<?php
set_time_limit(0);  // prevent timeout for big files
@ob_implicit_flush(true);
@ob_end_flush();

$cacheDir = __DIR__ . '/cache';
if (!is_dir($cacheDir)) {
    mkdir($cacheDir, 0755, true);
}

if (!isset($_GET['path'])) {
    http_response_code(400);
    echo "Missing 'path' parameter.";
    exit;
}

$relativePath = ltrim($_GET['path'], '/');
$ext = strtolower(pathinfo($relativePath, PATHINFO_EXTENSION));

if ($ext !== 'mp4') {
    http_response_code(403);
    echo "Only .mp4 files are allowed.";
    exit;
}

// FTP info
$server    = isset($_GET['server'])   ? $_GET['server']   : '192.168.0.1';
$username  = isset($_GET['username']) ? $_GET['username'] : 'anonymous';
$password  = isset($_GET['password']) ? $_GET['password'] : '';
$anonymous = isset($_GET['anonymous']) && $_GET['anonymous'] == '1';

if ($anonymous) {
    $username = 'anonymous';
    $password = 'anonymous@domain.com';
}

$cacheFile = $cacheDir . '/' . md5($server . $relativePath) . '.mp4';

// Handle direct play request: delete cache and stream from FTP directly
if (isset($_GET['direct']) && $_GET['direct'] == '1') {
    if (file_exists($cacheFile)) {
        @unlink($cacheFile);
    }
    // Stream directly from FTP without caching
    streamFTPDirect($server, $username, $password, $relativePath);
    exit;
}

// Function to stream file directly from FTP without caching
function streamFTPDirect($server, $username, $password, $remoteFile) {
    // Connect FTP
    $ftp = ftp_connect($server);
    if (!$ftp || !ftp_login($ftp, $username, $password)) {
        http_response_code(500);
        echo "FTP connection failed.";
        exit;
    }
    ftp_pasv($ftp, true);

    // Get size for content length
    $size = ftp_size($ftp, $remoteFile);
    if ($size <= 0) {
        ftp_close($ftp);
        http_response_code(404);
        echo "Remote file not found or size unknown.";
        exit;
    }

    // Handle Range header for partial content
    $start = 0;
    $end = $size - 1;
    $length = $size;
    $status = 200;

    if (isset($_SERVER['HTTP_RANGE']) &&
        preg_match('/bytes=(\d+)-(\d*)/', $_SERVER['HTTP_RANGE'], $matches)) {
        $start = intval($matches[1]);
        if (!empty($matches[2])) {
            $end = intval($matches[2]);
        }
        if ($end > $size - 1) $end = $size - 1;
        $length = $end - $start + 1;
        $status = 206;
    }

    // Set headers
    if (function_exists('http_response_code')) {
        http_response_code($status);
    } else {
        header($_SERVER["SERVER_PROTOCOL"] . " " . $status);
    }
    header("Content-Type: video/mp4");
    header("Accept-Ranges: bytes");
    header("Content-Length: $length");
    header('Content-Disposition: inline; filename="' . basename($remoteFile) . '"');
    if ($status === 206) {
        header("Content-Range: bytes $start-$end/$size");
    }

    // Open a temporary local stream for output buffering
    // Use ftp_nb_fget to fetch from FTP in chunks and output directly

    $tmpStream = fopen('php://output', 'wb');
    if (!$tmpStream) {
        ftp_close($ftp);
        http_response_code(500);
        echo "Failed to open output stream.";
        exit;
    }

    // ftp_nb_fget doesn't support offset, so we have to download full or partial file manually
    // We'll download full file into php://output but skip bytes before $start by reading and discarding

    // Unfortunately, FTP protocol itself doesn't support partial retrieval starting at offset
    // so we have to download and skip bytes, or use ftp_raw to send REST command (some FTP servers support it)
    // We'll try REST command

    ftp_raw($ftp, "TYPE I"); // Switch to binary mode

    // Attempt REST command for offset
    $restResp = ftp_raw($ftp, "REST $start");
    if (strpos(implode("\n", $restResp), '350') === false) {
        // REST not supported or failed - fallback to downloading entire file and skipping in PHP
        $start = 0; // ignore range start - will download entire file
        $length = $size;
        $status = 200;
    }

    $ret = ftp_nb_fget($ftp, $tmpStream, $remoteFile, FTP_BINARY);

    $bytesSent = 0;
    while ($ret == FTP_MOREDATA) {
        flush();
        $ret = ftp_nb_continue($ftp);
    }

    fclose($tmpStream);
    ftp_close($ftp);
}

// If cached file does NOT exist, do caching download with progress page and play button
if (!file_exists($cacheFile)) {
    // Show progress bar page with play button, video, speed and ETR display and direct play button
    echo '<!DOCTYPE html><html><head><title>Downloading...</title><style>
        #progress-container { width: 100%; background: #ddd; margin-bottom: 10px; }
        #progress-bar { width: 0; height: 30px; background: #4caf50; text-align: center; color: white; }
        body { font-family: Arial, sans-serif; padding: 20px; }
        #video-player { width: 100%; max-width: 720px; display: none; margin-top: 20px; }
        button { padding: 10px 20px; font-size: 16px; cursor: pointer; margin-right: 10px; }
        #stats { margin-top: 8px; font-size: 14px; color: #333; }
    </style></head><body>';
    echo "<h2>Downloading and caching video file...</h2>";
    echo '<div style="margin-bottom:10px;">
        <button id="direct-play-btn">Direct Play</button>
        <button id="play-btn" disabled>Play Now</button>
    </div>';
    echo '<div id="progress-container"><div id="progress-bar">0%</div></div>';
    echo '<div id="stats">Speed: 0 KB/s | Estimated time remaining: calculating...</div>';
    echo '<video id="video-player" controls preload="auto"></video>';
    echo '<script>
        const progressBar = document.getElementById("progress-bar");
        const playBtn = document.getElementById("play-btn");
        const directBtn = document.getElementById("direct-play-btn");
        const videoPlayer = document.getElementById("video-player");
        const statsDiv = document.getElementById("stats");

        let lastDownloaded = 0;
        let lastTimestamp = Date.now();

        function formatBytes(bytes) {
            if (bytes < 1024) return bytes + " B/s";
            else if (bytes < 1024*1024) return (bytes/1024).toFixed(1) + " KB/s";
            else return (bytes/(1024*1024)).toFixed(2) + " MB/s";
        }

        function formatTime(seconds) {
            if (seconds === Infinity || isNaN(seconds)) return "calculating...";
            let h = Math.floor(seconds / 3600);
            let m = Math.floor((seconds % 3600) / 60);
            let s = Math.floor(seconds % 60);
            return (h > 0 ? h + "h " : "") + (m > 0 ? m + "m " : "") + s + "s";
        }

        function updateProgress(pct, downloadedBytes, totalBytes) {
            progressBar.style.width = pct + "%";
            progressBar.textContent = pct + "%";

            const now = Date.now();
            const timeDiff = (now - lastTimestamp) / 1000; // seconds
            const bytesDiff = downloadedBytes - lastDownloaded;
            if (timeDiff > 0) {
                const speed = bytesDiff / timeDiff;
                const bytesLeft = totalBytes - downloadedBytes;
                const eta = bytesLeft / speed;

                statsDiv.textContent = "Speed: " + formatBytes(speed) + " | Estimated time remaining: " + formatTime(eta);
            }

            lastDownloaded = downloadedBytes;
            lastTimestamp = now;

            if (pct > 0) {
                playBtn.disabled = false; // enable play button once some progress
            }
            if (pct === 100) {
                playBtn.textContent = "Play Full Video";
                videoPlayer.src = "' . htmlspecialchars(basename($_SERVER['PHP_SELF'])) . '?path=' . rawurlencode($relativePath) . '&server=' . rawurlencode($server) . '&username=' . rawurlencode($username) . '&password=' . rawurlencode($password) . '";
                videoPlayer.style.display = "block";
                videoPlayer.play();
                playBtn.style.display = "none"; // hide play button after auto-play
                statsDiv.textContent = "Download complete.";
            }
        }

        playBtn.addEventListener("click", () => {
            videoPlayer.src = "' . htmlspecialchars(basename($_SERVER['PHP_SELF'])) . '?path=' . rawurlencode($relativePath) . '&server=' . rawurlencode($server) . '&username=' . rawurlencode($username) . '&password=' . rawurlencode($password) . '";
            videoPlayer.style.display = "block";
            videoPlayer.play();
        });

        directBtn.addEventListener("click", () => {
    // Redirect with ?direct=1 query param added
    const url = new URL(window.location.href);
    url.searchParams.set("direct", "1");
    window.location.href = url.toString();
});

       
    </script>';

    flush();

    // Connect FTP
    $ftp = ftp_connect($server);
    if (!$ftp || !ftp_login($ftp, $username, $password)) {
        http_response_code(500);
        echo "<p style='color:red;'>FTP connection failed.</p></body></html>";
        exit;
    }
    ftp_pasv($ftp, true);

    // Get file size for progress calculation
    $ftpSize = ftp_size($ftp, $relativePath);
    if ($ftpSize <= 0) {
        echo "<p style='color:red;'>Failed to get remote file size.</p></body></html>";
        ftp_close($ftp);
        exit;
    }

    $tmpFile = $cacheFile . '.part';
    $fp = fopen($tmpFile, 'wb');
    if (!$fp) {
        echo "<p style='color:red;'>Failed to open local file for writing.</p></body></html>";
        ftp_close($ftp);
        exit;
    }

    // Use ftp_nb_fget for non-blocking download to track progress
    $ret = ftp_nb_fget($ftp, $fp, $relativePath, FTP_BINARY);
    $downloaded = 0;

    while ($ret == FTP_MOREDATA) {
        clearstatcache(true, $tmpFile);
        $downloaded = filesize($tmpFile);
        $pct = min(100, round(($downloaded / $ftpSize) * 100));
        echo "<script>updateProgress($pct, $downloaded, $ftpSize);</script>";
        flush();

        $ret = ftp_nb_continue($ftp);
        usleep(50000); // slight delay to reduce CPU load
    }

    if ($ret != FTP_FINISHED) {
        echo "<p style='color:red;'>FTP download failed.</p></body></html>";
        fclose($fp);
        ftp_close($ftp);
        unlink($tmpFile);
        exit;
    }

    fclose($fp);
    ftp_close($ftp);

    rename($tmpFile, $cacheFile);

    // Download complete, set progress bar to 100%
    echo "<script>updateProgress(100, $ftpSize, $ftpSize);</script>";
    echo "<p>Download complete! Preparing video for streaming...</p>";
    echo '</body></html>';
    flush();

    // Give user 1 second to see 100% before redirecting to self without caching phase
    sleep(1);

    // Redirect to self to serve cached video directly
    header("Location: " . strtok($_SERVER["REQUEST_URI"], '?') . '?' . $_SERVER['QUERY_STRING']);
    exit;
}

// Serve cached file with Range support

$filesize = filesize($cacheFile);
$start = 0;
$end = $filesize - 1;
$length = $filesize;
$status = 200;

if (isset($_SERVER['HTTP_RANGE']) &&
    preg_match('/bytes=(\d+)-(\d*)/', $_SERVER['HTTP_RANGE'], $matches)) {
    $start = intval($matches[1]);
    if (!empty($matches[2])) {
        $end = intval($matches[2]);
    }
    if ($end > $filesize - 1) {
        $end = $filesize - 1;
    }
    $length = $end - $start + 1;
    $status = 206;
}

$fp = fopen($cacheFile, 'rb');
if ($fp === false) {
    http_response_code(500);
    echo "Failed to open cached file.";
    exit;
}

fseek($fp, $start);

if (function_exists('http_response_code')) {
    http_response_code($status);
} else {
    header($_SERVER["SERVER_PROTOCOL"] . " " . $status);
}

header("Content-Type: video/mp4");
header("Content-Length: $length");
header("Accept-Ranges: bytes");
header('Content-Disposition: inline; filename="' . basename($relativePath) . '"');
if ($status === 206) {
    header("Content-Range: bytes $start-$end/$filesize");
}

// Stream the file
$buffer = 8192;
$bytesSent = 0;
while (!feof($fp) && $bytesSent < $length) {
    $read = min($buffer, $length - $bytesSent);
    $data = fread($fp, $read);
    if ($data === false) {
        break;
    }
    echo $data;
    flush();
    $bytesSent += strlen($data);
}

fclose($fp);
exit;