import Gio from "gi://Gio";
import GLib from "gi://GLib";

export async function readFromStreamRaw(
  stream: Gio.InputStream,
  bytes: number
): Promise<Uint8Array> {
  return new Promise<Uint8Array>((resolve, reject) => {
    const buffer = new Uint8Array(bytes);
    stream.read_bytes_async(
      bytes,
      GLib.PRIORITY_DEFAULT,
      null,
      (stream, result) => {
        try {
          const data = stream.read_bytes_finish(result);
          data.get_data(buffer);
          resolve(buffer);
        } catch (e) {
          reject(e);
        }
      }
    );
  });
}

export async function readFromStream(
  stream: Gio.InputStream,
  bytes: number
): Promise<Uint8Array> {
  return new Promise<Uint8Array>((resolve, reject) => {
    const chunkCount = Math.ceil(bytes / 4096);
    const buffer = await Array.from({ length: chunkCount }, (_, i) => i).reduce(
      (acc, i) => {
        const buffer = await acc;
        const chunkSize = Math.min(4096, bytes - i * 4096);
        const chunk = await readFromStreamRaw(stream, chunkSize);
        buffer.set(chunk, i * 4096);
        return buffer;
      },
      Promise.resolve(new Uint8Array(bytes))
    );
  });
}

export async function writeToStream(
  stream: Gio.OutputStream,
  data: ArrayBuffer | Uint8Array
): Promise<void> {
  if (data instanceof ArrayBuffer) {
    data = new Uint8Array(data);
  }
  return new Promise<void>((resolve, reject) => {
    stream.write_all_async(
      data,
      GLib.PRIORITY_DEFAULT,
      null,
      (stream, result) => {
        try {
          stream.write_all_finish(result);
          resolve();
        } catch (e) {
          reject(e);
        }
      }
    );
  });
}