use std::collections::HashMap;
use std::env;
use std::fs::File;
use std::io::{BufWriter, Write};
use std::path::Path;

use quote::quote;
use syn::Type;

// macro_rules! map_types {
//     [$($rust:ty => $c:ty,)*] => {{
//         let mut map = std::collections::HashMap::<Type, Type>::new();
//         $(map.insert(
//             syn::parse2(quote!{ $rust })
//                 .expect(concat!("cannot parse", stringify!($rust), "as type")),

//             syn::parse2(quote!{ $c })
//                 .expect(concat!("cannot parse", stringify!($c), "as type")),
//         );)*
//         map
//     }}
// }

macro_rules! map_marshalers {
    [$($rust:ty => $c:ty,)*] => {{
        let mut map = std::collections::HashMap::<Type, syn::Path>::new();
        $(map.insert(
            syn::parse2(quote!{ $rust })
                .expect(concat!("cannot parse", stringify!($rust), "as type")),

            syn::parse2(quote!{ $c })
                .expect(concat!("cannot parse", stringify!($c), "as path")),

        );)*
        map
    }}
}

macro_rules! type_array {
    [$($rust:ty,)*] => {{
        vec![
            $(syn::parse2(quote!{ $rust })
                .expect(concat!("cannot parse", stringify!($rust), "as type")),
            )*
        ]
    }}
}

fn main() {
    let default_marshalers: HashMap<Type, syn::Path> = map_marshalers![
        bool => ::cffi::BoolMarshaler,
    ];

    let path = Path::new(&env::var("OUT_DIR").unwrap()).join("codegen.rs");
    let mut file = BufWriter::new(File::create(&path).unwrap());

    write!(
        &mut file,
        "static DEFAULT_MARSHALERS: phf::Map<&'static str, &'static str> = "
    )
    .unwrap();
    let mut map = phf_codegen::Map::new();
    for (key, value) in default_marshalers.iter() {
        map.entry(
            quote! { #key }.to_string(),
            &format!("\"{}\"", quote! { #value }.to_string()),
        );
    }
    map.build(&mut file).unwrap();
    write!(&mut file, ";\n").unwrap();

    let types: Vec<Type> = type_array![
        (),
        u8,
        i8,
        u16,
        i16,
        u32,
        i32,
        i64,
        u64,
        i128,
        u128,
        isize,
        usize,
        f32,
        f64,
        // bool,
        char,
    ];

    write!(
        &mut file,
        "static PASSTHROUGH_TYPES: &[&str] = &[\"{}\"];\n",
        types
            .into_iter()
            .map(|x| quote! { #x }.to_string())
            .collect::<Vec<_>>()
            .join("\", \"")
    )
    .unwrap();
}