extern crate proc_macro;
use proc_macro::TokenStream;
use proc_macro::TokenTree;
use proc_macro::Ident;
use proc_macro::Span;
use std::iter::FromIterator;
static mut TEMP_COUNTER: i64 = 0;

#[proc_macro]
pub fn temp(item: TokenStream) -> TokenStream {
    let mut iterator = item.clone().into_iter().peekable();
    if item.is_empty() {
	unsafe { TEMP_COUNTER += 1; }
    } else if let Some(TokenTree::Literal(_)) = iterator.peek() {
	if let Ok(number) = item.to_string().parse::<i64>() {
	    unsafe { TEMP_COUNTER = number; }
	}
    } else if let Some(TokenTree::Punct(i)) = iterator.next() {
	if i.as_char() == '+' {
	    if let Some(TokenTree::Literal(i)) = iterator.next() {
		if let Ok(number) = i.to_string().parse::<i64>() {
		    unsafe { TEMP_COUNTER += number; }
		}
	    }
	} else if i.as_char() == '-' {
	    if let Some(TokenTree::Literal(i)) = iterator.next() {
		if let Ok(number) = i.to_string().parse::<i64>() {
		    unsafe { TEMP_COUNTER -= number; }
		}
	    } else if let None = iterator.next() {
		
	    }
	}
    } else {
	panic!("Invalid input to temporary variable generator.");
    }
    TokenStream::from_iter([
	TokenTree::Ident(Ident::new(format!("temp{}", unsafe { TEMP_COUNTER }).as_str(), Span::call_site()))
    ])
}