<?php
/**
 * Product recipes.
 *
 * @package MadeCost
 */

namespace MadeCost;

defined( 'ABSPATH' ) || exit;

/**
 * One recipe per product, kept as product meta so it follows the product (duplicate, export, delete).
 */
final class Recipes {

	const META_KEY = '_madecost_recipe';

	/**
	 * Every recipe, keyed by product id (as a string).
	 *
	 * @return array[]
	 */
	public function all(): array {
		$query = new \WP_Query(
			array(
				'post_type'              => 'product',
				'post_status'            => array( 'publish', 'draft', 'pending', 'private', 'future' ),
				'posts_per_page'         => -1,
				'fields'                 => 'ids',
				'no_found_rows'          => true,
				'update_post_term_cache' => false,
				// Only the products that have a recipe.
				'meta_key'               => self::META_KEY, // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key
			)
		);
		$recipes = array();
		foreach ( $query->posts as $product_id ) {
			$recipe = $this->get( (int) $product_id );
			if ( null !== $recipe ) {
				$recipes[ (string) $product_id ] = $recipe;
			}
		}
		return $recipes;
	}

	/**
	 * The recipe of one product.
	 *
	 * @param int $product_id Product id.
	 * @return array|null
	 */
	public function get( int $product_id ): ?array {
		$raw = get_post_meta( $product_id, self::META_KEY, true );
		if ( ! is_string( $raw ) || '' === $raw ) {
			return null;
		}
		$recipe = json_decode( $raw, true );
		if ( ! is_array( $recipe ) || ! isset( $recipe['lines'] ) ) {
			return null;
		}
		$recipe['productId'] = (string) $product_id;
		return $recipe;
	}

	/**
	 * Save the recipe of a product (replaces the previous one).
	 *
	 * @param int   $product_id Product id.
	 * @param mixed $input      Decoded JSON.
	 * @return array Validator-style result; 'value' is the saved recipe. 'status' carries an HTTP code when not 422.
	 */
	public function save( int $product_id, $input ): array {
		$product = wc_get_product( $product_id );
		if ( ! $product || ! in_array( $product->get_type(), Catalog::SUPPORTED_TYPES, true ) || 'trash' === $product->get_status() ) {
			return array(
				'ok'     => false,
				'errors' => array( 'productId' => __( 'This is not a product MadeCost can handle (simple or variable products only).', 'madecost' ) ),
			);
		}
		if ( ! current_user_can( 'edit_post', $product_id ) ) {
			return array(
				'ok'     => false,
				'errors' => array( 'form' => __( 'You are not allowed to edit this product.', 'madecost' ) ),
				'status' => 403,
			);
		}

		$result = Validator::recipe( $input );
		if ( ! $result['ok'] ) {
			return $result;
		}
		$recipe = $result['value'];

		$known = array();
		foreach ( ( new Materials() )->all() as $material ) {
			$known[ $material['id'] ] = true;
		}
		foreach ( $recipe['lines'] as $line ) {
			if ( ! isset( $known[ $line['materialId'] ] ) ) {
				return array(
					'ok'     => false,
					'errors' => array( 'lines' => __( 'One of the materials no longer exists. Reload the page.', 'madecost' ) ),
				);
			}
		}

		$recipe['productTitle'] = $product->get_name();
		$recipe['updatedAt']    = gmdate( 'c' );
		// update_post_meta() strips slashes, so the JSON is slashed first.
		update_post_meta( $product_id, self::META_KEY, wp_slash( wp_json_encode( $recipe ) ) );
		$recipe['productId'] = (string) $product_id;

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

	/**
	 * Delete the recipe of a product.
	 *
	 * @param int $product_id Product id.
	 * @return bool False when there was no recipe.
	 */
	public function delete( int $product_id ): bool {
		if ( null === $this->get( $product_id ) ) {
			return false;
		}
		delete_post_meta( $product_id, self::META_KEY );
		return true;
	}

	/**
	 * In how many recipes each material is used.
	 *
	 * @param array[] $recipes Recipes, as returned by all().
	 * @return int[] Material id => number of recipes.
	 */
	public static function usage( array $recipes ): array {
		$usage = array();
		foreach ( $recipes as $recipe ) {
			foreach ( $recipe['lines'] as $line ) {
				$usage[ $line['materialId'] ] = ( $usage[ $line['materialId'] ] ?? 0 ) + 1;
			}
		}
		return $usage;
	}
}