<?php

namespace Automattic\WooCommerce\Blocks\AIContent;

use Automattic\WooCommerce\Blocks\AI\Connection;
use WP_Error;

/**
 * Pattern Images class.
 *
 * @internal
 */
class UpdateProducts {

	/**
	 * The dummy products.
	 */
	const DUMMY_PRODUCTS = [
		[
			'title'       => 'Vintage Typewriter',
			'image'       => 'assets/images/pattern-placeholders/writing-typing-keyboard-technology-white-vintage.jpg',
			'description' => 'A hit spy novel or a love letter? Anything you type using this vintage typewriter from the 20s is bound to make a mark.',
			'price'       => 90,
		],
		[
			'title'       => 'Leather-Clad Leisure Chair',
			'image'       => 'assets/images/pattern-placeholders/table-wood-house-chair-floor-window.jpg',
			'description' => 'Sit back and relax in this comfy designer chair. High-grain leather and steel frame add luxury to your your leisure.',
			'price'       => 249,
		],
		[
			'title'       => 'Black and White',
			'image'       => 'assets/images/pattern-placeholders/white-black-black-and-white-photograph-monochrome-photography.jpg',
			'description' => 'This 24" x 30" high-quality print just exudes summer. Hang it on the wall and forget about the world outside.',
			'price'       => 115,
		],
		[
			'title'       => '3-Speed Bike',
			'image'       => 'assets/images/pattern-placeholders/road-sport-vintage-wheel-retro-old.jpg',
			'description' => 'Zoom through the streets on this premium 3-speed bike. Manufactured and assembled in Germany in the 80s.',
			'price'       => 115,
		],
		[
			'title'       => 'Hi-Fi Headphones',
			'image'       => 'assets/images/pattern-placeholders/man-person-music-black-and-white-white-photography.jpg',
			'description' => 'Experience your favorite songs in a new way with these premium hi-fi headphones.',
			'price'       => 125,
		],
		[
			'title'       => 'Retro Glass Jug (330 ml)',
			'image'       => 'assets/images/pattern-placeholders/drinkware-liquid-tableware-dishware-bottle-fluid.jpg',
			'description' => 'Thick glass and a classic silhouette make this jug a must-have for any retro-inspired kitchen.',
			'price'       => 115,
		],
	];

	/**
	 * Generate AI content and assign AI-managed images to Products.
	 *
	 * @param Connection      $ai_connection The AI connection.
	 * @param string|WP_Error $token The JWT token.
	 * @param array|WP_Error  $images The array of images.
	 * @param string          $business_description The business description.
	 *
	 * @return array|WP_Error The generated content for the products. An error if the content could not be generated.
	 */
	public function generate_content( $ai_connection, $token, $images, $business_description ) {
		if ( is_wp_error( $token ) ) {
			return $token;
		}

		$images = ContentProcessor::verify_images( $images, $ai_connection, $token, $business_description );

		if ( is_wp_error( $images ) ) {
			return $images;
		}

		if ( empty( $business_description ) ) {
			return new \WP_Error( 'missing_business_description', __( 'No business description provided for generating AI content.', 'woocommerce' ) );
		}

		$dummy_products_to_update = $this->fetch_dummy_products_to_update();

		if ( is_wp_error( $dummy_products_to_update ) ) {
			return $dummy_products_to_update;
		}

		if ( empty( $dummy_products_to_update ) ) {
			return array(
				'product_content' => array(),
			);
		}

		$products_information_list = $this->assign_ai_selected_images_to_dummy_products( $dummy_products_to_update, $images['images'] );

		return $this->assign_ai_generated_content_to_dummy_products( $ai_connection, $token, $products_information_list, $business_description, $images['search_term'] );
	}

	/**
	 * Return all dummy products that were not modified by the store owner.
	 *
	 * @return array|WP_Error An array with the dummy products that need to have their content updated by AI.
	 */
	public function fetch_dummy_products_to_update() {
		$real_products       = $this->fetch_product_ids();
		$real_products_count = count( $real_products );

		if ( is_array( $real_products ) && $real_products_count > 6 ) {
			return array(
				'product_content' => array(),
			);
		}

		$dummy_products       = $this->fetch_product_ids( 'dummy' );
		$dummy_products_count = count( $dummy_products );
		$products_to_create   = max( 0, 6 - $real_products_count - $dummy_products_count );
		while ( $products_to_create > 0 ) {
			$this->create_new_product( self::DUMMY_PRODUCTS[ $products_to_create - 1 ] );
			--$products_to_create;
		}

		// Identify dummy products that need to have their content updated.
		$dummy_products_ids = $this->fetch_product_ids( 'dummy' );
		if ( ! is_array( $dummy_products_ids ) ) {
			return new \WP_Error( 'failed_to_fetch_dummy_products', __( 'Failed to fetch dummy products.', 'woocommerce' ) );
		}

		$dummy_products = array_map(
			function ( $product ) {
				return wc_get_product( $product->ID );
			},
			$dummy_products_ids
		);

		$dummy_products_to_update = [];
		foreach ( $dummy_products as $dummy_product ) {
			if ( ! $dummy_product instanceof \WC_Product ) {
				continue;
			}

			$should_update_dummy_product = $this->should_update_dummy_product( $dummy_product );

			if ( $should_update_dummy_product ) {
				$dummy_products_to_update[] = $dummy_product;
			}
		}

		return $dummy_products_to_update;
	}

	/**
	 * Verify if the dummy product should have its content generated and managed by AI.
	 *
	 * @param \WC_Product $dummy_product The dummy product.
	 *
	 * @return bool
	 */
	public function should_update_dummy_product( $dummy_product ): bool {
		$current_product_hash     = $this->get_hash_for_product( $dummy_product );
		$ai_modified_product_hash = $this->get_hash_for_ai_modified_product( $dummy_product );

		$date_created  = $dummy_product->get_date_created();
		$date_modified = $dummy_product->get_date_modified();

		if ( ! $date_created instanceof \WC_DateTime || ! $date_modified instanceof \WC_DateTime ) {
			return false;
		}

		$formatted_date_created  = $dummy_product->get_date_created()->date( 'Y-m-d H:i:s' );
		$formatted_date_modified = $dummy_product->get_date_modified()->date( 'Y-m-d H:i:s' );

		$timestamp_created  = strtotime( $formatted_date_created );
		$timestamp_modified = strtotime( $formatted_date_modified );
		$timestamp_current  = time();

		$dummy_product_recently_modified = abs( $timestamp_current - $timestamp_modified ) < 10;
		$dummy_product_not_modified      = abs( $timestamp_modified - $timestamp_created ) < 60;

		if ( $current_product_hash === $ai_modified_product_hash || $dummy_product_not_modified || $dummy_product_recently_modified ) {
			return true;
		}

		return false;
	}

	/**
	 * Creates a new product and assigns the _headstart_post meta to it.
	 *
	 * @param array $product_data The product data.
	 *
	 * @return bool|int|\WP_Error
	 */
	public function create_new_product( $product_data ) {
		$product          = new \WC_Product();
		$image_src        = plugins_url( $product_data['image'], dirname( __DIR__, 2 ) );
		$image_alt        = $product_data['title'];
		$product_image_id = $this->product_image_upload( $product->get_id(), $image_src, $image_alt );

		$saved_product = $this->product_update( $product, $product_image_id, $product_data['title'], $product_data['description'], $product_data['price'] );

		if ( is_wp_error( $saved_product ) ) {
			return $saved_product;
		}

		return update_post_meta( $saved_product, '_headstart_post', true );
	}

	/**
	 * Return all existing products that have the _headstart_post meta assigned to them.
	 *
	 * @param string $type The type of products to fetch.
	 *
	 * @return array|null
	 */
	public function fetch_product_ids( string $type = 'user_created' ) {
		global $wpdb;

		if ( 'user_created' === $type ) {
			return $wpdb->get_results( $wpdb->prepare( "SELECT ID FROM {$wpdb->posts} WHERE ID NOT IN ( SELECT p.ID FROM {$wpdb->posts} p JOIN {$wpdb->postmeta} pm ON p.ID = pm.post_id WHERE pm.meta_key = %s AND p.post_type = 'product' AND p.post_status = 'publish' ) AND post_type = 'product' AND post_status = 'publish' LIMIT 6", '_headstart_post' ) );
		}

		return $wpdb->get_results( $wpdb->prepare( "SELECT p.ID FROM {$wpdb->posts} p JOIN {$wpdb->postmeta} pm ON p.ID = pm.post_id WHERE pm.meta_key = %s AND p.post_type = 'product' AND p.post_status = 'publish'", '_headstart_post' ) );
	}

	/**
	 * Return the hash for a product based on its name, description and image_id.
	 *
	 * @param \WC_Product $product The product.
	 *
	 * @return false|string
	 */
	public function get_hash_for_product( $product ) {
		if ( ! $product instanceof \WC_Product ) {
			return false;
		}

		return md5( $product->get_name() . $product->get_description() . $product->get_image_id() );
	}

	/**
	 * Return the hash for a product that had its content AI-generated.
	 *
	 * @param \WC_Product $product The product.
	 *
	 * @return false|mixed
	 */
	public function get_hash_for_ai_modified_product( $product ) {
		if ( ! $product instanceof \WC_Product ) {
			return false;
		}

		return get_post_meta( $product->get_id(), '_ai_generated_content', true );
	}

	/**
	 * Create a hash with the AI-generated content and save it as a meta for the product.
	 *
	 * @param \WC_Product $product The product.
	 *
	 * @return bool|int
	 */
	public function create_hash_for_ai_modified_product( $product ) {
		if ( ! $product instanceof \WC_Product ) {
			return false;
		}

		$content = $this->get_hash_for_product( $product );

		return update_post_meta( $product->get_id(), '_ai_generated_content', $content );
	}

	/**
	 * Update the product content with the AI-generated content.
	 *
	 * @param array $ai_generated_product_content The AI-generated product content.
	 *
	 * @return void|WP_Error
	 */
	public function update_product_content( $ai_generated_product_content ) {
		if ( ! isset( $ai_generated_product_content['product_id'] ) ) {
			return;
		}

		$product = wc_get_product( $ai_generated_product_content['product_id'] );

		if ( ! $product instanceof \WC_Product ) {
			return;
		}

		if ( ! isset( $ai_generated_product_content['image']['src'] ) || ! isset( $ai_generated_product_content['image']['alt'] ) || ! isset( $ai_generated_product_content['title'] ) || ! isset( $ai_generated_product_content['description'] ) ) {
			return;
		}

		$product_image_id = $this->product_image_upload( $product->get_id(), $ai_generated_product_content['image']['src'], $ai_generated_product_content['image']['alt'] );

		$this->product_update( $product, $product_image_id, $ai_generated_product_content['title'], $ai_generated_product_content['description'], $ai_generated_product_content['price'] );
	}

	/**
	 * Upload the image for the product.
	 *
	 * @param int    $product_id The product ID.
	 * @param string $image_src The image source.
	 * @param string $image_alt The image alt.
	 *
	 * @return int|string|WP_Error
	 */
	private function product_image_upload( $product_id, $image_src, $image_alt ) {
		require_once ABSPATH . 'wp-admin/includes/media.php';
		require_once ABSPATH . 'wp-admin/includes/file.php';
		require_once ABSPATH . 'wp-admin/includes/image.php';

		// Since the media_sideload_image function is expensive and can take longer to complete
		// the process of downloading the external image and uploading it to the media library,
		// here we are increasing the time limit to avoid any issues.
		set_time_limit( 150 );
		wp_raise_memory_limit( 'image' );

		return media_sideload_image( $image_src, $product_id, $image_alt, 'id' );
	}

	/**
	 * Assigns the default content for the products.
	 *
	 * @param array $dummy_products_to_update The dummy products to update.
	 * @param array $ai_selected_images The images' information.
	 *
	 * @return array[]
	 */
	public function assign_ai_selected_images_to_dummy_products( $dummy_products_to_update, $ai_selected_images ) {
		$products_information_list = [];
		$dummy_products_count      = count( $dummy_products_to_update );
		for ( $i = 0; $i < $dummy_products_count; $i++ ) {
			$image_src = $ai_selected_images[ $i ]['URL'] ?? '';

			if ( wc_is_valid_url( $image_src ) ) {
				$image_src = ContentProcessor::adjust_image_size( $image_src, 'products' );
			}

			$image_alt = $ai_selected_images[ $i ]['title'] ?? '';

			$products_information_list[] = [
				'title'       => 'A product title',
				'description' => 'A product description',
				'price'       => 'The product price',
				'image'       => [
					'src' => $image_src,
					'alt' => $image_alt,
				],
				'product_id'  => $dummy_products_to_update[ $i ]->get_id(),
			];
		}

		return $products_information_list;
	}

	/**
	 * Generate the product content.
	 *
	 * @param Connection $ai_connection The AI connection.
	 * @param string     $token The JWT token.
	 * @param array      $products_information_list The products information list.
	 * @param string     $business_description The business description.
	 * @param string     $search_term The search term.
	 *
	 * @return array|int|string|\WP_Error
	 */
	public function assign_ai_generated_content_to_dummy_products( $ai_connection, $token, $products_information_list, $business_description, $search_term ) {
		$business_description = ContentProcessor::summarize_business_description( $business_description, $ai_connection, $token, 100 );

		if ( is_wp_error( $business_description ) ) {
			return $business_description;
		}

		$prompts = [];
		foreach ( $products_information_list as $product_information ) {
			if ( ! empty( $product_information['image']['alt'] ) ) {
				$prompts[] = sprintf( 'Considering that you are the owner of a store with the following description "%s", create the title for a product that is related to "%s" and to an image described as "%s". Do not include any adjectives or descriptions of the qualities of the product and always refer to objects or services, not humans.', $business_description, $search_term, $product_information['image']['alt'] );
			} else {
				$prompts[] = sprintf( 'You are the owner of a business described as: "%s". Create the title for a product that could be sold on your store. Do not include any adjectives or descriptions of the qualities of the product and always refer to objects or services, not humans.', $business_description );
			}
		}

		$expected_results_format = [];
		foreach ( $products_information_list as $index => $product ) {
			$expected_results_format[ $index ] = [
				'title' => '',
				'price' => '',
			];
		}

		$formatted_prompt = sprintf(
			"Generate two-words titles and price for products using the following prompts for each one of them: '%s'. Ensure each entry is unique and does not repeat the given examples. It should be a number and it's not too low or too high for the corresponding product title being advertised. Convert the price to this currency: '%s'. Do not include backticks or the word json in the response. Here's an example of the expected output format in JSON: '%s'.",
			wp_json_encode( $prompts ),
			get_woocommerce_currency(),
			wp_json_encode( $expected_results_format )
		);

		$ai_request_retries = 0;
		$success            = false;
		while ( $ai_request_retries < 5 && ! $success ) {
			++$ai_request_retries;
			$ai_response = $ai_connection->fetch_ai_response( $token, $formatted_prompt, 30 );
			if ( is_wp_error( $ai_response ) ) {
				continue;
			}

			if ( empty( $ai_response ) ) {
				continue;
			}

			if ( ! isset( $ai_response['completion'] ) ) {
				continue;
			}

			$completion = json_decode( $ai_response['completion'], true );

			if ( ! is_array( $completion ) ) {
				continue;
			}

			$diff = array_diff_key( $expected_results_format, $completion );

			if ( ! empty( $diff ) ) {
				continue;
			}

			$empty_results = false;
			foreach ( $completion as $completion_item ) {
				if ( empty( $completion_item ) ) {
					$empty_results = true;
					break;
				}
			}

			if ( $empty_results ) {
				continue;
			}

			foreach ( $products_information_list as $index => $product_information ) {
				$products_information_list[ $index ]['title'] = str_replace( '"', '', $completion[ $index ]['title'] );
				$products_information_list[ $index ]['price'] = $completion[ $index ]['price'];
			}

			$success = true;
		}

		if ( ! $success ) {
			return new WP_Error( 'failed_to_fetch_ai_responses', __( 'Failed to fetch AI responses for products.', 'woocommerce' ) );
		}

		return array(
			'product_content' => $products_information_list,
		);
	}

	/**
	 * Reset the products content.
	 */
	public function reset_products_content() {
		$dummy_products_to_update = $this->fetch_dummy_products_to_update();
		$i                        = 0;
		foreach ( $dummy_products_to_update as $product ) {
			$image_src        = plugins_url( self::DUMMY_PRODUCTS[ $i ]['image'], dirname( __DIR__, 2 ) );
			$image_alt        = self::DUMMY_PRODUCTS[ $i ]['title'];
			$product_image_id = $this->product_image_upload( $product->get_id(), $image_src, $image_alt );

			$this->product_update( $product, $product_image_id, self::DUMMY_PRODUCTS[ $i ]['title'], self::DUMMY_PRODUCTS[ $i ]['description'], self::DUMMY_PRODUCTS[ $i ]['price'] );

			++$i;
		}
	}

	/**
	 * Update the product with the new content.
	 *
	 * @param \WC_Product         $product The product.
	 * @param int|string|WP_Error $product_image_id The product image ID.
	 * @param string              $product_title The product title.
	 * @param string              $product_description The product description.
	 * @param int                 $product_price The product price.
	 *
	 * @return int|\WP_Error
	 */
	private function product_update( $product, $product_image_id, $product_title, $product_description, $product_price ) {
		if ( ! $product instanceof \WC_Product ) {
			return new WP_Error( 'invalid_product', __( 'Invalid product.', 'woocommerce' ) );
		}

		if ( ! is_wp_error( $product_image_id ) ) {
			$product->set_image_id( $product_image_id );
		} else {
			wc_get_logger()->warning(
				sprintf(
					// translators: %s is a generated error message.
					__( 'The image upload failed: "%s", creating the product without image', 'woocommerce' ),
					$product_image_id->get_error_message()
				),
			);
		}
		$product->set_name( $product_title );
		$product->set_description( $product_description );
		$product->set_price( $product_price );
		$product->set_regular_price( $product_price );
		$product->set_slug( sanitize_title( $product_title ) );
		$product->save();

		$this->create_hash_for_ai_modified_product( $product );

		return $product->get_id();
	}
}
