use std::marker::PhantomData;
use std::fmt::Error;

trait Sample {}
impl Sample for u8 {}
impl Sample for u16 {}
impl Sample for u32 {}

struct Parameters<S:?Sized> { sample_format: std::marker::PhantomData<S>, }

pub type InputSource<T> where T : ?Sized + Sample + 'static = Parameters<T>;
pub type OutputSource<T> where T : ?Sized + Sample + 'static = Parameters<T>;

pub struct InputFlow<T> where T : ?Sized + Sample + 'static { pub source: InputSource<T> }
pub struct OutputFlow<T> where T : ?Sized + Sample + 'static { pub source: OutputSource<T> }
pub trait AudioFlow<T> where T : ?Sized + Sample + 'static {}

impl <T> AudioFlow<T> for InputFlow<T> where T : ?Sized + Sample + 'static {}
impl <T> AudioFlow<T> for OutputFlow<T> where T : ?Sized + Sample + 'static {}

pub enum AudioType { Input, Output }
pub fn flow<T>(ty: AudioType) -> Result<Box<dyn AudioFlow<T>>, Error>
    where T : ?Sized + Sample + 'static {

    match ty {
        AudioType::Input => flow_input::<T>(),
        AudioType::Output => flow_output::<T>()
    }
}

pub fn flow_input<T>() -> Result<Box<InputFlow<T>>, Error>
    where T : ?Sized + Sample + 'static {

    let source = Parameters { sample_format: std::marker::PhantomData };
    return Ok(Box::new(InputFlow { source }))
}

pub fn flow_output<T>() -> Result<Box<OutputFlow<T>>, Error>
    where T : ?Sized + Sample + 'static {

    let source = Parameters { sample_format: std::marker::PhantomData };
    return Ok(Box::new(OutputFlow { source}))
}


fn main() {
    let a = flow::<u32>(AudioType::Input);
}