/**
 * activityDb.js
 * Local SQLite activity log database.
 * Opens (or creates) internal.db and provides logAttivita() for logging
 * every significant action sent to OTRS.
 */
const Database = require('better-sqlite3');
const path = require('path');
const crypto = require('crypto');

const DB_PATH = path.join(__dirname, 'internal.db');
const db = new Database(DB_PATH);

// Ensure WAL mode for better concurrent access
db.pragma('journal_mode = WAL');

// Create table if it does not exist
db.exec(`
  CREATE TABLE IF NOT EXISTS attivita (
    id            TEXT     PRIMARY KEY,
    agente_id     INTEGER  NOT NULL DEFAULT 0,
    agente_nome   TEXT     NOT NULL DEFAULT '',
    titolo_azione TEXT     NOT NULL,
    azione        TEXT     NOT NULL DEFAULT '{}',
    esito         TEXT     NOT NULL DEFAULT 'successo',
    creato_il     DATETIME NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now'))
  )
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS agent_settings (
    agent_id         INTEGER PRIMARY KEY,
    preview_limit    INTEGER NOT NULL DEFAULT 10,
    tickets_per_page INTEGER NOT NULL DEFAULT 50
  )
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS email_signatures (
    id         INTEGER PRIMARY KEY AUTOINCREMENT,
    agent_id   INTEGER NOT NULL,
    name       TEXT NOT NULL,
    body_html  TEXT NOT NULL DEFAULT '',
    is_default INTEGER NOT NULL DEFAULT 0,
    created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
    updated_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now'))
  )
`);

try {
  db.exec(`ALTER TABLE agent_settings ADD COLUMN tickets_per_page INTEGER NOT NULL DEFAULT 50`);
} catch (e) {
  // Column already exists
}

/**
 * Generate a UUID v7 (time-ordered).
 */
function uuidV7() {
  const tsMs = BigInt(Date.now());
  const tsMsHex = tsMs.toString(16).padStart(12, '0');
  const rand = crypto.randomBytes(10).toString('hex');
  const p1 = tsMsHex.slice(0, 8);
  const p2 = tsMsHex.slice(8, 12);
  const p3 = '7' + rand.slice(0, 3);
  const p4 = ((parseInt(rand.slice(3, 4), 16) & 0x3) | 0x8).toString(16) + rand.slice(4, 7);
  const p5 = rand.slice(7, 19);
  return `${p1}-${p2}-${p3}-${p4}-${p5}`;
}

const insertStmt = db.prepare(`
  INSERT INTO attivita (id, agente_id, agente_nome, titolo_azione, azione, esito)
  VALUES (?, ?, ?, ?, ?, ?)
`);

/**
 * Log an activity record.
 * @param {Object} params
 */
function logAttivita({ agente_id = 0, agente_nome = '', titolo_azione, azione = {}, esito = 'successo' }) {
  try {
    const id = uuidV7();
    const azioneStr = typeof azione === 'string' ? azione : JSON.stringify(azione, null, 2);
    insertStmt.run(id, agente_id, agente_nome, titolo_azione, azioneStr, esito);
  } catch (err) {
    console.error('[activityDb] Failed to log activity:', err.message);
  }
}

module.exports = { db, logAttivita };