first commit

server/src/db.ts

@@ -0,0 +1,94 @@
+import initSqlJs, { Database as SqlJsDatabase } from 'sql.js';
+import fs from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const dbPath = path.join(__dirname, '..', 'data.db');
+
+let db: SqlJsDatabase;
+
+export async function initDb(): Promise<SqlJsDatabase> {
+  const SQL = await initSqlJs();
+
+  if (fs.existsSync(dbPath)) {
+    const buffer = fs.readFileSync(dbPath);
+    db = new SQL.Database(buffer);
+  } else {
+    db = new SQL.Database();
+  }
+
+  db.run('PRAGMA foreign_keys = ON');
+
+  db.run(`
+    CREATE TABLE IF NOT EXISTS users (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      username TEXT UNIQUE NOT NULL,
+      password_hash TEXT NOT NULL,
+      points INTEGER DEFAULT 0,
+      created_at TEXT DEFAULT (datetime('now'))
+    )
+  `);
+
+  db.run(`
+    CREATE TABLE IF NOT EXISTS cats (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      user_id INTEGER NOT NULL REFERENCES users(id),
+      image_url TEXT NOT NULL,
+      caption TEXT DEFAULT '',
+      created_at TEXT DEFAULT (datetime('now'))
+    )
+  `);
+
+  db.run(`
+    CREATE TABLE IF NOT EXISTS likes (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      cat_id INTEGER NOT NULL REFERENCES cats(id),
+      user_id INTEGER NOT NULL REFERENCES users(id),
+      UNIQUE(cat_id, user_id)
+    )
+  `);
+
+  saveDb();
+  return db;
+}
+
+export function saveDb(): void {
+  const data = db.export();
+  const buffer = Buffer.from(data);
+  fs.writeFileSync(dbPath, buffer);
+}
+
+export function getDb(): SqlJsDatabase {
+  return db;
+}
+
+export function queryOne(sql: string, params: any[] = []): any {
+  const stmt = db.prepare(sql);
+  stmt.bind(params);
+  const result = stmt.step() ? stmt.getAsObject() : null;
+  stmt.free();
+  return result;
+}
+
+export function queryAll(sql: string, params: any[] = []): any[] {
+  const stmt = db.prepare(sql);
+  stmt.bind(params);
+  const results: any[] = [];
+  while (stmt.step()) {
+    results.push(stmt.getAsObject());
+  }
+  stmt.free();
+  return results;
+}
+
+export function execute(sql: string, params: any[] = []): { changes: number; lastInsertRowid: number } {
+  const stmt = db.prepare(sql);
+  stmt.bind(params);
+  stmt.step();
+  const lastId = db.exec('SELECT last_insert_rowid() AS id')[0]?.values[0][0] || 0;
+  const changes = db.getRowsModified();
+  stmt.free();
+  saveDb();
+  return { changes, lastInsertRowid: Number(lastId) };
+}