<?php
/**
 * Plain-language explanations for findings.
 *
 * The wording lives in data-explainers.php. This class picks the entry that fits a finding and
 * fills in the few names it needs. A finding with no entry keeps its technical text.
 *
 * @package shouldcheck
 */

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

/**
 * Explanations.
 */
final class ShouldCheck_Explain {

	/**
	 * Words for how worried to be.
	 *
	 * @var array<string,string>
	 */
	const WORRY = array(
		'fine'    => 'Fine, just so you know',
		'look'    => 'Worth a look',
		'fix'     => 'Fix before you go on',
		'unknown' => 'Not checked yet',
	);

	/**
	 * The entries, loaded once.
	 *
	 * @return array<int,array<string,mixed>>
	 */
	public static function entries() {
		static $entries = null;
		if ( null === $entries ) {
			$entries = is_file( __DIR__ . '/data-explainers.php' ) ? (array) include __DIR__ . '/data-explainers.php' : array();
		}
		return $entries;
	}

	/**
	 * The explanation for a finding, or null when there is none.
	 *
	 * @param array $check A check: title, status, blocking, optional explain key and facts.
	 * @return array{noticed:string,why:string,worry:string,worry_label:string,do:string}|null
	 */
	public static function say( array $check ) {
		$title  = (string) ( $check['title'] ?? '' );
		$status = (string) ( $check['status'] ?? '' );
		$key    = (string) ( $check['explain'] ?? '' );
		foreach ( self::entries() as $e ) {
			if ( isset( $e['s'] ) && ! in_array( $status, (array) $e['s'], true ) ) {
				continue;
			}
			$hit = false;
			if ( '' !== $key && isset( $e['k'] ) ) {
				$hit = ( $key === $e['k'] );
			} elseif ( isset( $e['m'] ) ) {
				$hit = ( $title === $e['m'] );
			} elseif ( isset( $e['re'] ) ) {
				$hit = (bool) preg_match( $e['re'], $title );
			}
			if ( ! $hit ) {
				continue;
			}
			$vars  = self::vars( $check );
			$worry = (string) ( $e['worry'] ?? '' );
			if ( 'pass' === $status ) {
				$worry = '';
			} elseif ( 'note' === $status ) {
				$worry = 'fine';
			} elseif ( '' === $worry ) {
				$worry = 'warning' === $status ? 'fix' : ( 'review' === $status ? 'look' : ( 'note' === $status ? 'fine' : ( 'not_checked' === $status ? 'unknown' : '' ) ) );
			}
			return array(
				'noticed'     => strtr( (string) $e['noticed'], $vars ),
				'why'         => strtr( (string) ( $e['why'] ?? '' ), $vars ),
				'worry'       => $worry,
				'worry_label' => self::WORRY[ $worry ] ?? '',
				'do'          => strtr( (string) ( $e['do'] ?? '' ), $vars ),
			);
		}
		return null;
	}

	/**
	 * Placeholder values for a finding.
	 *
	 * @param array $check The check.
	 * @return array<string,string>
	 */
	private static function vars( array $check ) {
		$title   = (string) ( $check['title'] ?? '' );
		$facts   = (array) ( $check['facts'] ?? array() );
		$noun    = '';
		$plugins = '';
		if ( preg_match( '~^(WordPress|PHP|WooCommerce)\b~', $title, $m ) ) {
			$noun = $m[1];
		}
		$slug = false !== strpos( $title, ': ' ) ? trim( (string) substr( strrchr( $title, ':' ), 1 ), " \n\r\t\v\x00" ) : '';
		if ( ! empty( $facts['plugins'] ) ) {
			$names   = array_values( array_unique( array_map( 'strval', (array) $facts['plugins'] ) ) );
			$last    = count( $names ) > 1 ? array_pop( $names ) : '';
			$plugins = '' === $last ? $names[0] : implode( ', ', $names ) . ' and ' . $last;
		}
		return array(
			'{noun}'    => $noun,
			'{slug}'    => $slug,
			'{plugins}' => '' !== $plugins ? $plugins : 'Some of your plugins',
		);
	}
}