import pkg from "../../package.json";
import { parsePrefs, type RenderPrefsV1 } from "../pdf/model/prefs";
import { buildRenderModel, type RenderModel } from "../pdf/model/build";
import { vendorFromSnapshot } from "../pdf/model/vendor";
import { Superseded } from "../pdf/render/client";
import type { RenderResult } from "../pdf/render/jobs";
import { api } from "./api";
import { loadLogoImages, logoForModel, type LogoImages } from "./logo";
import { getRenderClient, nextRenderJobId } from "./renderClient";
import type { BankAccount, Invoice, Settings } from "./types";

/**
 * The render model for an invoice whose images are already loaded (the live preview caches them).
 * Supplier and bank come from the snapshots frozen at issue; live settings are only a fallback.
 */
export function modelFromAssets(
  invoice: Invoice,
  settings: Settings,
  bank: BankAccount | null,
  logoImages: LogoImages | null,
  signatureDataUri: string | null,
): RenderModel {
  return buildRenderModel({
    invoice,
    vendor: settings,
    bank,
    logo: logoForModel(vendorFromSnapshot(invoice.vendorSnapshot, settings), logoImages),
    signatureDataUri,
    appVersion: pkg.version,
  });
}

/** Loads the invoice's logo and signature, then builds its render model. */
export async function buildModelForInvoice(invoice: Invoice, settings: Settings, bank: BankAccount | null): Promise<RenderModel> {
  const vendor = vendorFromSnapshot(invoice.vendorSnapshot, settings);
  const logoImages = await loadLogoImages(vendor, api.readAssetDataUri);
  const signatureDataUri = invoice.signaturePath ? await api.readAssetDataUri(invoice.signaturePath) : null;
  return modelFromAssets(invoice, settings, bank, logoImages, signatureDataUri);
}

/** Page setup for an invoice: what was frozen at issue, else the user's current default. */
export const prefsForInvoice = (invoice: Invoice, settings: Settings): RenderPrefsV1 =>
  parsePrefs(invoice.renderPrefs || settings.renderPrefs);

/**
 * Renders an issued invoice to PDF bytes through the shared render client (worker, or the main
 * thread if the worker cannot start), with the layout audit issues and fingerprint.
 */
export async function renderInvoicePdf(
  invoice: Invoice,
  settings: Settings,
  bank: BankAccount | null,
  prefs: RenderPrefsV1 = prefsForInvoice(invoice, settings),
): Promise<RenderResult> {
  const model = await buildModelForInvoice(invoice, settings, bank);
  return renderModelWithRetry(model, prefs);
}

/** Renders a ready model in the shared client. */
export async function renderModelWithRetry(model: RenderModel, prefs: RenderPrefsV1): Promise<RenderResult> {
  // The live preview shares the client; if it takes the worker first this render is superseded, so go again.
  for (let attempt = 0; ; attempt++) {
    try {
      return await getRenderClient().render({ id: nextRenderJobId(), model, prefs });
    } catch (err) {
      if (!(err instanceof Superseded) || attempt >= 4) throw err;
    }
  }
}