agora-ai/backend/src/db/schema.js

import Database from 'better-sqlite3';
import { dirname, join } from 'path';
import { fileURLToPath } from 'url';
import { mkdirSync, existsSync } from 'fs';

const __dirname = dirname(fileURLToPath(import.meta.url));
const dbPath = process.env.DATABASE_PATH || join(__dirname, '../../data/agora.db');

// Ensure data directory exists
const dataDir = dirname(dbPath);
if (!existsSync(dataDir)) {
  mkdirSync(dataDir, { recursive: true });
}

const db = new Database(dbPath);

// Enable foreign keys
db.pragma('foreign_keys = ON');

// Create collaborative sessions table
db.exec(`
  CREATE TABLE IF NOT EXISTS collaborative_sessions (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    initial_prompt TEXT NOT NULL,
    document_format TEXT DEFAULT 'md' CHECK(document_format IN ('md', 'txt')),
    status TEXT CHECK(status IN ('created', 'ongoing', 'completed', 'failed')) DEFAULT 'created',
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    completed_at TIMESTAMP,
    final_document TEXT
  )
`);

// Create document versions table
db.exec(`
  CREATE TABLE IF NOT EXISTS document_versions (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    session_id INTEGER NOT NULL,
    version_number INTEGER NOT NULL,
    content TEXT NOT NULL,
    modified_by TEXT NOT NULL,
    modification_reason TEXT,
    round_number INTEGER NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (session_id) REFERENCES collaborative_sessions(id) ON DELETE CASCADE
  )
`);

// Create document rounds table (track each round of agents)
db.exec(`
  CREATE TABLE IF NOT EXISTS document_rounds (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    session_id INTEGER NOT NULL,
    round_number INTEGER NOT NULL,
    agents_in_round TEXT NOT NULL,
    agents_made_changes TEXT DEFAULT '',
    completed_at TIMESTAMP,
    FOREIGN KEY (session_id) REFERENCES collaborative_sessions(id) ON DELETE CASCADE
  )
`);

console.log('Database initialized successfully');

export default db;