// Turn a report .md into a Metatroncube-branded PDF next to it.
// Usage: node tools/report-pdf/build.mjs <report.md> [more.md ...]
// Files with "-internal" in the name get an "INTERNAL — NOT FOR CLIENT" badge.

import { readFileSync, writeFileSync, existsSync, mkdtempSync, rmSync, copyFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { basename, dirname, join, resolve } from "node:path";
import { fileURLToPath, pathToFileURL } from "node:url";
import { execFileSync } from "node:child_process";
import { marked } from "marked";

const root = resolve(dirname(fileURLToPath(import.meta.url)), "..", "..");
const brandDir = join(root, "branding");

const BROWSERS = [
  "C:/Program Files/Google/Chrome/Application/chrome.exe",
  "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe",
  "C:/Program Files/Microsoft/Edge/Application/msedge.exe",
  "/usr/bin/google-chrome",
  "/usr/bin/google-chrome-stable",
  "/usr/bin/chromium",
  "/usr/bin/chromium-browser",
  "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome",
];

function findBrowser() {
  const found = [process.env.REPORT_PDF_BROWSER, ...BROWSERS].find((p) => p && existsSync(p));
  if (!found) throw new Error("No Chrome/Edge found. Set REPORT_PDF_BROWSER to a Chromium browser path.");
  return found;
}

function escapeHtml(s) {
  return s.replace(/[&<>"]/g, (c) => ({ "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;" })[c]);
}

// Optional front matter at the top of the .md:
// ---
// client: Wallaceton Eye Care
// report: Social media review · October 2026
// period: 12 Sep – 10 Oct 2026
// accounts: Instagram @handle · Facebook Page
// prepared: October 10, 2026          (defaults to today)
// kpis:
//   - 121 | People reached on Instagram | most don't follow you yet
//   - 0 | Clicks to your website | no link on the profile yet
// ---
// With front matter, the hero block and KPI tiles replace the markdown's own H1.
function parseFrontMatter(md) {
  const m = md.match(/^---\r?\n([\s\S]*?)\r?\n---\r?\n/);
  if (!m) return { meta: {}, content: md };
  const meta = { kpis: [] };
  let inKpis = false;
  for (const line of m[1].split(/\r?\n/)) {
    const item = line.match(/^\s+-\s+(.*)$/);
    if (inKpis && item) {
      const [value, label = "", note = ""] = item[1].split("|").map((s) => s.trim());
      meta.kpis.push({ value, label, note });
      continue;
    }
    const kv = line.match(/^(\w+):\s*(.*)$/);
    if (!kv) continue;
    inKpis = kv[1] === "kpis";
    if (!inKpis) meta[kv[1]] = kv[2].trim();
  }
  return { meta, content: md.slice(m[0].length) };
}

function heroHtml(meta) {
  const sub = [meta.period, meta.accounts].filter(Boolean).map((s) => `<span>${escapeHtml(s)}</span>`).join("");
  const kpis = meta.kpis.length
    ? `<section class="mc-kpis" style="--mc-kpi-cols:${Math.min(meta.kpis.length, 4)}">${meta.kpis.map((k) => `
    <div class="mc-kpi"><div class="mc-kpi-value">${escapeHtml(k.value)}</div><div class="mc-kpi-label">${escapeHtml(k.label)}</div>${k.note ? `<div class="mc-kpi-note">${escapeHtml(k.note)}</div>` : ""}</div>`).join("")}
  </section>`
    : "";
  return `<section class="mc-hero">
    ${meta.report ? `<div class="mc-eyebrow">${escapeHtml(meta.report)}</div>` : ""}
    <h1>${escapeHtml(meta.client)}</h1>
    ${sub ? `<div class="mc-hero-sub">${sub}</div>` : ""}
  </section>${kpis}`;
}

function buildHtml(mdPath) {
  const { meta, content } = parseFrontMatter(readFileSync(mdPath, "utf8"));
  const body = marked.parse(content, { gfm: true, breaks: true });
  const css = readFileSync(join(brandDir, "report.css"), "utf8");
  const logo = readFileSync(join(brandDir, "metatroncube-logo.png")).toString("base64");
  const h1 = content.match(/^#\s+(.+)$/m)?.[1];
  const title = (meta.client ? `${meta.client} — ${meta.report ?? "Report"}` : h1 ?? basename(mdPath, ".md")).replace(/[*_`]/g, "");
  const internal = /-internal/i.test(basename(mdPath));
  const date = meta.prepared || new Date().toLocaleDateString("en-CA", { year: "numeric", month: "long", day: "numeric" });

  return `<!doctype html>
<html lang="en"><head><meta charset="utf-8">
<title>${escapeHtml(title)}</title>
<link rel="preconnect" href="https://fonts.googleapis.com">
<link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Plus+Jakarta+Sans:wght@600;700;800&display=swap" rel="stylesheet">
<style>${css}</style>
</head><body>
<header class="mc-topbar">
  <div class="mc-logo-crop"><img src="data:image/png;base64,${logo}" alt="Metatroncube — Digital Solutions Simplified"></div>
  <div class="mc-topmeta">
    Prepared ${escapeHtml(date)}
    ${internal ? '<br><span class="mc-internal">INTERNAL — NOT FOR CLIENT</span>' : ""}
  </div>
</header>
${meta.client ? heroHtml(meta) : ""}
<main>${body}</main>
</body></html>`;
}

function toPdf(mdPath) {
  const abs = resolve(mdPath);
  const out = abs.replace(/\.md$/i, "") + ".pdf";
  const work = mkdtempSync(join(tmpdir(), "mc-report-"));
  let written = out;
  try {
    const htmlPath = join(work, "report.html");
    const tmpPdf = join(work, "report.pdf");
    writeFileSync(htmlPath, buildHtml(abs));
    execFileSync(findBrowser(), [
      "--headless=new",
      "--disable-gpu",
      "--no-first-run",
      ...(process.platform === "linux" ? ["--no-sandbox"] : []),
      `--user-data-dir=${join(work, "profile")}`,
      "--no-pdf-header-footer",
      "--virtual-time-budget=8000",
      `--print-to-pdf=${tmpPdf}`,
      pathToFileURL(htmlPath).href,
    ], { stdio: "pipe" });
    if (!existsSync(tmpPdf)) throw new Error(`PDF was not created for ${mdPath}`);
    try {
      copyFileSync(tmpPdf, out);
    } catch (err) {
      // Usually the old PDF is open in a viewer, which locks it on Windows.
      written = out.replace(/\.pdf$/, "-new.pdf");
      copyFileSync(tmpPdf, written);
      console.warn(`WARNING: ${basename(out)} is locked (open in a viewer?). Saved as ${basename(written)} instead.`);
    }
  } finally {
    rmSync(work, { recursive: true, force: true });
  }
  console.log(`PDF: ${written}`);
  return written;
}

export { toPdf, buildHtml };

// CLI: only when run directly (the dashboard imports toPdf instead).
if (process.argv[1] && resolve(process.argv[1]) === fileURLToPath(import.meta.url)) {
  const files = process.argv.slice(2);
  if (!files.length) {
    console.error("Usage: node tools/report-pdf/build.mjs <report.md> [more.md ...]");
    process.exit(1);
  }
  for (const f of files) toPdf(f);
}