<?php

namespace WP_CLI\Profile;

class Logger {

	public $time                = 0;
	public $query_count         = 0;
	public $query_time          = 0;
	public $cache_hits          = 0;
	public $cache_misses        = 0;
	public $cache_ratio         = null;
	public $hook_count          = 0;
	public $hook_time           = 0;
	public $request_count       = 0;
	public $request_time        = 0;
	private $start_time         = null;
	private $query_offset       = null;
	private $cache_hit_offset   = null;
	private $cache_miss_offset  = null;
	private $hook_start_time    = null;
	private $hook_depth         = 0;
	private $request_start_time = null;

	private $definitions = array();

	public static $active_loggers = array();

	public function __construct( $definition = array() ) {
		foreach ( $definition as $k => $v ) {
			$this->definitions[ $k ] = $v;
		}
	}

	public function __get( $key ) {
		if ( isset( $this->definitions[ $key ] ) ) {
			return $this->definitions[ $key ];
		}

		return null;
	}

	public function __set( $key, $value ) {
		$this->definitions[ $key ] = $value;
	}

	public function __isset( $key ) {
		return isset( $this->definitions[ $key ] );
	}

	/**
	 * Start this logger
	 */
	public function start() {
		global $wpdb, $wp_object_cache;
		$this->start_time   = microtime( true );
		$this->query_offset = ! empty( $wpdb->queries ) ? count( $wpdb->queries ) : 0;
		$key                = array_search( $this, self::$active_loggers, true );

		if ( false === $key ) {
			self::$active_loggers[] = $this;
		}
		$this->cache_hit_offset  = ! empty( $wp_object_cache->cache_hits ) ? $wp_object_cache->cache_hits : 0;
		$this->cache_miss_offset = ! empty( $wp_object_cache->cache_misses ) ? $wp_object_cache->cache_misses : 0;
	}

	/**
	 * Whether or not the logger is running
	 */
	public function running() {
		return ! is_null( $this->start_time );
	}

	/**
	 * Stop this logger
	 */
	public function stop() {
		global $wpdb, $wp_object_cache;

		if ( ! is_null( $this->start_time ) ) {
			$this->time += microtime( true ) - $this->start_time;
		}
		if ( ! is_null( $this->query_offset ) && isset( $wpdb ) && ! empty( $wpdb->queries ) ) {

			$query_total_count = count( $wpdb->queries );

			for ( $i = $this->query_offset; $i < $query_total_count; $i++ ) {
				$this->query_time += $wpdb->queries[ $i ][1];
				++$this->query_count;
			}
		}

		if ( ! is_null( $this->cache_hit_offset ) && ! is_null( $this->cache_miss_offset ) && isset( $wp_object_cache ) ) {
			$cache_hits         = ! empty( $wp_object_cache->cache_hits ) ? $wp_object_cache->cache_hits : 0;
			$cache_misses       = ! empty( $wp_object_cache->cache_misses ) ? $wp_object_cache->cache_misses : 0;
			$this->cache_hits   = $cache_hits - $this->cache_hit_offset;
			$this->cache_misses = $cache_misses - $this->cache_miss_offset;
			$cache_total        = $this->cache_hits + $this->cache_misses;
			if ( $cache_total ) {
				$ratio             = ( $this->cache_hits / $cache_total ) * 100;
				$this->cache_ratio = round( $ratio, 2 ) . '%';
			}
		}

		$this->start_time        = null;
		$this->query_offset      = null;
		$this->cache_hit_offset  = null;
		$this->cache_miss_offset = null;
		$key                     = array_search( $this, self::$active_loggers, true );

		if ( false !== $key ) {
			unset( self::$active_loggers[ $key ] );
		}
	}

	/**
	 * Start this logger's hook timer
	 */
	public function start_hook_timer() {
		++$this->hook_count;
		// Timer already running means a subhook has been called
		if ( ! is_null( $this->hook_start_time ) ) {
			++$this->hook_depth;
		} else {
			$this->hook_start_time = microtime( true );
		}
	}

	/**
	 * Stop this logger's hook timer
	 */
	public function stop_hook_timer() {
		if ( $this->hook_depth ) {
			--$this->hook_depth;
		} else {
			if ( ! is_null( $this->hook_start_time ) ) {
				$this->hook_time += microtime( true ) - $this->hook_start_time;
			}
			$this->hook_start_time = null;
		}
	}

	/**
	 * Start this logger's request timer
	 */
	public function start_request_timer() {
		++$this->request_count;
		$this->request_start_time = microtime( true );
	}

	/**
	 * Stop this logger's request timer
	 */
	public function stop_request_timer() {
		if ( ! is_null( $this->request_start_time ) ) {
			$this->request_time += microtime( true ) - $this->request_start_time;
		}
		$this->request_start_time = null;
	}
}