Just getting started with Rust, part 1 took a long time. Really amazed when I saw part 2, just needed to add 2 lines and was done due to the approach I had taken. Feedback more than welcome!

use std::{
    cmp, fs,
    io::{BufRead, BufReader},
};

fn main() {
    cube_conundrum_complete();
}

fn cube_conundrum_complete() {
    // Load the data file
    let filename = "./data/input_data/day_2_cubes.txt";
    let file = match fs::File::open(filename) {
        Ok(f) => f,
        Err(e) => {
            eprintln!("Error opening file: {}", e);
            return;
        }
    };
    let reader = BufReader::new(file);

    // iniatiate final results
    let mut total = 0;
    let mut total_power = 0;

    // loop over the games in the file
    for _line in reader.lines() {
        // Handle the data and extract game number and maximum number of cubes per color
        let (game_number, max_green, max_red, max_blue) = cube_conundrum_data_input(_line.unwrap());

        // Calculate the power for the day 2 result
        total_power += max_green * max_red * max_blue;

        //Calculate if the game was possible with the given number of cubes
        let result = cube_conundrum_game_possible(game_number, max_green, max_red, max_blue);
        total += result;
    }

    // print the final results
    println!("total part 1: {}", total);
    println!("total part 2: {}", total_power);
}

fn cube_conundrum_data_input(game_input: String) -> (i32, i32, i32, i32) {
    // Split the game number from the draws
    let (game_part, data_part) = game_input.split_once(":").unwrap();

    // Select the number of the round and parse into an integer
    let game_number: i32 = game_part
        .split_once(" ")
        .unwrap()
        .1
        .parse::()
        .expect("could not parse gamenumber to integer");

    // Split the data part into a vector both split on , and ; cause we only care about he maximum per color
    let parts: Vec<&str> = data_part
        .split(|c| c == ',' || c == ';')
        .map(|part| part.trim())
        .collect();

    // Set the intial values for the maximum per color to 0
    let (mut max_green, mut max_red, mut max_blue) = (0, 0, 0);

    // Loop over the different draws split them into color and nubmer of cubes, update maximum number of cubes
    for part in parts.iter() {
        let (nr_cubes_text, color) = part.split_once(" ").unwrap();
        let nr_cubes = nr_cubes_text
            .parse::()
            .expect("could not parse to integer");
        match color {
            "green" => max_green = cmp::max(max_green, nr_cubes),
            "red" => max_red = cmp::max(max_red, nr_cubes),
            "blue" => max_blue = cmp::max(max_blue, nr_cubes),
            _ => println!("unknown color: {}", color),
        };
    }

    return (game_number, max_green, max_red, max_blue);
}

fn cube_conundrum_game_possible(
    game_number: i32,
    max_green: i32,
    max_red: i32,
    max_blue: i32,
) -> i32 {
    // Compare the number of seen cubes per game with the proposed number. Return the game number if it was possible, otherwise 0
    let (comparison_red, comparison_green, comparison_blue) = (12, 13, 14);
    if max_green > comparison_green || max_red > comparison_red || max_blue > comparison_blue {
        return 0;
    };
    game_number
}