<?php
/**
 * Per-board settings.
 *
 * @package FeatureRequestSystem
 */

namespace FeatureRequestSystem\Content;

defined( 'ABSPATH' ) || exit;

/**
 * Settings stored on each board. A board without saved settings uses the defaults.
 */
final class BoardSettings {

	/**
	 * Term meta holding the board's settings array.
	 */
	public const META = '_mwtfrs_board_settings';

	/**
	 * Setting: who may vote on the board's requests. One of ANYONE, LOGGED_IN or NOBODY.
	 */
	public const VOTING = 'voting';

	/**
	 * Setting: who may submit new requests to the board. One of ANYONE, LOGGED_IN or NOBODY.
	 */
	public const SUBMITTING = 'submitting';

	/**
	 * Setting: whether new requests wait for approval before they appear.
	 */
	public const MODERATION = 'moderation';

	/**
	 * Setting: ID of the page that shows the board, or 0 when it is not known yet.
	 */
	public const PAGE = 'page';

	/**
	 * Setting: term IDs of the categories that the board's requests can have. Empty means every category.
	 */
	public const CATEGORIES = 'categories';

	/**
	 * Everyone may take part, including visitors who are not logged in.
	 */
	public const ANYONE = 'anyone';

	/**
	 * Only logged-in users may take part. The default, so visitors can read but not vote or submit.
	 */
	public const LOGGED_IN = 'logged_in';

	/**
	 * Nobody may take part. The action is turned off for the board.
	 */
	public const NOBODY = 'nobody';

	/**
	 * Default value of every setting.
	 *
	 * @return array<string, string|bool|int|int[]>
	 */
	public static function defaults(): array {
		return [
			self::VOTING     => self::LOGGED_IN,
			self::SUBMITTING => self::LOGGED_IN,
			self::MODERATION => true,
			self::PAGE       => 0,
			self::CATEGORIES => [],
		];
	}

	/**
	 * Returns a board's settings, using the default for anything missing or invalid.
	 *
	 * @param int $board_id Board term ID. 0 returns the defaults.
	 * @return array<string, string|bool|int|int[]>
	 */
	public static function get( int $board_id ): array {
		$stored = $board_id ? get_term_meta( $board_id, self::META, true ) : [];

		return self::sanitize( is_array( $stored ) ? $stored : [], self::defaults() );
	}

	/**
	 * Who may vote on a board: ANYONE, LOGGED_IN or NOBODY.
	 *
	 * @param int $board_id Board term ID.
	 */
	public static function voting( int $board_id ): string {
		return (string) self::get( $board_id )[ self::VOTING ];
	}

	/**
	 * Who may submit requests to a board: ANYONE, LOGGED_IN or NOBODY.
	 *
	 * @param int $board_id Board term ID.
	 */
	public static function submitting( int $board_id ): string {
		return (string) self::get( $board_id )[ self::SUBMITTING ];
	}

	/**
	 * Whether a board's new requests wait for approval.
	 *
	 * @param int $board_id Board term ID.
	 */
	public static function moderated( int $board_id ): bool {
		return (bool) self::get( $board_id )[ self::MODERATION ];
	}

	/**
	 * URL of the page that shows a board, or '' when it is not known or no longer published.
	 *
	 * @param int $board_id Board term ID.
	 */
	public static function page_url( int $board_id ): string {
		$page_id = (int) self::get( $board_id )[ self::PAGE ];

		return $page_id && 'publish' === get_post_status( $page_id ) ? (string) get_permalink( $page_id ) : '';
	}

	/**
	 * The categories a board's requests can have, as term IDs. Empty means every category.
	 *
	 * Categories that were deleted since the board was saved are left out. A board whose
	 * chosen categories are all gone is no longer limited.
	 *
	 * @param int $board_id Board term ID.
	 * @return int[]
	 */
	public static function categories( int $board_id ): array {
		$chosen = (array) self::get( $board_id )[ self::CATEGORIES ];
		if ( ! $chosen ) {
			return [];
		}

		$existing = get_terms(
			[
				'taxonomy'   => CategoryTaxonomy::NAME,
				'include'    => $chosen,
				'hide_empty' => false,
				'fields'     => 'ids',
			]
		);

		return is_array( $existing ) ? array_map( 'intval', $existing ) : [];
	}

	/**
	 * Saves settings for a board. Settings not passed, and invalid values, leave the current value in place.
	 *
	 * @param int                  $board_id Board term ID.
	 * @param array<string, mixed> $settings Settings to change.
	 */
	public static function update( int $board_id, array $settings ): void {
		update_term_meta( $board_id, self::META, self::sanitize( $settings, self::get( $board_id ) ) );
	}

	/**
	 * Applies the valid values from $settings on top of $base. Unknown keys and invalid values are dropped.
	 *
	 * @param array<string, mixed>                 $settings Raw settings.
	 * @param array<string, string|bool|int|int[]> $base     Valid settings to start from.
	 * @return array<string, string|bool|int|int[]>
	 */
	private static function sanitize( array $settings, array $base ): array {
		$clean = $base;

		foreach ( [ self::VOTING, self::SUBMITTING ] as $key ) {
			if ( in_array( $settings[ $key ] ?? null, [ self::ANYONE, self::LOGGED_IN, self::NOBODY ], true ) ) {
				$clean[ $key ] = $settings[ $key ];
			}
		}

		if ( isset( $settings[ self::MODERATION ] ) && is_bool( $settings[ self::MODERATION ] ) ) {
			$clean[ self::MODERATION ] = $settings[ self::MODERATION ];
		}

		if ( isset( $settings[ self::PAGE ] ) && is_numeric( $settings[ self::PAGE ] ) ) {
			$clean[ self::PAGE ] = max( 0, (int) $settings[ self::PAGE ] );
		}

		if ( isset( $settings[ self::CATEGORIES ] ) && is_array( $settings[ self::CATEGORIES ] ) ) {
			$clean[ self::CATEGORIES ] = array_values( array_unique( array_filter( array_map( 'absint', $settings[ self::CATEGORIES ] ) ) ) );
		}

		return $clean;
	}
}