use alloc::{collections::BTreeMap, string::String, vec::Vec};
use libcortex_a9::{mutex::Mutex, cache::dcci_slice};
use crate::kernel::DmaRecorder;

const ALIGNMENT: usize = 16 * 8;

static DMA_RECORD_STORE: Mutex<BTreeMap<String, (u32, Vec<u8>, i64)>> = Mutex::new(BTreeMap::new());


pub fn put_record(mut recorder: DmaRecorder) {
    recorder.buffer.reserve(ALIGNMENT - 1);
    let original_length = recorder.buffer.len();
    let padding = ALIGNMENT - recorder.buffer.as_ptr() as usize % ALIGNMENT;
    let padding = if padding == ALIGNMENT { 0 } else { padding };
    for _ in 0..padding {
        recorder.buffer.push(0);
    }
    // trailing zero to indicate end of buffer
    recorder.buffer.push(0);
    recorder.buffer.copy_within(0..original_length, padding);
    dcci_slice(&recorder.buffer);

    let ptr = recorder.buffer[padding..].as_ptr() as u32;

    DMA_RECORD_STORE
    .lock()
    .insert(recorder.name, (ptr, recorder.buffer, recorder.duration));
}

pub fn erase(name: String) {
    DMA_RECORD_STORE.lock().remove(&name);
}

pub fn retrieve(name: String) -> Option<(i32, i64)> {
    let (ptr, _v, duration) = DMA_RECORD_STORE.lock().get(&name)?.clone();
    Some((ptr as i32, duration))
}