/**
 * make-pdf — print a scenario document as a GM-readable A4 PDF.
 *
 * The scenarios live as Markdown because that is what a GM reads at the table and what the
 * pack builder parses. A convention folder needs paper, and "export from a Markdown viewer"
 * gives you a web page with a page break through the middle of the detention table.
 *
 * So the same document is rendered here with print rules that serve the house style:
 * every top-level section starts a page, tables and read-aloud blocks never split across
 * one, and the cited-figure comments are dropped rather than printed as noise.
 *
 * There is no LaTeX or wkhtmltopdf on these machines. Chrome is on all of them, and its
 * headless print is a real renderer with real page rules, so that is the engine.
 *
 *   node tools/make-pdf.mjs docs/scenarios/STANDING_ORDER.md [--out <path.pdf>] [--keep-html]
 *
 * --compact drops the page break before each section. A scenario wants one section per page,
 * because a GM turns to a section and reads it; a two-page update note does not, and giving
 * it one printed eight pages with a paragraph on each.
 */
import { readFileSync, readdirSync, writeFileSync, existsSync, mkdirSync } from "node:fs";
import { execFileSync } from "node:child_process";
import path from "node:path";

const ROOT = path.resolve(path.dirname(new URL(import.meta.url).pathname.replace(/^\/([A-Za-z]:)/, "$1")), "..");
const argv = process.argv.slice(2);
const SRC = argv.find(a => !a.startsWith("--"));
if (!SRC) { console.error("usage: node tools/make-pdf.mjs <scenario.md> [--out file.pdf]"); process.exit(1); }
const COMPACT = argv.includes("--compact");
const outArg = argv.indexOf("--out");
const OUT = path.resolve(ROOT, outArg > -1 ? argv[outArg + 1]
  : path.join("docs", "print", path.basename(SRC).replace(/\.md$/, ".pdf")));

const CHROME = [
  "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome",
  "/Applications/Chromium.app/Contents/MacOS/Chromium",
  "/usr/bin/google-chrome", "/usr/bin/chromium", "/usr/bin/chromium-browser"
].find(existsSync);
if (!CHROME) { console.error("make-pdf: no Chrome or Chromium found — it is the print engine."); process.exit(1); }

/* ── Markdown, the subset the scenarios actually use ──────────────────────── */

const esc = s => s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");

/** Inline: **bold**, *italic*, `code`, and the em dashes already in the source. */
function inline(s) {
  return esc(s)
    .replace(/`([^`]+)`/g, "<code>$1</code>")
    .replace(/\*\*\*([^*]+)\*\*\*/g, "<strong><em>$1</em></strong>")
    .replace(/\*\*([^*]+)\*\*/g, "<strong>$1</strong>")
    .replace(/\*([^*]+)\*/g, "<em>$1</em>");
}

const cells = line => line.trim().replace(/^\||\|$/g, "").split("|").map(c => inline(c.trim()));

function render(md) {
  // The cite markers are a build-time contract, not something a GM reads on paper.
  const lines = md.replace(/<!--[\s\S]*?-->/g, "").split("\n");
  const out = [];
  let i = 0;
  while (i < lines.length) {
    const line = lines[i];

    if (/^\s*$/.test(line)) { i++; continue; }

    if (/^---+\s*$/.test(line)) { out.push('<hr class="rule"/>'); i++; continue; }

    const h = /^(#{1,4})\s+(.*)$/.exec(line);
    if (h) {
      const n = h[1].length;
      out.push(`<h${n}>${inline(h[2])}</h${n}>`);
      i++; continue;
    }

    // Table: a header row, a divider, then rows. Kept whole on one page.
    if (/^\|/.test(line) && /^\|[\s:|-]+\|?\s*$/.test(lines[i + 1] ?? "")) {
      const head = cells(line);
      i += 2;
      const body = [];
      while (i < lines.length && /^\|/.test(lines[i])) { body.push(cells(lines[i])); i++; }
      out.push(`<table><thead><tr>${head.map(c => `<th>${c}</th>`).join("")}</tr></thead><tbody>`
        + body.map(r => `<tr>${r.map(c => `<td>${c}</td>`).join("")}</tr>`).join("")
        + "</tbody></table>");
      continue;
    }

    // Read-aloud and warning blocks.
    if (/^>/.test(line)) {
      const buf = [];
      while (i < lines.length && /^>/.test(lines[i])) { buf.push(lines[i].replace(/^>\s?/, "")); i++; }
      const text = buf.join("\n").trim();
      const warn = /^⚠/.test(text);
      // A handout's numbered clauses are consecutive lines, and joining them turns ORDERS
      // into one grey paragraph. Two or more "N." markers in a run means a list, so break
      // before each; ordinary read-aloud prose is wrapped mid-sentence and must not be.
      const para = t => {
        const flat = inline(t.replace(/\n/g, " "));
        return (flat.match(/(?:^|\s)\d\.\s/g) ?? []).length >= 2
          ? flat.replace(/(?!^)\s(\d\.\s)/g, "<br/>$1") : flat;
      };
      out.push(`<blockquote class="${warn ? "warn" : "aloud"}">${
        text.split(/\n{2,}/).map(p => `<p>${para(p)}</p>`).join("")}</blockquote>`);
      continue;
    }

    // Lists, ordered and not. A continuation line is indented.
    const li = /^(\s*)([-*]|\d+\.)\s+(.*)$/.exec(line);
    if (li) {
      const ordered = /\d/.test(li[2]);
      const items = [];
      while (i < lines.length) {
        const m = /^(\s*)([-*]|\d+\.)\s+(.*)$/.exec(lines[i]);
        if (m) { items.push(m[3]); i++; continue; }
        if (/^\s+\S/.test(lines[i]) && items.length) { items[items.length - 1] += " " + lines[i].trim(); i++; continue; }
        break;
      }
      out.push(`<${ordered ? "ol" : "ul"}>${items.map(t => `<li>${inline(t)}</li>`).join("")}</${ordered ? "ol" : "ul"}>`);
      continue;
    }

    // Paragraph: run on until a blank line or a block starts.
    const buf = [];
    while (i < lines.length && !/^\s*$/.test(lines[i]) && !/^(#{1,4}\s|>|\||---+\s*$)/.test(lines[i])
           && !/^(\s*)([-*]|\d+\.)\s+/.test(lines[i])) { buf.push(lines[i].trim()); i++; }
    if (buf.length) out.push(`<p>${inline(buf.join(" "))}</p>`);
  }
  return out.join("\n");
}

/* ── The page ─────────────────────────────────────────────────────────────── */

const md = readFileSync(path.resolve(ROOT, SRC), "utf8");
const title = (/^#\s+(.*)$/m.exec(md)?.[1] ?? path.basename(SRC)).replace(/\*/g, "");
const short = title.split(":").pop().trim();

/* A cover plate if the scenario has one. The art stems are the scenario's initials —
   STANDING_ORDER is so_, CLEAN GROUND cg_, THROUGH TRAIN tt_ — so build the prefix that
   way rather than from the first word, which gave "st" and silently found nothing. */
const stem = path.basename(SRC, ".md").toLowerCase().split(/[_\s-]+/).map(w => w[0]).join("");
const covers = readdirSync(path.join(ROOT, "art", "scenes"))
  .filter(f => f.startsWith(`${stem}_01`) && f.endsWith(".webp")).sort();
const cover = covers.length ? path.join(ROOT, "art", "scenes", covers[0]) : null;
if (!cover) console.warn(`make-pdf: no cover plate matching art/scenes/${stem}_01*.webp`);

const html = `<!DOCTYPE html>
<html lang="en-GB"><head><meta charset="utf-8"><title>${esc(title)}</title>
<style>
@page { size: A4; margin: 18mm 16mm 20mm; }
@page :first { margin: 0; }
html { font-family: Georgia, "Times New Roman", serif; font-size: 10.5pt; color: #1b1b1b; }
body { margin: 0; line-height: 1.45; }
h1, h2, h3, h4 { font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; line-height: 1.2; }
h1 { display: none; }                      /* the cover carries the title */
h2 { font-size: 15pt; letter-spacing: .04em; text-transform: uppercase;
     border-bottom: 2pt solid #7a1f1f; padding-bottom: 2mm; margin: ${COMPACT ? "7mm 0 4mm" : "0 0 4mm"};
     ${COMPACT ? "" : "break-before: page;"} break-after: avoid; }
h2:first-of-type { margin-top: 0; }
h3 { font-size: 12pt; margin: 6mm 0 2mm; break-after: avoid; }
h4 { font-size: 10.5pt; margin: 4mm 0 1mm; break-after: avoid; }
p { margin: 0 0 2.4mm; orphans: 3; widows: 3; }
ul, ol { margin: 0 0 3mm; padding-left: 6mm; }
li { margin-bottom: 1.2mm; }
code { font-family: "SF Mono", Menlo, monospace; font-size: 9pt; background: #f0ece2; padding: 0 1mm; }
hr.rule { border: 0; border-top: .5pt solid #bbb; margin: 5mm 0; }
table { border-collapse: collapse; width: 100%; font-size: 9.5pt; margin: 0 0 4mm; break-inside: avoid; }
th, td { border: .5pt solid #b9b2a4; padding: 1.4mm 2mm; text-align: left; vertical-align: top; }
th { background: #efe3c4; font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
     font-size: 9pt; letter-spacing: .04em; }
blockquote { margin: 0 0 4mm; padding: 2.5mm 4mm; break-inside: avoid; }
blockquote.aloud { background: #f6f1e4; border-left: 3pt solid #7a1f1f; font-style: italic; }
blockquote.warn { background: #fdf2f2; border-left: 3pt solid #a33; }
blockquote p { margin: 0 0 1.5mm; }
blockquote p:last-child { margin-bottom: 0; }
/* Handouts read as paper, not as quotations. */
h3 + p + blockquote.aloud, h3 + blockquote.aloud {
  font-style: normal; font-family: "Courier New", Courier, monospace; font-size: 9.5pt;
  background: #fbfaf5; border: .8pt solid #9a917f; border-left-width: .8pt;
}
.cover { position: relative; height: 297mm; break-after: page; color: #1b1b1b; }
.cover img { width: 100%; height: 170mm; object-fit: cover; display: block; filter: saturate(.92); }
.cover .plate { padding: 18mm 20mm 0; }
.cover h1.show { display: block; font-size: 26pt; letter-spacing: .06em; text-transform: uppercase;
     margin: 0 0 3mm; }
.cover .sub { font-size: 11pt; font-style: italic; color: #444; margin-bottom: 6mm; }
.cover .tag { border-top: 2.2pt solid #7a1f1f; padding-top: 4mm; font-size: 11pt; font-style: italic; }
.cover .foot { position: absolute; bottom: 14mm; left: 20mm; right: 20mm;
     font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; font-size: 8.5pt;
     letter-spacing: .1em; text-transform: uppercase; color: #777;
     display: flex; justify-content: space-between; }
</style></head><body>
<section class="cover">
  ${cover ? `<img src="file://${cover}" alt=""/>` : ""}
  <div class="plate">
    <h1 class="show">${esc(short)}</h1>
    <div class="sub">${esc(title)}</div>
    <div class="tag">${render(md.split("\n## ")[0].split("\n").filter(l => /^>/.test(l))
        .map(l => l.replace(/^>\s?/, "")).join(" ")).replace(/<\/?p>/g, "")}</div>
  </div>
  <div class="foot"><span>The Custodians</span><span>GM document — private convention play</span>
    <span>${new Date().toISOString().slice(0, 10)}</span></div>
</section>
${render(md.replace(/^#\s+.*$/m, "").replace(/^>[\s\S]*?(?=\n##\s)/m, ""))}
</body></html>`;

mkdirSync(path.dirname(OUT), { recursive: true });
const htmlPath = OUT.replace(/\.pdf$/, ".html");
writeFileSync(htmlPath, html);

execFileSync(CHROME, ["--headless", "--disable-gpu", "--no-pdf-header-footer",
  `--print-to-pdf=${OUT}`, `file://${htmlPath}`], { stdio: "pipe" });

if (!argv.includes("--keep-html")) execFileSync("/bin/rm", ["-f", htmlPath]);
console.log(`make-pdf: wrote ${path.relative(ROOT, OUT)}`);