/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: hulamy <marvin@42.fr>                      +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2019/11/25 13:54:29 by hulamy            #+#    #+#             */
/*   Updated: 2019/11/25 13:54:35 by hulamy           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

// int ft_atoi(const char *str)
// {
// 	long long nbr; // Use `long long` to detect overflow before it happens in `int`
// 	int i;		   // Current position in the string
// 	int n;		   // Sign multiplier: 1 (positive) or -1 (negative)

// 	i = 0;
// 	n = 1;
// 	nbr = 0;

// 	// skip leading whitespace
// 	while (ft_isspace(str[i]))
// 		i++;

// 	// handle optional sign
// 	if (str[i] == '-')
// 		n = -1;
// 	if (str[i] == '+' || str[i] == '-')
// 		i++;

// 	// convert digits to integer
// 	while (str[i] >= '0' && str[i] <= '9')
// 	{
// 		// --- Overflow Check ---
// 		// LLONG_MAX = 9223372036854775807 (maximum value for a 64-bit signed integer)
// 		// If `nbr` is already >= 922337203685477580 (LLONG_MAX / 10),
// 		// then multiplying by 10 and adding another digit could overflow.
// 		//
// 		// Cases:
// 		//   - For positive numbers: If `nbr >= 922337203685477580` and the next digit > 7,
// 		//     then `nbr * 10 + digit` would exceed LLONG_MAX (e.g., 9223372036854775808).
// 		//   - For negative numbers: If `nbr >= 922337203685477580` and the next digit > 8,
// 		//     then `nbr * 10 + digit` would exceed LLONG_MIN (e.g., -9223372036854775809).
// 		//
// 		// Why 7 and 8?
// 		//   - LLONG_MAX = 9223372036854775807 → Last digit is 7.
// 		//     So, if `nbr = 922337203685477580` and the next digit is > 7, overflow occurs.
// 		//   - LLONG_MIN = -9223372036854775808 → Last digit is 8.
// 		//     So, if `nbr = 922337203685477580` and the next digit is > 8, underflow occurs.
// 		if ((nbr >= 922337203685477580 && ((str[i] > 8 && n < 0) || (str[i] > 7 && n > 0))))
// 		{
// 			// Overflow: Return -1 for positive, 0 for negative (mimics INT_MAX/INT_MIN behavior)
// 			return ((n > 0) ? -1 : 0);
// 		}

// 		// convert digit to integer : `str[i] - '0'` converts the ASCII character to its numeric value (e.g., '5' → 5)
// 		nbr = nbr * 10 + (str[i] - '0');
// 		i++;
// 	}

// 	// apply sign and return
// 	return (nbr * n);
// }