<?php
// Start the session to manage admin login
session_name(defined('SESSION_NAME') ? SESSION_NAME : 'VeroziTrackerSession');
session_set_cookie_params(['lifetime' => 0, 'path' => '/', 'domain' => '', 'secure' => isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on', 'httponly' => true, 'samesite' => 'Lax']);
session_start();

// Include configuration and database connection
require_once __DIR__ . '/config.php';
require_once __DIR__ . '/app/db.php'; // Initializes $pdo

// --- Helper Function for GeoIP Lookup ---
function get_visitor_country_code($ip_address) {
    $api_url = "http://ip-api.com/json/" . urlencode($ip_address) . "?fields=status,countryCode";
    $response_json = @file_get_contents($api_url, false, stream_context_create(['http' => ['timeout' => 2]]));
    if ($response_json === false) { error_log("GeoIP API call failed for IP: " . $ip_address); return null; }
    $response_data = json_decode($response_json, true);
    if (isset($response_data['status']) && $response_data['status'] === 'success' && isset($response_data['countryCode'])) {
        return strtoupper($response_data['countryCode']);
    } else { error_log("GeoIP API returned non-success for IP: " . $ip_address . " Response: " . $response_json); return null; }
}

// --- URL Parsing ---
$request_uri = $_SERVER['REQUEST_URI'] ?? '/';
$request_parts = explode('?', $request_uri, 2);
$request_uri_path = $request_parts[0];
$original_query_string = $_SERVER['QUERY_STRING'] ?? (isset($request_parts[1]) ? $request_parts[1] : '');
$path = trim(filter_var($request_uri_path, FILTER_SANITIZE_URL), '/');
$segments = $path ? explode('/', $path) : [];

// --- Routing ---

// 1. Check for Admin Routes
if (isset($segments[0]) && $segments[0] === 'admin') {
    // --- Handle Logout Action ---
     if (isset($_GET['action']) && $_GET['action'] === 'logout') {
        $_SESSION = array(); if (ini_get("session.use_cookies")) { $params = session_get_cookie_params(); setcookie(session_name(), '', time() - 42000, $params["path"], $params["domain"], $params["secure"], $params["httponly"]); } session_destroy();
        $login_url = defined('BASE_URL') ? BASE_URL . '/admin' : '/admin'; if (ob_get_level()) ob_end_clean(); header('Location: ' . $login_url); exit;
    }
    // --- Check if logged in ---
    if (!isset($_SESSION['user_id'])) { if (file_exists(__DIR__ . '/views/login.php')) { require __DIR__ . '/views/login.php'; } else { http_response_code(500); echo "Error: Login view file not found."; } exit; }
    // --- User IS Logged In ---
    $admin_action = $segments[1] ?? 'dashboard'; $item_id = $segments[2] ?? null;
    switch ($admin_action) {
        case 'link-builder': if (file_exists(__DIR__ . '/views/link_builder.php')) { require __DIR__ . '/views/link_builder.php'; } else { http_response_code(500); echo "Error: Link builder view file not found."; } break;
        case 'settings': if (file_exists(__DIR__ . '/views/settings.php')) { require __DIR__ . '/views/settings.php'; } else { http_response_code(500); echo "Error: Settings view file not found."; } break;
        case 'edit-link': if (isset($item_id) && is_numeric($item_id)) { if (file_exists(__DIR__ . '/views/edit_link.php')) { require __DIR__ . '/views/edit_link.php'; } else { http_response_code(500); echo "Error: Edit link view file not found."; } } else { $_SESSION['flash_message'] = "Error: Invalid or missing ID for editing link."; $dashboard_url = defined('BASE_URL') ? BASE_URL . '/admin/dashboard' : '/admin/dashboard'; if (ob_get_level()) ob_end_clean(); header('Location: ' . $dashboard_url); exit; } break;
        case 'delete-link': if (isset($item_id) && is_numeric($item_id)) { try { $sql_delete = "DELETE FROM links WHERE id = :id"; $stmt_delete = $pdo->prepare($sql_delete); $stmt_delete->execute(['id' => $item_id]); $_SESSION['flash_message'] = ($stmt_delete->rowCount() > 0) ? "Link (ID: " . htmlspecialchars($item_id) . ") deleted successfully." : "Error: Link (ID: " . htmlspecialchars($item_id) . ") not found or already deleted."; } catch (PDOException $e) { error_log("Delete Link Error: " . $e->getMessage()); $_SESSION['flash_message'] = "Error deleting link. Database error."; } } else { $_SESSION['flash_message'] = "Error: Invalid link ID for deletion."; } $dashboard_url = defined('BASE_URL') ? BASE_URL . '/admin/dashboard' : '/admin/dashboard'; if (ob_get_level()) ob_end_clean(); header('Location: ' . $dashboard_url); exit; break;
        case 'dashboard': default: if (file_exists(__DIR__ . '/views/dashboard.php')) { require __DIR__ . '/views/dashboard.php'; } else { http_response_code(500); echo "Error: Dashboard view file not found."; } break;
    }
    exit; // Exit after handling admin action
} // --- End of Admin Route Check ---


// 2. Check for Tracking Link Route (e.g., /campaign_id/ad_id)
if (count($segments) === 2) {
    $campaign_id = preg_replace('/[^a-zA-Z0-9_-]/', '', $segments[0]);
    $ad_id = preg_replace('/[^a-zA-Z0-9_-]/', '', $segments[1]);

    if (empty($campaign_id) || empty($ad_id)) { goto handle_not_found; }

    try {
        $sql_find = "SELECT id, target_url FROM links WHERE campaign_id = :campaign_id AND ad_id = :ad_id LIMIT 1";
        $stmt_find = $pdo->prepare($sql_find); $stmt_find->execute(['campaign_id' => $campaign_id, 'ad_id' => $ad_id]); $link = $stmt_find->fetch();

        if ($link) {
            $link_id = $link['id']; $target_url = $link['target_url'];
            // --- Increment click count ---
            $sql_update = "UPDATE links SET click_count = click_count + 1 WHERE id = :id";
            $stmt_update = $pdo->prepare($sql_update); $stmt_update->execute(['id' => $link_id]);

            // --- Country Blocking Logic (Read from DB) --- <<<--- UPDATED BLOCK
            $redirect_url = $target_url; // Default to original target
            $blocked_countries_from_db = [];
            try {
                $stmt_fetch_block = $pdo->query("SELECT country_code FROM blocked_countries");
                $blocked_countries_from_db = $stmt_fetch_block->fetchAll(PDO::FETCH_COLUMN, 0);
            } catch (PDOException $e) {
                error_log("Error fetching blocked countries: " . $e->getMessage());
                // Fail-safe: If DB error, proceed without blocking
            }

            if (!empty($blocked_countries_from_db)) {
                $visitor_ip = $_SERVER['REMOTE_ADDR'] ?? null;
                if ($visitor_ip) {
                    $country_code = get_visitor_country_code($visitor_ip);
                    if ($country_code !== null && in_array($country_code, $blocked_countries_from_db)) {
                        error_log("Blocked access from country: " . $country_code . " (IP: " . $visitor_ip . ") for link ID: " . $link_id);
                        $redirect_url = BASE_URL . '/'; // Redirect to homepage
                        $original_query_string = ''; // Clear query string for blocked redirect
                    } elseif ($country_code === null) { error_log("GeoIP lookup failed for IP: " . $visitor_ip . ". Allowing redirect for link ID: " . $link_id); }
                    // Else: Country not blocked or code found, keep original redirect_url
                } else { error_log("Could not determine visitor IP. Allowing redirect for link ID: " . $link_id); }
            }
            // --- End Country Blocking Logic ---

            // --- Append Original Query String ---
            $final_redirect_url = $redirect_url;
            if (!empty($original_query_string)) { if (strpos($redirect_url, '?') === false) { $final_redirect_url .= '?' . $original_query_string; } else { $final_redirect_url .= '&' . $original_query_string; } }
            // --- End Append Logic ---

            // --- Perform Redirect ---
            if (!empty($final_redirect_url) && filter_var($final_redirect_url, FILTER_VALIDATE_URL)) {
                if (ob_get_level()) ob_end_clean();
                $redirect_code = ($redirect_url === $target_url) ? 301 : 302; header("Location: " . $final_redirect_url, true, $redirect_code); exit;
            } else { error_log("Invalid final redirect URL for link ID: " . $link_id . " (URL: " . $final_redirect_url . ")"); goto handle_not_found; }
        } else { goto handle_not_found; } // Link not found
    } catch (PDOException $e) { error_log("Database Error: " . $e->getMessage()); http_response_code(500); echo "Database error occurred."; exit; }
}

// 3. Handle Root Path (/) or other unmatched paths
handle_not_found:
if (empty($path)) { $homepage_file = __DIR__ . '/index.html'; if (file_exists($homepage_file)) { header('Content-Type: text/html; charset=utf-8'); if (ob_get_level()) ob_end_clean(); readfile($homepage_file); exit; } else { http_response_code(404); echo "Homepage file not found."; exit; } }
else { http_response_code(404); echo "404 - Page Not Found"; exit; }

?>