<?php

namespace App\Services\Crawler;

use App\Services\Database\Connection;
use PDO;
use Throwable;

class RssParser
{
    private PDO $pdo;

    public function __construct(Connection $connection)
    {
        $this->pdo = $connection->getPdo();
    }

    /**
     * Parse an RSS feed URL and return entries.
     */
    public function fetchEntries(string $url): array
    {
        $xml = false;
        if (function_exists('curl_init')) {
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
            curl_setopt($ch, CURLOPT_USERAGENT, 'ScoutIQ/1.0 (Crawler)');
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($ch, CURLOPT_TIMEOUT, 15);
            
            $xml = curl_exec($ch);
            $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
            curl_close($ch);

            if ($httpCode !== 200) {
                throw new \Exception("HTTP Error {$httpCode}");
            }
            if ($xml === false) {
                throw new \Exception("Connection failed via cURL");
            }
        } else {
            $context = stream_context_create([
                'http' => [
                    'timeout' => 15,
                    'user_agent' => 'ScoutIQ/1.0 (Crawler)',
                ],
                'ssl' => [
                    'verify_peer' => false,
                    'verify_peer_name' => false,
                ],
            ]);
            $xml = @file_get_contents($url, false, $context);
            if ($xml === false) {
                $status = "Connection failed";
                if (isset($http_response_header) && isset($http_response_header[0])) {
                    $status = $http_response_header[0];
                }
                throw new \Exception($status);
            }
        }

        $feed = @simplexml_load_string($xml);
        if (!$feed) {
            throw new \Exception("Invalid XML structure");
        }

        $entries = [];
        $items = $feed->channel->item ?? $feed->entry ?? [];

        foreach ($items as $item) {
            $title = (string)($item->title ?? '');
            $description = (string)($item->description ?? $item->summary ?? '');
            $link = (string)($item->link ?? $item->guid ?? '');
            $pubDate = (string)($item->pubDate ?? $item->updated ?? '');
            $categories = [];

            if (isset($item->category)) {
                foreach ($item->category as $cat) {
                    $categories[] = (string)$cat;
                }
            }

            if (empty($title)) {
                continue;
            }

            $entries[] = [
                'title' => $title,
                'description' => strip_tags($description),
                'url' => $link,
                'published_at' => $pubDate ? date('Y-m-d H:i:s', strtotime($pubDate)) : date('Y-m-d H:i:s'),
                'categories' => $categories,
                'source_raw' => $xml,
            ];
        }

        return $entries;
    }

    /**
     * Check if entry URL already exists in opportunities.
     */
    public function entryExists(string $url): bool
    {
        $stmt = $this->pdo->prepare("SELECT id FROM opportunities WHERE url = ? AND deleted_at IS NULL");
        $stmt->execute([$url]);
        return (bool)$stmt->fetch();
    }

    /**
     * Check if organization already exists by domain or name.
     */
    public function organizationExists(string $name, ?string $domain = null): ?int
    {
        if ($domain) {
            $stmt = $this->pdo->prepare("SELECT id FROM organizations WHERE domain = ? AND deleted_at IS NULL");
            $stmt->execute([$domain]);
            $id = $stmt->fetchColumn();
            if ($id) return (int)$id;
        }

        // Fuzzy match by name
        $stmt = $this->pdo->prepare("SELECT id FROM organizations WHERE name LIKE ? AND deleted_at IS NULL LIMIT 1");
        $stmt->execute(['%' . $name . '%']);
        $id = $stmt->fetchColumn();
        return $id ? (int)$id : null;
    }
}