use std::env;
use std::fs::{read_dir, File};
use std::io::ErrorKind::NotFound;
use std::io::Read;
use std::io::Write;
use std::path::{Path, PathBuf};

fn get_const_name<P: Clone + Into<PathBuf>>(p: &P) -> String {
  let mut file_name_without_extension = p.clone().into();
  file_name_without_extension.set_extension("");
  String::from(
    file_name_without_extension
      .file_name()
      .unwrap()
      .to_string_lossy(),
  )
  .to_uppercase()
}

pub fn create_static_output_files(source_dir: &str) {
  let out_dir = env::var("OUT_DIR").unwrap();
  let dest_path = Path::new(&out_dir).join("static_files.rs");
  let mut f = File::create(&dest_path).unwrap();
  match read_dir(source_dir) {
    Ok(dir_content) => {
      for maybe_dir_entry in dir_content {
        let file_path = maybe_dir_entry.unwrap().path();
        let mut buffer = String::new();
        File::open(file_path.clone())
          .unwrap()
          .read_to_string(&mut buffer)
          .unwrap();
        let fence = buffer.chars().filter(|c| *c == '#').collect::<String>() + "#";
        f.write_all(
          format!(
            "pub const {}: &str = r{1}\"{2}\"{1};\n",
            get_const_name(&file_path),
            fence,
            buffer
          )
          .as_bytes(),
        )
        .unwrap();
      }
    }
    Err(err) => {
      if err.kind() == NotFound {
      } else {
        Err(err).unwrap()
      }
    }
  }
}

#[allow(unused)]
fn main() {
  create_static_output_files("static_files");
}