use bnum::cast::As;
use bnum::types::{I256,I512};
use bnum::BInt;
use fixed::{FixedI64,FixedI128};
use typenum::{Sum,Unsigned};
use std::marker::PhantomData;

#[derive(Clone,Copy,Debug)]
pub struct Fixed<const CHUNKS:usize,Frac>{
	bits:BInt<{CHUNKS}>,
	frac:PhantomData<Frac>,
}
pub type FixedI192<Frac>=Fixed<3,Frac>;
pub type FixedI256<Frac>=Fixed<4,Frac>;
pub type FixedI512<Frac>=Fixed<8,Frac>;

impl<const CHUNKS:usize,FracDst:Unsigned> From<i128> for Fixed<CHUNKS,FracDst>{
	fn from(value:i128)->Self{
		Self{
			bits:BInt::<{CHUNKS}>::from(value)<<FracDst::U32,
			frac:PhantomData,
		}
	}
}

impl<const CHUNKS:usize,Frac> PartialEq for Fixed<CHUNKS,Frac>{
	fn eq(&self,other:&Self)->bool{
		self.bits.eq(&other.bits)
	}
}
impl<const CHUNKS:usize,Frac> Eq for Fixed<CHUNKS,Frac>{}

impl<const CHUNKS:usize,Frac> std::ops::Add for Fixed<CHUNKS,Frac>{
	type Output=Self;
	fn add(self,rhs:Self)->Self::Output{
		Self{
			bits:self.bits+rhs.bits,
			frac:PhantomData,
		}
	}
}

pub trait WideMul<Rhs=Self>{
	type Output;
	fn wide_mul(self,rhs:Rhs)->Self::Output;
}

//going wide from foreign fixed type
impl<A,B> WideMul<FixedI64<B>> for FixedI64<A>
	where
		A:std::ops::Add<B>,
		B:Unsigned,
{
	type Output=FixedI128<Sum<A,B>>;
	fn wide_mul(self,rhs:FixedI64<B>)->Self::Output{
		self.wide_mul(rhs)
	}
}
impl<A,B> WideMul<FixedI64<B>> for FixedI128<A>
	where
		A:std::ops::Add<B>,
		B:Unsigned,
{
	type Output=FixedI192<Sum<A,B>>;
	fn wide_mul(self,rhs:FixedI64<B>)->Self::Output{
		FixedI192{
			bits:BInt::<3>::from(self.to_bits())*BInt::<3>::from(rhs.to_bits()),
			frac:PhantomData,
		}
	}
}
impl<A,B> WideMul<FixedI128<B>> for FixedI64<A>
	where
		A:std::ops::Add<B>,
		B:Unsigned,
{
	type Output=FixedI192<Sum<A,B>>;
	fn wide_mul(self,rhs:FixedI128<B>)->Self::Output{
		FixedI192{
			bits:BInt::<3>::from(self.to_bits())*BInt::<3>::from(rhs.to_bits()),
			frac:PhantomData,
		}
	}
}
impl<A,B> WideMul<FixedI128<B>> for FixedI128<A>
	where
		A:std::ops::Add<B>,
		B:Unsigned,
{
	type Output=FixedI256<Sum<A,B>>;
	fn wide_mul(self,rhs:FixedI128<B>)->Self::Output{
		FixedI256{
			bits:I256::from(self.to_bits())*I256::from(rhs.to_bits()),
			frac:PhantomData,
		}
	}
}

//going wider native
macro_rules! impl_wide_mul {
	($lhs: expr,$rhs: expr) => {
		impl<A,B> WideMul<Fixed<$rhs,B>> for Fixed<$lhs,A>
			where
				A:std::ops::Add<B>,
				B:Unsigned,
		{
			type Output=Fixed<{$lhs+$rhs},Sum<A,B>>;
			fn wide_mul(self,rhs:Fixed<$rhs,B>)->Self::Output{
				Fixed{
					bits:self.bits.as_::<BInt<{$lhs+$rhs}>>()*rhs.bits.as_::<BInt<{$lhs+$rhs}>>(),
					frac:PhantomData,
				}
			}
		}
	};
}
impl_wide_mul!(3,3);impl_wide_mul!(4,3);impl_wide_mul!(5,3);impl_wide_mul!(6,3);impl_wide_mul!(7,3);impl_wide_mul!(8,3);
impl_wide_mul!(3,4);impl_wide_mul!(4,4);impl_wide_mul!(5,4);impl_wide_mul!(6,4);impl_wide_mul!(7,4);impl_wide_mul!(8,4);
impl_wide_mul!(3,5);impl_wide_mul!(4,5);impl_wide_mul!(5,5);impl_wide_mul!(6,5);impl_wide_mul!(7,5);impl_wide_mul!(8,5);
impl_wide_mul!(3,6);impl_wide_mul!(4,6);impl_wide_mul!(5,6);impl_wide_mul!(6,6);impl_wide_mul!(7,6);impl_wide_mul!(8,6);
impl_wide_mul!(3,7);impl_wide_mul!(4,7);impl_wide_mul!(5,7);impl_wide_mul!(6,7);impl_wide_mul!(7,7);impl_wide_mul!(8,7);
impl_wide_mul!(3,8);impl_wide_mul!(4,8);impl_wide_mul!(5,8);impl_wide_mul!(6,8);impl_wide_mul!(7,8);impl_wide_mul!(8,8);