import fs from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { openDb } from "./index.js";
import type { ExtractedSense } from "../stage-1-extract/scripts/extract.js";

// ── Paths ─────────────────────────────────────────────────────────────────────

const __dirname = path.dirname(fileURLToPath(import.meta.url));

const PATHS = {
  extracted: path.resolve(__dirname, "../stage-1-extract/output/en.json"),
};

// ── Import ────────────────────────────────────────────────────────────────────

export async function importKaikki(): Promise<void> {
  console.log("Loading extracted Kaikki data...");
  const raw = await fs.readFile(PATHS.extracted, "utf-8");
  const senses = JSON.parse(raw) as ExtractedSense[];
  console.log(`  Loaded ${senses.length.toLocaleString()} senses`);

  const db = openDb();

  const insertEntry = db.prepare(`
    INSERT INTO entries (headword, language, pos, sense_index, gloss, examples)
    VALUES (?, ?, ?, ?, ?, ?)
    ON CONFLICT (headword, language, pos, sense_index)
    DO UPDATE SET
      gloss    = excluded.gloss,
      examples = excluded.examples
    RETURNING id
  `);

  const insertTranslation = db.prepare(`
    INSERT INTO translations (entry_id, target_lang, word, sense_hint)
    VALUES (?, ?, ?, ?)
    ON CONFLICT (entry_id, target_lang, word) DO NOTHING
  `);

  // Track next available sense_index per (headword, pos) to handle
  // the same word appearing in multiple JSONL entries with the same POS.
  const senseIndexMap = new Map<string, number>();

  console.log("\nImporting into pipeline.db...");

  const importAll = db.transaction(() => {
    let entries = 0;
    let translations = 0;
    let skipped = 0;

    for (const sense of senses) {
      const key = `${sense.headword}|${sense.pos}`;
      const nextIndex = senseIndexMap.get(key) ?? 0;

      // Use the offset sense_index to avoid collisions when the same word
      // appears in multiple JSONL entries with the same POS.
      const senseIndex = nextIndex;
      senseIndexMap.set(key, nextIndex + 1);

      const row = insertEntry.get(
        sense.headword,
        "en",
        sense.pos,
        senseIndex,
        sense.gloss ?? null,
        JSON.stringify(sense.examples),
      ) as { id: number } | undefined;

      if (!row) {
        skipped++;
        continue;
      }

      entries++;

      for (const t of sense.translations) {
        insertTranslation.run(
          row.id,
          t.target_lang,
          t.word,
          t.sense_hint ?? null,
        );
        translations++;
      }
    }

    return { entries, translations, skipped };
  });

  const counts = importAll();

  console.log(`  entries:      ${counts.entries.toLocaleString()}`);
  console.log(`  translations: ${counts.translations.toLocaleString()}`);
  console.log(`  skipped:      ${counts.skipped.toLocaleString()}`);

  db.close();
  console.log("\nImport complete.");
}

// ── Check if already imported ─────────────────────────────────────────────────

export function isImported(): boolean {
  const db = openDb();
  const row = db.prepare("SELECT COUNT(*) as count FROM entries").get() as {
    count: number;
  };
  db.close();
  return row.count > 0;
}

// ── Main ─────────────────────────────────────────────────────────────────────

async function main(): Promise<void> {
  const db = openDb();
  const row = db.prepare("SELECT COUNT(*) as count FROM entries").get() as {
    count: number;
  };
  db.close();

  if (row.count > 0) {
    console.log(
      `pipeline.db already contains ${row.count.toLocaleString()} entries — skipping import.`,
    );
    console.log("Delete pipeline.db and re-run db:init to start fresh.");
    process.exit(0);
  }

  await importKaikki();
}

if (import.meta.url === `file://${process.argv[1]}`) {
  main().catch((err) => {
    console.error(err);
    process.exit(1);
  });
}