use crate::error::*;
use crate::expr::*;

pub trait Deserialize<'a>: Sized {
    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self>;
}

impl<'a> Deserialize<'a> for Parsed {
    /// Simply parses the provided string. Ignores the
    /// provided type.
    fn from_str(s: &'a str, _ty: Option<&Type>) -> Result<Self> {
        Ok(Parsed::parse_str(s).map_err(|_| ())?)
    }
}

impl<'a> Deserialize<'a> for Resolved {
    /// Parses and resolves the provided string. Ignores the
    /// provided type.
    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self> {
        Ok(Parsed::from_str(s, ty)?.resolve().map_err(|_| ())?)
    }
}

impl<'a> Deserialize<'a> for Typed {
    /// Parses, resolves and typechecks the provided string.
    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self> {
        // TODO: compare with provided type
        Ok(Resolved::from_str(s, ty)?.typecheck().map_err(|_| ())?)
    }
}

impl<'a> Deserialize<'a> for Normalized {
    /// Parses, resolves, typechecks and normalizes the provided string.
    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self> {
        Ok(Typed::from_str(s, ty)?.normalize())
    }
}

impl<'a> Deserialize<'a> for Type {
    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self> {
        Ok(Normalized::from_str(s, ty)?.into_type())
    }
}