<?php
header("Cache-Control: no-store, no-cache, must-revalidate, max-age=0");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

// ==================== CONFIGURATION ====================
// Replace with your bot token from @BotFather
$apiToken = "YOUR_BOT_TOKEN_HERE";

// Channel IDs - replace with your actual channel IDs
$channelId = "YOUR_CHANNEL_ID"; // Example: -1001234567890

// RSS feeds to monitor - add your feeds here
// Format: ["RSS_URL", "INSTANT_VIEW_HASH"] (leave second parameter empty if no instant view)
$rssFeeds = [
    ["https://example1.com/feed/",""],
    ["https://example2.com/feed/","YOUR_INSTANT_VIEW_HASH"]
];

// ==================== END CONFIGURATION ====================

// Files for state management
$stateFile = 'rss_state.json';
$logFile = 'rss_log.txt';

$formattedMessages = [];

// Load previous state to avoid duplicate messages
$previousState = file_exists($stateFile) ? json_decode(file_get_contents($stateFile), true) : [];

// Array to store all news to send to channel
$allNews = [];

// Get today's date
$todayDate = date('Y-m-d');
// Uncomment next line for testing yesterday's news
// $todayDate = date('Y-m-d', strtotime('-1 day'));

writeToLog("Script started for date: " . $todayDate);

// Process each RSS feed
foreach ($rssFeeds as $feed) {
    list($url, $instantView) = $feed;

    // Check if URL has already been processed today
    if (isset($previousState[$url][$todayDate])) {
        $sentLinks = $previousState[$url][$todayDate];
    } else {
        $sentLinks = [];
    }

    // Read and filter today's news for each RSS feed
    $newItems = readAndFilterRSS($url, $instantView, $todayDate, $sentLinks);

    // Add news to channel only if there are unsent items
    if (!empty($newItems)) {
        $allNews = array_merge($allNews, $newItems);

        // Update sent news with new links only
        $previousState[$url][$todayDate] = array_merge($sentLinks, getNewsLinks($newItems));
    }

    // Log processing results
    $itemCount = is_array($newItems) ? count($newItems) : 0;
    writeToLog("Feed: $url, New items: " . $itemCount);
}

// Clean up old state data (remove previous days)
if ($previousState) {
    foreach ($previousState as $url => $dates) {
        foreach ($dates as $date => $links) {
            if ($date !== $todayDate) {
                unset($previousState[$url][$date]);
            }
        }
    }
    
    // Save updated state
    file_put_contents($stateFile, json_encode($previousState));
}

// Send news to Telegram channel
if (!empty($formattedMessages)) {
    writeToLog("Sending " . count($formattedMessages) . " messages to Telegram");
    sendToTelegram($formattedMessages);
} else {
    writeToLog("No new messages to send");
}

writeToLog("Script completed");

/**
 * Write message to log file with timestamp
 */
function writeToLog($txt)
{
    global $logFile;
    $timestamp = date('[Y-m-d H:i:s]');
    $logMessage = $timestamp . ' ' . $txt . "\n";
    error_log($logMessage, 3, $logFile);
}

/**
 * Read and filter today's news from RSS feed
 */
function readAndFilterRSS($url, $instantView, $targetDate, $sentLinks)
{
    global $formattedMessages;

    try {
        // Load RSS feed using SimpleXML
        $feed = simplexml_load_file($url);
        if ($feed === false) {
            writeToLog('Error: Failed to load RSS feed - ' . $url);
            throw new Exception('Failed to load RSS feed: ' . $url);
        }
    
        $channelTitle = (string)$feed->channel->title;
        $newItems = [];

        // Process each item in the feed
        foreach ($feed->channel->item as $item) {
            $pubDate = new DateTime($item->pubDate);

            // Check if news is from target date and hasn't been sent already
            if ($pubDate->format('Y-m-d') == $targetDate && !in_array((string)$item->link, $sentLinks)) {
                $newItems[] = [
                    'title' => (string)$item->title,
                    'link' => (string)$item->link,
                ];
                
                // Prepare formatted message for Telegram
                $formattedMessages[] = prepareTelegramMessage($item, $instantView, $channelTitle);
            }
        }

        return $newItems;
    
    } catch (Exception $e) {
        writeToLog('Error processing RSS feed: ' . $e->getMessage());
        return [];
    }
}

/**
 * Extract links from news array
 */
function getNewsLinks($news)
{
    return array_map(function ($item) {
        return $item['link'];
    }, $news);
}

/**
 * Send messages to Telegram channel
 */
function sendToTelegram($messages)
{
    global $channelId, $apiToken;
    
    foreach ($messages as $message) {
        $data = [
            'chat_id' => $channelId,
            'text' => $message[0],
            'parse_mode' => "HTML",
        ];

        $response = file_get_contents("https://api.telegram.org/bot$apiToken/sendMessage?" . http_build_query($data));

        if ($response !== false && $response !== "") {
            writeToLog('Message sent successfully: ' . $message[1]);
        } else {
            writeToLog('Failed to send message: ' . $message[1]);
            // Wait before retry
            sleep(2);
        }
    }

    writeToLog('Total messages sent to Telegram channel: ' . count($messages));
}

/**
 * Prepare formatted message for Telegram
 */
function prepareTelegramMessage($item, $instantView, $channelTitle)
{
    $itemTitle = (string)$item->title;
    $itemLink = (string)$item->link;
    $itemDesc = (string)$item->description;
    $itemDesc = strip_tags($itemDesc, "<b>,<i>,<a>,<strong>,<em>");
    $itemPubDate = (string)$item->pubDate;
    $timestamp = strtotime($itemPubDate);
    $pubDate = date("d/m/Y", $timestamp);

    $message = "";
    
    // Add instant view if available
    if ($instantView !== "") {
        $instViewUrl = "https://t.me/iv?url=" . $itemLink . "&rhash=" . $instantView;
        $invisibleUrl = "<a href='$instViewUrl'>&#8204</a>";
        $message .= $invisibleUrl;
    }

    // Format message
    $message .= "Source: <i><b>" . $channelTitle . "</b> - " . $pubDate . "</i>" . PHP_EOL;
    $message .= PHP_EOL;
    $message .= "<b>" . $itemTitle . "</b>" . PHP_EOL;
    $message .= $itemDesc . PHP_EOL;
    $message .= PHP_EOL;
    $message .= $itemLink;    

    return [$message, $itemTitle];
}