use sha2::{Digest, Sha256};

/// Computes a unique hardware fingerprint (CPU / Machine identifier).
pub fn generate_hardware_id() -> String {
    let mut hasher = Sha256::new();
    let hostname = std::env::var("COMPUTERNAME")
        .or_else(|_| std::env::var("HOSTNAME"))
        .unwrap_or_else(|_| "UNKNOWN-HOST".to_string());
    
    let username = std::env::var("USERNAME")
        .or_else(|_| std::env::var("USER"))
        .unwrap_or_else(|_| "UNKNOWN-USER".to_string());

    let raw_id = format!("{}:{}", hostname, username);
    hasher.update(raw_id.as_bytes());
    format!("{:x}", hasher.finalize())
}