/**
 * D0 requirement 3 — review report for names that cannot be split safely.
 *
 * The migration backfills firstName = first token, lastName = the rest. That is
 * correct for two-token names and a guess for anything longer: "سید محمد
 * حسینی" should almost certainly be firstName="سید محمد", and the migration
 * writes firstName="سید" instead. Those rows need a human.
 *
 * READ-ONLY. It changes nothing; it prints what a person has to check.
 *
 *   node scripts/report-name-split.cjs              # print to stdout
 *   node scripts/report-name-split.cjs --csv out.csv
 *
 * Run it AFTER the 20260922120000_customer_name_parts migration.
 */
const { PrismaClient } = require('@prisma/client');
const fs = require('fs');

const prisma = new PrismaClient();

/** Same normalisation the migration's SQL uses. */
const tokens = (s) => String(s ?? '').trim().replace(/\s+/g, ' ').split(' ').filter(Boolean);

(async () => {
  const customers = await prisma.$queryRawUnsafe(`
    SELECT id, "fullName", "firstName", "lastName", mobile, "memberCode"
    FROM "Customer"
    ORDER BY "createdAt"
  `);

  const multi = [];
  const empty = [];
  const single = [];

  for (const c of customers) {
    const t = tokens(c.fullName);
    if (t.length === 0) empty.push(c);
    else if (t.length === 1) single.push(c);
    else if (t.length > 2) multi.push({ ...c, tokenCount: t.length });
  }

  console.log(`Customers scanned: ${customers.length}`);
  console.log(`  two tokens (split is reliable): ${customers.length - multi.length - empty.length - single.length}`);
  console.log(`  one token   (lastName is NULL): ${single.length}`);
  console.log(`  empty name  (nothing to split): ${empty.length}`);
  console.log(`  MORE THAN TWO TOKENS — NEEDS REVIEW: ${multi.length}`);

  if (single.length) {
    console.log('\n--- single-token names (no surname recorded) ---');
    for (const c of single) console.log(`  ${c.id}  ${c.mobile}  "${c.fullName}"`);
  }
  if (empty.length) {
    console.log('\n--- empty names ---');
    for (const c of empty) console.log(`  ${c.id}  ${c.mobile}`);
  }

  if (multi.length) {
    console.log('\n--- NEEDS REVIEW: more than two tokens ---');
    console.log('The migration guessed first-token / rest. Verify each one.\n');
    for (const c of multi) {
      console.log(`  ${c.id}  ${c.mobile}  (${c.tokenCount} tokens)`);
      console.log(`      fullName : "${c.fullName}"`);
      console.log(`      guessed  : firstName="${c.firstName}"  lastName="${c.lastName}"`);
    }
  }

  const csvArg = process.argv.indexOf('--csv');
  if (csvArg !== -1 && process.argv[csvArg + 1]) {
    const esc = (v) => `"${String(v ?? '').replace(/"/g, '""')}"`;
    const rows = [
      ['id', 'mobile', 'memberCode', 'fullName', 'guessedFirstName', 'guessedLastName', 'tokenCount'].join(','),
      ...multi.map((c) =>
        [c.id, c.mobile, c.memberCode, c.fullName, c.firstName, c.lastName, c.tokenCount].map(esc).join(','),
      ),
    ];
    // BOM so Excel opens the Persian text in the right encoding.
    fs.writeFileSync(process.argv[csvArg + 1], '' + rows.join('\n'), 'utf8');
    console.log(`\nCSV written: ${process.argv[csvArg + 1]} (${multi.length} rows)`);
  }

  await prisma.$disconnect();
})().catch(async (e) => {
  console.error(e);
  await prisma.$disconnect();
  process.exit(1);
});