use std::env;
use std::fs;
use std::collections::VecDeque;

fn main() {
    let (mut stacks, moves) = read_input(&env::args().nth(1).unwrap());
    println!("stack = {:?}", stacks);
    println!("moves = {:?}", moves);

    for (n, from, to) in moves {
        for _i in 1..=n {
            let item = stacks[from].pop_front().unwrap();
            stacks[to].push_front(item);
        }
    }

    let res: String = stacks.iter()
            .map(|stack| stack.front().unwrap())
            .collect();
    println!("res = {:?}", res);
}

fn read_input(file: &str) -> (Vec<VecDeque<char>>, Vec<(usize, usize, usize)>) {
    let input = fs::read_to_string(file).unwrap();

    let n_stacks = (input.lines().next().unwrap().len() + 1) / 4;
    let mut stacks: Vec<VecDeque<char>> = vec![VecDeque::new(); n_stacks];
    let mut moves: Vec<(usize, usize, usize)> = Vec::new();
    let mut reading_crates = true;

    for line in input.lines() {
        if line.is_empty() || (reading_crates && has_digit(line)) {
            reading_crates = false;
            continue;

        } else if reading_crates {
            for (i, c) in line.char_indices() {
                if i % 4 == 1 && c != ' '{
                    stacks[i/4].push_back(c);
                }
            }

        } else {
            let nums: Vec<usize> = line
                    .split(|c: char| !c.is_numeric())
                    .filter(|s| !s.is_empty())
                    .map(|num| num.parse::<usize>().unwrap())
                    .collect();
            moves.push((nums[0], nums[1] - 1, nums[2] - 1));
            
        }
    }
    (stacks, moves)
}

fn has_digit(line: &str) -> bool {
    !line.chars().filter(|c| c.is_digit(10)).collect::<Vec<char>>().is_empty()
}