<?php
/**
 * Global Site Settings & High-Resolution Favicon Management (Owner Exclusive)
 */

/**
 * Get site setting value by key.
 */
function get_site_setting($key, $default = '') {
    global $conn;
    if (!isset($conn)) return $default;

    $stmt = $conn->prepare("SELECT setting_value FROM site_settings WHERE setting_key = ? LIMIT 1");
    $stmt->bind_param("s", $key);
    $stmt->execute();
    $res = $stmt->get_result();

    if ($row = $res->fetch_assoc()) {
        $stmt->close();
        return $row['setting_value'];
    }
    $stmt->close();
    return $default;
}

/**
 * Update or insert site setting.
 */
function update_site_setting($key, $value) {
    global $conn;
    if (!isset($conn)) return false;

    $stmt = $conn->prepare("INSERT INTO site_settings (setting_key, setting_value) VALUES (?, ?) ON DUPLICATE KEY UPDATE setting_value = VALUES(setting_value)");
    $stmt->bind_param("ss", $key, $value);
    $res = $stmt->execute();
    $stmt->close();

    return $res;
}

/**
 * Upload and validate high-resolution site Favicon.
 */
function upload_site_favicon($file) {
    if (empty($file) || $file['error'] !== UPLOAD_ERR_OK) {
        return ['success' => false, 'message' => 'Errore nel caricamento del file favicon.'];
    }

    $ext = strtolower(pathinfo($file['name'], PATHINFO_EXTENSION));
    $allowed_extensions = ['png', 'ico', 'webp', 'svg', 'jpeg', 'jpg'];

    if (!in_array($ext, $allowed_extensions)) {
        return ['success' => false, 'message' => 'Formato favicon non supportato. Formati ammessi: PNG, ICO, WEBP, SVG, JPG.'];
    }

    // High resolution dimension check for raster formats (PNG, WEBP, JPG, ICO)
    if (in_array($ext, ['png', 'webp', 'jpeg', 'jpg', 'ico'])) {
        $image_info = @getimagesize($file['tmp_name']);
        if ($image_info) {
            $width = $image_info[0];
            $height = $image_info[1];

            // Minimum high resolution requirement: 64x64px
            if ($width < 64 || $height < 64) {
                return [
                    'success' => false, 
                    'message' => "Risoluzione favicon troppo bassa ({$width}x{$height}px). Per garantire la massima qualità visiva, carica un'immagine ad alta risoluzione (almeno 64x64px)."
                ];
            }
        }
    }

    // Ensure assets/img directory exists
    $img_dir = ROOT_DIR . "assets/img/";
    if (!is_dir($img_dir)) {
        @mkdir($img_dir, 0777, true);
    }

    $new_filename = "favicon_" . time() . "." . $ext;
    $target_file = $img_dir . $new_filename;
    $relative_path = "assets/img/" . $new_filename;

    if (move_uploaded_file($file['tmp_name'], $target_file)) {
        update_site_setting('site_favicon', $relative_path);
        return ['success' => true, 'message' => 'Favicon aggiornata con successo!'];
    }

    return ['success' => false, 'message' => 'Impossibile salvare il file favicon su disco.'];
}