<?php
if ( ! defined( 'ABSPATH' ) ) exit;

/**
 * Sync engine. Free tier = manual button only. Premium's
 * premium/background-sync module hooks 'adnvg_after_sync_product' and adds
 * scheduling/queueing on top — it does NOT duplicate this logic.
 */
class ADNVG_Sync {

	public function __construct() {
		add_action( 'admin_post_adnvg_sync_now', array( $this, 'handle_manual_sync' ) );

		// Auto re-sync a single product when it's saved (free feature —
		// keeps things fresh without needing a full manual sync every time).
		add_action( 'woocommerce_update_product', array( $this, 'maybe_sync_single_product' ) );
	}

	public function handle_manual_sync() {
		if ( ! current_user_can( 'manage_woocommerce' ) || ! check_admin_referer( 'adnvg_sync_now_nonce' ) ) {
			wp_die( 'Not allowed.' );
		}

		$count = self::sync_all();

		wp_safe_redirect( add_query_arg( array(
			'page'       => 'adnvg-settings',
			'adnvg_synced' => $count,
		), admin_url( 'admin.php' ) ) );
		exit;
	}

	public static function sync_all() {
		$product_ids = wc_get_products( array(
			'type'   => 'variable',
			'limit'  => -1,
			'return' => 'ids',
		) );

		foreach ( $product_ids as $product_id ) {
			self::sync_product( $product_id );
		}

		/**
		 * Premium hook: background-sync module listens here to log
		 * completion, update its sync-queue dashboard, etc.
		 */
		do_action( 'adnvg_after_bulk_sync', $product_ids );

		return count( $product_ids );
	}

	public function maybe_sync_single_product( $product_id ) {
		$product = wc_get_product( $product_id );
		if ( $product && $product->is_type( 'variable' ) ) {
			self::sync_product( $product_id );
		}
	}

	/**
	 * Core sync logic for a single variable product: copies category/tag
	 * terms onto variations, and flags one "representative" variation per
	 * primary-attribute group.
	 */
	public static function sync_product( $product_id ) {
		$options           = ADNVG_Options::get_all();
		$primary_attribute = $options['primary_attribute'];
		$product           = wc_get_product( $product_id );

		if ( ! $product || ! $product->is_type( 'variable' ) ) {
			return;
		}

		$taxonomies_to_copy = array( 'product_cat', 'product_tag' );
		$variation_ids      = $product->get_children();

		foreach ( $taxonomies_to_copy as $taxonomy ) {
			$terms = wp_get_object_terms( $product_id, $taxonomy, array( 'fields' => 'ids' ) );
			if ( ! is_wp_error( $terms ) ) {
				foreach ( $variation_ids as $variation_id ) {
					wp_set_object_terms( $variation_id, $terms, $taxonomy );
				}
			}
		}

		$groups = array();
		foreach ( $variation_ids as $variation_id ) {
			$variation = wc_get_product( $variation_id );
			if ( ! $variation ) {
				continue;
			}
			$attributes = $variation->get_variation_attributes();
			$key        = 'attribute_' . $primary_attribute;
			$value      = isset( $attributes[ $key ] ) ? $attributes[ $key ] : '';
			$groups[ $value ][] = $variation;

			update_post_meta( $variation_id, '_adnvg_representative', 0 );
			update_post_meta( $variation_id, '_adnvg_group_value', $value );
		}

		foreach ( $groups as $value => $variations ) {
			$representative = null;
			foreach ( $variations as $variation ) {
				if ( $variation->is_in_stock() ) {
					$representative = $variation;
					break;
				}
			}
			if ( ! $representative ) {
				$representative = $variations[0];
			}
			update_post_meta( $representative->get_id(), '_adnvg_representative', 1 );
		}

		update_post_meta( $product_id, '_adnvg_hidden_parent', $options['hide_parent'] === 'yes' ? 1 : 0 );

		/**
		 * Premium hook: analytics module can listen here to refresh
		 * cached stats for this product.
		 */
		do_action( 'adnvg_after_sync_product', $product_id );
	}
}