/**
 * seed-va.ts — Push Vaiśiṣṭyāṣṭakam (VA) into MongoDB.
 *
 * Collections written:
 *   - book_meta        → 1 doc  { book: "va", data: <intro.json> }
 *   - prose_chapters   → 8 chapter docs
 *
 * JSON sources:
 *   - lib/jsons/books/va/intro.json
 *   - lib/jsons/books/va/chapters/01.json through 08.json
 *
 * Usage:
 *   npx tsx scripts/seed-va.ts
 */

import dotenv from "dotenv";
import fs from "fs";
import path from "path";
import { MongoClient } from "mongodb";

// Load env
dotenv.config({ path: ".env.local" });
dotenv.config({ path: ".env" });

const DATABASE_URL = process.env.DATABASE_URL;
if (!DATABASE_URL) {
  console.error("❌ DATABASE_URL is not set in .env");
  process.exit(1);
}

const BASE_DIR = path.resolve(__dirname, "..");
const BOOK_DIR = path.join(BASE_DIR, "lib", "jsons", "books", "va");
const BOOK = "va";
const NO_VOLUME = 0;

// ---------------------------------------------------------------------------
// Types
// ---------------------------------------------------------------------------

type IntroJson = {
  book: string;
  title: string;
  author: string;
  year: number | null;
  description: string;
  totalChapters: number;
  chapters: { number: number; title: string }[];
};

type ChapterJson = {
  book: string;
  chapter: number;
  title: string;
  type: string;
  paragraphs: string[];
};

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

function readJson<T>(filePath: string): T {
  return JSON.parse(fs.readFileSync(filePath, "utf-8"));
}

// ---------------------------------------------------------------------------
// Main
// ---------------------------------------------------------------------------

async function main() {
  console.log("🌱 Seeding Vaiśiṣṭyāṣṭakam (VA)...\n");

  const client = new MongoClient(DATABASE_URL!);
  await client.connect();
  console.log("📡 Connected to MongoDB\n");

  const db = client.db();
  const start = Date.now();

  // ---- Read intro ----
  const introPath = path.join(BOOK_DIR, "intro.json");
  if (!fs.existsSync(introPath)) {
    console.error(`❌ Missing: ${introPath}`);
    process.exit(1);
  }
  const intro = readJson<IntroJson>(introPath);

  // ---- Book meta ----
  const metaCol = db.collection("book_meta");
  await metaCol.deleteMany({ book: BOOK });
  await metaCol.insertOne({ book: BOOK, data: intro });
  console.log(`📖 Inserted book_meta for "${intro.title}" (${BOOK})`);

  // ---- Chapters ----
  const proseCol = db.collection("prose_chapters");
  await proseCol.deleteMany({ book: BOOK });

  const chaptersDir = path.join(BOOK_DIR, "chapters");
  const chapterFiles = fs
    .readdirSync(chaptersDir)
    .filter((f) => f.endsWith(".json"))
    .sort();

  let inserted = 0;
  for (const file of chapterFiles) {
    const ch = readJson<ChapterJson>(path.join(chaptersDir, file));
    const chNum = ch.chapter;

    await proseCol.insertOne({
      book: BOOK,
      volume: NO_VOLUME,
      chapter: chNum,
      title: ch.title,
      type: ch.type || "chapter",
      slug: String(chNum),
      order: 100 + chNum,
      paragraphs: ch.paragraphs,
    });

    console.log(
      `  📄 Chapter ${chNum}: "${ch.title}" (${ch.paragraphs.length} paragraphs)`,
    );
    inserted++;
  }

  // Verify
  const totalDocs = await proseCol.countDocuments({ book: BOOK });
  console.log(`\n✅ Verified: ${totalDocs} prose_chapters docs for ${BOOK}`);

  const elapsed = ((Date.now() - start) / 1000).toFixed(1);
  console.log(`\n🎉 Done in ${elapsed}s (${inserted} chapters inserted)`);

  await client.close();
}

main().catch((err) => {
  console.error("❌ Seed failed:", err);
  process.exit(1);
});