// Migration: Add sync anomaly detection and BU drift monitoring tables
//
// Creates two new tables:
//   - ivanti_sync_anomaly_log — stores one row per sync cycle with the
//     anomaly summary breakdown (count deltas, classification, significance).
//   - ivanti_finding_bu_history — records BU change events detected on
//     individual findings across syncs.
//
// Safe to re-run — uses CREATE TABLE IF NOT EXISTS and CREATE INDEX IF NOT EXISTS.
//
// Usage: node backend/migrations/add_sync_anomaly_tables.js

const path    = require('path');
const sqlite3 = require('sqlite3').verbose();
const dbPath  = path.join(__dirname, '..', 'cve_database.db');
const db      = new sqlite3.Database(dbPath);

console.log('Starting sync anomaly tables migration...');

function run(sql, params = []) {
    return new Promise((resolve, reject) => {
        db.run(sql, params, function (err) {
            if (err) reject(err);
            else resolve(this);
        });
    });
}

function all(sql, params = []) {
    return new Promise((resolve, reject) => {
        db.all(sql, params, (err, rows) => {
            if (err) reject(err);
            else resolve(rows || []);
        });
    });
}

async function migrate() {
    // 1. Create ivanti_sync_anomaly_log table
    await run(`
        CREATE TABLE IF NOT EXISTS ivanti_sync_anomaly_log (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            sync_timestamp DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
            open_count_delta INTEGER NOT NULL DEFAULT 0,
            closed_count_delta INTEGER NOT NULL DEFAULT 0,
            newly_archived_count INTEGER NOT NULL DEFAULT 0,
            returned_count INTEGER NOT NULL DEFAULT 0,
            classification_json TEXT NOT NULL DEFAULT '{}',
            is_significant INTEGER NOT NULL DEFAULT 0,
            created_at DATETIME DEFAULT CURRENT_TIMESTAMP
        )
    `);
    console.log('✓ ivanti_sync_anomaly_log table ready');

    // 2. Create ivanti_finding_bu_history table
    await run(`
        CREATE TABLE IF NOT EXISTS ivanti_finding_bu_history (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            finding_id TEXT NOT NULL,
            finding_title TEXT NOT NULL DEFAULT '',
            host_name TEXT NOT NULL DEFAULT '',
            previous_bu TEXT NOT NULL,
            new_bu TEXT NOT NULL,
            detected_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
            created_at DATETIME DEFAULT CURRENT_TIMESTAMP
        )
    `);
    console.log('✓ ivanti_finding_bu_history table ready');

    // 3. Create indexes
    await run('CREATE INDEX IF NOT EXISTS idx_anomaly_sync_timestamp ON ivanti_sync_anomaly_log(sync_timestamp)');
    console.log('✓ idx_anomaly_sync_timestamp index ready');

    await run('CREATE INDEX IF NOT EXISTS idx_bu_history_finding_id ON ivanti_finding_bu_history(finding_id)');
    console.log('✓ idx_bu_history_finding_id index ready');

    await run('CREATE INDEX IF NOT EXISTS idx_bu_history_detected_at ON ivanti_finding_bu_history(detected_at)');
    console.log('✓ idx_bu_history_detected_at index ready');
}

migrate()
    .then(() => {
        console.log('Migration complete.');
        db.close();
    })
    .catch((err) => {
        console.error('Migration failed:', err);
        db.close();
        process.exit(1);
    });