import type { Database } from 'jsr:@db/sqlite';
import { bytesToHex } from '@noble/ciphers/utils';
import { nip19 } from '@nostr/tools';
import { bech32m } from '@scure/base';
import { sql } from './queries.ts';

export class InviteTree {
  public root: InviteNode;

  constructor(npub: string) {
    this.root = new InviteNode(npub);
  }

  public addChild(npub: string) {
    const child = new InviteNode(npub);
    this.root.children.push(child);
  }
}

export class InviteNode {
  public readonly npub: string;
  public readonly children: InviteNode[];

  constructor(npub: string) {
    this.npub = npub;
    this.children = [];
  }

  public addChild(npub: string) {
    const child = new InviteNode(npub);
    this.children.push(child);
  }
}

export function buildInviteTree(db: Database, ccnPubkey: string) {
  const ccnCreator = sql`
    SELECT pubkey FROM allowed_writes WHERE ccn_pubkey = ${ccnPubkey} AND pubkey NOT IN (
      SELECT invitee_pubkey FROM inviter_invitee WHERE ccn_pubkey = ${ccnPubkey}
    )
  `(db)[0]?.pubkey;

  if (!ccnCreator) {
    throw new Error('CCN creator not found');
  }

  const inviteTree = new InviteTree(ccnCreator);

  const invitees = sql`
    SELECT inviter_pubkey, invitee_pubkey FROM inviter_invitee WHERE ccn_pubkey = ${ccnPubkey}
  `(db);

  // populate the invite tree by traversing the inviters
  for (const invitee of invitees) {
    let inviterNode = inviteTree.root.children.find(
      (child) => child.npub === invitee.inviter_pubkey,
    );

    if (!inviterNode) {
      inviterNode = new InviteNode(invitee.inviter_pubkey);
      inviteTree.root.children.push(inviterNode);
    }

    inviterNode.addChild(invitee.invitee_pubkey);
  }

  return inviteTree;
}

export function readInvite(invite: `${string}1${string}`) {
  const decoded = bech32m.decode(invite, false);
  if (decoded.prefix !== 'eveinvite') return false;
  const hexBytes = bech32m.fromWords(decoded.words);
  const npub = nip19.npubEncode(bytesToHex(hexBytes.slice(0, 32)));
  const inviteCode = bytesToHex(hexBytes.slice(32));
  return { npub, invite: inviteCode };
}