/**
 * One-shot backfill: title-case existing `users.name` rows.
 *
 * After this lands, every NEW signup gets canonicalised in the better-auth
 * `user.create.before` hook (see apps/api/src/auth/auth.ts). Existing rows
 * pre-date that hook and still carry whatever the user typed at signup:
 * `mehmet`, `MEHMET`, `İLKER`, `OTO`, …. This script applies the same
 * `normalizeName()` Turkish-locale-aware title-case to historical rows so
 * mail subjects (`Sase.tr'ye hoş geldin, mehmet` → `, Mehmet`) and dashboard
 * greetings render consistently.
 *
 * Safe to re-run: the UPDATE is gated on `name <> normalized`, so already-
 * canonical rows aren't touched.
 *
 * Usage:
 *   pnpm tsx scripts/backfill-user-names.ts --dry-run        # preview only
 *   pnpm tsx scripts/backfill-user-names.ts                  # write
 *
 * Run against BOTH prod (sase) and dev (sase_dev) DBs separately by pointing
 * DATABASE_URL at each. mailAudit.md §9.3 #9.
 */

import * as path from "node:path";
import * as dotenv from "dotenv";
import postgres from "postgres";
import { normalizeName } from "@sase/shared";

dotenv.config({ path: path.join(__dirname, "../apps/api/.env") });

const argv = process.argv.slice(2);
const dryRun = argv.includes("--dry-run");

async function main() {
  if (!process.env.DATABASE_URL) {
    console.error("DATABASE_URL is not set");
    process.exit(1);
  }
  const sql = postgres(process.env.DATABASE_URL, { max: 1 });

  const rows = await sql<{ id: string; name: string }[]>`
    SELECT id, name FROM users WHERE name IS NOT NULL AND name <> ''
  `;
  console.log(`[backfill] scanned ${rows.length} users`);

  let changed = 0;
  let unchanged = 0;
  const samples: Array<{ before: string; after: string }> = [];

  for (const r of rows) {
    const norm = normalizeName(r.name);
    if (norm === r.name) {
      unchanged++;
      continue;
    }
    if (samples.length < 15) samples.push({ before: r.name, after: norm });
    if (!dryRun) {
      await sql`UPDATE users SET name = ${norm}, updated_at = NOW() WHERE id = ${r.id}`;
    }
    changed++;
  }

  console.log(`[backfill] ${changed} changed, ${unchanged} already canonical`);
  if (samples.length) {
    console.log("[backfill] sample diffs:");
    for (const s of samples) console.log(`  '${s.before}' → '${s.after}'`);
  }
  if (dryRun) console.log("[backfill] DRY RUN — no writes");

  await sql.end();
}

main().catch((e) => {
  console.error(e);
  process.exit(1);
});