<?php
/**
 * Threshold profile value object.
 *
 * @package Kayvandra\MarginBeacon
 */

declare(strict_types=1);

namespace Kayvandra\MarginBeacon\Application\Threshold;

use Kayvandra\MarginBeacon\Support\Constants;
use InvalidArgumentException;

/**
 * Global (or category) threshold boundaries in threshold_scale units.
 */
final class ThresholdProfile {

	/**
	 * @var int
	 */
	private $critical_below;

	/**
	 * @var int
	 */
	private $high_below;

	/**
	 * @var int
	 */
	private $warning_below;

	/**
	 * @param int $critical_below Scaled critical boundary (>= 0).
	 * @param int $high_below     Scaled high boundary.
	 * @param int $warning_below  Scaled warning boundary (= Safe floor).
	 */
	public function __construct( $critical_below, $high_below, $warning_below ) {
		$critical_below = (int) $critical_below;
		$high_below     = (int) $high_below;
		$warning_below  = (int) $warning_below;

		if ( $critical_below < 0 ) {
			throw new InvalidArgumentException( 'critical_below must be >= 0' );
		}
		if ( $high_below <= $critical_below ) {
			throw new InvalidArgumentException( 'high_below must be > critical_below' );
		}
		if ( $warning_below <= $high_below ) {
			throw new InvalidArgumentException( 'warning_below must be > high_below' );
		}

		$this->critical_below = $critical_below;
		$this->high_below     = $high_below;
		$this->warning_below  = $warning_below;
	}

	/**
	 * Default Free/Pro global profile.
	 *
	 * @return ThresholdProfile
	 */
	public static function defaults() {
		$d = Constants::default_thresholds();
		return new self( $d['critical_below'], $d['high_below'], $d['warning_below'] );
	}

	/**
	 * Parse percent string with max 4 decimal places into scaled int.
	 *
	 * @param string $percent e.g. "10" or "3.5".
	 * @return int
	 */
	public static function percent_to_scaled( $percent ) {
		$percent = trim( (string) $percent );
		if ( ! preg_match( '/^\d+(\.\d{1,4})?$/', $percent ) ) {
			throw new InvalidArgumentException( 'threshold percent accepts max 4 decimal places' );
		}
		$parts = explode( '.', $percent, 2 );
		$whole = (int) $parts[0];
		$frac  = isset( $parts[1] ) ? str_pad( $parts[1], 4, '0', STR_PAD_RIGHT ) : '0000';
		return ( $whole * Constants::THRESHOLD_SCALE ) + (int) $frac;
	}

	/**
	 * @return array{critical_below:int,high_below:int,warning_below:int}
	 */
	public function to_array() {
		return array(
			'critical_below' => $this->critical_below,
			'high_below'     => $this->high_below,
			'warning_below'  => $this->warning_below,
		);
	}

	/**
	 * @return int
	 */
	public function critical_below() {
		return $this->critical_below;
	}

	/**
	 * @return int
	 */
	public function high_below() {
		return $this->high_below;
	}

	/**
	 * @return int
	 */
	public function warning_below() {
		return $this->warning_below;
	}
}