feat: Add product price comparison table

- Add "Load Product Comparison" button in admin
- Display WooCommerce products with local price (sale/regular)
- Show Google Merchant Center price for each product
- Show match type (offerId vs gtin) and match status
- Helps debug product matching issues
- Limited to 50 in-stock products for performance

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

admin/class-informatiq-sp-admin.php

@@ -51,6 +51,7 @@ class Informatiq_SP_Admin {
 		add_action( 'wp_ajax_informatiq_sp_manual_sync', array( $this, 'handle_manual_sync' ) );
 		add_action( 'wp_ajax_informatiq_sp_test_connection', array( $this, 'handle_test_connection' ) );
 		add_action( 'wp_ajax_informatiq_sp_revoke_auth', array( $this, 'handle_revoke_auth' ) );
+		add_action( 'wp_ajax_informatiq_sp_compare_products', array( $this, 'handle_compare_products' ) );
 
 		// Enqueue admin assets.
 		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_admin_assets' ) );
@@ -333,6 +334,10 @@ class Informatiq_SP_Admin {
 
 					<hr>
 
+					<?php $this->render_product_comparison(); ?>
+
+					<hr>
+
 					<?php $this->render_logs_section(); ?>
 				</div>
 
@@ -575,6 +580,50 @@ class Informatiq_SP_Admin {
 		<?php
 	}
 
+	/**
+	 * Render product comparison section.
+	 */
+	private function render_product_comparison() {
+		?>
+		<div class="informatiq-sp-product-comparison">
+			<h2><?php esc_html_e( 'Product Price Comparison', 'informatiq-smart-pricing' ); ?></h2>
+			<p class="description">
+				<?php esc_html_e( 'Compare WooCommerce product prices with Google Merchant Center prices.', 'informatiq-smart-pricing' ); ?>
+			</p>
+
+			<?php if ( $this->is_authorized() ) : ?>
+				<p>
+					<button type="button" class="button button-secondary" id="informatiq-sp-compare-products">
+						<?php esc_html_e( 'Load Product Comparison', 'informatiq-smart-pricing' ); ?>
+					</button>
+					<span class="spinner" style="float: none; margin-top: 0;"></span>
+				</p>
+
+				<div id="informatiq-sp-comparison-results" style="display: none;">
+					<table class="widefat striped">
+						<thead>
+							<tr>
+								<th><?php esc_html_e( 'Product', 'informatiq-smart-pricing' ); ?></th>
+								<th><?php esc_html_e( 'SKU', 'informatiq-smart-pricing' ); ?></th>
+								<th><?php esc_html_e( 'Local Price', 'informatiq-smart-pricing' ); ?></th>
+								<th><?php esc_html_e( 'Google Price', 'informatiq-smart-pricing' ); ?></th>
+								<th><?php esc_html_e( 'Google Match', 'informatiq-smart-pricing' ); ?></th>
+								<th><?php esc_html_e( 'Status', 'informatiq-smart-pricing' ); ?></th>
+							</tr>
+						</thead>
+						<tbody id="informatiq-sp-comparison-tbody">
+						</tbody>
+					</table>
+				</div>
+			<?php else : ?>
+				<p class="description" style="color: #d63638;">
+					<?php esc_html_e( 'Please authorize with Google first to compare products.', 'informatiq-smart-pricing' ); ?>
+				</p>
+			<?php endif; ?>
+		</div>
+		<?php
+	}
+
 	/**
 	 * Render logs section.
 	 */
@@ -752,6 +801,120 @@ class Informatiq_SP_Admin {
 		wp_send_json_success( array( 'message' => __( 'Authorization revoked.', 'informatiq-smart-pricing' ) ) );
 	}
 
+	/**
+	 * Handle product comparison AJAX request.
+	 */
+	public function handle_compare_products() {
+		check_ajax_referer( 'informatiq_sp_admin', 'nonce' );
+
+		if ( ! current_user_can( 'manage_woocommerce' ) ) {
+			wp_send_json_error( array( 'message' => __( 'Insufficient permissions', 'informatiq-smart-pricing' ) ) );
+		}
+
+		$merchant_id   = get_option( 'informatiq_sp_merchant_id' );
+		$client_id     = get_option( 'informatiq_sp_client_id' );
+		$client_secret = get_option( 'informatiq_sp_client_secret' );
+		$refresh_token = get_option( 'informatiq_sp_refresh_token' );
+
+		if ( empty( $merchant_id ) || empty( $refresh_token ) ) {
+			wp_send_json_error( array( 'message' => __( 'Please configure settings and authorize first.', 'informatiq-smart-pricing' ) ) );
+		}
+
+		try {
+			$google_api = new Informatiq_SP_Google_API(
+				$merchant_id,
+				$client_id,
+				$client_secret,
+				$refresh_token,
+				$this->logger
+			);
+
+			// Get all Google products indexed by various identifiers.
+			$google_products_raw = $google_api->get_all_products();
+			$google_products = array();
+
+			foreach ( $google_products_raw as $gp ) {
+				// Index by offerId.
+				if ( ! empty( $gp['offerId'] ) ) {
+					$google_products['offer_' . $gp['offerId']] = $gp;
+				}
+				// Index by gtin.
+				if ( ! empty( $gp['gtin'] ) ) {
+					$google_products['gtin_' . $gp['gtin']] = $gp;
+				}
+			}
+
+			// Get WooCommerce in-stock products (limit to 50 for performance).
+			$wc_products = wc_get_products( array(
+				'status'       => 'publish',
+				'stock_status' => 'instock',
+				'limit'        => 50,
+				'return'       => 'objects',
+				'type'         => array( 'simple', 'variable' ),
+			) );
+
+			$comparison = array();
+
+			foreach ( $wc_products as $product ) {
+				$sku = $product->get_sku();
+				if ( empty( $sku ) ) {
+					continue;
+				}
+
+				// Get local price (sale price priority, then regular).
+				$sale_price    = $product->get_sale_price();
+				$regular_price = $product->get_regular_price();
+				$local_price   = ! empty( $sale_price ) ? $sale_price : $regular_price;
+				$price_type    = ! empty( $sale_price ) ? 'sale' : 'regular';
+
+				// Try to find matching Google product.
+				$google_product = null;
+				$match_type     = '';
+
+				// Try offerId match.
+				if ( isset( $google_products['offer_' . $sku] ) ) {
+					$google_product = $google_products['offer_' . $sku];
+					$match_type     = 'offerId';
+				}
+				// Try GTIN match (when SKU is a barcode).
+				elseif ( isset( $google_products['gtin_' . $sku] ) ) {
+					$google_product = $google_products['gtin_' . $sku];
+					$match_type     = 'gtin';
+				}
+
+				// Get Google price.
+				$google_price = null;
+				if ( $google_product ) {
+					if ( isset( $google_product['price']['amountMicros'] ) ) {
+						$google_price = (float) $google_product['price']['amountMicros'] / 1000000;
+					}
+				}
+
+				$comparison[] = array(
+					'id'            => $product->get_id(),
+					'name'          => $product->get_name(),
+					'sku'           => $sku,
+					'local_price'   => $local_price ? (float) $local_price : null,
+					'price_type'    => $price_type,
+					'google_price'  => $google_price,
+					'match_type'    => $match_type,
+					'found'         => ! empty( $google_product ),
+					'google_offer'  => $google_product ? ( $google_product['offerId'] ?? '' ) : '',
+				);
+			}
+
+			wp_send_json_success( array(
+				'products'       => $comparison,
+				'google_count'   => count( $google_products_raw ),
+				'wc_count'       => count( $wc_products ),
+				'currency'       => get_woocommerce_currency_symbol(),
+			) );
+
+		} catch ( Exception $e ) {
+			wp_send_json_error( array( 'message' => $e->getMessage() ) );
+		}
+	}
+
 	/**
 	 * Enqueue admin assets.
 	 *

assets/js/admin.js

@@ -20,6 +20,7 @@
 			$('#informatiq-sp-manual-sync').on('click', this.handleManualSync);
 			$('#informatiq-sp-test-connection').on('click', this.handleTestConnection);
 			$('#informatiq-sp-revoke-auth').on('click', this.handleRevokeAuth);
+			$('#informatiq-sp-compare-products').on('click', this.handleCompareProducts);
 		},
 
 		/**
@@ -179,6 +180,82 @@
 					$button.prop('disabled', false).text('Revoke Authorization');
 				}
 			});
+		},
+
+		/**
+		 * Handle compare products button click
+		 */
+		handleCompareProducts: function(e) {
+			e.preventDefault();
+
+			var $button = $(this);
+			var $spinner = $button.next('.spinner');
+			var $results = $('#informatiq-sp-comparison-results');
+			var $tbody = $('#informatiq-sp-comparison-tbody');
+
+			// Disable button and show spinner
+			$button.prop('disabled', true);
+			$spinner.addClass('is-active');
+
+			// Make AJAX request
+			$.ajax({
+				url: informatiqSP.ajaxUrl,
+				type: 'POST',
+				data: {
+					action: 'informatiq_sp_compare_products',
+					nonce: informatiqSP.nonce
+				},
+				success: function(response) {
+					if (response.success) {
+						var data = response.data;
+						var html = '';
+
+						if (data.products.length === 0) {
+							html = '<tr><td colspan="6">No in-stock products with SKU found.</td></tr>';
+						} else {
+							$.each(data.products, function(i, product) {
+								var localPrice = product.local_price ? data.currency + parseFloat(product.local_price).toFixed(2) : '-';
+								var googlePrice = product.google_price ? data.currency + parseFloat(product.google_price).toFixed(2) : '-';
+								var priceLabel = product.price_type === 'sale' ? ' <small>(sale)</small>' : ' <small>(regular)</small>';
+								var matchLabel = product.match_type ? product.match_type : '-';
+								var statusClass = product.found ? 'color: #00a32a;' : 'color: #d63638;';
+								var statusText = product.found ? 'Found' : 'Not Found';
+
+								if (product.found && product.google_offer) {
+									matchLabel += ' <small>(' + product.google_offer + ')</small>';
+								}
+
+								html += '<tr>';
+								html += '<td><a href="post.php?post=' + product.id + '&action=edit">' + product.name + '</a></td>';
+								html += '<td><code>' + product.sku + '</code></td>';
+								html += '<td>' + localPrice + priceLabel + '</td>';
+								html += '<td>' + googlePrice + '</td>';
+								html += '<td>' + matchLabel + '</td>';
+								html += '<td style="' + statusClass + '"><strong>' + statusText + '</strong></td>';
+								html += '</tr>';
+							});
+						}
+
+						$tbody.html(html);
+						$results.show();
+
+						// Show summary
+						var summary = 'Showing ' + data.products.length + ' WooCommerce products. ';
+						summary += data.google_count + ' products found in Google Merchant Center.';
+						$button.after('<p class="description" style="margin-top: 10px;">' + summary + '</p>');
+
+					} else {
+						alert('Error: ' + (response.data.message || 'Unknown error'));
+					}
+				},
+				error: function(jqXHR, textStatus, errorThrown) {
+					alert('Error: ' + errorThrown);
+				},
+				complete: function() {
+					$button.prop('disabled', false);
+					$spinner.removeClass('is-active');
+				}
+			});
 		}
 	};