extern crate bindgen;

use std::env;
use std::path::PathBuf;
use bindgen::callbacks::ParseCallbacks;

#[derive(Debug)]
struct Parse;
impl ParseCallbacks for Parse {
    fn int_macro(&self, name: &str, _value: i64) -> Option<bindgen::callbacks::IntKind> {
        if name.starts_with("USBDEVFS_URB_TYPE_") {
            Some(bindgen::callbacks::IntKind::U8)
        } else {
            None
        }
    }
    fn item_name(&self, original_item_name: &str) -> Option<String> {
        // TODO: maybe leave names unchanged to help online searches for these terms
        for prefix in &["USBDEVFS_", "usbdevfs_"] {
            if original_item_name.starts_with(prefix) {
                return Some(original_item_name[prefix.len()..].to_string());
            }
        }
        None
    }
}

fn main() {
    // The bindgen::Builder is the main entry point
    // to bindgen, and lets you build up options for
    // the resulting bindings.
    let bindings = bindgen::Builder::default()
        // TODO: actually might be simpler to copy the headers into this repo,
        .header("/usr/include/linux/usbdevice_fs.h")
        .generate_comments(true)
        .whitelist_type("^usbdevfs.*")
        .whitelist_function("^usbdevfs.*")
        .whitelist_var("^USBDEVFS.*")
        .parse_callbacks(Box::new(Parse))
        // Finish the builder and generate the bindings.
        .generate()
        // Unwrap the Result and panic on failure.
        .expect("Unable to generate bindings");

    // Write the bindings to the $OUT_DIR/bindings.rs file.
    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
    bindings
        .write_to_file(out_path.join("bindings.rs"))
        .expect("Couldn't write bindings!");
}