//! This shows how to transmit data continuously via I2S.
//!
//! Without an additional I2S sink device you can inspect the BCLK, WS
//! and DOUT with a logic analyzer.
//!
//! You can also connect e.g. a PCM510x to hear an annoying loud sine tone (full
//! scale), so turn down the volume before running this example.
//!
//! The following wiring is assumed:
//! - BCLK => GPIO2
//! - WS   => GPIO4
//! - DOUT => GPIO5
//!
//! PCM510x:
//! | Pin   | Connected to    |
//! |-------|-----------------|
//! | BCK   | GPIO1           |
//! | DIN   | GPIO3           |
//! | LRCK  | GPIO2           |
//! | SCK   | Gnd             |
//! | GND   | Gnd             |
//! | VIN   | +3V3            |
//! | FLT   | Gnd             |
//! | FMT   | Gnd             |
//! | DEMP  | Gnd             |
//! | XSMT  | +3V3            |

//% CHIPS: esp32 esp32c3 esp32c6 esp32h2 esp32s2 esp32s3
//% FEATURES: embassy-generic-timers

#![no_std]
#![no_main]

use embassy_executor::Spawner;
use esp_backtrace as _;
use esp_hal::{
    dma_buffers,
    i2s::master::{DataFormat, I2s, Standard},
    time::RateExtU32,
    timer::timg::TimerGroup,
};
use esp_println::println;

const SINE: [i16; 64] = [
    0, 3211, 6392, 9511, 12539, 15446, 18204, 20787, 23169, 25329, 27244, 28897, 30272, 31356,
    32137, 32609, 32767, 32609, 32137, 31356, 30272, 28897, 27244, 25329, 23169, 20787, 18204,
    15446, 12539, 9511, 6392, 3211, 0, -3211, -6392, -9511, -12539, -15446, -18204, -20787, -23169,
    -25329, -27244, -28897, -30272, -31356, -32137, -32609, -32767, -32609, -32137, -31356, -30272,
    -28897, -27244, -25329, -23169, -20787, -18204, -15446, -12539, -9511, -6392, -3211,
];

#[esp_hal_embassy::main]
async fn main(_spawner: Spawner) {
    println!("Init!");
    let peripherals = esp_hal::init(esp_hal::Config::default());

    let timg0 = TimerGroup::new(peripherals.TIMG0);
    esp_hal_embassy::init(timg0.timer0);

    cfg_if::cfg_if! {
        if #[cfg(any(feature = "esp32", feature = "esp32s2"))] {
            let dma_channel = peripherals.DMA_I2S0;
        } else {
            let dma_channel = peripherals.DMA_CH0;
        }
    }

    let (_, rx_descriptors, tx_buffer, tx_descriptors) = dma_buffers!(0, 32000);

    let i2s = I2s::new(
        peripherals.I2S0,
        Standard::Philips,
        DataFormat::Data16Channel16,
        44100u32.Hz(),
        dma_channel,
        rx_descriptors,
        tx_descriptors,
    )
    .into_async();

    let i2s_tx = i2s
        .i2s_tx
        .with_bclk(peripherals.GPIO2)
        .with_ws(peripherals.GPIO4)
        .with_dout(peripherals.GPIO5)
        .build();

    let data =
        unsafe { core::slice::from_raw_parts(&SINE as *const _ as *const u8, SINE.len() * 2) };

    let buffer = tx_buffer;
    let mut idx = 0;
    for i in 0..usize::min(data.len(), buffer.len()) {
        buffer[i] = data[idx];

        idx += 1;

        if idx >= data.len() {
            idx = 0;
        }
    }

    let mut filler = [0u8; 10000];
    let mut idx = 32000 % data.len();

    println!("Start");
    let mut transaction = i2s_tx.write_dma_circular_async(buffer).unwrap();
    loop {
        for i in 0..filler.len() {
            filler[i] = data[(idx + i) % data.len()];
        }
        println!("Next");

        let written = transaction.push(&filler).await.unwrap();
        idx = (idx + written) % data.len();
        println!("written {}", written);
    }
}
