use std::env;
use std::fs::File;
use std::io::Write;
use std::path::Path;
use walkdir::WalkDir;

fn main() {
    let out_dir = env::var("OUT_DIR").unwrap();
    let destination = Path::new(&out_dir).join("tests.rs");
    let mut test_file = File::create(&destination).unwrap();

    write_header(&mut test_file);

    let test_files = WalkDir::new("org_mode_samples")
        .into_iter()
        .filter(|e| match e {
            Ok(dir_entry) => {
                dir_entry.file_type().is_file()
                    && Path::new(dir_entry.file_name())
                        .extension()
                        .map(|ext| ext.to_ascii_lowercase() == "org")
                        .unwrap_or(false)
            }
            Err(_) => true,
        }).collect::<Result<Vec<_>, _>>().unwrap();
    for test in test_files {
        write_test(&mut test_file, &test);
    }

}

fn write_test(test_file: &mut File, test: &walkdir::DirEntry) {
    let test_name = test.path().strip_prefix("org_mode_samples/").expect("Paths should be under org_mode_samples/").to_string_lossy().to_lowercase().strip_suffix(".org").expect("Should have .org extension").replace("/", "_");


    write!(
        test_file,
        include_str!("./tests/test_template"),
        name = test_name,
        path = test.path().display()
    )
    .unwrap();
}

fn write_header(test_file: &mut File) {
    write!(
        test_file,
        r#"
#[feature(exit_status_error)]
use organic::compare_document;
use organic::document;
use organic::emacs_parse_org_document;
use organic::sexp;

"#
    )
    .unwrap();
}