<?php
/**
 * Relative weight score.
 *
 * @package Bloatwright
 */

namespace Bloatwright\Services;

/**
 * 0-100 composite, relative to the session maximum per dimension.
 */
class Scoring {

	/**
	 * Weights per dimension.
	 */
	const WEIGHTS = array(
		'php_ms'       => 0.40,
		'query_ms'     => 0.20,
		'blocking_kb'  => 0.20,
		'autoload_kb'  => 0.10,
		'cron_per_day' => 0.10,
	);

	/**
	 * Add 'weight' (0-100) and 'weight_parts' to each owner.
	 *
	 * @param array<string,array> $owners Owner summaries.
	 * @return array<string,array>
	 */
	public static function apply( array $owners ): array {
		$max = array();
		foreach ( self::WEIGHTS as $dim => $w ) {
			$max[ $dim ] = 0.0;
			foreach ( $owners as $o ) {
				if ( self::is_baseline( $o ) || ! empty( $o['excluded'] ) ) {
					continue; // Core/unknown and a plugin filtered out of the run never set the scale.
				}
				$max[ $dim ] = max( $max[ $dim ], (float) ( $o[ $dim ] ?? 0 ) );
			}
		}
		foreach ( $owners as $key => $o ) {
			$score = 0.0;
			$parts = array();
			foreach ( self::WEIGHTS as $dim => $w ) {
				$norm          = $max[ $dim ] > 0 && empty( $o['excluded'] ) ? min( 1.0, (float) ( $o[ $dim ] ?? 0 ) / $max[ $dim ] ) : 0.0;
				$parts[ $dim ] = round( $norm * $w * 100, 1 );
				$score        += $norm * $w;
			}
			$owners[ $key ]['weight']       = (int) round( $score * 100 );
			$owners[ $key ]['weight_parts'] = $parts;
		}
		uasort(
			$owners,
			static function ( $a, $b ) {
				$c = self::group( $a ) <=> self::group( $b );
				if ( 0 !== $c ) {
					return $c; // Plugins and themes first, then core/unknown, then a plugin filtered out of the run.
				}
				$c = $b['weight'] <=> $a['weight'];
				if ( 0 !== $c ) {
					return $c;
				}
				$c = ( $b['php_ms'] ?? 0 ) <=> ( $a['php_ms'] ?? 0 );
				return 0 !== $c ? $c : strcmp( (string) ( $a['key'] ?? '' ), (string) ( $b['key'] ?? '' ) );
			}
		);
		$rank = 0;
		foreach ( $owners as $key => $o ) {
			$owners[ $key ]['rank'] = empty( $o['excluded'] ) ? ++$rank : 0; // 0: not ranked.
		}
		return $owners;
	}

	/**
	 * Sort group: 0 plugins and themes, 1 core/unknown, 2 the plugin a "try without" run filtered out.
	 *
	 * @param array $o Owner summary.
	 */
	private static function group( array $o ): int {
		if ( ! empty( $o['excluded'] ) ) {
			return 2;
		}
		return self::is_baseline( $o ) ? 1 : 0;
	}

	/**
	 * Core and unknown rows are shown for context, never ranked against plugins.
	 *
	 * @param array $o Owner summary.
	 */
	public static function is_baseline( array $o ): bool {
		return in_array( (string) ( $o['type'] ?? '' ), array( 'core', 'unknown' ), true );
	}
}