//! This example runs on the STM32 LoRa Discovery board, which has a builtin Semtech Sx1276 radio.
//! It demonstrates LORA P2P receive functionality in conjunction with the lora_p2p_send example.
#![no_std]
#![no_main]
#![macro_use]
#![feature(type_alias_impl_trait)]

use defmt::*;
use embassy_executor::Spawner;
use embassy_lora::iv::Stm32l0InterfaceVariant;
use embassy_stm32::exti::{Channel, ExtiInput};
use embassy_stm32::gpio::{Input, Level, Output, Pin, Pull, Speed};
use embassy_stm32::spi;
use embassy_stm32::time::khz;
use embassy_time::{Delay, Duration, Timer};
use lora_phy::mod_params::*;
use lora_phy::sx1276_7_8_9::SX1276_7_8_9;
use lora_phy::LoRa;
use {defmt_rtt as _, panic_probe as _};

const LORA_FREQUENCY_IN_HZ: u32 = 903_900_000; // warning: set this appropriately for the region

#[embassy_executor::main]
async fn main(_spawner: Spawner) {
    let mut config = embassy_stm32::Config::default();
    config.rcc.mux = embassy_stm32::rcc::ClockSrc::HSI16;
    config.rcc.enable_hsi48 = true;
    let p = embassy_stm32::init(config);

    let mut spi_config = spi::Config::default();
    spi_config.frequency = khz(200);

    // SPI for sx1276
    let spi = spi::Spi::new(p.SPI1, p.PB3, p.PA7, p.PA6, p.DMA1_CH3, p.DMA1_CH2, spi_config);

    let nss = Output::new(p.PA15.degrade(), Level::High, Speed::Low);
    let reset = Output::new(p.PC0.degrade(), Level::High, Speed::Low);

    let irq_pin = Input::new(p.PB4.degrade(), Pull::Up);
    let irq = ExtiInput::new(irq_pin, p.EXTI4.degrade());

    let iv = Stm32l0InterfaceVariant::new(nss, reset, irq, None, None).unwrap();

    let mut lora = {
        match LoRa::new(SX1276_7_8_9::new(BoardType::Stm32l0Sx1276, spi, iv), false, Delay).await {
            Ok(l) => l,
            Err(err) => {
                info!("Radio error = {}", err);
                return;
            }
        }
    };

    let mut debug_indicator = Output::new(p.PB5, Level::Low, Speed::Low);
    let mut start_indicator = Output::new(p.PB6, Level::Low, Speed::Low);

    start_indicator.set_high();
    Timer::after(Duration::from_secs(5)).await;
    start_indicator.set_low();

    let mut receiving_buffer = [00u8; 100];

    let mdltn_params = {
        match lora.create_modulation_params(
            SpreadingFactor::_10,
            Bandwidth::_250KHz,
            CodingRate::_4_8,
            LORA_FREQUENCY_IN_HZ,
        ) {
            Ok(mp) => mp,
            Err(err) => {
                info!("Radio error = {}", err);
                return;
            }
        }
    };

    let rx_pkt_params = {
        match lora.create_rx_packet_params(4, false, receiving_buffer.len() as u8, true, false, &mdltn_params) {
            Ok(pp) => pp,
            Err(err) => {
                info!("Radio error = {}", err);
                return;
            }
        }
    };

    match lora
        .prepare_for_rx(&mdltn_params, &rx_pkt_params, None, None, false)
        .await
    {
        Ok(()) => {}
        Err(err) => {
            info!("Radio error = {}", err);
            return;
        }
    };

    loop {
        receiving_buffer = [00u8; 100];
        match lora.rx(&rx_pkt_params, &mut receiving_buffer).await {
            Ok((received_len, _rx_pkt_status)) => {
                if (received_len == 3)
                    && (receiving_buffer[0] == 0x01u8)
                    && (receiving_buffer[1] == 0x02u8)
                    && (receiving_buffer[2] == 0x03u8)
                {
                    info!("rx successful");
                    debug_indicator.set_high();
                    Timer::after(Duration::from_secs(5)).await;
                    debug_indicator.set_low();
                } else {
                    info!("rx unknown packet");
                }
            }
            Err(err) => info!("rx unsuccessful = {}", err),
        }
    }
}