import type { MastodonStatus, MastodonStatusContext } from './status';

// Oh jeez

export function reorderAndFilterPleromaReplies(
  status: MastodonStatus,
  context: MastodonStatusContext
): MastodonStatusContext {
  const findInOrig = (id: string): MastodonStatus | undefined =>
    context.ancestors.find((status) => status.id === id) ||
    context.descendants.find((status) => status.id === id);

  const newContext: MastodonStatusContext = { ancestors: [], descendants: [] };

  let currParent: MastodonStatus | undefined = status;
  while (currParent != null) {
    let replyingTo = currParent.in_reply_to_id;
    if (replyingTo != null) {
      currParent = findInOrig(replyingTo);
      if (currParent != null) {
        newContext.ancestors.unshift(currParent);
      }
    } else {
      currParent = undefined;
    }
  }

  const replyTree = new Map<string, MastodonStatus[]>();
  for (const descendant of context.descendants) {
    if (descendant.in_reply_to_id == null) {
      continue;
    }

    if (!replyTree.has(descendant.in_reply_to_id)) {
      replyTree.set(descendant.in_reply_to_id, []);
    }
    replyTree.get(descendant.in_reply_to_id)?.push(descendant);
  }

  let queue = [status];
  newContext.descendants.push(status);

  let potentialParent: MastodonStatus | undefined;
  while ((potentialParent = queue.shift()) != null) {
    const replies = replyTree.get(potentialParent.id);
    if (replies) {
      for (const reply of replies.reverse()) {
        const parentIndex = newContext.descendants.indexOf(potentialParent);
        newContext.descendants.splice(parentIndex + 1, 0, reply);
      }

      for (const reply of replies) {
        queue.push(reply);
      }
    }
  }
  newContext.descendants.shift();

  return newContext;
}