#![no_std]
#![no_main]
#![feature(type_alias_impl_trait)]
#![feature(async_fn_in_trait)]
#![allow(incomplete_features)]

mod pio;

use core::slice;
use core::str::from_utf8;

use defmt::*;
use embassy_executor::Spawner;
use embassy_net::tcp::TcpSocket;
use embassy_net::{Config, Stack, StackResources};
use embassy_rp::gpio::{Flex, Level, Output};
use embassy_rp::peripherals::{DMA_CH0, PIN_23, PIN_24, PIN_25, PIN_29};
use embassy_rp::pio::{Pio0, PioPeripherial, PioStateMachineInstance, Sm0};
use embedded_io::asynch::Write;
use static_cell::StaticCell;
use {defmt_rtt as _, panic_probe as _};

use crate::pio::PioSpi;

macro_rules! singleton {
    ($val:expr) => {{
        type T = impl Sized;
        static STATIC_CELL: StaticCell<T> = StaticCell::new();
        STATIC_CELL.init_with(move || $val)
    }};
}

#[embassy_executor::task]
async fn wifi_task(
    runner: cyw43::Runner<
        'static,
        Output<'static, PIN_23>,
        PioSpi<PIN_25, PioStateMachineInstance<Pio0, Sm0>, DMA_CH0>,
    >,
) -> ! {
    runner.run().await
}

#[embassy_executor::task]
async fn net_task(stack: &'static Stack<cyw43::NetDriver<'static>>) -> ! {
    stack.run().await
}

#[embassy_executor::main]
async fn main(spawner: Spawner) {
    info!("Hello World!");

    let p = embassy_rp::init(Default::default());

    // Include the WiFi firmware and Country Locale Matrix (CLM) blobs.
    let fw = include_bytes!("../../../firmware/43439A0.bin");
    let clm = include_bytes!("../../../firmware/43439A0_clm.bin");

    // To make flashing faster for development, you may want to flash the firmwares independently
    // at hardcoded addresses, instead of baking them into the program with `include_bytes!`:
    //     probe-rs-cli download 43439A0.bin --format bin --chip RP2040 --base-address 0x10100000
    //     probe-rs-cli download 43439A0_clm.bin --format bin --chip RP2040 --base-address 0x10140000
    //let fw = unsafe { core::slice::from_raw_parts(0x10100000 as *const u8, 224190) };
    //let clm = unsafe { core::slice::from_raw_parts(0x10140000 as *const u8, 4752) };

    let pwr = Output::new(p.PIN_23, Level::Low);
    let cs = Output::new(p.PIN_25, Level::High);
    // let clk = Output::new(p.PIN_29, Level::Low);
    // let mut dio = Flex::new(p.PIN_24);
    // dio.set_low();
    // dio.set_as_output();
    // // let bus = MySpi { clk, dio };

    let (_, sm, _, _, _) = p.PIO0.split();
    let dma = p.DMA_CH0;
    let spi = PioSpi::new(sm, cs, p.PIN_24, p.PIN_29, dma);

    let state = singleton!(cyw43::State::new());
    let (net_device, mut control, runner) = cyw43::new(state, pwr, spi, fw).await;

    control.init(clm).await;
    control
        .set_power_management(cyw43::PowerManagementMode::PowerSave)
        .await;

    let config = Config::Dhcp(Default::default());
    //let config = embassy_net::Config::Static(embassy_net::Config {
    //    address: Ipv4Cidr::new(Ipv4Address::new(192, 168, 69, 2), 24),
    //    dns_servers: Vec::new(),
    //    gateway: Some(Ipv4Address::new(192, 168, 69, 1)),
    //});

    // Generate random seed
    let seed = 0x0123_4567_89ab_cdef; // chosen by fair dice roll. guarenteed to be random.

    // Init network stack
    let stack = &*singleton!(Stack::new(
        net_device,
        config,
        singleton!(StackResources::<2>::new()),
        seed
    ));

    unwrap!(spawner.spawn(wifi_task(runner)));
    unwrap!(spawner.spawn(net_task(stack)));

    //control.join_open(env!("WIFI_NETWORK")).await;
    control.join_wpa2(env!("WIFI_NETWORK"), env!("WIFI_PASSWORD")).await;

    // And now we can use it!

    let mut rx_buffer = [0; 4096];
    let mut tx_buffer = [0; 4096];
    let mut buf = [0; 4096];

    loop {
        let mut socket = TcpSocket::new(stack, &mut rx_buffer, &mut tx_buffer);
        socket.set_timeout(Some(embassy_net::SmolDuration::from_secs(10)));

        control.gpio_set(0, false).await;
        info!("Listening on TCP:1234...");
        if let Err(e) = socket.accept(1234).await {
            warn!("accept error: {:?}", e);
            continue;
        }

        info!("Received connection from {:?}", socket.remote_endpoint());
        control.gpio_set(0, true).await;

        loop {
            let n = match socket.read(&mut buf).await {
                Ok(0) => {
                    warn!("read EOF");
                    break;
                }
                Ok(n) => n,
                Err(e) => {
                    warn!("read error: {:?}", e);
                    break;
                }
            };

            info!("rxd {}", from_utf8(&buf[..n]).unwrap());

            match socket.write_all(&buf[..n]).await {
                Ok(()) => {}
                Err(e) => {
                    warn!("write error: {:?}", e);
                    break;
                }
            };
        }
    }
}

struct MySpi {
    /// SPI clock
    clk: Output<'static, PIN_29>,

    /// 4 signals, all in one!!
    /// - SPI MISO
    /// - SPI MOSI
    /// - IRQ
    /// - strap to set to gSPI mode on boot.
    dio: Flex<'static, PIN_24>,

    /// Chip select
    cs: Output<'static, PIN_25>,
}

impl MySpi {
    async fn read(&mut self, words: &mut [u32]) {
        self.dio.set_as_input();
        for word in words {
            let mut w = 0;
            for _ in 0..32 {
                w = w << 1;

                // rising edge, sample data
                if self.dio.is_high() {
                    w |= 0x01;
                }
                self.clk.set_high();

                // falling edge
                self.clk.set_low();
            }
            *word = w
        }
    }

    async fn write(&mut self, words: &[u32]) {
        self.dio.set_as_output();
        for word in words {
            let mut word = *word;
            for _ in 0..32 {
                // falling edge, setup data
                self.clk.set_low();
                if word & 0x8000_0000 == 0 {
                    self.dio.set_low();
                } else {
                    self.dio.set_high();
                }

                // rising edge
                self.clk.set_high();

                word = word << 1;
            }
        }
        self.clk.set_low();

        self.dio.set_as_input();
    }
}

impl cyw43::SpiBusCyw43 for MySpi {
    async fn cmd_write(&mut self, write: &[u32]) {
        self.cs.set_low();
        self.write(write).await;
        self.cs.set_high();
    }

    async fn cmd_read(&mut self, write: u32, read: &mut [u32]) {
        self.cs.set_low();
        self.write(slice::from_ref(&write)).await;
        self.read(read).await;
        self.cs.set_high();
    }
}