// Brand kit per client: saved hashtag sets, approved phrases/CTAs, words to avoid.
// checkCaption() flags problems before a post goes for approval (shared by the dashboard, the queue and the MCP tools).
import fs from "node:fs";
import path from "node:path";
import { PROJECT_ROOT } from "./env.js";

const FILE = process.env.QUORLA_BRANDKIT_FILE || path.join(PROJECT_ROOT, "data", "brandkit.json");
const CLIENTS = path.join(PROJECT_ROOT, "clients");
fs.mkdirSync(path.dirname(FILE), { recursive: true });
const read = () => { try { return JSON.parse(fs.readFileSync(FILE, "utf8")); } catch { return {}; } };
const err = (msg, status = 400) => Object.assign(new Error(msg), { status });

// Phrases that read as AI-written or generic (project writing rules).
const GENERIC = ["elevate your", "unlock", "in today's fast-paced world", "look no further", "game-changer", "game changer", "take it to the next level", "dive into", "seamless", "revolutionize", "embark on"];
// White-label: the agency must never appear in a client's public post.
const AGENCY_WORDS = ["metatroncube", "metatron cube", "quorla"];
const LIMITS = { instagram: 2200, facebook: 63206, tiktok: 2200, youtube: 5000, gbp: 1500, linkedin: 3000, threads: 500, pinterest: 500, reddit: 40000 };

function checkClient(slug) {
  if (!/^[a-z0-9][a-z0-9-]*$/.test(String(slug || "")) || !fs.existsSync(path.join(CLIENTS, slug))) throw err("Unknown client.", 404);
  return slug;
}
const tagList = (v) => [...new Set(String(Array.isArray(v) ? v.join(" ") : v || "").split(/[\s,]+/).map((t) => t.trim()).filter(Boolean).map((t) => `#${t.replace(/^#+/, "")}`).filter((t) => /^#[\p{L}\p{N}_]{1,60}$/u.test(t)))];
const lines = (v) => (Array.isArray(v) ? v : String(v || "").split(/\n/)).map((x) => String(x).trim()).filter(Boolean).slice(0, 200);

export function get(client) {
  checkClient(client);
  const k = read()[client] || {};
  return { hashtagSets: k.hashtagSets || [], phrases: k.phrases || [], avoid: k.avoid || [], notes: k.notes || "", updatedAt: k.updatedAt || null, updatedBy: k.updatedBy || null };
}

export function save(client, patch, by = "team") {
  checkClient(client);
  const db = read();
  const cur = get(client);
  const next = {
    hashtagSets: patch.hashtagSets !== undefined ? (patch.hashtagSets || []).slice(0, 30).map((s) => ({ name: String(s.name || "").trim().slice(0, 60) || "Set", tags: tagList(s.tags).slice(0, 30) })).filter((s) => s.tags.length) : cur.hashtagSets,
    phrases: patch.phrases !== undefined ? lines(patch.phrases).map((x) => x.slice(0, 300)) : cur.phrases,
    avoid: patch.avoid !== undefined ? lines(patch.avoid).map((x) => x.slice(0, 80)) : cur.avoid,
    notes: patch.notes !== undefined ? String(patch.notes || "").slice(0, 3000) : cur.notes,
    updatedAt: new Date().toISOString(), updatedBy: by,
  };
  db[client] = next;
  const tmp = FILE + ".tmp"; fs.writeFileSync(tmp, JSON.stringify(db, null, 1)); fs.renameSync(tmp, FILE);
  return next;
}

const EMOJI = /\p{Extended_Pictographic}/gu;
/**
 * Problems in a caption for this client: { level: "bad" | "warn", text }.
 * bad = must fix (agency named in a client post, over the platform limit); warn = worth a second look.
 */
export function checkCaption(client, caption, { platforms = [] } = {}) {
  const text = String(caption || "");
  const low = text.toLowerCase();
  const out = [];
  let kit = { avoid: [] };
  try { kit = get(client); } catch { /* unknown client: generic checks only */ }
  // The agency's own account (its client name contains the agency name) may of course mention itself.
  let ownName = "";
  try { ownName = JSON.parse(fs.readFileSync(path.join(CLIENTS, client, "client.json"), "utf8")).name || ""; } catch { /* no client.json */ }
  const isAgencyItself = AGENCY_WORDS.some((w) => `${ownName} ${client}`.toLowerCase().replace(/[-_]/g, " ").includes(w));
  if (!isAgencyItself) for (const w of AGENCY_WORDS) if (low.includes(w)) out.push({ level: "bad", text: `Mentions “${w}”. Client posts must never name the agency.` });
  for (const p of platforms) if (LIMITS[p] && text.length > LIMITS[p]) out.push({ level: "bad", text: `Too long for ${p}: ${text.length} of ${LIMITS[p]} characters.` });
  for (const w of kit.avoid) if (w && low.includes(w.toLowerCase())) out.push({ level: "warn", text: `Uses “${w}”, which is on this client's avoid list.` });
  for (const g of GENERIC) if (low.includes(g)) out.push({ level: "warn", text: `“${g}” sounds generic. Say it the way the client would.` });
  const tags = text.match(/#[\p{L}\p{N}_]+/gu) || [];
  if (tags.length > 10) out.push({ level: "warn", text: `${tags.length} hashtags. 3–8 relevant ones usually do better.` });
  if ((text.match(EMOJI) || []).length > 8) out.push({ level: "warn", text: "Lots of emoji. Keep a few that add meaning." });
  return out;
}