<?php
require_once __DIR__ . '/config.php';

try {
    $db = db();
    
    // Add new columns to units table
    $db->exec("ALTER TABLE units ADD COLUMN IF NOT EXISTS cost_resource_id INT NULL AFTER faction_id");
    $db->exec("ALTER TABLE units ADD COLUMN IF NOT EXISTS cost_amount INT DEFAULT 1 AFTER cost_resource_id");
    
    $db->exec("ALTER TABLE units ADD COLUMN IF NOT EXISTS destruction_resource_id INT NULL AFTER bonus_destruction");
    $db->exec("ALTER TABLE units ADD COLUMN IF NOT EXISTS destruction_amount INT DEFAULT 0 AFTER destruction_resource_id");
    
    $db->exec("ALTER TABLE units ADD COLUMN IF NOT EXISTS capture_resource_id INT NULL AFTER bonus_capture");
    $db->exec("ALTER TABLE units ADD COLUMN IF NOT EXISTS capture_amount INT DEFAULT 0 AFTER capture_resource_id");

    echo "Migration successful: new resource columns added to 'units' table.\n";
} catch (PDOException $e) {
    echo "Migration failed: " . $e->getMessage() . "\n";
}