// Fully type-checked (tsconfig.server.json); leading import type keeps Node type-stripping active.
import type { Req, Res, Next } from '../types/http';
('use strict');

const express = require('express');
const router = express.Router();
const { getDb } = require('../db/database.cts');
const { seedDemoData } = require('../scripts/seedDemoData.cts');
const { demoDataLimiter } = require('../middleware/rateLimiter.cts');
const { eraseUserData, clearSeededDemoData } = require('../services/userDataService.cts');
const { ApiError, ValidationError } = require('../utils/apiError.cts');

// 4xx service errors keep their message/code on the wire; anything else is
// rethrown raw so the terminal handler masks + logs it as a 5xx.
function toUserOpError(err: any, fallbackCode: string) {
  if (err.status && err.status < 500) {
    return new ApiError(err.code || fallbackCode, err.message, err.status);
  }
  return err;
}

// GET /api/user/seeded-status — whether the current user has demo data, with counts
router.get('/seeded-status', (req: Req, res: Res) => {
  try {
    const db = getDb();
    const userId = req.user.id;
    const one = (sql: string) => db.prepare(sql).get(userId).count as number;

    const seededBills = one(
      'SELECT COUNT(*) as count FROM bills WHERE user_id = ? AND is_seeded = 1',
    );
    const seededCategories = one(
      'SELECT COUNT(*) as count FROM categories WHERE user_id = ? AND is_seeded = 1',
    );
    // Bill-children (cascade with the seeded bill) counted via their bill.
    const seededPayments = one(
      'SELECT COUNT(*) as count FROM payments WHERE bill_id IN (SELECT id FROM bills WHERE user_id = ? AND is_seeded = 1)',
    );
    const seededTransactions = one(
      'SELECT COUNT(*) as count FROM transactions WHERE user_id = ? AND is_seeded = 1',
    );

    res.json({
      seeded: seededBills > 0 || seededCategories > 0,
      seededBills,
      seededCategories,
      seededPayments,
      seededTransactions,
    });
  } catch (err) {
    throw toUserOpError(err, 'SEEDED_STATUS_ERROR');
  }
});

// POST /api/user/clear-demo-data — surgically remove ONLY seeded demo data for the
// requesting user (in one transaction, child → parent). Marker tables are removed
// by is_seeded; bill-children cascade with their seeded bill. A seeded category is
// removed only if no remaining (non-seeded) bill references it, so a user's own bill
// that reused a demo category keeps its category. Mirrors eraseUserData().
router.post('/clear-demo-data', demoDataLimiter, (req: Req, res: Res) => {
  try {
    const result = clearSeededDemoData(getDb(), req.user.id);
    res.json({
      success: true,
      removed: result.removed,
      billsDeleted: result.counts.bills || 0,
      categoriesDeleted: result.counts.categories || 0,
      counts: result.counts,
    });
  } catch (err) {
    throw toUserOpError(err, 'CLEAR_DEMO_ERROR');
  }
});

// POST /api/user/seed-demo-data — seed the full demo dataset for the requesting user
router.post('/seed-demo-data', demoDataLimiter, (req: Req, res: Res) => {
  try {
    const db = getDb();
    const result = seedDemoData(req.user.id);
    db.prepare(
      `INSERT INTO import_history (user_id, imported_at, source_filename, file_type, rows_parsed, rows_created, rows_updated, rows_skipped, rows_ambiguous, rows_errored, options_json, summary_json)
       VALUES (?, datetime('now'), 'seed-demo-data', 'seed-demo', ?, ?, 0, 0, 0, 0, ?, ?)`,
    ).run(
      req.user.id,
      result.billsCreated + result.paymentsCreated + result.transactionsCreated,
      result.billsCreated,
      JSON.stringify({ action: 'seed-demo-data' }),
      JSON.stringify(result.counts),
    );
    res.json({
      success: true,
      message: `Created ${result.billsCreated} bills, ${result.paymentsCreated} payments and ${result.transactionsCreated} transactions`,
      billsCreated: result.billsCreated,
      categoriesCreated: result.categoriesCreated,
      paymentsCreated: result.paymentsCreated,
      transactionsCreated: result.transactionsCreated,
      counts: result.counts,
    });
  } catch (err) {
    throw toUserOpError(err, 'SEED_ERROR');
  }
});

// POST /api/user/erase-data — permanently wipe the requesting user's financial +
// imported data (bills, payments, transactions, connections, categories, imports).
// Preserves the account, login, 2FA, and preferences. Requires a type-to-confirm token.
router.post('/erase-data', demoDataLimiter, (req: Req, res: Res) => {
  const confirm = String(req.body?.confirm ?? '')
    .trim()
    .toUpperCase();
  if (confirm !== 'ERASE') {
    throw ValidationError('Type ERASE to confirm.', 'confirm', 'ERASE_CONFIRM_REQUIRED');
  }
  try {
    const result = eraseUserData(getDb(), req.user.id);
    res.json({ success: true, ...result });
  } catch (err) {
    throw toUserOpError(err, 'ERASE_ERROR');
  }
});

module.exports = router;