<?php
/**
 * @package     Freemius
 * @copyright   Copyright (c) 2015, Freemius, Inc.
 * @license     https://www.gnu.org/licenses/gpl-3.0.html GNU General Public License Version 3
 * @since       1.0.3
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class FS_Logger {
	private $_id;
	private $_on = false;
	private $_echo = false;
	private $_file_start = 0;
	/**
	 * @var int PHP Process ID.
	 */
	private static $_processID;
	/**
	 * @var string PHP Script user name.
	 */
	private static $_ownerName;
	/**
	 * @var bool Is storage logging turned on.
	 */
	private static $_isStorageLoggingOn;
	/**
	 * @var int ABSPATH length.
	 */
	private static $_abspathLength;

	private static $LOGGERS = array();
	private static $LOG = array();
	private static $CNT = 0;
	private static $_HOOKED_FOOTER = false;

	private function __construct( $id, $on = false, $echo = false ) {
		$this->_id = $id;

		$bt     = debug_backtrace();
		$caller = $bt[2];

		if ( false !== strpos( $caller['file'], 'plugins' ) ) {
			$this->_file_start = strpos( $caller['file'], 'plugins' ) + strlen( 'plugins/' );
		} else {
			$this->_file_start = strpos( $caller['file'], 'themes' ) + strlen( 'themes/' );
		}

		if ( $on ) {
			$this->on();
		}
		if ( $echo ) {
			$this->echo_on();
		}
	}

	/**
	 * @param string $id
	 * @param bool $on
	 * @param bool $echo
	 *
	 * @return FS_Logger
	 */
	public static function get_logger( $id, $on = false, $echo = false ) {
		$id = strtolower( $id );

		if ( ! isset( self::$_processID ) ) {
			self::init();
		}

		if ( ! isset( self::$LOGGERS[ $id ] ) ) {
			self::$LOGGERS[ $id ] = new FS_Logger( $id, $on, $echo );
		}

		return self::$LOGGERS[ $id ];
	}

	/**
	 * Initialize logging global info.
	 *
	 * @author Vova Feldman (@svovaf)
	 * @since  1.2.1.6
	 */
	private static function init() {
		self::$_ownerName          = function_exists( 'get_current_user' ) ?
			get_current_user() :
			'unknown';
		self::$_isStorageLoggingOn = ( 1 == get_option( 'fs_storage_logger', 0 ) );
		self::$_abspathLength      = strlen( ABSPATH );
		self::$_processID          = mt_rand( 0, 32000 );

		// Process ID may be `false` on errors.
		if ( ! is_numeric( self::$_processID ) ) {
			self::$_processID = 0;
		}
	}

	private static function hook_footer() {
		if ( self::$_HOOKED_FOOTER ) {
			return;
		}

		if ( is_admin() ) {
			add_action( 'admin_footer', 'FS_Logger::dump', 100 );
		} else {
			add_action( 'wp_footer', 'FS_Logger::dump', 100 );
		}
	}

	function is_on() {
		return $this->_on;
	}

	function on() {
		$this->_on = true;

		if ( ! function_exists( 'dbDelta' ) ) {
			require_once ABSPATH . 'wp-admin/includes/upgrade.php';
		}

		self::hook_footer();
	}

	function echo_on() {
		$this->on();

		$this->_echo = true;
	}

	function is_echo_on() {
		return $this->_echo;
	}

	function get_id() {
		return $this->_id;
	}

	function get_file() {
		return $this->_file_start;
	}

	private function _log( &$message, $type = 'log', $wrapper ) {
		if ( ! $this->is_on() ) {
			return;
		}

		$bt    = debug_backtrace();
		$depth = $wrapper ? 3 : 2;
		while ( $depth < count( $bt ) - 1 && 'eval' === $bt[ $depth ]['function'] ) {
			$depth ++;
		}

		$caller = $bt[ $depth ];

		/**
		 * Retrieve the correct call file & line number from backtrace
		 * when logging from a wrapper method.
		 *
		 * @author Vova Feldman
		 * @since  1.2.1.6
		 */
		if ( empty( $caller['line'] ) ) {
			$depth --;

			while ( $depth >= 0 ) {
				if ( ! empty( $bt[ $depth ]['line'] ) ) {
					$caller['line'] = $bt[ $depth ]['line'];
					$caller['file'] = $bt[ $depth ]['file'];
					break;
				}
			}
		}

		$log = array_merge( $caller, array(
			'cnt'       => self::$CNT ++,
			'logger'    => $this,
			'timestamp' => microtime( true ),
			'log_type'  => $type,
			'msg'       => $message,
		) );

		if ( self::$_isStorageLoggingOn ) {
			$this->db_log( $type, $message, self::$CNT, $caller );
		}

		self::$LOG[] = $log;

		if ( $this->is_echo_on() && ! Freemius::is_ajax() ) {
			echo self::format_html( $log ) . "\n";
		}
	}

	function log( $message, $wrapper = false ) {
		$this->_log( $message, 'log', $wrapper );
	}

	function info( $message, $wrapper = false ) {
		$this->_log( $message, 'info', $wrapper );
	}

	function warn( $message, $wrapper = false ) {
		$this->_log( $message, 'warn', $wrapper );
	}

	function error( $message, $wrapper = false ) {
		$this->_log( $message, 'error', $wrapper );
	}

	/**
	 * Log API error.
	 *
	 * @author Vova Feldman (@svovaf)
	 * @since  1.2.1.5
	 *
	 * @param mixed $api_result
	 * @param bool $wrapper
	 */
	function api_error( $api_result, $wrapper = false ) {
		$message = '';
		if ( is_object( $api_result ) && isset( $api_result->error ) ) {
			$message = $api_result->error->message;
		} else if ( is_object( $api_result ) ) {
			$message = var_export( $api_result, true );
		} else if ( is_string( $api_result ) ) {
			$message = $api_result;
		} else if ( empty( $api_result ) ) {
			$message = 'Empty API result.';
		}

		$message = 'API Error: ' . $message;

		$this->_log( $message, 'error', $wrapper );
	}

	function entrance( $message = '', $wrapper = false ) {
		$msg = 'Entrance' . ( empty( $message ) ? '' : ' > ' ) . $message;

		$this->_log( $msg, 'log', $wrapper );
	}

	function departure( $message = '', $wrapper = false ) {
		$msg = 'Departure' . ( empty( $message ) ? '' : ' > ' ) . $message;

		$this->_log( $msg, 'log', $wrapper );
	}

	#--------------------------------------------------------------------------------
	#region Log Formatting
	#--------------------------------------------------------------------------------

	private static function format( $log, $show_type = true ) {
		return '[' . str_pad( $log['cnt'], strlen( self::$CNT ), '0', STR_PAD_LEFT ) . '] [' . $log['logger']->_id . '] ' . ( $show_type ? '[' . $log['log_type'] . ']' : '' ) . ( ! empty( $log['class'] ) ? $log['class'] . $log['type'] : '' ) . $log['function'] . ' >> ' . $log['msg'] . ( isset( $log['file'] ) ? ' (' . substr( $log['file'], $log['logger']->_file_start ) . ' ' . $log['line'] . ') ' : '' ) . ' [' . $log['timestamp'] . ']';
	}

	private static function format_html( $log ) {
		return '<div style="font-size: 13px; font-family: monospace; color: #7da767; padding: 8px 3px; background: #000; border-bottom: 1px solid #555;">[' . $log['cnt'] . '] [' . $log['logger']->_id . '] [' . $log['log_type'] . '] <b><code style="color: #c4b1e0;">' . ( ! empty( $log['class'] ) ? $log['class'] . $log['type'] : '' ) . $log['function'] . '</code> >> <b style="color: #f59330;">' . esc_html( $log['msg'] ) . '</b></b>' . ( isset( $log['file'] ) ? ' (' . substr( $log['file'], $log['logger']->_file_start ) . ' ' . $log['line'] . ')' : '' ) . ' [' . $log['timestamp'] . ']</div>';
	}

	#endregion

	static function dump() {
		?>
        <!-- BEGIN: Freemius PHP Console Log -->
        <script type="text/javascript">
			<?php
			foreach ( self::$LOG as $log ) {
				echo 'console.' . $log['log_type'] . '(' . json_encode( self::format( $log, false ) ) . ')' . "\n";
			}
			?>
        </script>
        <!-- END: Freemius PHP Console Log -->
		<?php
	}

	static function get_log() {
		return self::$LOG;
	}

	#--------------------------------------------------------------------------------
	#region Database Logging
	#--------------------------------------------------------------------------------

	/**
	 * @author Vova Feldman (@svovaf)
	 * @since  1.2.1.6
	 *
	 * @return bool
	 */
	public static function is_storage_logging_on() {
		if ( ! isset( self::$_isStorageLoggingOn ) ) {
			self::$_isStorageLoggingOn = ( 1 == get_option( 'fs_storage_logger', 0 ) );
		}

		return self::$_isStorageLoggingOn;
	}

	/**
	 * Turns on/off database persistent debugging to capture
	 * multi-session logs to debug complex flows like
	 * plugin auto-deactivate on premium version activation.
	 *
	 * @todo   Check if Theme Check has issues with DB tables for themes.
	 *
	 * @author Vova Feldman (@svovaf)
	 * @since  1.2.1.6
	 *
	 * @param bool $is_on
	 *
	 * @return bool
	 */
	public static function _set_storage_logging( $is_on = true ) {
		global $wpdb;

		$table = "{$wpdb->prefix}fs_logger";

		if ( $is_on ) {
			/**
			 * Create logging table.
			 *
			 * NOTE:
			 *  dbDelta must use KEY and not INDEX for indexes.
			 *
			 * @link https://core.trac.wordpress.org/ticket/2695
			 */
			$result = $wpdb->query( "CREATE TABLE {$table} (
`id` BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
`process_id` INT UNSIGNED NOT NULL,
`user_name` VARCHAR(64) NOT NULL,
`logger` VARCHAR(128) NOT NULL,
`log_order` INT UNSIGNED NOT NULL,
`type` ENUM('log','info','warn','error') NOT NULL DEFAULT 'log',
`message` TEXT NOT NULL,
`file` VARCHAR(256) NOT NULL,
`line` INT UNSIGNED NOT NULL,
`function` VARCHAR(256) NOT NULL,
`request_type` ENUM('call','ajax','cron') NOT NULL DEFAULT 'call',
`request_url` VARCHAR(1024) NOT NULL,
`created` DECIMAL(16, 6) NOT NULL,
PRIMARY KEY (`id`),
KEY `process_id` (`process_id` ASC),
KEY `process_logger` (`process_id` ASC, `logger` ASC),
KEY `function` (`function` ASC),
KEY `type` (`type` ASC))" );
		} else {
			/**
			 * Drop logging table.
			 */
			$result = $wpdb->query( "DROP TABLE IF EXISTS $table;" );
		}

		if ( false !== $result ) {
			update_option( 'fs_storage_logger', ( $is_on ? 1 : 0 ) );
		}

		return ( false !== $result );
	}

	/**
	 * @author Vova Feldman (@svovaf)
	 * @since  1.2.1.6
	 *
	 * @param string $type
	 * @param string $message
	 * @param int $log_order
	 * @param array $caller
	 *
	 * @return false|int
	 */
	private function db_log(
		&$type,
		&$message,
		&$log_order,
		&$caller
	) {
		global $wpdb;

		$request_type = 'call';
		if ( defined( 'DOING_CRON' ) && DOING_CRON ) {
			$request_type = 'cron';
		} else if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
			$request_type = 'ajax';
		}

		$request_url = WP_FS__IS_HTTP_REQUEST ?
			$_SERVER['REQUEST_URI'] :
			'';

		return $wpdb->insert(
			"{$wpdb->prefix}fs_logger",
			array(
				'process_id'   => self::$_processID,
				'user_name'    => self::$_ownerName,
				'logger'       => $this->_id,
				'log_order'    => $log_order,
				'type'         => $type,
				'request_type' => $request_type,
				'request_url'  => $request_url,
				'message'      => $message,
				'file'         => isset( $caller['file'] ) ?
					substr( $caller['file'], self::$_abspathLength ) :
					'',
				'line'         => $caller['line'],
				'function'     => ( ! empty( $caller['class'] ) ? $caller['class'] . $caller['type'] : '' ) . $caller['function'],
				'created'      => microtime( true ),
			)
		);
	}

	/**
	 * Persistent DB logger columns.
	 *
	 * @var array
	 */
	private static $_log_columns = array(
		'id',
		'process_id',
		'user_name',
		'logger',
		'log_order',
		'type',
		'message',
		'file',
		'line',
		'function',
		'request_type',
		'request_url',
		'created',
	);

	/**
	 * Create DB logs query.
	 *
	 * @author Vova Feldman (@svovaf)
	 * @since  1.2.1.6
	 *
	 * @param bool $filters
	 * @param int $limit
	 * @param int $offset
	 * @param bool $order
	 * @param bool $escape_eol
	 *
	 * @return string
	 */
	private static function build_db_logs_query(
		$filters = false,
		$limit = 200,
		$offset = 0,
		$order = false,
		$escape_eol = false
	) {
		global $wpdb;

		$select = '*';

		if ( $escape_eol ) {
			$select = '';
			for ( $i = 0, $len = count( self::$_log_columns ); $i < $len; $i ++ ) {
				if ( $i > 0 ) {
					$select .= ', ';
				}

				if ( 'message' !== self::$_log_columns[ $i ] ) {
					$select .= self::$_log_columns[ $i ];
				} else {
					$select .= 'REPLACE(message , \'\n\', \' \') AS message';
				}
			}
		}

		$query = "SELECT {$select} FROM {$wpdb->prefix}fs_logger";
		if ( is_array( $filters ) ) {
			$criteria = array();

			if ( ! empty( $filters['type'] ) && 'all' !== $filters['type'] ) {
				$filters['type'] = strtolower( $filters['type'] );

				switch ( $filters['type'] ) {
					case 'warn_error':
						$criteria[] = array( 'col' => 'type', 'val' => array( 'warn', 'error' ) );
						break;
					case 'error':
					case 'warn':
						$criteria[] = array( 'col' => 'type', 'val' => $filters['type'] );
						break;
					case 'info':
					default:
						$criteria[] = array( 'col' => 'type', 'val' => array( 'info', 'log' ) );
						break;
				}
			}

			if ( ! empty( $filters['request_type'] ) ) {
				$filters['request_type'] = strtolower( $filters['request_type'] );

				if ( in_array( $filters['request_type'], array( 'call', 'ajax', 'cron' ) ) ) {
					$criteria[] = array( 'col' => 'request_type', 'val' => $filters['request_type'] );
				}
			}

			if ( ! empty( $filters['file'] ) ) {
				$criteria[] = array(
					'col' => 'file',
					'op'  => 'LIKE',
					'val' => '%' . esc_sql( $filters['file'] ),
				);
			}

			if ( ! empty( $filters['function'] ) ) {
				$criteria[] = array(
					'col' => 'function',
					'op'  => 'LIKE',
					'val' => '%' . esc_sql( $filters['function'] ),
				);
			}

			if ( ! empty( $filters['process_id'] ) && is_numeric( $filters['process_id'] ) ) {
				$criteria[] = array( 'col' => 'process_id', 'val' => $filters['process_id'] );
			}

			if ( ! empty( $filters['logger'] ) ) {
				$criteria[] = array(
					'col' => 'logger',
					'op'  => 'LIKE',
					'val' => '%' . esc_sql( $filters['logger'] ) . '%',
				);
			}

			if ( ! empty( $filters['message'] ) ) {
				$criteria[] = array(
					'col' => 'message',
					'op'  => 'LIKE',
					'val' => '%' . esc_sql( $filters['message'] ) . '%',
				);
			}

			if ( 0 < count( $criteria ) ) {
				$query .= "\nWHERE\n";

				$first = true;
				foreach ( $criteria as $c ) {
					if ( ! $first ) {
						$query .= "AND\n";
					}

					if ( is_array( $c['val'] ) ) {
						$operator = 'IN';

						for ( $i = 0, $len = count( $c['val'] ); $i < $len; $i ++ ) {
							$c['val'][ $i ] = "'" . esc_sql( $c['val'][ $i ] ) . "'";
						}

						$val = '(' . implode( ',', $c['val'] ) . ')';
					} else {
						$operator = ! empty( $c['op'] ) ? $c['op'] : '=';
						$val      = "'" . esc_sql( $c['val'] ) . "'";
					}

					$query .= "`{$c['col']}` {$operator} {$val}\n";

					$first = false;
				}
			}
		}

		if ( ! is_array( $order ) ) {
			$order = array(
				'col'   => 'id',
				'order' => 'desc'
			);
		}

		$query .= " ORDER BY {$order['col']} {$order['order']} LIMIT {$offset},{$limit}";

		return $query;
	}

	/**
	 * Load logs from DB.
	 *
	 * @author Vova Feldman (@svovaf)
	 * @since  1.2.1.6
	 *
	 * @param bool $filters
	 * @param int $limit
	 * @param int $offset
	 * @param bool $order
	 *
	 * @return object[]|null
	 */
	public static function load_db_logs(
		$filters = false,
		$limit = 200,
		$offset = 0,
		$order = false
	) {
		global $wpdb;

		$query = self::build_db_logs_query(
			$filters,
			$limit,
			$offset,
			$order
		);

		return $wpdb->get_results( $query );
	}

	/**
	 * Load logs from DB.
	 *
	 * @author Vova Feldman (@svovaf)
	 * @since  1.2.1.6
	 *
	 * @param bool $filters
	 * @param string $filename
	 * @param int $limit
	 * @param int $offset
	 * @param bool $order
	 *
	 * @return false|string File download URL or false on failure.
	 */
	public static function download_db_logs(
		$filters = false,
		$filename = '',
		$limit = 10000,
		$offset = 0,
		$order = false
	) {
		global $wpdb;

		$query = self::build_db_logs_query(
			$filters,
			$limit,
			$offset,
			$order,
			true
		);

		$upload_dir = wp_upload_dir();
		if ( empty( $filename ) ) {
			$filename = 'fs-logs-' . date( 'Y-m-d_H-i-s', WP_FS__SCRIPT_START_TIME ) . '.csv';
		}
		$filepath = rtrim( $upload_dir['path'], '/' ) . "/{$filename}";

		$query .= " INTO OUTFILE '{$filepath}' FIELDS TERMINATED BY '\t' ESCAPED BY '\\\\' OPTIONALLY ENCLOSED BY '\"' LINES TERMINATED BY '\\n'";

		$columns = '';
		for ( $i = 0, $len = count( self::$_log_columns ); $i < $len; $i ++ ) {
			if ( $i > 0 ) {
				$columns .= ', ';
			}

			$columns .= "'" . self::$_log_columns[ $i ] . "'";
		}

		$query = "SELECT {$columns} UNION ALL " . $query;

		$result = $wpdb->query( $query );

		if ( false === $result ) {
			return false;
		}

		return rtrim( $upload_dir['url'], '/' ) . '/' . $filename;
	}

	/**
	 * @author Vova Feldman (@svovaf)
	 * @since  1.2.1.6
	 *
	 * @param string $filename
	 *
	 * @return string
	 */
	public static function get_logs_download_url( $filename = '' ) {
		$upload_dir = wp_upload_dir();
		if ( empty( $filename ) ) {
			$filename = 'fs-logs-' . date( 'Y-m-d_H-i-s', WP_FS__SCRIPT_START_TIME ) . '.csv';
		}

		return rtrim( $upload_dir['url'], '/' ) . $filename;
	}

	#endregion
}