// Shared helpers for the logo scripts: rasterise a Canva PDF page with pdf.js and @napi-rs/canvas.
import { readFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

export const ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..");
export const PDF_DIR = path.join(ROOT, "templates", "Modern Neutral Invoice Template");
export const SCALE = 4;
export const PAGE = { w: 595.5, h: 842.25 };
export const OUT_DIR = "/tmp/invoice-c2";

export async function loadCanvas() {
  try {
    return await import("@napi-rs/canvas");
  } catch {
    console.error("@napi-rs/canvas is not installed (it is an optional dev dependency); run npm install");
    process.exit(1);
  }
}

/** Renders page 1 of the Canva PDF `n` at SCALE x. Returns the canvas. */
export async function renderPage(n, scale = SCALE) {
  const { createCanvas } = await loadCanvas();
  const pdfjs = await import("pdfjs-dist/legacy/build/pdf.mjs");
  const data = new Uint8Array(readFileSync(path.join(PDF_DIR, `${n}.pdf`)));
  const doc = await pdfjs.getDocument({ data, isEvalSupported: false, verbosity: 0 }).promise;
  const page = await doc.getPage(1);
  const vp = page.getViewport({ scale });
  const canvas = createCanvas(Math.round(vp.width), Math.round(vp.height));
  await page.render({ canvasContext: canvas.getContext("2d"), viewport: vp, canvas }).promise;
  return canvas;
}

/** Copies a pt rectangle of a page canvas into a new canvas (same scale). */
export async function cropCanvas(canvas, rect, scale = SCALE) {
  const { createCanvas } = await loadCanvas();
  const x = Math.round(rect.x * scale);
  const y = Math.round(rect.y * scale);
  const w = Math.round(rect.w * scale);
  const h = Math.round(rect.h * scale);
  const out = createCanvas(w, h);
  out.getContext("2d").drawImage(canvas, x, y, w, h, 0, 0, w, h);
  return out;
}

/** Canva PDF number of each template (docs/templates/README.md). */
export const TEMPLATE_PDF = {
  marble: 1, highlighter: 2, monolith: 3, linea: 4, monogram: 5, serenity: 6, "crimson-grid": 7,
  "cobalt-stripe": 8, "slate-band": 9, "teal-swoosh": 10, "tangerine-ledger": 11, "purple-pop": 12, "citrus-split": 13,
};