// simple_logic.h :		include file for simple logical operation
//
// Purpose:				to parse and execute a logical expression like 'b1 && !(b2 || b3) ^ b4 && b5'
//
// Date:				2023-09-03
//
// Author:				gb
//
// Supporting opers:	&&, ||, ^
// 
// Priority:			(&&, ^, ), (||)

#pragma once

#include <string>
#include <vector>

namespace string_util
{
	// Function:	find the ending position in str
	//
	// Parameter:	str - the string beginning after the first letter 'head'
	//
	//				head - the leading letter, can be emblaced
	//
	//				tail - the ending letter
	//
	// Return:		position at the ending letter, or '\0' in the string
	int find_end_of_pair(const char* str, char head, char tail);
	void skip_space(const char*& ptr, const char* space = " \t");

	enum
	{
		TRIM_LEFT = 1,
		TRIM_RIGHT,
		TRIM_BOTH,
	};
	void trim(std::string& str, int type = TRIM_BOTH);
};

class simple_logic
{
	int				oper_;
	bool			not_;
	std::string		expr_;
	simple_logic*	l_;
	simple_logic*	r_;

	void clear(void);
	void copy(const simple_logic& r);
	void set_not(bool notv);
	bool parse_internal(const char* expr, int* end, void(*leaf)(const char*, void*), void* leaf_param);
	simple_logic* make_binary(const std::vector<simple_logic*>& eles, const std::vector<int>& opers);
	std::string to_string_internal(bool& single);

public:
	simple_logic();
	simple_logic(const simple_logic& r);
	~simple_logic();

	// && == ^ > ||
	enum
	{
		LOGIC_OPER_NONE = 0,
		LOGIC_OPER_LEAF,
		LOGIC_OPER_OR,
		LOGIC_OPER_AND,
		LOGIC_OPER_XOR,
	};

	simple_logic& operator=(const simple_logic& r);

public:
	bool parse(const char* expr, int *end_pos = nullptr, void(*leaf)(const char*, void*) = nullptr, void* leaf_param = nullptr);	// leaf: callback for leaf notifying
	bool value(bool(*simple_expr_value)(const char*, void*), void* param);
	std::string to_expression(void);
};