Bookshelf/umbra-bookshelf/includes/books/class-umbra-retail-sites.php

<?php
// Copyright 2026 Umbra Tools (umbratools.com)
// SPDX-License-Identifier: Apache-2.0

/**
 * Retail Sites management class
 *
 * @package Umbra_Bookshelf
 */

if (!defined('ABSPATH')) {
    exit;
}

class Umbra_Retail_Sites {

    /**
     * Get all retail sites
     */
    public static function get_sites($active_only = true) {
        global $wpdb;

        $table = Umbra_Database::table('retail_sites');
        
        $where = $active_only ? 'is_active = 1' : '1=1';
        
        $sites = $wpdb->get_results(
            "SELECT * FROM {$table} WHERE {$where} ORDER BY is_custom ASC, name ASC"
        );
        
        return $sites;
    }

    /**
     * Get site by ID
     */
    public static function get_site($site_id) {
        global $wpdb;

        $table = Umbra_Database::table('retail_sites');
        
        return $wpdb->get_row(
            $wpdb->prepare(
                "SELECT * FROM {$table} WHERE id = %d",
                $site_id
            )
        );
    }

    /**
     * Create new retail site
     */
    public static function create_site($data) {
        global $wpdb;

        $table = Umbra_Database::table('retail_sites');
        
        $result = $wpdb->insert($table, [
            'name' => sanitize_text_field($data['name']),
            'url_pattern' => esc_url_raw($data['url_pattern']),
            'icon' => sanitize_text_field($data['icon'] ?? ''),
            'affiliate_param' => sanitize_text_field($data['affiliate_param'] ?? ''),
            'affiliate_code' => sanitize_text_field($data['affiliate_code'] ?? ''),
            'is_custom' => 1,
            'is_active' => 1,
        ]);
        
        return $result ? $wpdb->insert_id : false;
    }

    /**
     * Update retail site
     */
    public static function update_site($site_id, $data) {
        global $wpdb;

        $table = Umbra_Database::table('retail_sites');
        
        $update_data = [];
        
        if (isset($data['name'])) {
            $update_data['name'] = sanitize_text_field($data['name']);
        }
        
        if (isset($data['url_pattern'])) {
            $update_data['url_pattern'] = esc_url_raw($data['url_pattern']);
        }
        
        if (isset($data['icon'])) {
            $update_data['icon'] = sanitize_text_field($data['icon']);
        }
        
        if (isset($data['affiliate_param'])) {
            $update_data['affiliate_param'] = sanitize_text_field($data['affiliate_param']);
        }
        
        if (isset($data['affiliate_code'])) {
            $update_data['affiliate_code'] = sanitize_text_field($data['affiliate_code']);
        }
        
        if (isset($data['is_active'])) {
            $update_data['is_active'] = absint($data['is_active']);
        }
        
        if (empty($update_data)) {
            return false;
        }
        
        $result = $wpdb->update(
            $table,
            $update_data,
            ['id' => $site_id],
            null,
            ['%d']
        );
        
        return $result !== false;
    }

    /**
     * Delete retail site
     */
    public static function delete_site($site_id) {
        global $wpdb;

        // Only allow deleting custom sites
        $site = self::get_site($site_id);
        if ($site && $site->is_custom) {
            $wpdb->delete(Umbra_Database::table('retail_links'), ['site_id' => $site_id], ['%d']);
            return $wpdb->delete(Umbra_Database::table('retail_sites'), ['id' => $site_id], ['%d']) !== false;
        }
        
        return false;
    }

    /**
     * Generate links for a book
     */
    public static function generate_links_for_book($book_id) {
        global $wpdb;

        $book = Umbra_Book_Manager::get_book($book_id);
        if (!$book) {
            return false;
        }
        
        $sites = self::get_sites(true);
        $links_table = Umbra_Database::table('retail_links');
        
        // Delete existing links
        $wpdb->delete($links_table, ['book_id' => $book_id], ['%d']);
        
        // Format to ISBN mapping
        $formats = [
            'ebook' => $book->isbn_ebook,
            'paperback' => $book->isbn_paperback,
            'hardcover' => $book->isbn_hardcover,
            'audio' => $book->isbn_audio,
        ];
        
        // Use Amazon ASIN for Amazon if available
        $amazon_asin = $book->amazon_asin ?: '';
        
        foreach ($formats as $format => $isbn) {
            if (empty($isbn)) {
                continue;
            }
            
            foreach ($sites as $site) {
                $site_isbn = $isbn;
                
                // Special handling for Amazon - needs ISBN-10 for /dp/ path
                if ($site->name === 'Amazon') {
                    // Use ASIN if available (it's already ISBN-10 format)
                    if (!empty($amazon_asin)) {
                        $site_isbn = $amazon_asin;
                        $url = str_replace('{ISBN}', $site_isbn, $site->url_pattern);
                    } else {
                        // Try to convert ISBN-13 to ISBN-10
                        $isbn10 = self::convert_isbn13_to_isbn10($isbn);
                        if ($isbn10) {
                            $url = str_replace('{ISBN}', $isbn10, $site->url_pattern);
                        } else {
                            // Use search fallback for ISBNs that can't convert (979 prefix)
                            $url = 'https://www.amazon.com/s?k=' . urlencode($isbn) . '&i=stripbooks';
                        }
                    }
                    
                    // Add affiliate code if available
                    if (!empty($site->affiliate_param) && !empty($site->affiliate_code)) {
                        $separator = strpos($url, '?') !== false ? '&' : '?';
                        $url .= $separator . $site->affiliate_param . '=' . $site->affiliate_code;
                    }
                    
                    $wpdb->insert($links_table, [
                        'book_id' => $book_id,
                        'site_id' => $site->id,
                        'format' => $format,
                        'url' => $url,
                        'is_custom' => 0,
                    ]);
                    continue;
                }
                
                $url = str_replace('{ISBN}', $site_isbn, $site->url_pattern);
                
                // Add affiliate code if available
                if (!empty($site->affiliate_param) && !empty($site->affiliate_code)) {
                    $separator = strpos($url, '?') !== false ? '&' : '?';
                    $url .= $separator . $site->affiliate_param . '=' . $site->affiliate_code;
                }
                
                $wpdb->insert($links_table, [
                    'book_id' => $book_id,
                    'site_id' => $site->id,
                    'format' => $format,
                    'url' => $url,
                    'is_custom' => 0,
                ]);
            }
        }
        
        return true;
    }

    /**
     * Convert ISBN-13 to ISBN-10
     *
     * @param string $isbn13 ISBN-13 to convert.
     * @return string|false ISBN-10 on success, false on failure.
     */
    private static function convert_isbn13_to_isbn10($isbn13) {
        // Clean the ISBN
        $isbn13 = preg_replace('/[^0-9X]/i', '', $isbn13);
        
        // Must be 13 digits
        if (strlen($isbn13) !== 13) {
            return false;
        }
        
        // Must start with 978 (Bookland prefix)
        if (substr($isbn13, 0, 3) !== '978') {
            return false;
        }
        
        // Take the first 9 digits (drop 978 prefix and last check digit)
        $isbn10 = substr($isbn13, 3, 9);
        
        // Calculate check digit
        $sum = 0;
        for ($i = 0; $i < 9; $i++) {
            $sum += (int)$isbn10[$i] * (10 - $i);
        }
        $remainder = $sum % 11;
        $check_digit = (11 - $remainder) % 11;
        
        // Convert check digit to ISBN-10 format (10 = X)
        $check_digit = ($check_digit === 10) ? 'X' : (string)$check_digit;
        
        return $isbn10 . $check_digit;
    }

    /**
     * Update custom link
     */
    public static function update_link($link_id, $url) {
        global $wpdb;

        $table = Umbra_Database::table('retail_links');
        
        return $wpdb->update(
            $table,
            ['url' => esc_url_raw($url), 'is_custom' => 1],
            ['id' => $link_id],
            ['%s', '%d'],
            ['%d']
        ) !== false;
    }

    /**
     * Create custom link
     */
    public static function create_custom_link($book_id, $site_id, $format, $url) {
        global $wpdb;

        $table = Umbra_Database::table('retail_links');
        
        $result = $wpdb->insert($table, [
            'book_id' => $book_id,
            'site_id' => $site_id,
            'format' => $format,
            'url' => esc_url_raw($url),
            'is_custom' => 1,
        ]);
        
        return $result ? $wpdb->insert_id : false;
    }
}