<?php
/**
 * Agent selection step.
 *
 * @package Bookline
 */

declare( strict_types=1 );

namespace Bookline\Domain\Steps\Core;

use Bookline\Domain\Steps\BookingSession;
use Bookline\Domain\Steps\StepDescriptor;
use Bookline\Domain\Steps\ValidationResult;

/**
 * Choose a staff member ("any" permitted) — skipped when ≤1 eligible.
 *
 * @since 0.1.0
 */
final class AgentStep extends AbstractStep {

	/**
	 * Step name.
	 */
	public function name(): string {
		return 'agent';
	}

	/**
	 * Progress label.
	 */
	public function label(): string {
		return 'Staff';
	}

	/**
	 * Front-end component key.
	 */
	protected function component(): string {
		return 'agent_picker';
	}

	/**
	 * Whether the step should be skipped.
	 *
	 * @param BookingSession $session Session.
	 */
	public function should_skip( BookingSession $session ): bool {
		return $session->form()->eligible_agent_count() <= 1;
	}

	/**
	 * Build the step descriptor.
	 *
	 * @param BookingSession $session Session.
	 */
	public function descriptor( BookingSession $session ): StepDescriptor {
		return $this->build_descriptor(
			$session,
			[ 'eligible_count' => $session->form()->eligible_agent_count() ],
			[
				[
					'key'      => 'agent_id',
					'type'     => 'integer',
					'required' => false,
				],
				[
					'key'      => 'any_agent',
					'type'     => 'boolean',
					'required' => false,
				],
			]
		);
	}

	/**
	 * Validate submitted input.
	 *
	 * @param BookingSession       $session Session.
	 * @param array<string, mixed> $input   Payload.
	 */
	public function validate( BookingSession $session, array $input ): ValidationResult {
		if ( $this->should_skip( $session ) ) {
			return ValidationResult::ok();
		}
		$any = isset( $input['any_agent'] ) && true === $input['any_agent'];
		$id  = $this->positive_int( $input, 'agent_id' );
		if ( ! $any && null === $id ) {
			return ValidationResult::invalid( [ 'agent_id' => 'Please choose a staff member or any available.' ] );
		}
		return ValidationResult::ok();
	}

	/**
	 * Apply validated input.
	 *
	 * @param BookingSession       $session Session.
	 * @param array<string, mixed> $input   Payload.
	 */
	public function apply( BookingSession $session, array $input ): BookingSession {
		$any = isset( $input['any_agent'] ) && true === $input['any_agent'];
		$id  = $any ? null : $this->positive_int( $input, 'agent_id' );
		return $session->with_draft( $session->draft()->with_agent( $id, $any ) );
	}
}