import { DatabaseSync } from "node:sqlite";
import path from "path";

const DB_PATH =
  process.env.DB_PATH || path.join(process.cwd(), "data", "app.db");

let _db: DatabaseSync | null = null;

export function getDb(): DatabaseSync {
  if (!_db) {
    _db = new DatabaseSync(DB_PATH);
    _db.exec("PRAGMA journal_mode = WAL");
    _db.exec("PRAGMA foreign_keys = ON");
    migrate(_db);
  }
  return _db;
}

function migrate(db: DatabaseSync) {
  db.exec(`
    CREATE TABLE IF NOT EXISTS users (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      email TEXT NOT NULL UNIQUE,
      password_hash TEXT NOT NULL,
      name TEXT NOT NULL,
      role TEXT NOT NULL DEFAULT 'admin',
      created_at TEXT NOT NULL DEFAULT (datetime('now'))
    );

    CREATE TABLE IF NOT EXISTS clients (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      name TEXT NOT NULL,
      email TEXT,
      phone TEXT,
      address TEXT,
      notes TEXT,
      created_at TEXT NOT NULL DEFAULT (datetime('now')),
      updated_at TEXT NOT NULL DEFAULT (datetime('now'))
    );

    CREATE TABLE IF NOT EXISTS projects (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      client_id INTEGER NOT NULL REFERENCES clients(id),
      title TEXT NOT NULL,
      description TEXT,
      status TEXT NOT NULL DEFAULT 'active',
      created_at TEXT NOT NULL DEFAULT (datetime('now')),
      updated_at TEXT NOT NULL DEFAULT (datetime('now'))
    );

    CREATE TABLE IF NOT EXISTS quotes (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      project_id INTEGER NOT NULL REFERENCES projects(id),
      title TEXT NOT NULL,
      status TEXT NOT NULL DEFAULT 'draft',
      notes TEXT,
      sent_at TEXT,
      accepted_at TEXT,
      created_at TEXT NOT NULL DEFAULT (datetime('now')),
      updated_at TEXT NOT NULL DEFAULT (datetime('now'))
    );

    CREATE TABLE IF NOT EXISTS quote_items (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      quote_id INTEGER NOT NULL REFERENCES quotes(id) ON DELETE CASCADE,
      description TEXT NOT NULL,
      quantity REAL NOT NULL DEFAULT 1,
      unit TEXT,
      unit_price REAL NOT NULL DEFAULT 0,
      total REAL GENERATED ALWAYS AS (quantity * unit_price) VIRTUAL,
      sort_order INTEGER NOT NULL DEFAULT 0
    );
  `);
}