#ifndef LIBQCROSS_CNONOGRAMSOLVER_H
#define LIBQCROSS_CNONOGRAMSOLVER_H

#include <QObject>

namespace libqnono {
	class CNonogram;
	
	class CNonogramSolver : public QObject {
		Q_OBJECT
	public:
		CNonogramSolver(QObject * parent = 0);
		~CNonogramSolver();
		
		void setNonogram(CNonogram * nonogram);
	public slots:
		bool solve();
	signals:
		void markRequested(int x, int y, int type);
	protected:
		enum MarkerType {CMT_UNMARKED = 0, CMT_MARKED = 1, CMT_CROSSED = 2, CMT_NONE = 3};
		
		struct NumberOverlay {
			int borderLeft;
			int borderRight;
			
			quint16 entry;
			bool finished;
		};
		
		struct LineOverlay {
			NumberOverlay * numbers;
			int numbersSize;
			
			bool dirty;
			
			inline int borderLeftDef(int index, int def) {
				return (index > -1 && index < numbersSize) ? numbers[index].borderLeft : def; 
			}
			
			inline int borderRightDef(int index, int def) {
				return (index > -1 && index < numbersSize) ? numbers[index].borderRight : def; 
			}
			
			LineOverlay() : numbers(NULL), dirty(false) {}
			~LineOverlay() { if (numbers) delete[] numbers; }
		};
		
		CNonogram * m_Nonogram;
		
		LineOverlay * m_RowsOverlay;
		LineOverlay * m_ColumnsOverlay;
		
		int ** m_OverlayData;
		
		void cleanup();
		void prepare();
		
		inline void mark(int x, int y, int marker);
		inline void fillRow(int index, int marker);
		inline void fillColumn(int index, int marker);
		
		void printOverlays();
		bool solveLine_ng(int index, bool isRow);
		
		inline bool solveLine(int index, bool isRow);
		inline bool fillGaps(int index, bool isRow);
		inline void prepareBorders(LineOverlay * overlay);
		inline void updateBorders(int index, bool isRow);
		
		void updateBorders();
		
		inline int safeLength(NumberOverlay * overlay) {
			return (overlay->entry * 2) + overlay->borderLeft - overlay->borderRight;
		}
	};
}

#endif