package main

import (
	"os"

	"github.com/01-edu/z01"
)

const SIZE = 2048

func main() {
	if len(os.Args) == 2 {
		progpoint := []byte(os.Args[1])
		var arby [SIZE]byte
		pos := 0
		openBr := 0         //opened brackets
		i := 0              //iterates through the source code passed in the argument
		N := len(progpoint) //length of the source code
		for i >= 0 && i < N {
			switch progpoint[i] {
			case '>':
				//Increment the pointer
				pos++
			case '<':
				//decrement the pointes
				pos--
			case '+':
				//increment the pointed byte
				arby[pos]++
			case '-':
				//decrement the pointed byte
				arby[pos]--
			case '.':
				//print the pointed byte on std output
				z01.PrintRune(rune(arby[pos]))
			case '[':
				//go to the matching ']' if the pointed byte is 0 (while start)
				openBr = 0
				if arby[pos] == 0 {
					for i < N && (progpoint[i] != byte(']') || openBr > 1) {
						if progpoint[i] == byte('[') {
							openBr++
						} else if progpoint[i] == byte(']') {
							openBr--
						}
						i++
					}
				}
			case ']':
				//go to the matching '[' if the pointed byte is not 0 (while end)
				openBr = 0
				if arby[pos] != 0 {
					for i >= 0 && (progpoint[i] != byte('[') || openBr > 1) {
						if progpoint[i] == byte(']') {
							openBr++
						} else if progpoint[i] == byte('[') {
							openBr--
						}
						i--
					}
				}
			}
			i++
		}
	} else {
		z01.PrintRune('\n')
	}
}