<?php
$visitsFile = "visits.json";

// Check if the cookie exists to track if the visitor has been here before
$cookieName = "EIJT";
$cookieLifetime = 60 * 60 * 24 * 30; // Cookie valid for 30 days
$firstVisit = !isset($_COOKIE[$cookieName]);

// Get user-agent for browser and OS info
$userAgent = $_SERVER["HTTP_USER_AGENT"];
$browser = "Unknown Browser";
$os = "Unknown OS";

// Detect browser using simple substr checks
if (strpos($userAgent, "Firefox") !== false) {
    $browser = "Firefox";
} elseif (strpos($userAgent, "Chrome") !== false) {
    $browser = "Chrome";
} elseif (strpos($userAgent, "Safari") !== false) {
    $browser = "Safari";
} elseif (strpos($userAgent, "Edge") !== false) {
    $browser = "Edge";
} elseif (
    strpos($userAgent, "MSIE") !== false ||
    strpos($userAgent, "Trident") !== false
) {
    $browser = "Internet Explorer";
}

// Detect operating system
if (strpos($userAgent, "Windows NT") !== false) {
    $os = "Windows";
} elseif (strpos($userAgent, "Macintosh") !== false) {
    $os = "macOS";
} elseif (strpos($userAgent, "Linux") !== false) {
    $os = "Linux";
} elseif (strpos($userAgent, "Android") !== false) {
    $os = "Android";
} elseif (strpos($userAgent, "iPhone") !== false) {
    $os = "iOS";
}

// Open the file in read/write mode, creating it if it doesn't exist
$fp = fopen($visitsFile, "c+");
if ($fp === false) {
    die("Error opening the file.");
}

// Lock the file to avoid race conditions
if (flock($fp, LOCK_EX)) {
    // Read the file content to get the stats
    $data = fgets($fp); // Read the entire file content (assuming one line per file)
    if ($data) {
        $stats = json_decode($data, true);
    } else {
        $stats = [
            "total_visits" => 0,
            "unique_visits" => 0,
            "last_visit" => null,
            "monthly" => [],
            "weekly" => [],
            "browsers" => [],
            "operating_systems" => [],
        ];
    }

    // Increment the total visit count
    $stats["total_visits"]++;

    // If it's a new visitor, increase the unique visit count
    if ($firstVisit) {
        $stats["unique_visits"]++;
        setcookie($cookieName, "1", time() + $cookieLifetime, "/"); // Set cookie for this user
    }

    // Update the last visit timestamp
    $timestamp = time();
    $stats["last_visit"] = $timestamp;

    // Track by week and month
    $week = date("W", $timestamp); // Week number (ISO 8601 format)
    $month = date("Y-m", $timestamp); // Month in YYYY-MM format

    // Increment weekly stats
    if (!isset($stats["weekly"][$week])) {
        $stats["weekly"][$week] = 0;
    }
    $stats["weekly"][$week]++;

    // Increment monthly stats
    if (!isset($stats["monthly"][$month])) {
        $stats["monthly"][$month] = 0;
    }
    $stats["monthly"][$month]++;

    // Track browser type
    if (!isset($stats["browsers"][$browser])) {
        $stats["browsers"][$browser] = 0;
    }
    $stats["browsers"][$browser]++;

    // Track operating system
    if (!isset($stats["operating_systems"][$os])) {
        $stats["operating_systems"][$os] = 0;
    }
    $stats["operating_systems"][$os]++;

    // Write the updated stats back to the file
    fseek($fp, 0);
    fwrite($fp, json_encode($stats));
    fflush($fp);

    // Unlock the file
    flock($fp, LOCK_UN);
}

// Close the file
fclose($fp);
?>