investor-flow/app/server/src/db/client.ts

// Investor Flow — SQLite DB client (node:sqlite). DESIGN.md §1 schema seam.
//
// Runtime adaptation (reversible): design specified Bun + bun:sqlite. Implemented on
// Node 26 native TS (type-stripping) + node:sqlite (built-in) so the backend has ZERO
// native dependencies. Deep-module architecture (CacheRepository, etc.) is unchanged.
import { DatabaseSync } from 'node:sqlite';
import { readFileSync, mkdirSync } from 'node:fs';
import { dirname, join, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';

const __dirname = dirname(fileURLToPath(import.meta.url));
const SCHEMA_PATH = join(__dirname, 'schema.sql');
const DEFAULT_DB_DIR = join(__dirname, '..', '..', 'data');
const DEFAULT_DB_PATH = join(DEFAULT_DB_DIR, 'investor-flow.db');

export interface DbOptions {
  /** SQLite file path. Defaults to $IFLOW_DB_PATH or <server>/data/investor-flow.db. Use ':memory:' for tests. */
  path?: string;
  readonly?: boolean;
}

/** Open a SQLite connection with foreign keys + WAL enabled. */
export function createDb(opts: DbOptions = {}): DatabaseSync {
  const path = opts.path ?? process.env.IFLOW_DB_PATH ?? DEFAULT_DB_PATH;
  if (!opts.readonly && path !== ':memory:') {
    mkdirSync(dirname(path), { recursive: true });
  }
  const database = new DatabaseSync(path, {
    readOnly: opts.readonly ?? false,
    enableForeignKeyConstraints: true,
  });
  // WAL is persistent on the file; setting per-connection is harmless and ensures it.
  try {
    database.exec('PRAGMA journal_mode = WAL;');
  } catch {
    /* readOnly or disallowed — ignore */
  }
  return database;
}

/** Apply the full schema (CREATE TABLE IF NOT EXISTS). Idempotent. */
export function initSchema(database: DatabaseSync): void {
  const sql = readFileSync(SCHEMA_PATH, 'utf8');
  database.exec(sql);
}

let _db: DatabaseSync | null = null;
/** Process-wide singleton connection (auto-creates + inits schema on first call). */
export function db(): DatabaseSync {
  if (!_db) {
    _db = createDb();
    initSchema(_db);
    // Ensure the anonymous user exists for unauthenticated watchlist/portfolio usage.
    try {
      _db.prepare("INSERT OR IGNORE INTO users (id, email, pw_hash, created_at) VALUES (?, ?, ?, ?)")
        .run('anonymous', 'anonymous@investor-flow.local', '', new Date().toISOString());
    } catch { /* table may not exist yet or already exists */ }
  }
  return _db;
}

/** CLI entry: `node src/db/client.ts` initializes the on-disk database. */
const isMain = process.argv[1] ? resolve(process.argv[1]) === fileURLToPath(import.meta.url) : false;
if (isMain) {
  const d = createDb();
  initSchema(d);
  const path = process.env.IFLOW_DB_PATH ?? DEFAULT_DB_PATH;
  const rows = d.prepare("SELECT name FROM sqlite_master WHERE type='table' ORDER BY name").all() as Array<{ name: string }>;
  console.log(`[investor-flow] schema initialized at ${path} (${rows.length} tables)`);
  d.close();
}