<?php
declare(strict_types=1);

namespace Unsupervised\Schedular\Registration;

class QuestionRepository {

	private string $table;

	public function __construct( private \wpdb $db ) {
		$this->table = $db->prefix . 'us_questions';
	}

	public function insert( Question $question ): int {
		$this->db->insert(
			$this->table,
			$this->columns( $question ) + [ 'created_at' => current_time( 'mysql' ) ],
			[ '%d', '%s', '%s', '%s', '%s', '%d', '%d', '%d', '%s' ]
		);

		return $this->db->insert_id;
	}

	public function update( int $id, Question $question ): bool {
		return false !== $this->db->update(
			$this->table,
			$this->columns( $question ),
			[ 'id' => $id ],
			[ '%d', '%s', '%s', '%s', '%s', '%d', '%d', '%d' ],
			[ '%d' ]
		);
	}

	/**
	 * Column values shared by insert and update (excludes created_at).
	 *
	 * @return array<string, mixed>
	 */
	private function columns( Question $question ): array {
		return [
			'offering_id' => $question->offeringId,
			'scope'       => $question->scope,
			'label'       => $question->label,
			'field_type'  => $question->fieldType,
			'options'     => null === $question->options ? null : (string) wp_json_encode( $question->options ),
			'is_required' => $question->isRequired ? 1 : 0,
			'sort_order'  => $question->sortOrder,
			'is_active'   => $question->isActive ? 1 : 0,
		];
	}

	/**
	 * Find questions for an offering, ordered for display.
	 *
	 * @return list<Question>
	 */
	public function findByOffering( int $offeringId, bool $activeOnly = false ): array {
		$sql    = 'SELECT * FROM %i WHERE offering_id = %d';
		$params = [ $this->table, $offeringId ];

		if ( $activeOnly ) {
			$sql     .= ' AND is_active = %d';
			$params[] = 1;
		}

		$sql .= ' ORDER BY sort_order ASC, id ASC';

		$rows = $this->db->get_results( $this->db->prepare( $sql, $params ) );

		return array_map( Question::fromRow( ... ), $rows ?? [] );
	}

	/**
	 * Find questions for a scope (e.g. account-signup), ordered for display.
	 *
	 * @return list<Question>
	 */
	public function findByScope( string $scope, bool $activeOnly = false ): array {
		$sql    = 'SELECT * FROM %i WHERE scope = %s';
		$params = [ $this->table, $scope ];

		if ( $activeOnly ) {
			$sql     .= ' AND is_active = %d';
			$params[] = 1;
		}

		$sql .= ' ORDER BY sort_order ASC, id ASC';

		$rows = $this->db->get_results( $this->db->prepare( $sql, $params ) );

		return array_map( Question::fromRow( ... ), $rows ?? [] );
	}

	public function findById( int $id ): ?Question {
		$row = $this->db->get_row(
			$this->db->prepare( 'SELECT * FROM %i WHERE id = %d', $this->table, $id )
		);

		return $row ? Question::fromRow( $row ) : null;
	}

	public function delete( int $id ): bool {
		return (bool) $this->db->delete(
			$this->table,
			[ 'id' => $id ],
			[ '%d' ]
		);
	}

	/**
	 * Relax `offering_id` to allow NULL for account-scope questions (which are
	 * not tied to an offering).
	 *
	 * The account-questions feature (v1.1.0) made the column nullable in the
	 * schema, but dbDelta does not reliably change a column from NOT NULL to
	 * NULL, so sites created before then keep the old NOT NULL column and reject
	 * account-scope inserts with "Column 'offering_id' cannot be null". This
	 * MODIFY is idempotent — re-applying the nullable definition is a no-op.
	 *
	 * @return bool True when the statement ran (or was already applied), false
	 *              if it could not be prepared or the query failed.
	 */
	public function ensureOfferingNullable(): bool {
		$sql = $this->db->prepare(
			'ALTER TABLE %i MODIFY offering_id BIGINT UNSIGNED NULL DEFAULT NULL',
			$this->table
		);

		return null !== $sql && false !== $this->db->query( $sql );
	}
}