// @ts-nocheck — route controller converted to .cts; handler req/res typed, full type-check deferred (thin glue over typed services).
import type { Req, Res, Next } from '../types/http';
const express = require('express');
const { ValidationError, NotFoundError, ConflictError } = require('../utils/apiError.cts');
const router = express.Router();
const { getDb, ensureUserDefaultCategories } = require('../db/database.cts');
const { accountingActiveSql } = require('../services/paymentAccountingService.cts');
const { kysely, all } = require('../db/kysely.cts');
const { sql } = require('kysely');

// Maps a SQLite UNIQUE-constraint violation to a friendly 409; re-throws anything
// else so the terminal handler returns a safe 500.
function asConflict(e, message, field) {
  if (e.message?.includes('UNIQUE')) throw ConflictError(message, field);
  throw e;
}

// GET /api/categories
router.get('/', (req: Req, res: Res) => {
  const db = getDb();
  ensureUserDefaultCategories(req.user.id);

  const categories = db
    .prepare(
      `
    SELECT id, user_id, name, sort_order, spending_enabled, group_id, created_at, updated_at
    FROM categories
    WHERE user_id = ?
      AND deleted_at IS NULL
    ORDER BY CASE WHEN sort_order IS NULL THEN 1 ELSE 0 END,
      sort_order ASC,
      name COLLATE NOCASE ASC
  `,
    )
    .all(req.user.id);

  const billsByCategory = db.prepare(`
    SELECT
      b.id,
      b.category_id,
      b.name,
      b.active,
      b.expected_amount,
      b.due_day,
      COUNT(p.id) AS payment_count,
      COALESCE(SUM(p.amount), 0) AS total_paid,
      MAX(p.paid_date) AS last_paid_date
    FROM bills b
    LEFT JOIN payments p
      ON p.bill_id = b.id
     AND p.deleted_at IS NULL
     AND ${accountingActiveSql('p')}
    WHERE b.user_id = ?
      AND b.category_id = ?
      AND b.deleted_at IS NULL
    GROUP BY b.id
    ORDER BY b.active DESC, b.due_day ASC, b.name COLLATE NOCASE ASC
  `);

  const shaped = categories.map((category) => {
    const bills = billsByCategory.all(req.user.id, category.id).map((bill) => ({
      ...bill,
      active: !!bill.active,
      payment_count: Number(bill.payment_count || 0),
      total_paid: Number(bill.total_paid || 0),
      last_paid_date: bill.last_paid_date || null,
    }));

    const activeBillCount = bills.filter((bill) => bill.active).length;
    const inactiveBillCount = bills.length - activeBillCount;
    const paymentCount = bills.reduce((sum, bill) => sum + bill.payment_count, 0);

    return {
      ...category,
      spending_enabled: !!category.spending_enabled,
      bill_count: activeBillCount,
      active_bill_count: activeBillCount,
      inactive_bill_count: inactiveBillCount,
      payment_count: paymentCount,
      bill_names: bills.map((bill) => bill.name),
      bills,
    };
  });

  res.json(shaped);
});

// PUT /api/categories/reorder
router.put('/reorder', (req: Req, res: Res) => {
  const db = getDb();
  const entries = Object.entries(req.body || {}).map(([categoryId, sortOrder]) => ({
    categoryId: Number(categoryId),
    sortOrder: Number(sortOrder),
  }));

  if (entries.length === 0) {
    throw ValidationError('At least one category order is required', 'reorder');
  }

  const invalid = entries.find(
    ({ categoryId, sortOrder }) =>
      !Number.isInteger(categoryId) ||
      categoryId <= 0 ||
      !Number.isInteger(sortOrder) ||
      sortOrder < 0,
  );
  if (invalid) {
    throw ValidationError(
      'Reorder payload must map category ids to non-negative integer positions',
      'reorder',
    );
  }

  const ids = entries.map((item) => item.categoryId);
  const placeholders = ids.map(() => '?').join(',');
  const owned = db
    .prepare(
      `
    SELECT id
    FROM categories
    WHERE user_id = ? AND deleted_at IS NULL AND id IN (${placeholders})
  `,
    )
    .all(req.user.id, ...ids);
  if (owned.length !== ids.length) {
    throw NotFoundError('One or more categories were not found', 'category_id');
  }

  const update = db.prepare(
    "UPDATE categories SET sort_order = ?, updated_at = datetime('now') WHERE id = ? AND user_id = ?",
  );
  db.transaction((items) => {
    for (const item of items) update.run(item.sortOrder, item.categoryId, req.user.id);
  })(entries);

  res.json({ success: true });
});

// POST /api/categories
router.post('/', (req: Req, res: Res) => {
  const db = getDb();
  const { name } = req.body;
  if (!name) throw ValidationError('name is required', 'name');

  try {
    const result = db
      .prepare('INSERT INTO categories (user_id, name) VALUES (?, ?)')
      .run(req.user.id, name.trim());
    const created = db.prepare('SELECT * FROM categories WHERE id = ?').get(result.lastInsertRowid);
    res.status(201).json(created);
  } catch (e) {
    asConflict(e, 'Category already exists', 'name');
  }
});

// PUT /api/categories/:id
router.put('/:id', (req: Req, res: Res) => {
  const db = getDb();
  const { name, spending_enabled, group_id } = req.body;
  if (!name) throw ValidationError('name is required', 'name');

  const cat = db
    .prepare('SELECT id FROM categories WHERE id = ? AND user_id = ? AND deleted_at IS NULL')
    .get(req.params.id, req.user.id);
  if (!cat) throw NotFoundError('Category not found', 'id');

  if (group_id !== undefined && group_id !== null) {
    const group = db
      .prepare('SELECT id FROM category_groups WHERE id = ? AND user_id = ?')
      .get(group_id, req.user.id);
    if (!group) throw NotFoundError('Category group not found', 'group_id');
  }

  try {
    const fields = ['name = ?', "updated_at = datetime('now')"];
    const values = [name.trim()];
    if (spending_enabled !== undefined) {
      fields.push('spending_enabled = ?');
      values.push(spending_enabled ? 1 : 0);
    }
    if (group_id !== undefined) {
      fields.push('group_id = ?');
      values.push(group_id);
    }
    db.prepare(`UPDATE categories SET ${fields.join(', ')} WHERE id = ? AND user_id = ?`).run(
      ...values,
      req.params.id,
      req.user.id,
    );
    const updated = db
      .prepare(
        'SELECT id, name, sort_order, spending_enabled, group_id, created_at, updated_at FROM categories WHERE id = ? AND user_id = ? AND deleted_at IS NULL',
      )
      .get(req.params.id, req.user.id);
    res.json({ ...updated, spending_enabled: !!updated.spending_enabled });
  } catch (e) {
    asConflict(e, 'Category already exists', 'name');
  }
});

// ── Category groups ──────────────────────────────────────────────────────────

// GET /api/category-groups — typed via Kysely (built, then run synchronously).
router.get('/groups', (req: Req, res: Res) => {
  const groups = all(
    kysely()
      .selectFrom('category_groups')
      .select(['id', 'name', 'sort_order', 'created_at', 'updated_at'])
      .where('user_id', '=', req.user.id)
      .orderBy('sort_order', 'asc')
      .orderBy(sql`name collate nocase`, 'asc'),
  );
  res.json(groups);
});

// POST /api/category-groups
router.post('/groups', (req: Req, res: Res) => {
  const db = getDb();
  const { name } = req.body;
  if (!name?.trim()) throw ValidationError('name is required', 'name');

  try {
    const maxOrder = db
      .prepare('SELECT COALESCE(MAX(sort_order), -1) AS m FROM category_groups WHERE user_id = ?')
      .get(req.user.id).m;
    const result = db
      .prepare('INSERT INTO category_groups (user_id, name, sort_order) VALUES (?, ?, ?)')
      .run(req.user.id, name.trim(), maxOrder + 1);
    const created = db
      .prepare(
        'SELECT id, name, sort_order, created_at, updated_at FROM category_groups WHERE id = ?',
      )
      .get(result.lastInsertRowid);
    res.status(201).json(created);
  } catch (e) {
    asConflict(e, 'Category group already exists', 'name');
  }
});

// PUT /api/category-groups/:id
router.put('/groups/:id', (req: Req, res: Res) => {
  const db = getDb();
  const { name, sort_order } = req.body;

  const group = db
    .prepare('SELECT id FROM category_groups WHERE id = ? AND user_id = ?')
    .get(req.params.id, req.user.id);
  if (!group) throw NotFoundError('Category group not found', 'id');

  try {
    const fields = ["updated_at = datetime('now')"];
    const values = [];
    if (name !== undefined) {
      if (!name.trim()) throw ValidationError('name is required', 'name');
      fields.push('name = ?');
      values.push(name.trim());
    }
    if (sort_order !== undefined) {
      fields.push('sort_order = ?');
      values.push(Number(sort_order));
    }
    db.prepare(`UPDATE category_groups SET ${fields.join(', ')} WHERE id = ? AND user_id = ?`).run(
      ...values,
      req.params.id,
      req.user.id,
    );
    const updated = db
      .prepare(
        'SELECT id, name, sort_order, created_at, updated_at FROM category_groups WHERE id = ? AND user_id = ?',
      )
      .get(req.params.id, req.user.id);
    res.json(updated);
  } catch (e) {
    asConflict(e, 'Category group already exists', 'name');
  }
});

// DELETE /api/category-groups/:id
router.delete('/groups/:id', (req: Req, res: Res) => {
  const db = getDb();
  const group = db
    .prepare('SELECT id FROM category_groups WHERE id = ? AND user_id = ?')
    .get(req.params.id, req.user.id);
  if (!group) throw NotFoundError('Category group not found', 'id');

  db.prepare('DELETE FROM category_groups WHERE id = ? AND user_id = ?').run(
    req.params.id,
    req.user.id,
  );
  res.json({ success: true });
});

// PATCH /api/categories/:id/spending — toggle spending_enabled without requiring name
router.patch('/:id/spending', (req: Req, res: Res) => {
  const db = getDb();
  const cat = db
    .prepare(
      'SELECT id, spending_enabled FROM categories WHERE id = ? AND user_id = ? AND deleted_at IS NULL',
    )
    .get(req.params.id, req.user.id);
  if (!cat) throw NotFoundError('Category not found', 'id');

  const enabled =
    req.body?.spending_enabled !== undefined ? !!req.body.spending_enabled : !cat.spending_enabled;
  db.prepare(
    "UPDATE categories SET spending_enabled=?, updated_at=datetime('now') WHERE id=? AND user_id=?",
  ).run(enabled ? 1 : 0, req.params.id, req.user.id);
  res.json({ id: cat.id, spending_enabled: enabled });
});

// DELETE /api/categories/:id
router.delete('/:id', (req: Req, res: Res) => {
  const db = getDb();
  const cat = db
    .prepare('SELECT id, name FROM categories WHERE id = ? AND user_id = ? AND deleted_at IS NULL')
    .get(req.params.id, req.user.id);
  if (!cat) throw NotFoundError('Category not found', 'id');

  const deleted = db
    .prepare(
      "UPDATE categories SET deleted_at = datetime('now'), updated_at = datetime('now') WHERE id = ? AND user_id = ? AND deleted_at IS NULL",
    )
    .run(req.params.id, req.user.id);

  res.json({
    success: true,
    deleted: deleted.changes,
    deleted_category_id: cat.id,
    deleted_category_name: cat.name,
    recoverable_until_days: 30,
  });
});

// POST /api/categories/:id/restore — undo category soft delete
router.post('/:id/restore', (req: Req, res: Res) => {
  const db = getDb();
  const cat = db
    .prepare(
      'SELECT id, name FROM categories WHERE id = ? AND user_id = ? AND deleted_at IS NOT NULL',
    )
    .get(req.params.id, req.user.id);
  if (!cat) throw NotFoundError('Deleted category not found', 'id');

  db.prepare(
    "UPDATE categories SET deleted_at = NULL, updated_at = datetime('now') WHERE id = ? AND user_id = ?",
  ).run(req.params.id, req.user.id);
  res.json(
    db
      .prepare('SELECT * FROM categories WHERE id = ? AND user_id = ?')
      .get(req.params.id, req.user.id),
  );
});

module.exports = router;