SQLite Testing

public function __construct(&$db)
**Purpose:** Initializes the Http object and sets up HTTP session handling.
**Parameters:**
  - ##$db## - Database object reference
**Initialization Steps:**
  1. Stores database reference
  2. Extracts and normalizes REQUEST_URI
  3. Detects TLS/HTTPS session status
  4. Determines client's real IP address
  5. Sets up TLS mark cookie name
  6. Enforces TLS session upgrade if needed
**Example:**

$http->session(0);  // Normal session
$http->session(2);  // Static file serving mode
==== Caching System ====
===== ##check_cache($page, $method): void## =====
Determines if a page can be cached and prepares the cache check.
**Parameters:**
  - ##$page## (string) - Page name to cache
  - ##$method## (string) - Request method/action (e.g., 'show', 'edit')
**Caching Rules:**
  - ✅ Enabled for GET requests only
  - ✅ Disabled for POST requests
  - ❌ Never cached for 'edit' or 'watch' methods
  - ✅ Only cached for anonymous users (no logged-in users)
**Example:**

// Called at end of page rendering
$http->store_cache();
===== ##invalidate_page($page): int## =====
Invalidates all cached versions of a page.
**Parameters:**
  - ##$page## (string) - Page name to invalidate
**Returns:**
  - Number of cache entries invalidated
**Process:**
  1. Finds all cached versions (different methods/languages)
  2. Touches files to past timestamp (faster than deletion)
  3. Removes entries from cache metadata table
  4. Returns count of invalidated caches
**Example:**

$http->secure_base_url();
// $db->base_url now uses https://
===== ##ensure_tls($url): void## =====
Enforces HTTPS for a specific URL and redirects if necessary.
**Parameters:**
  - ##$url## (string) - URL to secure
**Behavior:**
  - If not already HTTPS and TLS is enabled, forces HTTPS redirect
  - Handles both relative and absolute URLs
  - Converts relative URLs using current server name
**Example:**

$client_ip = $http->ip;  // e.g., "203.0.113.42"
==== HTTPS Detection ====
===== ##tls_session(): bool## (Private) =====
Detects if current connection uses HTTPS/TLS.
**Checks (any being true = HTTPS):**
  - ##$_SERVER['HTTPS']## is 'on'
  - ##$_SERVER['SERVER_PORT']## is 443
  - ##$_SERVER['HTTP_X_FORWARDED_PROTO']## is 'https'
  - ##$_SERVER['HTTP_X_FORWARDED_SSL']## is 'on'
  - ##$_SERVER['HTTP_X_FORWARDED_PORT']## is 443
==== Security Headers ====
=====##http_security_headers(): void##=====
Sets security-related HTTP headers.
**Headers Set:**
#|
*| Header | Purpose | Config Key |*
|| Content-Security-Policy | XSS/injection protection | ##csp## ||
|| Permissions-Policy | Control browser features | ##permissions_policy## ||
|| Referrer-Policy | Control referrer information | ##referrer_policy## ||
|| Strict-Transport-Security | Force HTTPS | Auto (TLS only) ||
|| X-Frame-Options | Clickjacking protection | Hardcoded: ##SAMEORIGIN## ||
|| X-Content-Type-Options | MIME sniffing prevention | Hardcoded: ##nosniff## ||
|#
**CSP Configuration Options:**
  - ##0## - Disabled
  - ##1## - Default policy (from ##csp.conf##)
  - ##2## - Custom policy (from ##csp_custom.conf##)
**Example:**

$http->redirect('http://example.com/new-page', true);  // 301
$http->redirect('/wiki/HomePage');                       // 302
===== ##terminate(): void## =====
Safe exit/die with cleanup.
**Cleanup Operations:**
  - Saves diagnostic logs to session flash data
  - Ends script execution
**Example:**

200 => 'OK'
206 => 'Partial Content'
301 => 'Moved Permanently'
302 => 'Moved Temporarily'
304 => 'Not Modified'
400 => 'Bad Request'
401 => 'Unauthorized'
403 => 'Forbidden'
404 => 'Not Found'
405 => 'Method Not Allowed'
409 => 'Conflict'
410 => 'Gone'
416 => 'Requested Range Not Satisfiable'
500 => 'Internal Server Error'
501 => 'Not Implemented'
503 => 'Service Unavailable'
**Example:**

$http->no_cache();        // Client-side only
$http->no_cache(false);   // Both client & server
===== ##cache_promisc(): void## =====
Marks page as publicly cacheable.
**Headers Set:**
  - ##Cache-Control: public##
**Example:**

$all_langs = $http->available_languages(false);
$allowed = $http->available_languages(true);
==== File Serving ====
===== ##sendfile($path, $filename = null, $age = null): void## =====
Serves files with proper HTTP headers and caching.
**Parameters:**
  - ##$path## (string) - File path (or HTTP_XXX constant for error pages)
  - ##$filename## (string, optional) - Custom download filename
  - ##$age## (int, optional) - Cache age in days
**Features:**
  - HTTP range request support (partial file downloads)
  - ETag and Last-Modified conditional requests
  - Proper MIME type detection
  - Content-Security-Policy for special file types
  - Streaming for large files
  - GZip compression for text files
**Special Paths:**

$http->sendfile('uploads/document.pdf', 'my-document.pdf', 30);
===== ##mime_type($path): string## =====
Returns MIME type for a file.
**Returns:**
  - MIME type string (e.g., 'application/pdf')
  - Default: ##'application/octet-stream'##
**Example:**

$http->gzip();
==== Utility Methods ====
===== ##parse_str($str): array## (Private) =====
Parses URL-encoded strings with special character handling.
**Purpose:**
  - Safely handles special characters in query/form data
  - Converts encoding properly
**Example:**

// In main wiki entry point
$http = new Http($db);
$http->session(0);  // Start session
// Check if page can be served from cache
$http->check_cache('HomePage', 'show');
// ... render page content ...
// Store rendered page in cache if applicable
$http->store_cache();
// Send security headers
$http->http_security_headers();
// Possibly compress output
$http->gzip();
==== Example 2: Handling TLS/HTTPS Upgrade ====

// User edits a page
$http = new Http($db);
$count = $http->invalidate_page('HomePage');
// All cached versions (different languages, methods) are invalidated
==== Example 4: Serving a File ====