utils.js

import { getPageSizeMm } from "./layout.js";

export function getOptions({ layout, pageSize, orientation, marginMm, title, captionMode, removeBg, enhance, useRemoveBgApi, removeBgApiKey }) {
  const pageSizeKey = pageSize.toLowerCase(); // jsPDF expects "a4", "letter", "legal"
  const { w, h } = getPageSizeMm(pageSizeKey);
  const isLandscape = orientation === "landscape";
  const pageWmm = isLandscape ? Math.max(w, h) : Math.min(w, h);
  const pageHmm = isLandscape ? Math.min(w, h) : Math.max(w, h);

  return {
    layoutKey: layout,
    pageSizeKey,
    pageWmm,
    pageHmm,
    orientation,
    marginMm: Math.max(0, marginMm),
    title,
    captionMode: captionMode || "below",
    removeBg: !!removeBg,
    enhance: !!enhance,
    useRemoveBgApi: !!useRemoveBgApi,
    removeBgApiKey: removeBgApiKey || ""
  };
}

// Heuristic layout suggestion based on image count and aspect ratios
export function suggestLayout(items, { pageWmm, pageHmm }) {
  const n = items.length;
  const ratios = [];
  for (const it of items) {
    // Try to read dimensions from file name patterns if possible; fallback to square
    ratios.push(1);
  }

  // Prefer denser grids for many images
  let layoutKey = "4_grid";
  if (n <= 1) layoutKey = "1_center";
  else if (n === 2) layoutKey = "2_row";
  else if (n <= 3) layoutKey = pageWmm >= pageHmm ? "3_row" : "3_col";
  else if (n <= 6) layoutKey = "6_grid";
  else if (n <= 12) layoutKey = pageWmm >= pageHmm ? "4x3" : "3x4";
  else if (n <= 16) layoutKey = "4x4";
  else if (n <= 20) layoutKey = "4x5";
  else layoutKey = "4x6";

  // Margins: smaller for dense pages, larger for few items
  let marginMm = 15;
  if (n <= 2) marginMm = 20;
  else if (n <= 6) marginMm = 15;
  else if (n <= 12) marginMm = 12;
  else if (n <= 20) marginMm = 10;
  else marginMm = 8;

  return { layoutKey, marginMm };
}