// Two signing paths: NIP-07 browser extension and NIP-46 remote signer
// (covers Primal app + Amber via bunker:// URI). The active signer is held
// in module state — there's only one logged-in user at a time.

import type { Event as NostrEvent, EventTemplate } from "nostr-tools";

export type SignerKind = "extension" | "bunker";

export type Signer = {
  kind: SignerKind;
  getPublicKey(): Promise<string>;
  signEvent(template: EventTemplate): Promise<NostrEvent>;
};

let activeSigner: Signer | null = null;

export function getActiveSigner(): Signer | null {
  return activeSigner;
}

export function clearSigner(): void {
  activeSigner = null;
}

export async function loginWithExtension(): Promise<string> {
  if (!window.nostr) {
    throw new Error("No NIP-07 extension found. Try Alby, nos2x, or Primal extension.");
  }
  const ext = window.nostr;
  const pubkey = await ext.getPublicKey();
  activeSigner = {
    kind: "extension",
    getPublicKey: async () => pubkey,
    signEvent: async (template: EventTemplate) =>
      (await ext.signEvent({
        kind: template.kind,
        created_at: template.created_at,
        tags: template.tags,
        content: template.content,
      })) as NostrEvent,
  };
  return pubkey;
}

export async function loginWithBunker(bunkerUri: string): Promise<string> {
  // Lazy-load applesauce-signers — only pulled when bunker login is attempted
  // so the dashboard works for users who only use NIP-07.
  const mod = await import("applesauce-signers");
  const Ctor =
    (mod as { NostrConnectSigner?: any }).NostrConnectSigner ??
    ((mod as { default?: { NostrConnectSigner?: any } }).default?.NostrConnectSigner);
  if (!Ctor) {
    throw new Error("applesauce-signers does not expose NostrConnectSigner");
  }
  const fromUri = Ctor.fromBunkerURI ?? Ctor.fromURI;
  if (!fromUri) {
    throw new Error("NostrConnectSigner has no fromBunkerURI / fromURI helper");
  }
  const signer = await fromUri.call(Ctor, bunkerUri);
  const pubkey: string = await signer.getPublicKey();
  activeSigner = {
    kind: "bunker",
    getPublicKey: async () => pubkey,
    signEvent: async (template: EventTemplate) =>
      (await signer.signEvent(template)) as NostrEvent,
  };
  return pubkey;
}