use hcl::platform::PeripheralRef;
use hcl::platform::Location;
use hcl::platform::spi;
use hcl::platform::gpio;

pub fn read<SPIAddr, GPIOAddr>(spi: &mut PeripheralRef<spi::SPI, SPIAddr>,
                               nss_gpio: &mut PeripheralRef<gpio::GPIO, GPIOAddr>,
                               nss_idx: u32)
                               -> Result<f32, &'static str>
    where SPIAddr: Location,
          GPIOAddr: Location
{
    spi.configure(|s| {
        s.set_enabled(true)
        .set_master_mode(true)
        .set_software_slave_select(true)
        .set_clock_divider(128)
        .set_data_16bit(true)
        .set_clock_skip_first(true)
        // required for master mode, even if ss is done manually
        .set_slave_select_output_enabled(true)
    });

    nss_gpio.reset_bit(nss_idx);

    spi.set_data(0x0000);
    while !spi.rx_buffer_not_empty() {}
    let raw_result = spi.data();

    while spi.busy() {}

    nss_gpio.set_bit(nss_idx);
    spi.set_enabled(false);


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