#ifndef NAMESPACEITEMMODEL_H
#define NAMESPACEITEMMODEL_H

#include <QAbstractItemModel>
#include "PgNamespace.h"
#include <vector>
#include <iterator>

class PgNamespaceContainer;

class NamespaceItemModel: public QAbstractItemModel {
public:
	NamespaceItemModel(QObject *parent = 0);

	void init(std::shared_ptr<const PgNamespaceContainer> ns);

	virtual QModelIndex index(int row, int column,
		const QModelIndex &parent = QModelIndex()) const override;
	virtual QModelIndex parent(const QModelIndex &index) const override;

	virtual int rowCount(const QModelIndex &parent = QModelIndex()) const override;
	virtual int columnCount(const QModelIndex &parent = QModelIndex()) const override;
	virtual QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
	virtual bool setData(const QModelIndex &index, const QVariant &value, int role) override;
	virtual Qt::ItemFlags flags(const QModelIndex &index) const override;

	template <typename I>
	void getCheckedNamespaces(I inserter) const
	{
		for (auto g : groups)
			for (auto l : g->leaves)
				if (l->checked)
					inserter = l->ns.oid;
	}
private:
	class Node {
	public:

		virtual ~Node() {}
		virtual int getRowCount() const = 0;
		virtual Qt::CheckState getCheckState() const = 0;

	};
	class GroupNode;

	class LeafNode: public Node {
	public:
		std::weak_ptr<GroupNode> parent;
		bool checked = false;

		PgNamespace ns;
		LeafNode(std::weak_ptr<GroupNode> p, const PgNamespace &nspace)
			: parent(p)
			, ns(nspace)
		{}

		virtual int getRowCount() const override
		{
			return 0;
		}

		virtual Qt::CheckState getCheckState() const override
		{
			return checked ? Qt::Checked : Qt::Unchecked;
		}

		bool operator < (const LeafNode &rhs) const
		{
			return ns.name < rhs.ns.name;
		}
	};

	class GroupNode: public Node {
	public:
		using LeafVec = std::vector<std::shared_ptr<LeafNode>>;

		QString name;
		LeafVec leaves;

		GroupNode(QString n)
			: name(n)
		{}
		virtual int getRowCount() const override
		{
			return leaves.size();
		}
		void sortLeaves()
		{
			std::sort(leaves.begin(), leaves.end(),
					  [] (auto l, auto r) -> bool { return *l < *r; });
		}
		virtual Qt::CheckState getCheckState() const override
		{
			bool some_checked = false;
			bool some_unchecked = false;
			for (auto l : leaves) {
				if (l->checked)
					some_checked = true;
				else
					some_unchecked = true;
			}
			Qt::CheckState result;
			if (some_checked && some_unchecked)
				result = Qt::PartiallyChecked;
			else if (some_checked)
				result = Qt::Checked;
			else
				result = Qt::Unchecked;

			return result;
		}
	};

	using GroupVec = std::vector<std::shared_ptr<GroupNode>>;

	GroupVec groups;

};

#endif // NAMESPACEITEMMODEL_H