use crate::*;

use rand::Rng;

#[test]
fn correctness_random() {
	const MAX_APPEND_LEN: usize = 256;
	const CHUNK_SIZE: usize = 32;

	let mut rng = rand::thread_rng();
	let mut ringbuf = RingBuf::new(1024, 0_u32);
	let mut buf = [0; 32];
	let mut current_value = 0;
	for _ in 0_u32..1024 {
		let append_len = rng.gen_range(0..MAX_APPEND_LEN);
		ringbuf.push_from_iter(current_value as u32..current_value as u32 + append_len as u32);
		for (j, chunk) in ringbuf.chunks_exact_mut(CHUNK_SIZE).enumerate() {
			assert_eq!(chunk.len(), CHUNK_SIZE);
			for (k, v) in chunk.iter().enumerate() {
				assert_eq!(
					*v as usize,
					current_value - current_value % CHUNK_SIZE + j * CHUNK_SIZE + k
				);
			}
		}
		current_value += append_len;
	}
}

#[test]
fn correctness_manual() {
	let mut ringbuf = RingBuf::new(8, 0_u32);

	ringbuf.push_from_iter(1..4);
	let mut iter = ringbuf.chunks_exact_mut(4);
	assert_eq!(iter.next(), None);
	ringbuf.push(4);
	let mut iter = ringbuf.chunks_exact_mut(4);
	assert_eq!(iter.next(), Some([1, 2, 3, 4].as_mut_slice()));
	assert_eq!(iter.next(), None);
	ringbuf.push_from_iter(5..8);
	let mut iter = ringbuf.chunks_exact_mut(4);
	assert_eq!(iter.next(), None);
	ringbuf.push_from_iter(8..14);
	let mut iter = ringbuf.chunks_exact_mut(4);
	assert_eq!(iter.next(), Some([13, 6, 7, 8].as_mut_slice()));
	assert_eq!(iter.next(), Some([9, 10, 11, 12].as_mut_slice()));
	assert_eq!(iter.next(), None);
}