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

/**
 * Amazon Scraper class
 *
 * Fetches author and book data from Amazon
 *
 * @package BD_Bookshelf
 */

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

class BDM_Amazon_Scraper {

    private $user_agent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36';

    /**
     * Search Amazon for a book by title and author
     *
     * @param string $title  Book title.
     * @param string $author Author name.
     * @return array List of books found.
     */
    public function search_books($title, $author = '') {
        $query = $title;
        if ($author) {
            $query .= ' ' . $author;
        }
        
        $url = 'https://www.amazon.com/s?k=' . urlencode($query) . '&i=stripbooks';
        
        $response = wp_remote_get($url, [
            'timeout' => 30,
            'headers' => [
                'User-Agent' => $this->user_agent,
                'Accept' => 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
                'Accept-Language' => 'en-US,en;q=0.5',
            ],
        ]);
        
        if (is_wp_error($response)) {
            return ['error' => $response->get_error_message()];
        }
        
        $body = wp_remote_retrieve_body($response);
        
        return $this->parse_search_results($body);
    }

    /**
     * Parse Amazon search results
     */
    private function parse_search_results($html) {
        $books = [];
        
        // Match search result items with data-asin
        if (preg_match_all('/<div[^>]*data-asin="([A-Z0-9]{10})"[^>]*class="[^"]*s-result-item[^"]*"[^>]*>(.*?)<\/div>\s*<\/div>\s*<\/div>/si', $html, $matches)) {
            foreach ($matches as $index => $match) {
                $asin = $match[1];
                $item_html = $match[2];
                
                $book = $this->parse_search_item($item_html, $asin);
                if ($book) {
                    $books[] = $book;
                }
            }
        }
        
        // Alternative pattern
        if (empty($books)) {
            if (preg_match_all('/data-asin="([A-Z0-9]{10})"/si', $html, $asin_matches)) {
                foreach ($asin_matches[1] as $asin) {
                    // Try to find context around this ASIN
                    $pattern = '/data-asin="' . preg_quote($asin) . '"[^>]*>(.*?)(?=data-asin="|$)/si';
                    if (preg_match($pattern, $html, $context_match)) {
                        $book = $this->parse_search_item($context_match[1], $asin);
                        if ($book) {
                            $books[] = $book;
                        }
                    }
                }
            }
        }
        
        return $books;
    }

    /**
     * Parse a single search result item
     */
    private function parse_search_item($html, $asin) {
        $book = [
            'asin' => $asin,
            'title' => '',
            'author' => '',
            'format' => '',
            'rating' => 0,
            'ratings_count' => 0,
            'cover_image' => '',
            'url' => 'https://www.amazon.com/dp/' . $asin,
        ];
        
        // Extract title
        if (preg_match('/<h2[^>]*>.*?<span[^>]*>(.*?)<\/span>/si', $html, $matches)) {
            $book['title'] = trim(strip_tags($matches[1]));
        } elseif (preg_match('/<a[^>]*>.*?<span[^>]*class="[^"]*a-size[^"]*"[^>]*>(.*?)<\/span>/si', $html, $matches)) {
            $book['title'] = trim(strip_tags($matches[1]));
        }
        
        // Extract author
        if (preg_match('/<span[^>]*class="[^"]*a-size[^"]*"[^>]*>\s*by\s+<a[^>]*>(.*?)<\/a>/si', $html, $matches)) {
            $book['author'] = trim(strip_tags($matches[1]));
        }
        
        // Extract format (Kindle, Paperback, Hardcover, Audio)
        if (preg_match('/(Kindle\s*Edition|Paperback|Hardcover|Audio\s*CD|Audible|MP3\s*CD)/si', $html, $matches)) {
            $book['format'] = trim($matches[1]);
        }
        
        // Extract rating
        if (preg_match('/(\d+\.?\d*)\s*out\s*of\s*5\s*stars?/si', $html, $matches)) {
            $book['rating'] = (float) $matches[1];
        }
        
        // Extract ratings count
        if (preg_match('/([\d,]+)\s*ratings?/si', $html, $matches)) {
            $book['ratings_count'] = absint(str_replace(',', '', $matches[1]));
        }
        
        // Extract cover image
        if (preg_match('/<img[^>]*src="(https:\/\/[^"]*\.jpg)"/si', $html, $matches)) {
            $book['cover_image'] = $matches[1];
        }
        
        if (empty($book['title'])) {
            return null;
        }
        
        return $book;
    }

    /**
     * Look up book by ASIN and get full details including ISBN
     *
     * @param string $asin Amazon ASIN.
     * @return array Book details.
     */
    public function lookup_by_asin($asin) {
        $url = 'https://www.amazon.com/dp/' . $asin;
        
        $response = wp_remote_get($url, [
            'timeout' => 30,
            'headers' => [
                'User-Agent' => $this->user_agent,
                'Accept' => 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
                'Accept-Language' => 'en-US,en;q=0.5',
            ],
        ]);
        
        if (is_wp_error($response)) {
            return ['error' => $response->get_error_message()];
        }
        
        $body = wp_remote_retrieve_body($response);
        
        return $this->parse_product_page($body, $asin);
    }

    /**
     * Parse Amazon product page for full book details
     */
    private function parse_product_page($html, $asin) {
        $book = [
            'asin' => $asin,
            'title' => '',
            'author' => '',
            'isbn' => '',
            'isbn13' => '',
            'rating' => 0,
            'ratings_count' => 0,
            'cover_image' => '',
            'description' => '',
            'formats' => [],
        ];
        
        // Extract title
        if (preg_match('/<h1[^>]*id="title"[^>]*>(.*?)<\/h1>/si', $html, $matches)) {
            $book['title'] = trim(strip_tags($matches[1]));
        }
        
        // Extract author
        if (preg_match('/by\s+<a[^>]*>(.*?)<\/a>/si', $html, $matches)) {
            $book['author'] = trim(strip_tags($matches[1]));
        }
        
        // Extract rating
        if (preg_match('/(\d+\.?\d*)\s*out\s*of\s*5\s*stars?/si', $html, $matches)) {
            $book['rating'] = (float) $matches[1];
        }
        
        // Extract ratings count
        if (preg_match('/([\d,]+)\s*ratings?/si', $html, $matches)) {
            $book['ratings_count'] = absint(str_replace(',', '', $matches[1]));
        }
        
        // Extract cover image
        if (preg_match('/<img[^>]*id="landingImage"[^>]*src="([^"]+)"/si', $html, $matches)) {
            $book['cover_image'] = $matches[1];
        }
        
        // Extract ISBN from product details
        if (preg_match('/ISBN-10:\s*(\d{10})/si', $html, $matches)) {
            $book['isbn'] = $matches[1];
        }
        if (preg_match('/ISBN-13:\s*(\d{13})/si', $html, $matches)) {
            $book['isbn13'] = $matches[1];
        }
        
        // Extract ASIN
        if (preg_match('/ASIN:\s*([A-Z0-9]{10})/si', $html, $matches)) {
            $book['asin'] = $matches[1];
        }
        
        // Extract description
        if (preg_match('/<div[^>]*id="bookDescription_feature_div"[^>]*>.*?<span[^>]*>(.*?)<\/span>/si', $html, $matches)) {
            $book['description'] = trim(strip_tags($matches[1]));
        }
        
        // Look for other format links (Kindle, Paperback, Hardcover)
        if (preg_match_all('/<li[^>]*>.*?<a[^>]*href="\/dp\/([A-Z0-9]{10})"[^>]*>.*?<span[^>]*>(.*?)<\/span>/si', $html, $matches)) {
            foreach ($matches[1] as $index => $format_asin) {
                $format_name = trim(strip_tags($matches[2][$index]));
                if ($format_asin !== $asin && !empty($format_name)) {
                    $book['formats'][] = [
                        'asin' => $format_asin,
                        'format' => $format_name,
                        'url' => 'https://www.amazon.com/dp/' . $format_asin,
                    ];
                }
            }
        }
        
        return $book;
    }

    /**
     * Get all format ASINs for a book by searching
     *
     * @param string $title  Book title.
     * @param string $author Author name.
     * @return array Format => ASIN mapping.
     */
    public function get_format_asins($title, $author = '') {
        $formats = [
            'kindle' => '',
            'paperback' => '',
            'hardcover' => '',
            'audio' => '',
        ];
        
        // Search for the book
        $results = $this->search_books($title, $author);
        
        if (isset($results['error']) || empty($results)) {
            return $formats;
        }
        
        // Match results to formats
        foreach ($results as $book) {
            $book_title = strtolower($book['title'] ?? '');
            $book_format = strtolower($book['format'] ?? '');
            
            // Check if this is the same book (title match)
            similar_text(strtolower($title), $book_title, $percent);
            if ($percent < 60) {
                continue;
            }
            
            if (strpos($book_format, 'kindle') !== false || strpos($book_format, 'ebook') !== false) {
                $formats['kindle'] = $book['asin'];
            } elseif (strpos($book_format, 'paperback') !== false) {
                $formats['paperback'] = $book['asin'];
            } elseif (strpos($book_format, 'hardcover') !== false) {
                $formats['hardcover'] = $book['asin'];
            } elseif (strpos($book_format, 'audio') !== false || strpos($book_format, 'audible') !== false) {
                $formats['audio'] = $book['asin'];
            }
        }
        
        return $formats;
    }
}