<?php

// @usage: DebugLazyLogger::log($mixedArg, $type, $msg, $logFileName);
class DebugLazyLogger {

	function __construct() {
		$this->_items = [];
		$prefix = ('production' == V::get('P5_ENV', 'production', $_SERVER)) ? "" : "dev-";
		$this->_logFileName = "/tmp/{$prefix}se-debug-" . implode('-', [
			date("Y-m-d"),
			User::getLogin(),
			Request::getUserIp(),
			substr(session_id(), 0, 6),
			V::get('REQUEST_TIME', '', $_SERVER)// [REQUEST_TIME] => 1485770466
		]) . '.log';
	}

	function _addLog($mixedArg, $type, $msg, $trace, $moreMsg) {
		$microTime = date("Y-m-d H:i:s") . substr((string)microtime(), 1, 6);
		$this->_items[] = [ $microTime, $mixedArg, $type, $msg, $trace, $moreMsg ];
	}

	function __destruct() {
		$startSaveLog = date("Y-m-d H:i:s") . substr((string)microtime(), 1, 6);
		$firstItem = reset($this->_items);
		foreach ($this->_items as $logItem) { // $logItem: [ $mixedArg, $type, $msg, $logFileName ]
			list($microTime, $mixedArg, $type, $msg, $trace, $moreMsg) = $logItem;
			self::saveLogItemToFile($this->_logFileName, $microTime, $type, $msg, $moreMsg, $trace);
		}
		$endSaveLog = date("Y-m-d H:i:s") . substr((string)microtime(), 1, 6);
		self::saveLogItemToFile($this->_logFileName, $startSaveLog, $type = 'string', $msg = "Start saving log");
		self::saveLogItemToFile($this->_logFileName, $endSaveLog,   $type = 'string', $msg = "End saving log");
		self::saveLogItemToFile($this->_logFileName, $endSaveLog,   $type = 'array', $msg = "Summary", $moreMsg = implode("\n", [
			"{$firstItem[0]} diff(-----) - first log entry",
			"{$startSaveLog} diff(" . V::milisecondsStringDiff($startSaveLog, $firstItem[0]) . ") - start saving log to file",
			"{$endSaveLog} diff(" . V::milisecondsStringDiff($endSaveLog, $startSaveLog) . ") - end saving log to file",
		]));
	}

	static function getInstance() {
		static $instance;
		if (!$instance) $instance = new DebugLazyLogger();
		return $instance;
	}

	static function log($mixedArg, $type = '', $msg = '') {
		$logger = self::getInstance();
		$trace = '';
		$moreMsg = '';

		if ($mixedArg instanceof Exception) {
			$type = 'Exception';
			if (!empty($msg)) $msg .= ". ";
			$msg .= $mixedArg->getMessage();
			$moreMsg = [
				'code' => $mixedArg->getCode(),
				'line' => $mixedArg->getLine(),
				'file' => str_replace(APP_PATH_ROOT, 'SE', $mixedArg->getFile()),
			];
			$trace = $mixedArg->getTraceAsString();// getTrace
		} else if (is_string($mixedArg)) {
			if ('sql' == $type) {
				if (!$type) $type = 'sql';
				if (empty($msg)) $msg = "sql";
				$moreMsg = $mixedArg;
			} else {
				if (empty($type)) $type = 'string';
				if (empty($msg)) {
					$msg = $mixedArg;
					$moreMsg = '';
				} else {
					$moreMsg = $mixedArg;
				}
			}
			ob_start();
			debug_print_backtrace();
			$trace = ob_get_clean();
		} else if ('array' == $type || is_array($mixedArg)) {
			$mixedArg = (array)$mixedArg;
			if (!$type) $type = 'array';
			if (!empty($msg) && !empty($mixedArg['msg'])) $msg .= ". {$mixedArg['msg']}";
			else if (empty($msg) && !empty($mixedArg['msg'])) $msg = $mixedArg['msg'];
			if (!empty($mixedArg['msg'])) unset($mixedArg['msg']);
			$moreMsg = $mixedArg;
			ob_start();
			debug_print_backtrace();
			$trace = ob_get_clean();
		}
		if (!empty($trace) && 'Exception' !== $type) {// remove #0 and #1 (DBG::log and DBG::_log)
			$pos = strpos($trace, "\n#2");
			// if (false !== $pos) $trace = substr($trace, $pos + 1); // TODO
		}
		$trace = str_replace(APP_PATH_ROOT, 'SE', $trace);
		$trace .= (("\n" == substr($trace, -1)) ? '' :  "\n") . "#URI: " . V::get('REQUEST_URI', '', $_SERVER);
		if (!$type) $type = 'unknown';

		$logger->_addLog($mixedArg, $type, $msg, $trace, $moreMsg);
	}

	static function saveLogItemToFile($logFileName, $microTime, $type, $msg, $moreMsg = '', $trace = '') {
		$logInfo = [
			'date' => $microTime,
			'type' => $type,
			'msg' => $msg,
			'log' => $moreMsg,
			'trace' => $trace,
		];
		if (!empty($logInfo['trace'])) {
			$trace = array_map(function ($part) {
				if ('URI: ' === substr($part, 0, strlen('URI: '))) return "#{$part}";
				if ($pos = strpos($part, '{closure}')) {
					// #10 Route_Storage_AclStruct->{closure}(Array ([namespace] => default_db/BI_audit_ENERGA_PRAC ... )
					return "#" . substr($part, 0, 200) . ( strlen($part) > 200 ? '...' : '' );
				}
				if ($pos = strrpos($part, ' called at [')) {
					$spacePos = strpos($part, ' ');
					$spacePos = (' ' === $part[$spacePos + 1]) ? $spacePos + 1 : $spacePos;
					$spacePos = (' ' === $part[$spacePos + 1]) ? $spacePos + 1 : $spacePos;
					$spacePos += 1;
					$called = substr($part, $pos + strlen(' called at ['), -1);
					$nr = substr($part, 0, $spacePos);
					$line = substr($part, $spacePos, ($pos > 200) ? 200 : $pos - $spacePos);
					if ($pos > 200) $line .= "...";
					$line = str_replace("\n", '\\n', $line);
					return "#{$nr}{$called}: {$line}";
				}
				return "#" . substr($part, 0, 200) . ( strlen($part) > 200 ? '...' : '' );
			}, explode("\n#", $logInfo['trace']));
			array_shift($trace);
			$logInfo['trace'] = implode("\n", $trace);
		}

		error_log(
			json_encode($logInfo) . "\n"
			, 3
			, $logFileName
		);
	}

}