import { decodeBase64, encodeBase64 } from 'jsr:@std/encoding@0.224/base64';
import { exists } from 'jsr:@std/fs';
import * as nostrTools from '@nostr/tools';
import * as nip06 from '@nostr/tools/nip06';
import {
  decryptUint8Array,
  encryptUint8Array,
  encryptionKey,
} from './utils/encryption.ts';
import { getEveFilePath } from './utils/files.ts';

export function isLocalhost(req: Request): boolean {
  const url = new URL(req.url);
  const hostname = url.hostname;
  return (
    hostname === '127.0.0.1' || hostname === '::1' || hostname === 'localhost'
  );
}

export function isValidJSON(str: string) {
  try {
    JSON.parse(str);
  } catch {
    return false;
  }
  return true;
}

export function isArray<T>(obj: unknown): obj is T[] {
  return Array.isArray(obj);
}

export function randomTimeUpTo2DaysInThePast() {
  const now = Date.now();
  const twoDaysAgo = now - 2 * 24 * 60 * 60 * 1000 - 3600 * 1000; // 1 hour buffer in case of clock skew
  return Math.floor(
    (Math.floor(Math.random() * (now - twoDaysAgo)) + twoDaysAgo) / 1000,
  );
}

export async function getCCNPubkey(): Promise<string> {
  const ccnPubPath = await getEveFilePath('ccn.pub');
  const seedPath = await getEveFilePath('ccn.seed');
  const doWeHaveKey = await exists(ccnPubPath);
  if (doWeHaveKey) return Deno.readTextFileSync(ccnPubPath);
  const ccnSeed =
    Deno.env.get('CCN_SEED') ||
    ((await exists(seedPath))
      ? Deno.readTextFileSync(seedPath)
      : nip06.generateSeedWords());
  const ccnPrivateKey = nip06.privateKeyFromSeedWords(ccnSeed);
  const ccnPublicKey = nostrTools.getPublicKey(ccnPrivateKey);
  const encryptedPrivateKey = encryptUint8Array(ccnPrivateKey, encryptionKey);

  Deno.writeTextFileSync(ccnPubPath, ccnPublicKey);
  Deno.writeTextFileSync(
    await getEveFilePath('ccn.priv'),
    encodeBase64(encryptedPrivateKey),
  );
  Deno.writeTextFileSync(seedPath, ccnSeed);

  return ccnPublicKey;
}

export async function getCCNPrivateKey(): Promise<Uint8Array> {
  const encryptedPrivateKey = Deno.readTextFileSync(
    await getEveFilePath('ccn.priv'),
  );
  return decryptUint8Array(decodeBase64(encryptedPrivateKey), encryptionKey);
}

export function isReplaceableEvent(kind: number): boolean {
  return (kind >= 10000 && kind < 20000) || kind === 0 || kind === 3;
}

export function isAddressableEvent(kind: number): boolean {
  return kind >= 30000 && kind < 40000;
}

export function isRegularEvent(kind: number): boolean {
  return (
    (kind >= 1000 && kind < 10000) ||
    (kind >= 4 && kind < 45) ||
    kind === 1 ||
    kind === 2
  );
}

export function isCCNReplaceableEvent(kind: number): boolean {
  return kind >= 60000 && kind < 65536;
}

export function parseATagQuery(aTagValue: string): {
  kind: number;
  pubkey: string;
  dTag?: string;
} {
  const parts = aTagValue.split(':');
  if (parts.length < 2) return { kind: 0, pubkey: '' };

  return {
    kind: Number.parseInt(parts[0], 10),
    pubkey: parts[1],
    dTag: parts.length > 2 ? parts[2] : undefined,
  };
}