//! Benchmarks for dataset_hash
//! 
//! Compares BLAKE3 hashing performance

use criterion::{black_box, criterion_group, criterion_main, Criterion};
use dataset_hash::{hash_file, hash_directory_batch, hash_directory_combined};
use std::io::Write;
use tempfile::TempDir;

fn create_test_file(dir: &TempDir, name: &str, size: usize) -> std::path::PathBuf {
    let path = dir.path().join(name);
    let mut file = std::fs::File::create(&path).unwrap();
    let data = vec![0u8; size];
    file.write_all(&data).unwrap();
    path
}

fn bench_hash_file_small(c: &mut Criterion) {
    let temp = TempDir::new().unwrap();
    let path = create_test_file(&temp, "small.bin", 1024); // 1KB
    
    c.bench_function("rust_hash_file_1kb", |b| {
        b.iter(|| {
            black_box(hash_file(&path).unwrap());
        });
    });
}

fn bench_hash_file_medium(c: &mut Criterion) {
    let temp = TempDir::new().unwrap();
    let path = create_test_file(&temp, "medium.bin", 1024 * 1024); // 1MB
    
    c.bench_function("rust_hash_file_1mb", |b| {
        b.iter(|| {
            black_box(hash_file(&path).unwrap());
        });
    });
}

fn bench_hash_directory_batch(c: &mut Criterion) {
    let temp = TempDir::new().unwrap();
    
    // Create 100 small files
    for i in 0..100 {
        create_test_file(&temp, &format!("file_{}.bin", i), 1024);
    }
    
    c.bench_function("rust_hash_dir_100files", |b| {
        b.iter(|| {
            black_box(hash_directory_batch(temp.path()).unwrap());
        });
    });
}

fn bench_hash_directory_combined(c: &mut Criterion) {
    let temp = TempDir::new().unwrap();
    
    // Create 100 small files
    for i in 0..100 {
        create_test_file(&temp, &format!("file_{}.bin", i), 1024);
    }
    
    c.bench_function("rust_hash_dir_combined", |b| {
        b.iter(|| {
            black_box(hash_directory_combined(temp.path()).unwrap());
        });
    });
}

criterion_group!(benches, 
    bench_hash_file_small, 
    bench_hash_file_medium, 
    bench_hash_directory_batch,
    bench_hash_directory_combined
);
criterion_main!(benches);