// Client documents: render markdown for the in-app viewer, export/serve branded PDFs.
import fs from "node:fs";
import path from "node:path";
import { marked } from "marked";
import { safeSlug } from "./clients.js";
import { toPdf } from "../../tools/report-pdf/build.mjs";
import { reportOptions } from "./workspace.js";

/** Resolve a document path inside one client's folder (blocks ../ escapes). */
export function resolveDoc(slug, rel) {
  const dir = safeSlug(slug);
  const full = path.resolve(dir, String(rel || ""));
  if (!full.startsWith(dir + path.sep) || !/\.(md|pdf)$/.test(full) || !fs.existsSync(full)) {
    throw Object.assign(new Error("Document not found."), { status: 404 });
  }
  return full;
}

function splitFrontMatter(md) {
  const m = md.match(/^---\r?\n([\s\S]*?)\r?\n---\r?\n/);
  if (!m) return { meta: {}, body: md };
  const meta = {};
  const kpis = [];
  for (const line of m[1].split(/\r?\n/)) {
    const kpi = line.match(/^\s+-\s+(.*)$/);
    if (kpi) { const [value, label = "", note = ""] = kpi[1].split("|").map((s) => s.trim()); kpis.push({ value, label, note }); continue; }
    const kv = line.match(/^(\w+):\s*(.*)$/);
    if (kv && kv[1] !== "kpis") meta[kv[1]] = kv[2].trim();
  }
  return { meta: { ...meta, kpis }, body: md.slice(m[0].length) };
}

export function renderDoc(slug, rel) {
  const full = resolveDoc(slug, rel);
  if (!full.endsWith(".md")) throw Object.assign(new Error("Only markdown documents can be previewed."), { status: 400 });
  const { meta, body } = splitFrontMatter(fs.readFileSync(full, "utf8"));
  // Content is written by our own team/AI runs; links open in a new tab.
  const html = marked.parse(body, { gfm: true, breaks: true }).replace(/<a href=/g, '<a target="_blank" rel="noopener" href=');
  const pdf = full.replace(/\.md$/, ".pdf");
  return { path: rel, meta, html, updatedAt: fs.statSync(full).mtime.toISOString(), hasPdf: fs.existsSync(pdf) };
}

export function exportPdf(slug, rel) {
  const full = resolveDoc(slug, rel);
  if (!full.endsWith(".md")) throw Object.assign(new Error("Pick a markdown document."), { status: 400 });
  const written = toPdf(full, reportOptions());
  return path.relative(safeSlug(slug), written).replace(/\\/g, "/");
}