<?php

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014-2019 British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package    CodeIgniter
 * @author     CodeIgniter Dev Team
 * @copyright  2014-2019 British Columbia Institute of Technology (https://bcit.ca/)
 * @license    https://opensource.org/licenses/MIT	MIT License
 * @link       https://codeigniter.com
 * @since      Version 4.0.0
 * @filesource
 */

namespace CodeIgniter\Debug;

/**
 * Class Timer
 *
 * Provides a simple way to measure the amount of time
 * that elapses between two points.
 *
 * NOTE: All methods are static since the class is intended
 * to measure throughout an entire application's life cycle.
 *
 * @package CodeIgniter\Benchmark
 */
class Timer
{

	/**
	 * List of all timers.
	 *
	 * @var array
	 */
	protected $timers = [];

	//--------------------------------------------------------------------

	/**
	 * Starts a timer running.
	 *
	 * Multiple calls can be made to this method so that several
	 * execution points can be measured.
	 *
	 * @param string $name The name of this timer.
	 * @param float  $time Allows user to provide time.
	 *
	 * @return Timer
	 */
	public function start(string $name, float $time = null)
	{
		$this->timers[strtolower($name)] = [
			'start' => ! empty($time) ? $time : microtime(true),
			'end'   => null,
		];

		return $this;
	}

	//--------------------------------------------------------------------

	/**
	 * Stops a running timer.
	 *
	 * If the timer is not stopped before the timers() method is called,
	 * it will be automatically stopped at that point.
	 *
	 * @param string $name The name of this timer.
	 *
	 * @return Timer
	 */
	public function stop(string $name)
	{
		$name = strtolower($name);

		if (empty($this->timers[$name]))
		{
			throw new \RuntimeException('Cannot stop timer: invalid name given.');
		}

		$this->timers[$name]['end'] = microtime(true);

		return $this;
	}

	//--------------------------------------------------------------------

	/**
	 * Returns the duration of a recorded timer.
	 *
	 * @param string  $name     The name of the timer.
	 * @param integer $decimals Number of decimal places.
	 *
	 * @return null|float       Returns null if timer exists by that name.
	 *                          Returns a float representing the number of
	 *                          seconds elapsed while that timer was running.
	 */
	public function getElapsedTime(string $name, int $decimals = 4)
	{
		$name = strtolower($name);

		if (empty($this->timers[$name]))
		{
			return null;
		}

		$timer = $this->timers[$name];

		if (empty($timer['end']))
		{
			$timer['end'] = microtime(true);
		}

		return (float) number_format($timer['end'] - $timer['start'], $decimals);
	}

	//--------------------------------------------------------------------

	/**
	 * Returns the array of timers, with the duration pre-calculated for you.
	 *
	 * @param integer $decimals Number of decimal places
	 *
	 * @return array
	 */
	public function getTimers(int $decimals = 4): array
	{
		$timers = $this->timers;

		foreach ($timers as &$timer)
		{
			if (empty($timer['end']))
			{
				$timer['end'] = microtime(true);
			}

			$timer['duration'] = (float) number_format($timer['end'] - $timer['start'], $decimals);
		}

		return $timers;
	}

	//--------------------------------------------------------------------

	/**
	 * Checks whether or not a timer with the specified name exists.
	 *
	 * @param string $name
	 *
	 * @return boolean
	 */
	public function has(string $name): bool
	{
		return array_key_exists(strtolower($name), $this->timers);
	}

	//--------------------------------------------------------------------
}