<?php
/**
 * Database initialization and connection for Dispensa Manager
 */

define('DB_PATH', __DIR__ . '/../data/dispensa.db');

function getDB(): PDO {
    $isNew = !file_exists(DB_PATH);
    $db = new PDO('sqlite:' . DB_PATH);
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
    $db->exec("PRAGMA journal_mode=WAL");
    $db->exec("PRAGMA foreign_keys=ON");
    
    if ($isNew) {
        initializeDB($db);
    }
    return $db;
}

function initializeDB(PDO $db): void {
    $db->exec("
        CREATE TABLE IF NOT EXISTS products (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            barcode TEXT UNIQUE,
            name TEXT NOT NULL,
            brand TEXT DEFAULT '',
            category TEXT DEFAULT '',
            image_url TEXT DEFAULT '',
            unit TEXT DEFAULT 'pz',
            default_quantity REAL DEFAULT 1,
            notes TEXT DEFAULT '',
            created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
            updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
        );

        CREATE TABLE IF NOT EXISTS inventory (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            product_id INTEGER NOT NULL,
            location TEXT NOT NULL DEFAULT 'dispensa',
            quantity REAL NOT NULL DEFAULT 1,
            expiry_date DATE,
            added_at DATETIME DEFAULT CURRENT_TIMESTAMP,
            updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
            FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE CASCADE
        );

        CREATE TABLE IF NOT EXISTS transactions (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            product_id INTEGER NOT NULL,
            type TEXT NOT NULL CHECK(type IN ('in', 'out')),
            quantity REAL NOT NULL,
            location TEXT NOT NULL DEFAULT 'dispensa',
            notes TEXT DEFAULT '',
            created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
            FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE CASCADE
        );

        CREATE INDEX IF NOT EXISTS idx_products_barcode ON products(barcode);
        CREATE INDEX IF NOT EXISTS idx_inventory_product ON inventory(product_id);
        CREATE INDEX IF NOT EXISTS idx_inventory_location ON inventory(location);
        CREATE INDEX IF NOT EXISTS idx_transactions_product ON transactions(product_id);
        CREATE INDEX IF NOT EXISTS idx_transactions_date ON transactions(created_at);
    ");
}