//! I2S Loopback Test (Async)
//!
//! It's assumed GPIO2 is connected to GPIO3
//!
//! This test uses I2S TX to transmit known data to I2S RX (forced to slave mode
//! with loopback mode enabled). It's using circular DMA mode

//% CHIPS: esp32c3 esp32c6 esp32s3 esp32h2

#![no_std]
#![no_main]

use defmt_rtt as _;
use esp_backtrace as _;
use esp_hal::{
    clock::ClockControl,
    dma::{Dma, DmaChannel0, DmaPriority},
    gpio::Io,
    i2s::{asynch::*, DataFormat, I2s, Standard},
    peripheral::Peripheral,
    peripherals::Peripherals,
    prelude::*,
    system::SystemControl,
};

// choose values which DON'T restart on every descriptor buffer's start
const ADD: u8 = 5;
const CUT_OFF: u8 = 113;

#[embassy_executor::task]
async fn writer(
    i: u8,
    mut transfer: I2sWriteDmaTransferAsync<
        'static,
        esp_hal::peripherals::I2S0,
        DmaChannel0,
        &'static mut [u8; 2000],
    >,
) {
    let mut i = i;
    loop {
        transfer
            .push_with(|buffer| {
                for b in buffer.iter_mut() {
                    *b = i;
                    i = (i + ADD) % CUT_OFF;
                }
                buffer.len()
            })
            .await
            .unwrap();
    }
}

#[cfg(test)]
#[embedded_test::tests(executor = esp_hal_embassy::Executor::new())]
mod tests {
    use super::*;

    #[init]
    async fn init() {}

    #[test]
    async fn test_i2s_loopback() {
        let spawner = embassy_executor::Spawner::for_current_executor().await;

        let peripherals = Peripherals::take();
        let system = SystemControl::new(peripherals.SYSTEM);
        let clocks = ClockControl::boot_defaults(system.clock_control).freeze();

        let mut io = Io::new(peripherals.GPIO, peripherals.IO_MUX);

        let dma = Dma::new(peripherals.DMA);
        let dma_channel = dma.channel0;

        #[allow(non_upper_case_globals)]
        let (tx_buffer, tx_descriptors, rx_buffer, rx_descriptors) =
            esp_hal::dma_circular_buffers!(2000, 2000);

        let i2s = I2s::new(
            peripherals.I2S0,
            Standard::Philips,
            DataFormat::Data16Channel16,
            16000.Hz(),
            dma_channel.configure_for_async(false, DmaPriority::Priority0),
            tx_descriptors,
            rx_descriptors,
            &clocks,
        );

        let i2s_tx = i2s
            .i2s_tx
            .with_bclk(unsafe { io.pins.gpio0.clone_unchecked() })
            .with_ws(unsafe { io.pins.gpio1.clone_unchecked() })
            .with_dout(unsafe { io.pins.gpio2.clone_unchecked() })
            .build();

        let i2s_rx = i2s
            .i2s_rx
            .with_bclk(io.pins.gpio0)
            .with_ws(io.pins.gpio1)
            .with_din(io.pins.gpio3)
            .build();

        // enable loopback testing
        unsafe {
            let i2s = esp_hal::peripherals::I2S0::steal();
            i2s.tx_conf().modify(|_, w| w.sig_loopback().set_bit());

            i2s.rx_conf().modify(|_, w| w.rx_slave_mod().set_bit());

            i2s.tx_conf().modify(|_, w| w.tx_update().clear_bit());
            i2s.tx_conf().modify(|_, w| w.tx_update().set_bit());

            i2s.rx_conf().modify(|_, w| w.rx_update().clear_bit());
            i2s.rx_conf().modify(|_, w| w.rx_update().set_bit());
        }

        let mut iteration = 0;
        let mut failed = false;
        let mut check_i: u8 = 0;
        let mut i = 0;
        for b in tx_buffer.iter_mut() {
            *b = i;
            i = (i + ADD) % CUT_OFF;
        }

        let mut rcv = [0u8; 2000];

        let mut rx_transfer = i2s_rx.read_dma_circular_async(rx_buffer).unwrap();
        let tx_transfer = i2s_tx.write_dma_circular_async(tx_buffer).unwrap();

        spawner.must_spawn(writer(i, tx_transfer));

        'outer: loop {
            let len = rx_transfer.pop(&mut rcv).await.unwrap();
            for &b in &rcv[..len] {
                if b != check_i {
                    failed = true;
                    break 'outer;
                }
                check_i = (check_i + ADD) % CUT_OFF;
            }
            iteration += 1;

            if iteration > 30 {
                break;
            }
        }

        assert!(!failed);
    }
}
