Remove extraneous CustomData

.gitignore

/target

Cargo.toml

[package]
name = "removecustomname"
version = "0.1.0"
edition = "2024"

[dependencies]
fastnbt = "2.5.0"
flate2 = "1.1.1"

main.rs

use fastnbt::Value;
use fastnbt::{from_reader, to_writer};
use flate2::{Compression, read::GzDecoder, write::GzEncoder};
use std::error::Error;
use std::fs::{self, File};
use std::io::{self};
use std::path::Path;

fn process_file(path: &Path) -> Result<(), Box<dyn Error>> {
    let metadata = fs::metadata(path)?;

    let original_mtime = metadata.modified()?;

    let file = File::open(path)?;

    let mut decoder = GzDecoder::new(file);
    let mut root = from_reader(&mut decoder)?;

    if let Value::Compound(compound) = &mut root {
        if compound.remove_entry("CustomName").is_some() {
            compound.remove_entry("CustomNameVisible");
            println!("{}: removed CustomName", path.display());

            let file = File::create(path)?;

            let mut encoder = GzEncoder::new(&file, Compression::default());

            to_writer(&mut encoder, &root)?;

            encoder.finish()?;

            file.set_modified(original_mtime)?;
        }
    }
    Ok(())
}

fn main() -> io::Result<()> {
    let args = std::env::args().collect::<Vec<_>>();
    let dir_path = Path::new(&args[1]);

    for entry in fs::read_dir(dir_path)? {
        let entry = entry?;
        let path = entry.path();

        if path.is_file() && path.extension().map(|ext| ext == "dat").unwrap_or(false) {
            if let Err(e) = process_file(&path) {
                eprintln!("{}: error processing file: {}", path.display(), e);
            }
        }
    }

    Ok(())
}