<?php
/**
 * Product Feed — catalog completeness, scored locally, before anything is sent.
 *
 * ⛔⛔ INGESTION IS PERMANENT. OpenAI's feed ingestion is additive and there is
 * no delete: dropping a product from a later upload does not remove it, deleting
 * a feed does not remove its products (they are account-scoped and simply become
 * orphans with no UI or API path to them), and the Advertiser API has no DELETE
 * verb at all. Anything a merchant sends is in their advertising account
 * forever. The instinct to "just test with a few products first" permanently
 * pollutes it. That is why nothing is delivered from this screen without an
 * explicit, informed confirmation, and why the diagnostics run BEFORE delivery.
 *
 * ⛔ An empty description is an ERROR, not a warning — the platform reports it
 * as a misformatted column and the row suffers for it.
 *
 * ⛔ Never claim this feed produces organic ChatGPT placement. An Ads-Manager
 * feed is ads-only; organic search and in-chat checkout come through a separate
 * merchant programme.
 *
 * @package AgenticCommerceForWooCommerce
 */

defined( 'ABSPATH' ) || exit;

/**
 * Class Xpay_Screen_Feed.
 */
class Xpay_Screen_Feed {

	/** Products sampled for the health score. Bounded so a huge catalog can't time out a page load. */
	const SAMPLE = 200;

	/**
	 * Render.
	 *
	 * @return void
	 */
	public static function render() {
		Xpay_UI::open( __( 'Product Feed', 'agentic-commerce-for-woocommerce' ) );

		Xpay_UI::hero(
			array(
				'eyebrow' => __( 'PRODUCT FEED', 'agentic-commerce-for-woocommerce' ),
				'title'   => __( 'Getting listed is easy. Getting chosen is the hard part.', 'agentic-commerce-for-woocommerce' ),
				'sub'     => __( 'AI assistants compare products on attributes. Anything missing is a reason to skip you. This scores your catalog the way they read it — before a single row is sent anywhere.', 'agentic-commerce-for-woocommerce' ),
			)
		);

		$h = self::health();
		self::render_health( $h );
		self::render_issues( $h );
		self::permanence_warning();

		Xpay_UI::close();
	}

	/**
	 * Score a sample of the catalog on the fields that decide whether a product
	 * can compete in an AI answer.
	 *
	 * @return array{sampled:int,total:int,issues:array<string,array{n:int,label:string,detail:string,sev:string}>,score:int}
	 */
	public static function health() {
		$out = array(
			'sampled' => 0,
			'total'   => 0,
			'issues'  => array(),
			'score'   => 0,
		);
		if ( ! function_exists( 'wc_get_products' ) ) {
			return $out;
		}

		$counts        = function_exists( 'wp_count_posts' ) ? wp_count_posts( 'product' ) : null;
		$out['total']  = ( $counts && isset( $counts->publish ) ) ? (int) $counts->publish : 0;

		$products = wc_get_products(
			array(
				'limit'  => self::SAMPLE,
				'status' => 'publish',
				'return' => 'objects',
			)
		);
		if ( ! is_array( $products ) || ! $products ) {
			return $out;
		}

		$defs = array(
			'description' => array( __( 'Missing description', 'agentic-commerce-for-woocommerce' ), __( 'An empty description is rejected as a misformatted column, and the assistant has nothing to compare on.', 'agentic-commerce-for-woocommerce' ), 'high' ),
			'image'       => array( __( 'No product image', 'agentic-commerce-for-woocommerce' ), __( 'Products without an image are routinely skipped in shopping answers.', 'agentic-commerce-for-woocommerce' ), 'high' ),
			'price'       => array( __( 'No usable price', 'agentic-commerce-for-woocommerce' ), __( 'A blank or zero price is read as unknown, not as free. Quote-priced products cannot be listed.', 'agentic-commerce-for-woocommerce' ), 'high' ),
			'gtin'        => array( __( 'No brand or product identifier', 'agentic-commerce-for-woocommerce' ), __( 'Identifiers are how an assistant knows two listings are the same item. Without one you compete poorly on price comparisons.', 'agentic-commerce-for-woocommerce' ), 'med' ),
			'short'       => array( __( 'Very short description', 'agentic-commerce-for-woocommerce' ), __( 'Under about 100 characters rarely carries the attributes a shopper asks about.', 'agentic-commerce-for-woocommerce' ), 'med' ),
		);

		$fail = array();
		foreach ( $products as $p ) {
			if ( ! is_a( $p, 'WC_Product' ) ) {
				continue;
			}
			$out['sampled']++;

			$desc = trim( wp_strip_all_tags( (string) $p->get_description() ) );
			if ( '' === $desc ) {
				$fail['description'] = ( isset( $fail['description'] ) ? $fail['description'] : 0 ) + 1;
			} elseif ( ( function_exists( 'mb_strlen' ) ? mb_strlen( $desc ) : strlen( $desc ) ) < 100 ) {
				$fail['short'] = ( isset( $fail['short'] ) ? $fail['short'] : 0 ) + 1;
			}

			if ( ! $p->get_image_id() ) {
				$fail['image'] = ( isset( $fail['image'] ) ? $fail['image'] : 0 ) + 1;
			}

			// ⛔ price 0 means UNKNOWN, never free. Both are unlistable, and they
			// are counted the same way here for that reason.
			$price = $p->get_price();
			if ( '' === $price || null === $price || 0.0 === (float) $price ) {
				$fail['price'] = ( isset( $fail['price'] ) ? $fail['price'] : 0 ) + 1;
			}

			$gtin = '';
			foreach ( array( '_wpm_gtin_code', '_gtin', 'gtin', '_global_unique_id' ) as $key ) {
				$v = $p->get_meta( $key );
				if ( $v ) {
					$gtin = (string) $v;
					break;
				}
			}
			if ( '' === $gtin && '' === (string) $p->get_sku() ) {
				$fail['gtin'] = ( isset( $fail['gtin'] ) ? $fail['gtin'] : 0 ) + 1;
			}
		}

		foreach ( $fail as $key => $n ) {
			$out['issues'][ $key ] = array(
				'n'      => $n,
				'label'  => $defs[ $key ][0],
				'detail' => $defs[ $key ][1],
				'sev'    => $defs[ $key ][2],
			);
		}
		uasort(
			$out['issues'],
			static function ( $a, $b ) {
				return $b['n'] <=> $a['n'];
			}
		);

		// Score weights blocking issues twice as heavily as advisory ones.
		$weighted = 0;
		foreach ( $out['issues'] as $i ) {
			$weighted += ( 'high' === $i['sev'] ) ? $i['n'] * 2 : $i['n'];
		}
		$worst        = max( 1, $out['sampled'] * 2 );
		$out['score'] = (int) max( 0, min( 100, round( 100 - ( $weighted / $worst ) * 100 ) ) );

		return $out;
	}

	/**
	 * The score ring.
	 *
	 * @param array $h Health.
	 * @return void
	 */
	private static function render_health( $h ) {
		if ( ! $h['sampled'] ) {
			echo '<div class="xc-table-wrap">';
			Xpay_UI::empty_state(
				__( 'No published products to score', 'agentic-commerce-for-woocommerce' ),
				__( 'Add products and publish them, and this fills in automatically.', 'agentic-commerce-for-woocommerce' )
			);
			echo '</div>';
			return;
		}

		Xpay_UI::section(
			__( 'Catalog health', 'agentic-commerce-for-woocommerce' ),
			sprintf(
				/* translators: 1: sampled count, 2: total published. */
				__( 'Scored from your %1$s most recently added products, of %2$s published. Nothing has been sent anywhere.', 'agentic-commerce-for-woocommerce' ),
				number_format_i18n( $h['sampled'] ),
				number_format_i18n( $h['total'] )
			)
		);
		echo '<div style="display:flex;gap:26px;align-items:center;flex-wrap:wrap;">';
		Xpay_UI::ring( $h['score'], __( 'Catalog health score', 'agentic-commerce-for-woocommerce' ) );
		echo '<p class="xc-section-sub" style="flex:1;min-width:240px;">'
			. esc_html__( 'This is a sample, not an audit of every product. It is meant to tell you whether you have a systemic gap worth fixing, not to grade individual items.', 'agentic-commerce-for-woocommerce' )
			. '</p></div>';
	}

	/**
	 * Issue list.
	 *
	 * @param array $h Health.
	 * @return void
	 */
	private static function render_issues( $h ) {
		if ( ! $h['sampled'] ) {
			return;
		}
		Xpay_UI::section( __( 'What to fix first', 'agentic-commerce-for-woocommerce' ) );

		if ( ! $h['issues'] ) {
			echo '<div class="xc-table-wrap">';
			Xpay_UI::empty_state(
				__( 'Nothing blocking found', 'agentic-commerce-for-woocommerce' ),
				__( 'Every sampled product had a description, an image, a usable price and an identifier.', 'agentic-commerce-for-woocommerce' )
			);
			echo '</div>';
			return;
		}

		echo '<div class="xc-checks">';
		foreach ( $h['issues'] as $i ) {
			Xpay_UI::check(
				$i['sev'],
				sprintf(
					/* translators: 1: issue label, 2: affected count, 3: sampled count. */
					__( '%1$s — %2$s of %3$s sampled', 'agentic-commerce-for-woocommerce' ),
					$i['label'],
					number_format_i18n( $i['n'] ),
					number_format_i18n( $h['sampled'] )
				),
				$i['detail'],
				admin_url( 'edit.php?post_type=product' ),
				__( 'Products', 'agentic-commerce-for-woocommerce' )
			);
		}
		echo '</div>';
	}

	/**
	 * The warning that must be read before a first delivery ever happens.
	 *
	 * @return void
	 */
	private static function permanence_warning() {
		Xpay_UI::section( __( 'Before you send a feed anywhere', 'agentic-commerce-for-woocommerce' ) );
		Xpay_UI::note(
			'warn',
			'<strong>' . esc_html__( 'Anything you send to a ChatGPT Ads feed is permanent.', 'agentic-commerce-for-woocommerce' ) . '</strong> '
			. esc_html__( 'The platform adds products but never removes them. Taking a product out of a later upload does not delete it, and deleting the feed itself does not delete the products either — they stay in your advertising account with no way to reach them. This is why we score your catalog here first, and why testing with "just a few products" is the one thing you should not do.', 'agentic-commerce-for-woocommerce' )
		);
		Xpay_UI::note(
			'info',
			esc_html__( 'A ChatGPT Ads feed is for advertising only. Appearing in ordinary ChatGPT shopping answers comes through a separate route and is not affected by anything on this screen.', 'agentic-commerce-for-woocommerce' )
		);
	}
}