<?php
/**
 * Copyright 2010-2013 Craig Campbell
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
namespace wpCloud\StatelessMedia {

  if( !class_exists( 'wpCloud\StatelessMedia\Logger' ) ) {

      /**
       * Server Side Chrome PHP debugger class
       *
       * @package ChromePhp
       * @author Craig Campbell <iamcraigcampbell@gmail.com>
       */
    class Logger {
      /**
       * @var string
       */
      const VERSION = '4.1.0';

      /**
       * @var string
       */
      const HEADER_NAME = 'X-ChromeLogger-Data';

      /**
       * @var string
       */
      const BACKTRACE_LEVEL = 'backtrace_level';

      /**
       * @var string
       */
      const LOG = 'log';

      /**
       * @var string
       */
      const WARN = 'warn';

      /**
       * @var string
       */
      const ERROR = 'error';

      /**
       * @var string
       */
      const GROUP = 'group';

      /**
       * @var string
       */
      const INFO = 'info';

      /**
       * @var string
       */
      const GROUP_END = 'groupEnd';

      /**
       * @var string
       */
      const GROUP_COLLAPSED = 'groupCollapsed';

      /**
       * @var string
       */
      const TABLE = 'table';

      /**
       * @var string
       */
      protected $_php_version;

      /**
       * @var int
       */
      protected $_timestamp;

      /**
       * @var array
       */
      protected $_json = array(
        'version' => self::VERSION,
        'columns' => array( 'log', 'backtrace', 'type' ),
        'rows' => array()
      );

      /**
       * @var array
       */
      protected $_backtraces = array();

      /**
       * @var bool
       */
      protected $_error_triggered = false;

      /**
       * @var array
       */
      protected $_settings = array(
        self::BACKTRACE_LEVEL => 1
      );

      /**
       * @var ChromePhp
       */
      protected static $_instance;

      /**
       * Prevent recursion when working with objects referring to each other
       *
       * @var array
       */
      protected $_processed = array();

      /**
       * constructor
       */
      private function __construct() {
        $this->_php_version = phpversion();
        $this->_timestamp = $this->_php_version >= 5.1 ? $_SERVER[ 'REQUEST_TIME' ] : time();
        $this->_json[ 'request_uri' ] = $_SERVER[ 'REQUEST_URI' ];
      }

      /**
       * gets instance of this class
       *
       * @return ChromePhp
       */
      public static function getInstance() {
        if( self::$_instance === null ) {
          self::$_instance = new self();
        }
        return self::$_instance;
      }

      /**
       * logs a variable to the console
       *
       * @param mixed $data,... unlimited OPTIONAL number of additional logs [...]
       * @return void
       */
      public static function log() {
        $args = func_get_args();
        return self::_log( '', $args );
      }

      /**
       * logs a warning to the console
       *
       * @param mixed $data,... unlimited OPTIONAL number of additional logs [...]
       * @return void
       */
      public static function warn() {
        $args = func_get_args();
        return self::_log( self::WARN, $args );
      }

      /**
       * logs an error to the console
       *
       * @param mixed $data,... unlimited OPTIONAL number of additional logs [...]
       * @return void
       */
      public static function error() {
        $args = func_get_args();
        return self::_log( self::ERROR, $args );
      }

      /**
       * sends a group log
       *
       * @param string value
       */
      public static function group() {
        $args = func_get_args();
        return self::_log( self::GROUP, $args );
      }

      /**
       * sends an info log
       *
       * @param mixed $data,... unlimited OPTIONAL number of additional logs [...]
       * @return void
       */
      public static function info() {
        $args = func_get_args();
        return self::_log( self::INFO, $args );
      }

      /**
       * sends a collapsed group log
       *
       * @param string value
       */
      public static function groupCollapsed() {
        $args = func_get_args();
        return self::_log( self::GROUP_COLLAPSED, $args );
      }

      /**
       * ends a group log
       *
       * @param string value
       */
      public static function groupEnd() {
        $args = func_get_args();
        return self::_log( self::GROUP_END, $args );
      }

      /**
       * sends a table log
       *
       * @param string value
       */
      public static function table() {
        $args = func_get_args();
        return self::_log( self::TABLE, $args );
      }

      /**
       * internal logging call
       *
       * @param string $type
       * @return void
       */
      protected static function _log( $type, array $args ) {
        // nothing passed in, don't do anything
        if( count( $args ) == 0 && $type != self::GROUP_END ) {
          return;
        }

        $logger = self::getInstance();

        $logger->_processed = array();

        $logs = array();
        foreach( $args as $arg ) {
          $logs[] = $logger->_convert( $arg );
        }

        $backtrace = debug_backtrace( false );
        $level = $logger->getSetting( self::BACKTRACE_LEVEL );

        $backtrace_message = 'unknown';
        if( isset( $backtrace[ $level ][ 'file' ] ) && isset( $backtrace[ $level ][ 'line' ] ) ) {
          $backtrace_message = $backtrace[ $level ][ 'file' ] . ' : ' . $backtrace[ $level ][ 'line' ];
        }

        $logger->_addRow( $logs, $backtrace_message, $type );
      }

      /**
       * converts an object to a better format for logging
       *
       * @param Object
       * @return array
       */
      protected function _convert( $object ) {
        // if this isn't an object then just return it
        if( !is_object( $object ) ) {
          return $object;
        }

        //Mark this object as processed so we don't convert it twice and it
        //Also avoid recursion when objects refer to each other
        $this->_processed[] = $object;

        $object_as_array = array();

        // first add the class name
        $object_as_array[ '___class_name' ] = get_class( $object );

        // loop through object vars
        $object_vars = get_object_vars( $object );
        foreach( $object_vars as $key => $value ) {

          // same instance as parent object
          if( $value === $object || in_array( $value, $this->_processed, true ) ) {
            $value = 'recursion - parent object [' . get_class( $value ) . ']';
          }
          $object_as_array[ $key ] = $this->_convert( $value );
        }

        $reflection = new ReflectionClass( $object );

        // loop through the properties and add those
        foreach( $reflection->getProperties() as $property ) {

          // if one of these properties was already added above then ignore it
          if( array_key_exists( $property->getName(), $object_vars ) ) {
            continue;
          }
          $type = $this->_getPropertyKey( $property );

          if( $this->_php_version >= 5.3 ) {
            $property->setAccessible( true );
          }

          try {
            $value = $property->getValue( $object );
          } catch ( ReflectionException $e ) {
            $value = 'only PHP 5.3 can access private/protected properties';
          }

          // same instance as parent object
          if( $value === $object || in_array( $value, $this->_processed, true ) ) {
            $value = 'recursion - parent object [' . get_class( $value ) . ']';
          }

          $object_as_array[ $type ] = $this->_convert( $value );
        }
        return $object_as_array;
      }

      /**
       * takes a reflection property and returns a nicely formatted key of the property name
       *
       * @param ReflectionProperty
       * @return string
       */
      protected function _getPropertyKey( ReflectionProperty $property ) {
        $static = $property->isStatic() ? ' static' : '';
        if( $property->isPublic() ) {
          return 'public' . $static . ' ' . $property->getName();
        }

        if( $property->isProtected() ) {
          return 'protected' . $static . ' ' . $property->getName();
        }

        if( $property->isPrivate() ) {
          return 'private' . $static . ' ' . $property->getName();
        }
      }

      /**
       * adds a value to the data array
       *
       * @var mixed
       * @return void
       */
      protected function _addRow( array $logs, $backtrace, $type ) {
        // if this is logged on the same line for example in a loop, set it to null to save space
        if( in_array( $backtrace, $this->_backtraces ) ) {
          $backtrace = null;
        }

        // for group, groupEnd, and groupCollapsed
        // take out the backtrace since it is not useful
        if( $type == self::GROUP || $type == self::GROUP_END || $type == self::GROUP_COLLAPSED ) {
          $backtrace = null;
        }

        if( $backtrace !== null ) {
          $this->_backtraces[] = $backtrace;
        }

        $row = array( $logs, $backtrace, $type );

        $this->_json[ 'rows' ][] = $row;
        $this->_writeHeader( $this->_json );
      }

      protected function _writeHeader( $data ) {
        header( self::HEADER_NAME . ': ' . $this->_encode( $data ) );
      }

      /**
       * encodes the data to be sent along with the request
       *
       * @param array $data
       * @return string
       */
      protected function _encode( $data ) {
        return base64_encode( utf8_encode( json_encode( $data ) ) );
      }

      /**
       * adds a setting
       *
       * @param string key
       * @param mixed value
       * @return void
       */
      public function addSetting( $key, $value ) {
        $this->_settings[ $key ] = $value;
      }

      /**
       * add ability to set multiple settings in one call
       *
       * @param array $settings
       * @return void
       */
      public function addSettings( array $settings ) {
        foreach( $settings as $key => $value ) {
          $this->addSetting( $key, $value );
        }
      }

      /**
       * gets a setting
       *
       * @param string key
       * @return mixed
       */
      public function getSetting( $key ) {
        if( !isset( $this->_settings[ $key ] ) ) {
          return null;
        }
        return $this->_settings[ $key ];
      }
    }

  }

}