1 files changed, 187 insertions, 0 deletions
diff --git a/engine/logging.php b/engine/logging.php
new file mode 100644
index 0000000..f77a5fa
--- /dev/null
+++ b/engine/logging.php
@@ -0,0 +1,187 @@
+<?php
+
+require_once 'engine/ansi.php';
+use \ansi\Color;
+use function \ansi\wrap;
+
+enum LogLevel {
+    case ERROR;
+    case WARNING;
+    case INFO;
+    case DEBUG;
+}
+
+function logDebug(...$args): void   { logging::logCustom(LogLevel::DEBUG, ...$args); }
+function logInfo(...$args): void    { logging::logCustom(LogLevel::INFO, ...$args); }
+function logWarning(...$args): void { logging::logCustom(LogLevel::WARNING, ...$args); }
+function logError(...$args): void   { logging::logCustom(LogLevel::ERROR, ...$args); }
+
+class logging {
+
+    // private static $instance = null;
+
+    protected static ?string $logFile = null;
+    protected static bool $enabled = false;
+    protected static int $counter = 0;
+
+    /** @var ?callable $filter */
+    protected static $filter = null;
+
+    public static function setLogFile(string $log_file): void {
+        self::$logFile = $log_file;
+    }
+
+    public static function setErrorFilter(callable $filter): void {
+        self::$filter = $filter;
+    }
+
+    public static function disable(): void {
+        self::$enabled = false;
+
+        restore_error_handler();
+        register_shutdown_function(function() {});
+    }
+
+    public static function enable(): void {
+        self::$enabled = true;
+
+        set_error_handler(function($no, $str, $file, $line) {
+            if (is_callable(self::$filter) && !(self::$filter)($no, $file, $line, $str))
+                return;
+
+            self::write(LogLevel::ERROR, $str,
+                errno: $no,
+                errfile: $file,
+                errline: $line);
+        });
+
+        register_shutdown_function(function() {
+            if (!($error = error_get_last()))
+                return;
+
+            if (is_callable(self::$filter)
+                && !(self::$filter)($error['type'], $error['file'], $error['line'], $error['message'])) {
+                return;
+            }
+
+            self::write(LogLevel::ERROR, $error['message'],
+                errno: $error['type'],
+                errfile:  $error['file'],
+                errline: $error['line']);
+        });
+    }
+
+    public static function logCustom(LogLevel $level, ...$args): void {
+        self::write($level, self::strVars($args));
+    }
+
+    protected static function write(LogLevel $level,
+                                    string $message,
+                                    ?int $errno = null,
+                                    ?string $errfile = null,
+                                    ?string $errline = null): void {
+
+        // TODO test
+        if (is_null(self::$logFile)) {
+            fprintf(STDERR, __METHOD__.': logfile is not set');
+            return;
+        }
+
+        $num = self::$counter++;
+        $time = time();
+
+        // TODO rewrite using sprintf
+        $exec_time = strval(exectime());
+        if (strlen($exec_time) < 6)
+            $exec_time .= str_repeat('0', 6 - strlen($exec_time));
+
+        // $bt = backtrace(2);
+
+        $title = PHP_SAPI == 'cli' ? 'cli' : $_SERVER['REQUEST_URI'];
+        $date = date('d/m/y H:i:s', $time);
+
+        $buf = '';
+        if ($num == 0) {
+            $buf .= wrap(" $title ",
+                fg: Color::WHITE,
+                bg: Color::MAGENTA,
+                fg_bright: true,
+                bold: true);
+            $buf .= wrap(" $date ", fg: Color::WHITE, bg: Color::BLUE, fg_bright: true);
+            $buf .= "\n";
+        }
+
+        $letter = strtoupper($level->name[0]);
+        $color = match ($level) {
+            LogLevel::ERROR => Color::RED,
+            LogLevel::INFO, LogLevel::DEBUG => Color::WHITE,
+            LogLevel::WARNING => Color::YELLOW
+        };
+
+        $buf .= wrap($letter.wrap('='.wrap($num, bold: true)), fg: $color).' ';
+        $buf .= wrap($exec_time, fg: Color::CYAN).' ';
+        if (!is_null($errno)) {
+            $buf .= wrap($errfile, fg: Color::GREEN);
+            $buf .= wrap(':', fg: Color::WHITE);
+            $buf .= wrap($errline, fg: Color::GREEN, fg_bright: true);
+            $buf .= ' ('.self::getPhpErrorName($errno).') ';
+        }
+
+        $buf .= $message."\n";
+        if (in_array($level, [LogLevel::ERROR, LogLevel::WARNING]))
+            $buf .= backtrace(2)."\n";
+
+        // TODO test
+        $set_perm = !file_exists(self::$logFile);
+        $f = fopen(self::$logFile, 'a');
+        if (!$f) {
+            fprintf(STDERR, __METHOD__.': failed to open file "'.self::$logFile.'" for writing');
+            return;
+        }
+
+        fwrite($f, $buf);
+        fclose($f);
+
+        if ($set_perm)
+            setperm($f);
+    }
+
+    protected static function getPhpErrorName(int $errno): string {
+        static $errors = null;
+        if (is_null($errors))
+            $errors = array_flip(array_slice(get_defined_constants(true)['Core'], 0, 15, true));
+        return $errors[$errno];
+    }
+
+    protected static function strVarDump($var, bool $print_r = false): string {
+        ob_start();
+        $print_r ? print_r($var) : var_dump($var);
+        return trim(ob_get_clean());
+    }
+
+    protected static function strVars(array $args): string {
+        $args = array_map(fn($a) => match (gettype($a)) {
+            'string' => $a,
+            'array', 'object' => self::strVarDump($a, true),
+            default => self::strVarDump($a)
+        }, $args);
+        return implode(' ', $args);
+    }
+
+}
+
+function backtrace(int $shift = 0): string {
+    $bt = debug_backtrace();
+    $lines = [];
+    foreach ($bt as $i => $t) {
+        if ($i < $shift)
+            continue;
+
+        if (!isset($t['file'])) {
+            $lines[] = 'from ?';
+        } else {
+            $lines[] = 'from '.$t['file'].':'.$t['line'];
+        }
+    }
+    return implode("\n", $lines);
+}