use lubeck::common::reader::Reader;
use lubeck::common::transformer::optiont::OptionT;
use lubeck::prelude::Applicative;
use lubeck::prelude::Functor;
use lubeck::prelude::Monad;

#[derive(Clone)]
pub struct Config {
    is_on: bool,
}

#[derive(Debug)]
pub struct Voltage(pub f32);

type ConfigMaybe<'a, T> = OptionT<Reader<'a, Config, T>, T>;

fn main() {
    {
        // very simplistic example
        let create_configurable_volt_calculation_pipeline = || {
            let configurable_one_volt = ConfigMaybe::<Voltage>::pure(Voltage(1.0));
            let configurable_three_volt = configurable_one_volt.fmap(|Voltage(v)| Voltage(v + 2.0));

            let double_if_on = move |Voltage(v)| -> ConfigMaybe<Voltage> {
                let reader_opt_f = move |config: Config| {
                    if config.is_on {
                        Some(Voltage(v * 2.0))
                    } else {
                        None
                    }
                };
                ConfigMaybe::new(reader_opt_f)
            };

            configurable_three_volt.bind(double_if_on)
        };

        println!(
            "With switch disabled: {:?}",
            create_configurable_volt_calculation_pipeline().run(Config { is_on: false })
        );

        println!(
            "With switch enabled: {:?}",
            create_configurable_volt_calculation_pipeline().run(Config { is_on: true })
        );
    }
}