import fs from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { SUPPORTED_LANGUAGE_CODES } from "@lila/shared";
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 OUTPUT_DIR = path.resolve(__dirname, "../stage-1-extract/output");

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

export async function importKaikki(): Promise<void> {
  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
  `);

  let totalEntries = 0;
  let totalTranslations = 0;
  let totalSkipped = 0;

  for (const lang of SUPPORTED_LANGUAGE_CODES) {
    const filePath = path.join(OUTPUT_DIR, `${lang}.json`);

    let senses: ExtractedSense[];
    try {
      const raw = await fs.readFile(filePath, "utf-8");
      senses = JSON.parse(raw) as ExtractedSense[];
    } catch {
      console.warn(`  Warning: no output file found for ${lang}, skipping`);
      continue;
    }

    console.log(
      `  Importing ${lang}: ${senses.length.toLocaleString()} senses...`,
    );

    // 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>();

    const importLang = 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;
        senseIndexMap.set(key, nextIndex + 1);

        const row = insertEntry.get(
          sense.headword,
          sense.language,
          sense.pos,
          nextIndex,
          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 = importLang();
    totalEntries += counts.entries;
    totalTranslations += counts.translations;
    totalSkipped += counts.skipped;

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

  db.close();

  console.log(`\nImport complete:`);
  console.log(`  Total entries:      ${totalEntries.toLocaleString()}`);
  console.log(`  Total translations: ${totalTranslations.toLocaleString()}`);
  console.log(`  Total skipped:      ${totalSkipped.toLocaleString()}`);
}

// ── 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);
  }

  console.log("Importing Kaikki data into pipeline.db...");
  await importKaikki();
}

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