//! Helper module used in cli/build.rs and runtime/build.rs
use crate::JsRuntime;
use std::path::Path;
use std::path::PathBuf;

pub fn create_snapshot(
  mut js_runtime: JsRuntime,
  snapshot_path: &Path,
  files: Vec<PathBuf>,
) {
  // TODO(nayeemrmn): https://github.com/rust-lang/cargo/issues/3946 to get the
  // workspace root.
  let display_root = Path::new(env!("CARGO_MANIFEST_DIR")).parent().unwrap();
  for file in files {
    println!("cargo:rerun-if-changed={}", file.display());
    let display_path = file.strip_prefix(display_root).unwrap();
    let display_path_str = display_path.display().to_string();
    js_runtime
      .execute(
        &("deno:".to_string() + &display_path_str.replace('\\', "/")),
        &std::fs::read_to_string(&file).unwrap(),
      )
      .unwrap();
  }

  let snapshot = js_runtime.snapshot();
  let snapshot_slice: &[u8] = &*snapshot;
  println!("Snapshot size: {}", snapshot_slice.len());
  std::fs::write(&snapshot_path, snapshot_slice).unwrap();
  println!("Snapshot written to: {} ", snapshot_path.display());
}

pub fn get_js_files(d: &Path) -> Vec<PathBuf> {
  let mut js_files = std::fs::read_dir(d)
    .unwrap()
    .map(|dir_entry| {
      let file = dir_entry.unwrap();
      d.join(file.path())
    })
    .filter(|path| path.extension().unwrap_or_default() == "js")
    .collect::<Vec<PathBuf>>();
  js_files.sort();
  js_files
}