<?php

declare( strict_types=1 );

namespace Senti\Roadmap;

use Senti\Shared\Infrastructure\RelationshipRepository;
use Senti\Shared\WordPress\Identifiers;
use wpdb;

/**
 * Domain service for managing roadmap items, stages, and linked feedback.
 */
final class RoadmapService {

	public function __construct(
		private readonly RelationshipRepository $relationships
	) {
	}

	/**
	 * Sets the stage and sorting position for a roadmap entry.
	 *
	 * @throws RoadmapException When the roadmap entry or stage is invalid.
	 */
	public function set_stage_and_position( int $roadmap_id, int $stage_id, int $position ): bool {
		if ( ! $this->is_post_type( $roadmap_id, Identifiers::POST_TYPE_ROADMAP ) ) {
			throw new RoadmapException( esc_html__( 'The roadmap entry does not exist.', 'senti-feedback' ) );
		}

		$stage = get_term( $stage_id, Identifiers::TAXONOMY_ROADMAP_STAGE );
		if ( $stage === null || is_wp_error( $stage ) ) {
			throw new RoadmapException( esc_html__( 'The roadmap stage does not exist.', 'senti-feedback' ) );
		}

		wp_set_object_terms( $roadmap_id, [ $stage_id ], Identifiers::TAXONOMY_ROADMAP_STAGE, false );
		update_post_meta( $roadmap_id, Identifiers::META_ROADMAP_POSITION, max( 0, $position ) );

		return true;
	}

	/**
	 * Links a feedback item to a roadmap entry.
	 *
	 * @throws RoadmapException When the roadmap entry or feedback item is invalid, or the relationship cannot be saved.
	 */
	public function relate_feedback( int $roadmap_id, int $feedback_id ): bool {
		if ( ! $this->is_post_type( $roadmap_id, Identifiers::POST_TYPE_ROADMAP ) || ! $this->is_post_type( $feedback_id, Identifiers::POST_TYPE_FEEDBACK ) ) {
			throw new RoadmapException( esc_html__( 'Roadmap entries can only link to existing feedback.', 'senti-feedback' ) );
		}

		if ( ! $this->relationships->relate( $feedback_id, $roadmap_id, 'feedback_roadmap' ) ) {
			throw new RoadmapException( esc_html__( 'The feedback relationship could not be saved.', 'senti-feedback' ) );
		}

		return true;
	}

	/**
	 * Replaces all linked feedback items for a roadmap entry.
	 *
	 * @param int[] $feedback_ids
	 * @throws RoadmapException When the roadmap entry or any feedback item is invalid, or saving fails.
	 */
	public function replace_feedback( int $roadmap_id, array $feedback_ids ): bool {
		if ( ! $this->is_post_type( $roadmap_id, Identifiers::POST_TYPE_ROADMAP ) ) {
			throw new RoadmapException( esc_html__( 'The roadmap entry does not exist.', 'senti-feedback' ) );
		}

		$feedback_ids = array_values( array_unique( array_filter( array_map( 'absint', $feedback_ids ), static fn ( int $id ): bool => $id > 0 ) ) );
		foreach ( $feedback_ids as $feedback_id ) {
			if ( ! $this->is_post_type( $feedback_id, Identifiers::POST_TYPE_FEEDBACK ) ) {
				throw new RoadmapException( esc_html__( 'Roadmap entries can only link to existing feedback.', 'senti-feedback' ) );
			}
		}

		$this->relationships->delete_by_target( $roadmap_id, 'feedback_roadmap' );
		foreach ( $feedback_ids as $feedback_id ) {
			$this->relate_feedback( $roadmap_id, $feedback_id );
		}

		return true;
	}

	/**
	 * Returns the feedback IDs linked to a roadmap entry.
	 *
	 * @return int[]
	 */
	public function feedback_ids( int $roadmap_id ): array {
		return $this->relationships->find_source_ids( $roadmap_id, 'feedback_roadmap', Identifiers::POST_TYPE_FEEDBACK );
	}

	/**
	 * Returns the roadmap IDs linked to a feedback item.
	 *
	 * @return int[]
	 */
	public function roadmap_ids( int $feedback_id ): array {
		return $this->relationships->find_target_ids( $feedback_id, 'feedback_roadmap', Identifiers::POST_TYPE_ROADMAP );
	}

	private function is_post_type( int $post_id, string $post_type ): bool {
		return get_post_type( $post_id ) === $post_type;
	}
}