/*************************************************************************/
/*  vset.h                                                               */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
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/* "Software"), to deal in the Software without restriction, including   */
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/*************************************************************************/

#ifndef VSET_H
#define VSET_H

#include "core/templates/vector.h"
#include "core/typedefs.h"

template <class T>
class VSet {
	Vector<T> _data;

	_FORCE_INLINE_ int _find(const T &p_val, bool &r_exact) const {
		r_exact = false;
		if (_data.is_empty()) {
			return 0;
		}

		int low = 0;
		int high = _data.size() - 1;
		const T *a = &_data[0];
		int middle = 0;

#ifdef DEBUG_ENABLED
		if (low > high) {
			ERR_PRINT("low > high, this may be a bug");
		}
#endif

		while (low <= high) {
			middle = (low + high) / 2;

			if (p_val < a[middle]) {
				high = middle - 1; //search low end of array
			} else if (a[middle] < p_val) {
				low = middle + 1; //search high end of array
			} else {
				r_exact = true;
				return middle;
			}
		}

		//return the position where this would be inserted
		if (a[middle] < p_val) {
			middle++;
		}
		return middle;
	}

	_FORCE_INLINE_ int _find_exact(const T &p_val) const {
		if (_data.is_empty()) {
			return -1;
		}

		int low = 0;
		int high = _data.size() - 1;
		int middle;
		const T *a = &_data[0];

		while (low <= high) {
			middle = (low + high) / 2;

			if (p_val < a[middle]) {
				high = middle - 1; //search low end of array
			} else if (a[middle] < p_val) {
				low = middle + 1; //search high end of array
			} else {
				return middle;
			}
		}

		return -1;
	}

public:
	void insert(const T &p_val) {
		bool exact;
		int pos = _find(p_val, exact);
		if (exact) {
			return;
		}
		_data.insert(pos, p_val);
	}

	bool has(const T &p_val) const {
		return _find_exact(p_val) != -1;
	}

	void erase(const T &p_val) {
		int pos = _find_exact(p_val);
		if (pos < 0) {
			return;
		}
		_data.remove(pos);
	}

	int find(const T &p_val) const {
		return _find_exact(p_val);
	}

	_FORCE_INLINE_ bool is_empty() const { return _data.is_empty(); }

	_FORCE_INLINE_ int size() const { return _data.size(); }

	inline T &operator[](int p_index) {
		return _data.write[p_index];
	}

	inline const T &operator[](int p_index) const {
		return _data[p_index];
	}
};

#endif // VSET_H