<?php

declare(strict_types=1);

/**
 * This file is part of CodeIgniter 4 framework.
 *
 * (c) CodeIgniter Foundation <admin@codeigniter.com>
 *
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

namespace CodeIgniter\Debug;

use CodeIgniter\HTTP\CLIRequest;
use CodeIgniter\HTTP\IncomingRequest;
use CodeIgniter\HTTP\RequestInterface;
use CodeIgniter\HTTP\ResponseInterface;
use Config\Exceptions as ExceptionsConfig;
use Throwable;

/**
 * Provides common functions for exception handlers,
 * especially around displaying the output.
 */
abstract class BaseExceptionHandler
{
 /**
 * Config for debug exceptions.
 */
 protected ExceptionsConfig $config;

 /**
 * Nesting level of the output buffering mechanism
 */
 protected int $obLevel;

 /**
 * The path to the directory containing the
 * cli and html error view directories.
 */
 protected ?string $viewPath = null;

 public function __construct(ExceptionsConfig $config)
 {
 $this->config = $config;

 $this->obLevel = ob_get_level();

 if ($this->viewPath === null) {
 $this->viewPath = rtrim($this->config->errorViewPath, '\\/ ') . DIRECTORY_SEPARATOR;
 }
 }

 /**
 * The main entry point into the handler.
 *
 * @param CLIRequest|IncomingRequest $request
 *
 * @return void
 */
 abstract public function handle(
 Throwable $exception,
 RequestInterface $request,
 ResponseInterface $response,
 int $statusCode,
 int $exitCode,
 );

 /**
 * Gathers the variables that will be made available to the view.
 */
 protected function collectVars(Throwable $exception, int $statusCode): array
 {
 // Get the first exception.
 $firstException = $exception;

 while ($prevException = $firstException->getPrevious()) {
 $firstException = $prevException;
 }

 $trace = $firstException->getTrace();

 if ($this->config->sensitiveDataInTrace !== []) {
 $trace = $this->maskSensitiveData($trace, $this->config->sensitiveDataInTrace);
 }

 return [
 'title' => $exception::class,
 'type' => $exception::class,
 'code' => $statusCode,
 'message' => $exception->getMessage(),
 'file' => $exception->getFile(),
 'line' => $exception->getLine(),
 'trace' => $trace,
 ];
 }

 /**
 * Mask sensitive data in the trace.
 */
 protected function maskSensitiveData(array $trace, array $keysToMask, string $path = ''): array
 {
 foreach ($trace as $i => $line) {
 $trace[$i]['args'] = $this->maskData($line['args'], $keysToMask);
 }

 return $trace;
 }

 /**
 * @param array|object $args
 *
 * @return array|object
 */
 private function maskData($args, array $keysToMask, string $path = '')
 {
 foreach ($keysToMask as $keyToMask) {
 $explode = explode('/', $keyToMask);
 $index = end($explode);

 if (str_starts_with(strrev($path . '/' . $index), strrev($keyToMask))) {
 if (is_array($args) && array_key_exists($index, $args)) {
 $args[$index] = '******************';
 } elseif (
 is_object($args) && property_exists($args, $index)
 && isset($args->{$index}) && is_scalar($args->{$index})
 ) {
 $args->{$index} = '******************';
 }
 }
 }

 if (is_array($args)) {
 foreach ($args as $pathKey => $subarray) {
 $args[$pathKey] = $this->maskData($subarray, $keysToMask, $path . '/' . $pathKey);
 }
 } elseif (is_object($args)) {
 foreach ($args as $pathKey => $subarray) {
 $args->{$pathKey} = $this->maskData($subarray, $keysToMask, $path . '/' . $pathKey);
 }
 }

 return $args;
 }

 /**
 * Describes memory usage in real-world units. Intended for use
 * with memory_get_usage, etc.
 *
 * @used-by app/Views/errors/html/error_exception.php
 */
 protected static function describeMemory(int $bytes): string
 {
 helper('number');

 return number_to_size($bytes, 2);
 }

 /**
 * Creates a syntax-highlighted version of a PHP file.
 *
 * @used-by app/Views/errors/html/error_exception.php
 *
 * @return bool|string
 */
 protected static function highlightFile(string $file, int $lineNumber, int $lines = 15)
 {
 if ($file === '' || ! is_readable($file)) {
 return false;
 }

 // Set our highlight colors:
 if (function_exists('ini_set')) {
 ini_set('highlight.comment', '#767a7e; font-style: italic');
 ini_set('highlight.default', '#c7c7c7');
 ini_set('highlight.html', '#06B');
 ini_set('highlight.keyword', '#f1ce61;');
 ini_set('highlight.string', '#869d6a');
 }

 try {
 $source = file_get_contents($file);
 } catch (Throwable) {
 return false;
 }

 $source = str_replace(["\r\n", "\r"], "\n", $source);
 $source = explode("\n", highlight_string($source, true));

 if (PHP_VERSION_ID < 80300) {
 $source = str_replace('<br />', "\n", $source[1]);
 $source = explode("\n", str_replace("\r\n", "\n", $source));
 } else {
 // We have to remove these tags since we're preparing the result
 // ourselves and these tags are added manually at the end.
 $source = str_replace(['<pre><code>', '</code></pre>'], '', $source);
 }

 // Get just the part to show
 $start = max($lineNumber - (int) round($lines / 2), 0);

 // Get just the lines we need to display, while keeping line numbers...
 $source = array_splice($source, $start, $lines, true);

 // Used to format the line number in the source
 $format = '% ' . strlen((string) ($start + $lines)) . 'd';

 $out = '';
 // Because the highlighting may have an uneven number
 // of open and close span tags on one line, we need
 // to ensure we can close them all to get the lines
 // showing correctly.
 $spans = 0;

 foreach ($source as $n => $row) {
 $spans += substr_count($row, '<span') - substr_count($row, '</span');
 $row = str_replace(["\r", "\n"], ['', ''], $row);

 if (($n + $start + 1) === $lineNumber) {
 preg_match_all('#<[^>]+>#', $row, $tags);

 $out .= sprintf(
 "<span class='line highlight'><span class='number'>{$format}</span> %s\n</span>%s",
 $n + $start + 1,
 strip_tags($row),
 implode('', $tags[0]),
 );
 } else {
 $out .= sprintf('<span class="line"><span class="number">' . $format . '</span> %s', $n + $start + 1, $row) . "\n";
 // We're closing only one span tag we added manually line before,
 // so we have to increment $spans count to close this tag later.
 $spans++;
 }
 }

 if ($spans > 0) {
 $out .= str_repeat('</span>', $spans);
 }

 return '<pre><code>' . $out . '</code></pre>';
 }

 /**
 * Given an exception and status code will display the error to the client.
 *
 * @param string|null $viewFile
 */
 protected function render(Throwable $exception, int $statusCode, $viewFile = null): void
 {
 if ($viewFile === null) {
 echo 'The error view file was not specified. Cannot display error view.';

 exit(1);
 }

 if (! is_file($viewFile)) {
 echo 'The error view file "' . $viewFile . '" was not found. Cannot display error view.';

 exit(1);
 }

 echo (function () use ($exception, $statusCode, $viewFile): string {
 $vars = $this->collectVars($exception, $statusCode);
 extract($vars, EXTR_SKIP);

 // CLI error views output to STDERR/STDOUT, so ob_start() does not work.
 ob_start();
 include $viewFile;

 return ob_get_clean();
 })();
 }
}