class Reddit {
  def fetchSubreddit(subreddit, maxItems = 5) {
    url = "https://www.reddit.com/r/" + subreddit + ".json"
    data = sync(def(ret) = http(url, combine(::jsondecode, ret))).data ?? []
    if (!length(data)) return []
    return stream(data.children)
      .map(def(child) = child.data)
      .limit(min(maxItems, data.dist ?? 0))
      .map(def(post) = {
        "id": post.id,
        "sub": subreddit,
        "url": post.url,
        "time": post.created_utc,
        "title": post.title,
        "permalink": post.permalink,
        "flair_text": arrayKeyExists("link_flair_text", post) ? post.link_flair_text : ""
      })
      .toArray()
  }

  def fetchSubreddits(subreddits, maxItems = 5) =
    stream(subreddits)
      .flatMap(def(r) = this.fetchSubreddit(r, maxItems))
      .toArray()
}