<?php
/**
 * Raw materials.
 *
 * @package MadeCost
 */

namespace MadeCost;

defined( 'ABSPATH' ) || exit;

/**
 * The merchant's materials (wax, fabric, boxes...), kept in one option that is not loaded on every request.
 */
final class Materials {

	const OPTION = 'madecost_materials';

	/**
	 * All materials, sorted by name without regard to case.
	 *
	 * @return array[]
	 */
	public function all(): array {
		$stored = get_option( self::OPTION, array() );
		$list   = is_array( $stored ) ? array_values( array_filter( $stored, 'is_array' ) ) : array();
		usort(
			$list,
			static function ( $a, $b ) {
				return strcmp( self::fold( (string) ( $a['name'] ?? '' ) ), self::fold( (string) ( $b['name'] ?? '' ) ) );
			}
		);
		return $list;
	}

	/**
	 * One material by id.
	 *
	 * @param string $id Material id.
	 * @return array|null
	 */
	public function get( string $id ): ?array {
		foreach ( $this->all() as $material ) {
			if ( ( $material['id'] ?? '' ) === $id ) {
				return $material;
			}
		}
		return null;
	}

	/**
	 * Create a material, or update it when $id is given. Names are unique, ignoring case.
	 *
	 * @param mixed       $input Decoded JSON.
	 * @param string|null $id    Id of the material to update.
	 * @return array Validator-style result; 'value' is the saved material.
	 */
	public function save( $input, ?string $id = null ): array {
		$result = Validator::material( $input );
		if ( ! $result['ok'] ) {
			return $result;
		}
		$value = $result['value'];
		$list  = $this->all();

		if ( null !== $id && null === $this->get( $id ) ) {
			return array(
				'ok'     => false,
				'errors' => array( 'form' => __( 'This material no longer exists.', 'madecost' ) ),
				'status' => 404,
			);
		}
		foreach ( $list as $other ) {
			if ( ( $other['id'] ?? '' ) !== $id && self::fold( (string) $other['name'] ) === self::fold( $value['name'] ) ) {
				return array(
					'ok'     => false,
					'errors' => array( 'name' => __( 'A material with this name already exists.', 'madecost' ) ),
				);
			}
		}

		$record = $value + array(
			'id'        => $id ?? wp_generate_uuid4(),
			'updatedAt' => gmdate( 'c' ),
		);
		$found  = false;
		foreach ( $list as $index => $existing ) {
			if ( ( $existing['id'] ?? '' ) === $record['id'] ) {
				$list[ $index ] = $record;
				$found          = true;
			}
		}
		if ( ! $found ) {
			$list[] = $record;
		}
		update_option( self::OPTION, array_values( $list ), false );

		return array(
			'ok'    => true,
			'value' => $record,
		);
	}

	/**
	 * Delete a material that no recipe uses.
	 *
	 * @param string $id   Material id.
	 * @param int    $used In how many recipes the material is used.
	 * @return array array( 'ok' => true ) or array( 'ok' => false, 'reason' => 'not_found'|'in_use', 'recipes' => int ).
	 */
	public function delete( string $id, int $used ): array {
		if ( null === $this->get( $id ) ) {
			return array(
				'ok'     => false,
				'reason' => 'not_found',
			);
		}
		if ( $used > 0 ) {
			return array(
				'ok'      => false,
				'reason'  => 'in_use',
				'recipes' => $used,
			);
		}
		$list = array_values(
			array_filter(
				$this->all(),
				static function ( $material ) use ( $id ) {
					return ( $material['id'] ?? '' ) !== $id;
				}
			)
		);
		update_option( self::OPTION, $list, false );
		return array( 'ok' => true );
	}

	/**
	 * Lower-case form used to compare names.
	 *
	 * @param string $text Text.
	 */
	private static function fold( string $text ): string {
		return function_exists( 'mb_strtolower' ) ? mb_strtolower( $text ) : strtolower( $text );
	}
}