<?php
/**
 * Input, error and permission helpers shared by the abilities.
 *
 * @package SeebAbilities
 */

namespace SeebAbilities\Support;

use WP_Error;
use WP_Post;

defined( 'ABSPATH' ) || exit;

/**
 * Helpers.
 */
final class Helpers {

	/**
	 * Post types that can't be managed with the content abilities. Patterns, templates and
	 * navigation have their own abilities.
	 */
	const EXCLUDED_POST_TYPES = [
		'attachment',
		'nav_menu_item',
		'wp_block',
		'wp_template',
		'wp_template_part',
		'wp_navigation',
		'wp_global_styles',
		'wp_font_family',
		'wp_font_face',
	];

	/**
	 * Returns an integer input value.
	 *
	 * @param array  $input         Ability input.
	 * @param string $key           Input key.
	 * @param int    $default_value Value when the key is missing.
	 *
	 * @return int
	 */
	public static function int( array $input, string $key, int $default_value = 0 ): int {
		return isset( $input[ $key ] ) ? (int) $input[ $key ] : $default_value;
	}

	/**
	 * Returns a boolean input value.
	 *
	 * @param array  $input         Ability input.
	 * @param string $key           Input key.
	 * @param bool   $default_value Value when the key is missing.
	 *
	 * @return bool
	 */
	public static function bool( array $input, string $key, bool $default_value = false ): bool {
		return isset( $input[ $key ] ) ? rest_sanitize_boolean( $input[ $key ] ) : $default_value;
	}

	/**
	 * Returns a string input value.
	 *
	 * @param array  $input         Ability input.
	 * @param string $key           Input key.
	 * @param string $default_value Value when the key is missing.
	 *
	 * @return string
	 */
	public static function string( array $input, string $key, string $default_value = '' ): string {
		return isset( $input[ $key ] ) && is_scalar( $input[ $key ] ) ? (string) $input[ $key ] : $default_value;
	}

	/**
	 * Whether the input has a non-null value for the key.
	 *
	 * @param array  $input Ability input.
	 * @param string $key   Input key.
	 *
	 * @return bool
	 */
	public static function has( array $input, string $key ): bool {
		return isset( $input[ $key ] );
	}

	/**
	 * Returns per_page and page from the input.
	 *
	 * @param array $input           Ability input.
	 * @param int   $default_per_page Default page size.
	 * @param int   $max_per_page     Maximum page size.
	 *
	 * @return int[] [ per_page, page ]
	 */
	public static function pagination( array $input, int $default_per_page = 20, int $max_per_page = 100 ): array {

		$per_page = min( $max_per_page, max( 1, self::int( $input, 'per_page', $default_per_page ) ) );
		$page     = max( 1, self::int( $input, 'page', 1 ) );

		return [ $per_page, $page ];
	}

	/**
	 * Builds a paginated list result.
	 *
	 * @param array $items    Items on this page.
	 * @param int   $total    Total number of items.
	 * @param int   $per_page Page size.
	 * @param int   $page     Current page.
	 *
	 * @return array
	 */
	public static function list_result( array $items, int $total, int $per_page, int $page ): array {
		return [
			'items'       => array_values( $items ),
			'total'       => $total,
			'total_pages' => (int) ceil( $total / max( 1, $per_page ) ),
			'page'        => $page,
		];
	}

	/**
	 * Creates an error.
	 *
	 * @param string $code    Error code without prefix.
	 * @param string $message Error message.
	 * @param int    $status  HTTP status.
	 * @param array  $data    Additional error data.
	 *
	 * @return WP_Error
	 */
	public static function error( string $code, string $message, int $status = 400, array $data = [] ): WP_Error {
		return new WP_Error( 'seeb_abilities_' . $code, $message, array_merge( $data, [ 'status' => $status ] ) );
	}

	/**
	 * Creates a permission error.
	 *
	 * @param string $message Error message.
	 *
	 * @return WP_Error
	 */
	public static function forbidden( string $message = '' ): WP_Error {
		return self::error(
			'forbidden',
			'' !== $message ? $message : __( 'Sorry, you are not allowed to do that.', 'seeb-abilities' ),
			rest_authorization_required_code()
		);
	}

	/**
	 * Creates a not found error.
	 *
	 * @param string $message Error message.
	 *
	 * @return WP_Error
	 */
	public static function not_found( string $message ): WP_Error {
		return self::error( 'not_found', $message, 404 );
	}

	/**
	 * Post types that the content abilities work with: those shown in the REST API, without
	 * attachments, patterns, templates and other internal types.
	 *
	 * @return string[]
	 */
	public static function post_types(): array {
		return array_values( array_diff( get_post_types( [ 'show_in_rest' => true ] ), self::EXCLUDED_POST_TYPES ) );
	}

	/**
	 * Post types whose content the block abilities can read and edit: the content post types,
	 * patterns and navigation menus.
	 *
	 * @return string[]
	 */
	public static function block_post_types(): array {
		return array_merge( self::post_types(), [ 'wp_block', 'wp_navigation' ] );
	}

	/**
	 * Post types whose revisions can be listed and restored: the block post types, customized
	 * templates, global styles and Additional CSS.
	 *
	 * @return string[]
	 */
	public static function revision_post_types(): array {
		return array_merge( self::block_post_types(), [ 'wp_template', 'wp_template_part', 'wp_global_styles', 'custom_css' ] );
	}

	/**
	 * Saves the current state of a post as a revision if it has none yet. Core only stores the
	 * state after each update, so without this the first change could not be undone.
	 *
	 * @param int $post_id Post ID.
	 *
	 * @return void
	 */
	public static function ensure_revision( int $post_id ) {

		if ( wp_revisions_enabled( get_post( $post_id ) ) && ! wp_get_post_revisions( $post_id, [ 'fields' => 'ids' ] ) ) {
			wp_save_post_revision( $post_id );
		}
	}

	/**
	 * Whether the current user may see the content of a post. Password-protected posts need the
	 * edit_post capability, since abilities can't ask for the password.
	 *
	 * @param WP_Post $post Post.
	 *
	 * @return bool
	 */
	public static function can_read_content( WP_Post $post ): bool {
		return '' === $post->post_password || current_user_can( 'edit_post', $post->ID );
	}

	/**
	 * Returns a post of one of the given post types.
	 *
	 * @param int           $id    Post ID.
	 * @param string[]|null $types Allowed post types. Defaults to the content post types.
	 *
	 * @return WP_Post|WP_Error
	 */
	public static function get_post( int $id, ?array $types = null ) {

		$post = $id > 0 ? get_post( $id ) : null;

		if ( ! $post instanceof WP_Post || ! in_array( $post->post_type, $types ?? self::post_types(), true ) ) {
			/* translators: %d: post ID */
			return self::not_found( sprintf( __( 'No post found with ID %d.', 'seeb-abilities' ), $id ) );
		}

		return $post;
	}

	/**
	 * Permission check for an ability that works on one post.
	 *
	 * @param array         $input Ability input.
	 * @param string        $cap   Meta capability, e.g. "edit_post".
	 * @param string        $key   Input key that holds the post ID.
	 * @param string[]|null $types Allowed post types.
	 *
	 * @return true|WP_Error
	 */
	public static function check_post( array $input, string $cap, string $key = 'id', ?array $types = null ) {

		$post = self::get_post( self::int( $input, $key ), $types );

		if ( is_wp_error( $post ) ) {
			return $post;
		}

		return current_user_can( $cap, $post->ID ) ? true : self::forbidden();
	}

	/**
	 * Formats errors and warnings of a block validation as one message.
	 *
	 * @param array $issues Validation errors.
	 *
	 * @return string
	 */
	public static function issues_message( array $issues ): string {
		return implode(
			' ',
			array_map(
				function ( $issue ) {
					return sprintf( '[%s] %s', $issue['path'], $issue['message'] );
				},
				$issues
			)
		);
	}
}