use std::path::Path;

use crate::error::Result;
use crate::model::ContentHash;

const BUFFER_SIZE: usize = 65536;

pub async fn compute_file_hash(path: &Path) -> Result<ContentHash> {
    let path = path.to_path_buf();
    let hash = tokio::task::spawn_blocking(move || -> Result<ContentHash> {
        let mut hasher = blake3::Hasher::new();
        let mut file = std::fs::File::open(&path)?;
        let mut buf = vec![0u8; BUFFER_SIZE];
        loop {
            let n = std::io::Read::read(&mut file, &mut buf)?;
            if n == 0 {
                break;
            }
            hasher.update(&buf[..n]);
        }
        Ok(ContentHash::new(hasher.finalize().to_hex().to_string()))
    })
    .await
    .map_err(|e| crate::error::PinakesError::Io(std::io::Error::other(e)))??;
    Ok(hash)
}

pub fn compute_hash_sync(data: &[u8]) -> ContentHash {
    let hash = blake3::hash(data);
    ContentHash::new(hash.to_hex().to_string())
}