import getPool from "@cocalc/database/pool";

async function checkPathExists(public_path_id: string): Promise<void> {
  if (typeof public_path_id != "string" || public_path_id.length != 40) {
    throw Error(`invalid public path id ${public_path_id}`);
  }
  const pool = getPool();
  const { rows } = await pool.query(
    "SELECT COUNT(*)::INT FROM public_paths WHERE id=$1",
    [public_path_id]
  );
  if (rows[0].count == 0) {
    throw Error(`no public path with id ${public_path_id}`);
  }
}

export async function star(
  public_path_id: string,
  account_id: string
): Promise<void> {
  await checkPathExists(public_path_id);
  const pool = getPool();
  await pool.query(
    "INSERT INTO public_path_stars (public_path_id, account_id, time) VALUES($1,$2,NOW())",
    [public_path_id, account_id]
  );
}

export async function unstar(
  public_path_id: string,
  account_id: string
): Promise<void> {
  await checkPathExists(public_path_id);
  const pool = getPool();
  await pool.query(
    "DELETE FROM public_path_stars WHERE public_path_id=$1 AND account_id=$2",
    [public_path_id, account_id]
  );
}

// see https://stackoverflow.com/questions/66389300/postgres-cast-count-as-integer for why ::int is needed; it's due to BigInt.
export async function numStars(public_path_id: string): Promise<number> {
  const pool = getPool();
  const { rows } = await pool.query(
    "SELECT COUNT(*)::INT FROM public_path_stars WHERE public_path_id=$1",
    [public_path_id]
  );
  return rows[0].count ?? 0;
}

export async function isStarred(
  public_path_id: string,
  account_id: string
): Promise<boolean> {
  const pool = getPool();
  const { rows } = await pool.query(
    "SELECT COUNT(*)::INT FROM public_path_stars WHERE public_path_id=$1 AND account_id=$2",
    [public_path_id, account_id]
  );
  return rows[0].count > 0;
}

export async function getStars(
  account_id: string
): Promise<{ public_path_id: string; path?: string; name?: string }[]> {
  const pool = getPool();
  const { rows } = await pool.query(
    "SELECT public_path_id FROM public_path_stars WHERE account_id=$1",
    [account_id]
  );
  return rows;
}

/*
// commented out since might not need it.
// Do a global query of all stars by everybody and return a map from
// public paths to how many times they have been stared, for all paths
// with at least 1 star.  This is cached for a bit.
// TODO: This does not scale indefinitely, but is an easy way to get started.
// This will obviously (hopefully!) have to get rewritten at some point in the future.
export async function globalStarCounts(): Promise<{
  [public_path_id: string]: number;
}> {
  const pool = getPool("medium");
  const { rows } = await pool.query(
    "select public_path_id, count(*)::INT from public_path_stars group by public_path_id"
  );
  const v: { [public_path_id: string]: number } = {};
  for (const row of rows) {
    v[row.public_path_id] = row.count;
  }
  return v;
}
*/