const router = require('express').Router();
const { getDb } = require('../db/database');
const { standardizeError } = require('../middleware/errorFormatter');
const { decorateDataSource, ensureManualDataSource } = require('../services/transactionService');

const VALID_TYPES = new Set(['manual', 'file_import', 'provider_sync']);
const VALID_STATUSES = new Set(['active', 'inactive', 'error']);

function cleanFilter(value) {
  return typeof value === 'string' ? value.trim() : '';
}

// GET /api/data-sources?type=&status=
router.get('/', (req, res) => {
  const db = getDb();
  ensureManualDataSource(db, req.user.id);

  const type = cleanFilter(req.query.type);
  const status = cleanFilter(req.query.status);

  if (type && !VALID_TYPES.has(type)) {
    return res.status(400).json(standardizeError('type must be manual, file_import, or provider_sync', 'VALIDATION_ERROR', 'type'));
  }
  if (status && !VALID_STATUSES.has(status)) {
    return res.status(400).json(standardizeError('status must be active, inactive, or error', 'VALIDATION_ERROR', 'status'));
  }

  let query = `
    SELECT
      ds.id, ds.user_id, ds.type, ds.provider, ds.name, ds.status,
      ds.config_json, ds.last_sync_at, ds.last_error, ds.created_at, ds.updated_at,
      COUNT(DISTINCT fa.id) AS account_count,
      COUNT(DISTINCT t.id) AS transaction_count
    FROM data_sources ds
    LEFT JOIN financial_accounts fa ON fa.data_source_id = ds.id AND fa.user_id = ds.user_id
    LEFT JOIN transactions t ON t.data_source_id = ds.id AND t.user_id = ds.user_id
    WHERE ds.user_id = ?
  `;
  const params = [req.user.id];

  if (type) {
    query += ' AND ds.type = ?';
    params.push(type);
  }
  if (status) {
    query += ' AND ds.status = ?';
    params.push(status);
  }

  query += `
    GROUP BY ds.id
    ORDER BY
      CASE WHEN ds.type = 'manual' THEN 0 ELSE 1 END,
      ds.name COLLATE NOCASE ASC
  `;

  res.json(db.prepare(query).all(...params).map(decorateDataSource));
});

module.exports = router;