<?php
// Sanitize and validate all shortcode attributes
function aa_spaypal_parse_atts($atts) {
    $atts = shortcode_atts([
        'email'         => '',
        'item_name'     => '',
        'amount'        => '',
        'currency'      => 'USD',
        'quantity'      => '1',
        'custom'        => '',
        'return_url'    => '',
        'cancel_url'    => '',
        'sandbox'       => 'no',
        'type'          => 'buynow', // buynow, donate, subscribe
        'style'         => 'classic', // classic, elegant, custom
        'button_image'  => '',
        'shipping'      => '0.00',
        'css_class'     => '',
    ], $atts);

    // Basic validations
    $atts['sandbox'] = in_array($atts['sandbox'], ['yes', 'no']) ? $atts['sandbox'] : 'no';
    $atts['type'] = in_array($atts['type'], ['buynow', 'donate', 'subscribe']) ? $atts['type'] : 'buynow';
    $atts['style'] = in_array($atts['style'], ['classic', 'elegant', 'custom']) ? $atts['style'] : 'classic';

    return $atts;
}

function aa_spaypal_get_button_image($type, $style) {
    $base = 'https://www.paypalobjects.com/en_US/i/btn/';
    $styles = [
        'buynow' => [
            'classic' => $base . 'btn_buynowCC_LG.gif',
            'elegant' => $base . 'btn_buynow_SM.gif',
        ],
        'donate' => [
            'classic' => $base . 'btn_donateCC_LG.gif',
            'elegant' => $base . 'btn_donate_SM.gif',
        ],
        'subscribe' => [
            'classic' => $base . 'btn_subscribeCC_LG.gif',
            'elegant' => $base . 'btn_subscribe_SM.gif',
        ],
    ];

    return $styles[$type][$style] ?? $styles['buynow']['classic'];
}