<?php
namespace Careback;

defined( 'ABSPATH' ) || exit;

/**
 * The portal's field set, split into fields that cannot be removed and fields
 * the merchant may turn off.
 *
 * The mandatory set is a legal floor, not a preference: order number + email
 * identify the contract and gate the lookup; name and at least one item are
 * needed to act on the request. `reason` is deliberately absent from the
 * mandatory set — a statutory withdrawal is reason-free, so the reason field
 * can be hidden but must never be forced to be required.
 */
class Fields {

	const MANDATORY  = array( 'order_number', 'email', 'name', 'items' );
	const TOGGLEABLE = array( 'reason', 'comment', 'quantity' );

	public static function mandatory() {
		return self::MANDATORY;
	}

	public static function toggleable() {
		return self::TOGGLEABLE;
	}

	public static function is_enabled( $key, Settings $settings ) {
		if ( in_array( $key, self::MANDATORY, true ) ) {
			return true;
		}

		// A field a route cannot be filed without is shown whatever the toggle
		// says. The two settings live on different screens, and the pair
		// "required on this route" + "hidden on the form" is saveable — it left
		// the route refusing every request for a field the customer was never
		// shown, with nothing on either screen to say why.
		if ( self::required_by_a_route( $key, $settings ) ) {
			return true;
		}

		if ( in_array( $key, self::TOGGLEABLE, true ) ) {
			return (bool) $settings->get( 'field_' . $key, 1 );
		}
		return false;
	}

	/**
	 * True when some route cannot be filed without this field.
	 *
	 * Only the reason and the description can be required that way: the reason by
	 * the route's own setting, and the description alongside it on a route that
	 * asks for both (the one that reports a fault, which cannot be looked into
	 * without one).
	 */
	private static function required_by_a_route( $key, Settings $settings ) {
		if ( 'reason' !== $key && 'comment' !== $key ) {
			return false;
		}

		foreach ( Routes::keys() as $route ) {
			// A route the customer cannot reach requires nothing of the form.
			if ( ! Routes::offered( $route, $settings ) ) {
				continue;
			}

			if ( 'required' !== Reasons::mode( $route, $settings ) ) {
				continue;
			}

			if ( 'reason' === $key || Routes::property( $route, 'comment_with_reason' ) ) {
				return true;
			}
		}

		return false;
	}

	/** Flags handed to the front end so the script renders the same set. */
	public static function flags( Settings $settings ) {
		$out = array();
		foreach ( self::TOGGLEABLE as $key ) {
			$out[ $key ] = self::is_enabled( $key, $settings );
		}
		return $out;
	}
}