<?php
/**
 * Checksums of one plugin version from downloads.wordpress.org (N§A2).
 *
 * - slug, version string
 * - files array<string, array{md5:string[], sha256:string[]}>  path relative to the plugin
 *   folder => accepted sums. The API gives a string OR a list; both become lists here.
 *   A file conforms when its sum is one of the values; sha256 is compared when the
 *   entry has one and the FileEntry carries one, md5 otherwise (WP-CLI behaviour).
 *
 * @package Timaub\AfterHackChecklist
 */

namespace Timaub\AfterHackChecklist\Domain;

final class PluginChecksums {
	/** @var string */
	public $slug = '';
	/** @var string */
	public $version = '';
	/** @var array<string, array{md5:string[], sha256:string[]}> */
	public $files = array();

	/**
	 * @param mixed $decoded json_decode( $body, true ) of a 200 answer.
	 * @return self|null null when the shape is not the documented one.
	 */
	public static function fromApiResponse( $decoded, string $slug, string $version ) {
		if ( ! is_array( $decoded ) || ! isset( $decoded['files'] ) || ! is_array( $decoded['files'] ) ) {
			return null;
		}
		$p          = new self();
		$p->slug    = $slug;
		$p->version = $version;
		foreach ( $decoded['files'] as $path => $sums ) {
			if ( ! is_array( $sums ) ) {
				return null;
			}
			$p->files[ (string) $path ] = array(
				'md5'    => self::toList( isset( $sums['md5'] ) ? $sums['md5'] : array() ),
				'sha256' => self::toList( isset( $sums['sha256'] ) ? $sums['sha256'] : array() ),
			);
		}
		return $p;
	}

	/** @param mixed $v String or list. */
	private static function toList( $v ): array {
		$out = array();
		foreach ( (array) $v as $s ) {
			if ( is_string( $s ) && '' !== $s ) {
				$out[] = strtolower( $s );
			}
		}
		return $out;
	}

	public function has( string $relPath ): bool {
		return isset( $this->files[ $relPath ] );
	}

	/**
	 * @param string      $relPath Path relative to the plugin folder, present in files.
	 * @param string|null $md5     File md5.
	 * @param string|null $sha256  File sha256.
	 * @return array{0:bool|null,1:string} conforms (null = nothing comparable on one side), algorithm used.
	 */
	public function compare( string $relPath, $md5, $sha256 ): array {
		$entry = $this->files[ $relPath ];
		if ( $entry['sha256'] && null !== $sha256 ) {
			return array( in_array( strtolower( $sha256 ), $entry['sha256'], true ), 'sha256' );
		}
		if ( ! $entry['md5'] || null === $md5 ) {
			return array( null, 'md5' );
		}
		return array( in_array( strtolower( $md5 ), $entry['md5'], true ), 'md5' );
	}

	public function toArray(): array {
		return array(
			'slug'    => $this->slug,
			'version' => $this->version,
			'files'   => $this->files,
		);
	}

	public static function fromArray( array $a ): self {
		$p          = new self();
		$p->slug    = (string) $a['slug'];
		$p->version = (string) $a['version'];
		$p->files   = (array) $a['files'];
		return $p;
	}
}