/**
 * Database service using express-pouchdb for self-hosted database sync.
 * Provides PouchDB HTTP API compatible with client-side PouchDB replication.
 */

import PouchDB from 'pouchdb';
import PouchDBAdapterMemory from 'pouchdb-adapter-memory';
import expressPouchdb from 'express-pouchdb';
import path from 'path';
import { fileURLToPath } from 'url';

// Register memory adapter (works in Node.js without leveldown issues)
PouchDB.plugin(PouchDBAdapterMemory);

const __dirname = path.dirname(fileURLToPath(import.meta.url));

// Data directory for persistent storage (used for logs)
const DATA_DIR = process.env.DATA_DIR || path.join(__dirname, '../../data');

// Use memory adapter for now - data persists while server is running
// TODO: Switch to leveldb once version conflicts are resolved
const memPouchDB = PouchDB.defaults({
  adapter: 'memory'
});

// Create express-pouchdb middleware
// Using 'minimumForPouchDB' mode for lightweight operation
// Include routes needed for PouchDB replication
const pouchApp = expressPouchdb(memPouchDB, {
  mode: 'minimumForPouchDB',
  overrideMode: {
    include: [
      'routes/root',        // GET / - server info
      'routes/db',          // PUT/GET/DELETE /:db
      'routes/all-dbs',     // GET /_all_dbs
      'routes/changes',     // GET /:db/_changes
      'routes/bulk-docs',   // POST /:db/_bulk_docs
      'routes/bulk-get',    // POST /:db/_bulk_get
      'routes/all-docs',    // GET /:db/_all_docs
      'routes/revs-diff',   // POST /:db/_revs_diff
      'routes/documents'    // GET/PUT/DELETE /:db/:docid
    ]
  },
  logPath: path.join(DATA_DIR, 'logs', 'pouchdb.log')
});

console.log(`[Database] Initialized express-pouchdb with data dir: ${DATA_DIR}`);

// Test that PouchDB can create databases
(async () => {
  try {
    const testDb = new memPouchDB('_test_db');
    const info = await testDb.info();
    console.log('[Database] Test DB created successfully:', info);
    await testDb.destroy();
    console.log('[Database] Test DB destroyed');
  } catch (err) {
    console.error('[Database] Failed to create test database:', err);
  }
})();

export { memPouchDB as PouchDB, pouchApp };