use embedded_hal::blocking::spi;
use embedded_hal::digital::v2::OutputPin;
use rtt_target::rprintln;

pub fn read<SPI, NSS>(spi: &mut SPI, nss_pin: &mut NSS) -> Result<f32, &'static str>
where
    SPI: spi::Transfer<u8>,
    NSS: OutputPin,
{
    let mut buffer = [0u8, 0u8];

    nss_pin.set_low().map_err(|_| "Unable to set pin low")?;
    let res = spi.transfer(&mut buffer);
    nss_pin.set_high().map_err(|_| "Unable to set pin high")?;

    let raw_result = match res {
        Ok(value) => (value[0] as u16) << 8 | (value[1] as u16),
        Err(_) => return Err("SPI transfer failed"),
    };

    if raw_result & (1 << 2) != 0 {
        Err("MAX6675: Termocouple measures open")
    } else {
        let result = ((raw_result >> 3) as f32) * 0.25;
        Ok(result)
    }
}