import { nip19 } from 'nostr-tools';

/**
 * Cordn coordinator support — mostly *formats*, taken from Cordn itself so we
 * don't invent anything interoperable.
 *
 *  - A coordinator is identified by a Nostr pubkey plus the ContextVM relays
 *    that reach it (see `nprofile`).
 *  - Cordn's own server prints the canonical "add me" link as
 *    `https://cordn.net/chat/coordinators?c=<nprofile>`
 *    (`packages/server/src/main.ts`), and defaults to `wss://relay.contextvm.org`
 *    (`packages/server/src/coordinatorServer.ts`).
 *  - Cordn is a ContextVM server, so a coordinator can be probed the same way
 *    our own CVM server is: look for events it authored on that relay.
 */

/** Cordn's default ContextVM relay. */
export const CORDN_RELAY_URL = 'wss://relay.contextvm.org';

/** Cordn's "add this coordinator" URL base. */
export const CORDN_ADD_BASE = 'https://cordn.net/chat/coordinators';

/** Cordn's home — where the docs/one-liner/phone app live. */
export const CORDN_HOME = 'https://cordn.net';

/** The self-host one-liner advertised on cordn.net. */
export const CORDN_DOCKER_COMMAND = 'docker run --rm ghcr.io/cordn-msg/cordn:latest';

/** Where a user gets a coordinator they can run on a phone. */
export const CORDN_APP_URL = 'https://cordn.net';

/** Device-local: which coordinator this user points at. */
export const COORDINATOR_STORAGE_KEY = 'skatespots:coordinator';

export interface CoordinatorConfig {
  /** Coordinator server pubkey (hex). */
  pubkey: string;
  /** ContextVM relays that reach it (deduped, sorted-ish). */
  relays: string[];
  addedAt: number;
}

const HEX64 = /^[0-9a-f]{64}$/i;

function uniqueRelays(relays: Iterable<string>): string[] {
  return [...new Set([...relays].map((r) => r.trim()).filter((r) => /^wss?:\/\//i.test(r)))];
}

/** Pull the `c=` nprofile out of a cordn.net add URL. */
function extractFromUrl(input: string): string | null {
  try {
    return new URL(input).searchParams.get('c');
  } catch {
    return null;
  }
}

/**
 * Parse anything a user might paste: an `nprofile`, an `npub`, a bare hex
 * pubkey, or a `cordn.net/chat/coordinators?c=<nprofile>` link. Returns null
 * when it isn't a usable coordinator pointer.
 */
export function parseCoordinatorInput(raw: string): Omit<CoordinatorConfig, 'addedAt'> | null {
  const input = raw.trim();
  if (!input) return null;

  const candidate = input.includes('://') ? extractFromUrl(input) ?? input : input;

  try {
    const decoded = nip19.decode(candidate);
    if (decoded.type === 'nprofile') {
      return { pubkey: decoded.data.pubkey, relays: uniqueRelays(decoded.data.relays ?? []) };
    }
    if (decoded.type === 'npub') {
      return { pubkey: decoded.data, relays: [] };
    }
  } catch {
    // Not bech32 — try a raw hex pubkey below.
  }

  if (HEX64.test(candidate)) return { pubkey: candidate.toLowerCase(), relays: [] };
  return null;
}

/** The canonical cordn.net link that adds this coordinator. */
export function coordinatorAddUrl(config: Pick<CoordinatorConfig, 'pubkey' | 'relays'>): string {
  const nprofile = nip19.nprofileEncode({ pubkey: config.pubkey, relays: config.relays });
  return `${CORDN_ADD_BASE}?c=${nprofile}`;
}

/** `npub1abcd…wxyz` for display; falls back to a hex prefix. */
export function shortNpub(pubkey: string): string {
  try {
    const npub = nip19.npubEncode(pubkey);
    return `${npub.slice(0, 12)}…${npub.slice(-6)}`;
  } catch {
    return `${pubkey.slice(0, 12)}…`;
  }
}

/** A crew coordinator as stored on the crew event: `['coordinator', url, pubkey?, operator?]`. */
export interface CrewCoordinatorPointer {
  /** Endpoint: a `wss://` ContextVM relay, or an http(s) coordinator URL. */
  url: string;
  /** Coordinator service pubkey (hex), when addressed by identity. */
  pubkey?: string;
}

/**
 * Parse what a crew founder pastes into the crew's coordinator field. Accepts
 * everything Settings → Coordinator does (nprofile / npub / hex / cordn.net
 * link) **plus** a plain endpoint URL — so a coordinator run from Cordn's phone
 * app (which yields an nprofile, not a URL) is enterable, not just a
 * self-hosted endpoint.
 */
export function parseCrewCoordinatorInput(raw: string): CrewCoordinatorPointer | null {
  const input = raw.trim();
  if (!input) return null;

  const pointer = parseCoordinatorInput(input);
  if (pointer) {
    return { url: pointer.relays[0] ?? CORDN_RELAY_URL, pubkey: pointer.pubkey };
  }
  if (/^(https?|wss?):\/\//i.test(input)) return { url: input };
  return null;
}

/** Rebuild a paste-able input from a stored crew coordinator (round-trips). */
export function crewCoordinatorInputValue(
  coordinator: { url: string; pubkey?: string } | undefined,
): string {
  if (!coordinator?.url) return '';
  if (coordinator.pubkey && /^wss?:\/\//i.test(coordinator.url)) {
    return nip19.nprofileEncode({ pubkey: coordinator.pubkey, relays: [coordinator.url] });
  }
  return coordinator.url;
}

/**
 * Best-effort coordinator display name from an announcement event. Cordn relies
 * on the ContextVM transport announcement, whose exact shape we don't hard-code
 * here — so we look in the obvious places and give up gracefully.
 */
export function coordinatorNameFromEvent(event: {
  tags: string[][];
  content: string;
}): string | null {
  const tagName = event.tags.find(([t]) => t === 'name')?.[1];
  if (tagName?.trim()) return tagName.trim().slice(0, 40);

  try {
    const parsed = JSON.parse(event.content) as {
      name?: unknown;
      serverInfo?: { name?: unknown };
    };
    const candidates = [parsed.serverInfo?.name, parsed.name];
    for (const value of candidates) {
      if (typeof value === 'string' && value.trim()) return value.trim().slice(0, 40);
    }
  } catch {
    // content isn't JSON — no name to show.
  }
  return null;
}