use {
    repc::layout::{Type, TypeVariant},
    std::{
        env,
        fs::{File, OpenOptions},
        io::{self, BufWriter, Write},
        path::PathBuf,
    },
};

#[allow(unused_macros)]
macro_rules! cenum {
    ($name:ident, $uc:ident; $($name2:ident = $val:expr,)*) => {
        #[derive(Copy, Clone, Debug, Eq, PartialEq)]
        pub struct $name(pub i32);

        impl $name {
            pub fn raw(self) -> i32 {
                self.0
            }
        }

        $(
            pub const $name2: $name = $name($val);
        )*

        pub const $uc: &[i32] = &[$($val,)*];
    };
}

#[path = "src/consts.rs"]
mod consts;

fn open(s: &str) -> io::Result<BufWriter<File>> {
    let mut path = PathBuf::from(env::var("OUT_DIR").unwrap());
    path.push(s);
    Ok(BufWriter::new(
        OpenOptions::new()
            .create(true)
            .write(true)
            .truncate(true)
            .open(path)?,
    ))
}

fn get_target() -> repc::Target {
    let rustc_target = env::var("TARGET").unwrap();
    repc::TARGET_MAP
        .iter()
        .cloned()
        .find(|t| t.0 == rustc_target)
        .unwrap()
        .1
}

fn get_enum_ty(variants: Vec<i128>) -> anyhow::Result<u64> {
    let target = get_target();
    let ty = Type {
        layout: (),
        annotations: vec![],
        variant: TypeVariant::Enum(variants),
    };
    let ty = repc::compute_layout(target, &ty)?;
    assert!(ty.layout.pointer_alignment_bits <= ty.layout.size_bits);
    Ok(ty.layout.size_bits)
}

fn write_ty<W: Write>(f: &mut W, vals: &[i32], ty: &str) -> anyhow::Result<()> {
    let variants: Vec<_> = vals.iter().cloned().map(|v| v as i128).collect();
    let size = get_enum_ty(variants)?;
    writeln!(f, "#[allow(clippy::allow_attributes, dead_code)]")?;
    writeln!(f, "pub type {} = i{};", ty, size)?;
    Ok(())
}

fn main() -> anyhow::Result<()> {
    let mut f = open("pango_tys.rs")?;
    write_ty(&mut f, consts::CAIRO_FORMATS, "cairo_format_t")?;
    write_ty(&mut f, consts::CAIRO_STATUSES, "cairo_status_t")?;
    write_ty(&mut f, consts::CAIRO_OPERATORS, "cairo_operator_t")?;
    write_ty(&mut f, consts::PANGO_ELLIPSIZE_MODES, "PangoEllipsizeMode_")?;

    println!("cargo:rerun-if-changed=src/consts.rs");
    Ok(())
}