s3util-rs 1.8.0

use std::collections::HashMap;

use regex::Regex;

const INVALID_METADATA: &str = "invalid metadata.";

pub fn check_metadata(metadata: &str) -> Result<String, String> {
    let regex = Regex::new(r"^[a-zA-Z0-9_.-]+=[a-zA-Z0-9_.-]*(,[a-zA-Z0-9_.-]+=[a-zA-Z0-9_.-]*)*$")
        .unwrap();

    if !regex.is_match(metadata) {
        return Err(INVALID_METADATA.to_string());
    }

    Ok(metadata.to_string())
}

pub fn parse_metadata(value: &str) -> anyhow::Result<HashMap<String, String>, String> {
    check_metadata(value)?;

    Ok(value
        .split(',')
        .map(|key_value| key_value.split('=').collect::<Vec<&str>>())
        .map(|key_value| (key_value[0].to_string(), key_value[1].to_string()))
        .collect::<HashMap<String, String>>())
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn check_metadata_test() {
        check_metadata("key=value").unwrap();
        check_metadata("key1=value1,key2=value2").unwrap();

        assert!(check_metadata("key").is_err());
        assert!(check_metadata("key=Va-lu_e.%1").is_err());
        assert!(check_metadata(",key=value").is_err());
        // Pairs must be comma-separated: the pre-anchored pattern accepted
        // this via backtracking as ("a=b")("c=d").
        assert!(check_metadata("a=bc=d").is_err());
    }

    #[test]
    fn parse_valid_metadata() {
        assert_eq!(parse_metadata("key1=value1").unwrap(), {
            let mut map = HashMap::new();
            map.insert("key1".to_string(), "value1".to_string());
            map
        });
    }
}