) != 0; }

    bool insert(Node *n);

    Feature *feature;

    Node *parent;

    QList<Node*> children; // maybe convert to Map to get keys sorted

};

Node::~Node()

{

    while (!children.isEmpty())

        delete children.takeFirst();

}

Node* Node::find(const Feature *f) const

{

    if (this->feature == f)

	return const_cast<Node*>(this);

    foreach (Node *n, children)

	if (Node *m = n->find(f))

	    return m;

    return 0;

}

static bool nodePtrLessThan(const Node *n1, const Node *n2)

{

    return (n1->feature->key() < n2->feature->key());

}

/*

  Try insert \a n into the tree with this node as root.

  n is inserted as a child if it has a dependency to this node.

  Returns true if child is inserted into the tree, false otherwise.

*/

bool Node::insert(Node *n)

{

    Feature *f = const_cast<Feature*>(n->feature);

    if (feature->supports().contains(f)) {

        children.append(n);

	qSort(children.begin(), children.end(), nodePtrLessThan);

	n->parent = this;

        return true;

    }

    foreach (Node *child, children)

        if (child->insert(n))

            return true;

    return false;

}

static bool isSection(const QModelIndex &index)

{

    return index.isValid() && (index.internalId() == 0);

}

FeatureTreeModel::FeatureTreeModel(QObject *parent)

    : QAbstractItemModel(parent)

{

}

FeatureTreeModel::~FeatureTreeModel()

{

    foreach (QString section, sections.keys())

	while (!sections[section].isEmpty())

	    delete sections[section].takeFirst();

}

/*

  Returns true if the model already contains \a in \a section, false otherwise.

*/

bool FeatureTreeModel::contains(const QString &section, const Feature *f) const

{

    return (find(section, f) != 0);

}

Node* FeatureTreeModel::find(const QString &section, const Feature *f) const

{

    QList<Node*> roots = sections[section];

    foreach (Node *root, roots)

        if (Node *n = root->find(f))

            return n;

    return 0;

}

/*

  Add new \a feature to the tree.

  When all feature is added, buildTree() must be called to build the

  dependency tree.

*/

void FeatureTreeModel::addFeature(Feature *feature)

{

    const QString section = feature->section();

    Q_ASSERT(!contains(section, feature));

    connect(feature, SIGNAL(changed()), this, SLOT(featureChanged()));

    Node *node = new Node(feature, 0);

    // try insert any toplevel nodes as child of this one

    foreach (Node *n, sections[section])

	if (node->insert(n))

	    sections[section].removeAll(n);

    // try insert this node as a child of any existing node

    foreach (Node *n, sections[section])

	if (n->insert(node)) {

            emit layoutChanged();

	    return;

        }

    // not a child, insert as a toplevel node

    sections[section].append(node);

    qSort(sections[section].begin(), sections[section].end(), nodePtrLessThan);

    emit layoutChanged();

}

QModelIndex FeatureTreeModel::createIndex(int row, int column,

					  const QModelIndex &parent,

					  const Node *node) const

{

    QModelIndex index = QAbstractItemModel::createIndex(row, column,

							(void*)node);

    if (parent.isValid())

	parentMap[index] = parent;

    if (node)

        featureIndexMap[node->feature] = index;

    return index;

}

QModelIndex FeatureTreeModel::index(int row, int column,

                                    const QModelIndex &parent) const

{

    if (!parent.isValid()) { // index is a section

        if (row < sections.size() && column == 0)

            return QAbstractItemModel::createIndex(row, column, 0);

	return QModelIndex();

    }

    if (isSection(parent)) { // index is a toplevel feature

        const int parentRow = parent.row();

        if (parentRow < sections.size()) {

            QString section = sections.keys().at(parentRow);

	    QList<Node*> nodes = sections[section];

            if (row < nodes.size() && column < 2)

                return createIndex(row, column, parent, nodes.at(row));

        }

	return QModelIndex();

    }

    // parent is a feature

    Node *parentNode = static_cast<Node*>(parent.internalPointer());

    QList<Node*> children = parentNode->children;

    if (row < children.size() && column < 2)

	return createIndex(row, column, parent, children.at(row));

    return QModelIndex();

}

QModelIndex FeatureTreeModel::index(const QModelIndex &parent,

                                    const Feature *feature) const

{

    const int rows = rowCount(parent);

    for (int i = 0; i < rows; ++i) {

        QModelIndex child = index(i, 0, parent);

        Node *node = static_cast<Node*>(child.internalPointer());

        if (node && node->feature == feature)

            return child;

        QModelIndex childSearch = index(child, feature);

        if (childSearch.isValid())

            return childSearch;

    }

    return QModelIndex();

}

QModelIndex FeatureTreeModel::index(const Feature *feature) const

{

    if (featureIndexMap.contains(feature))

        return featureIndexMap.value(feature);

    // exhaustive search

    int sectionRow = sections.keys().indexOf(feature->section());

    QModelIndex sectionIndex = index(sectionRow, 0, QModelIndex());

    return index(sectionIndex, feature);

}

QModelIndex FeatureTreeModel::parent(const QModelIndex &index) const

{

    if (!index.isValid())

        return QModelIndex();

    if (parentMap.contains(index))

	return parentMap.value(index);

    return QModelIndex();

}

int FeatureTreeModel::rowCount(const QModelIndex &parent) const

{

    if (!parent.isValid())

        return sections.size();

    if (isSection(parent)) {

	const QString section = sections.keys().at(parent.row());

	return sections[section].size();

    }

    const Node *node = static_cast<Node*>(parent.internalPointer());

    return node->children.size();

}

int FeatureTreeModel::columnCount(const QModelIndex &parent) const

{

#if 0

    if (!parent.isValid())

        return 0;

    if (isSection(parent))

       return 1;

#endif

    Q_UNUSED(parent);

    return 2; // Feature: [key, name]

}

QVariant FeatureTreeModel::data(const QModelIndex &index, int role) const

{

    if (!index.isValid())

        return QVariant();

    const Node *node = static_cast<Node*>(index.internalPointer());

    switch (role) {

	case Qt::DisplayRole: {

	    if (node == 0)  // index is a section

		return sections.keys().at(index.row());

	    if (index.column() == 0)

		return node->feature->key();

	    Q_ASSERT(index.column() == 1);

	    return node->feature->title();

	}

	case Qt::CheckStateRole: {

	    if (node && index.column() == 0)

		return (node->feature->enabled() ?

			Qt::Checked : Qt::Unchecked);

	    break;

	}

	case Qt::TextColorRole: {

	    if (node && index.column() == 0)  // feature key

		if (node->feature->selectable())

		    return QApplication::palette().color(QPalette::Link);

	    break;

	}

	case Qt::TextAlignmentRole:

	case Qt::BackgroundColorRole:

	case Qt::FontRole:

	case Qt::ToolTipRole: // TODO

	case Qt::StatusTipRole: // TODO

	case Qt::WhatsThisRole: // TODO

	case Qt::DecorationRole:

	case Qt::EditRole:

 	default:

	    break;

    }

    return QVariant();

}

bool FeatureTreeModel::setData(const QModelIndex &index,

                               const QVariant &value, int role)

{

    if (!index.isValid())

        return false;

    Node *node = static_cast<Node*>(index.internalPointer());

    if (!node)

        return false;

    if (role == Qt::CheckStateRole) {

        Qt::CheckState state = static_cast<Qt::CheckState>(value.toInt());

        if (state == Qt::Checked)

            node->feature->setEnabled(true);

        else if (state == Qt::Unchecked)

            node->feature->setEnabled(false);

        emit dataChanged(index, index);

        return true;

    }

    return false;

}

Qt::ItemFlags FeatureTreeModel::flags(const QModelIndex &index) const

{

    if (!index.isValid() || index.internalPointer() == 0)

	return Qt::ItemIsEnabled | Qt::ItemIsSelectable;

    const Node *node = static_cast<Node*>(index.internalPointer());

    const Feature *feature = node->feature;

    Qt::ItemFlags flags = Qt::ItemIsUserCheckable | Qt::ItemIsSelectable;

    if (feature->selectable())

	flags |= Qt::ItemIsEnabled;

    return flags;

}

QVariant FeatureTreeModel::headerData(int section, Qt::Orientation orientation,

				      int role) const

{

    if (orientation == Qt::Horizontal && role == Qt::DisplayRole) {

        if (section == 0)

            return QString("Id");

        else if (section == 1)

            return QString("Name");

    }

    return QVariant();

}

Feature* FeatureTreeModel::getFeature(const QModelIndex &index) const

{

    if (!index.isValid())

	return 0;

    if (isSection(index))

	return 0;

    Node *node = static_cast<Node*>(index.internalPointer());

    return const_cast<Feature*>(node->feature);

}

void FeatureTreeModel::featureChanged()

{

    Feature *feature = qobject_cast<Feature*>(sender());

    if (feature) {

        QModelIndex featureIndex = index(feature);

        emit dataChanged(featureIndex, featureIndex);

    } else {

        emit layoutChanged();

    }

}

void FeatureTreeModel::readConfig(QTextStream &stream)

{

    static QRegExp regexp("\\s*#\\s*define\\s+QT_NO_(\\S+)\\s*");

    while (!stream.atEnd()) {

	QString line = stream.readLine();

        if (regexp.exactMatch(line)) {

            Feature *f = Feature::getInstance(regexp.cap(1));

            f->setEnabled(false);

        }

    }

}

/*

  Search for all disabled child features of \a parent.

  Returns a list of feature keys for the disabled items.

*/

QStringList FeatureTreeModel::findDisabled(const QModelIndex &parent) const

{

    QStringList stringList;

    const int rows = rowCount(parent);

    for (int i = 0; i < rows; ++i) {

        QModelIndex child = index(i, 0, parent);

        Node *node = static_cast<Node*>(child.internalPointer());

        if (node && node->feature && !node->feature->enabled())

            stringList << node->feature->key();

        stringList << findDisabled(child);

    }

    return stringList;

}

void FeatureTreeModel::writeConfig(QTextStream &stream) const

{

    const int sectionCount = rowCount(QModelIndex());

    for (int i = 0; i < sectionCount; ++i) {

        QModelIndex section = index(i, 0, QModelIndex());

        QStringList disabled = findDisabled(section);

        if (disabled.size() > 0) {

            stream << '\n' << "/* " << sections.keys().at(i) << " */" << '\n';

            foreach (QString feature, disabled)

                stream << "#ifndef QT_NO_" << feature << '\n'

                       << "#  define QT_NO_" << feature << '\n'

                       << "#endif" << '\n';

        }

    }

}

void FeatureTreeModel::clear()

{

    Feature::clear();

    sections.clear();

    parentMap.clear();

    featureIndexMap.clear();

    emit layoutChanged();

}

QT_END_NAMESPACE