<?php
/**
 * Fix: normalize existing product attributes into clean machine-readable form.
 *
 * @package AgentReadyForWooCommerce
 */

defined( 'ABSPATH' ) || exit;

/**
 * Class ARWC_Fix_Attributes
 *
 * Free, zero-cost, no-AI fix. It tidies the merchant's EXISTING custom (local)
 * product attributes so agents read consistent, machine-friendly facts:
 *  - trims/collapses whitespace in attribute names and values,
 *  - normalizes the visible attribute name to Title Case,
 *  - de-duplicates and tidies the pipe-separated value list.
 *
 * It never invents attributes or values, and it deliberately leaves global
 * (taxonomy) attributes alone — those are normalized centrally in WooCommerce
 * and editing terms here would have store-wide side effects.
 */
class ARWC_Fix_Attributes extends ARWC_Abstract_Fix {

	/**
	 * {@inheritDoc}
	 */
	public function get_id() {
		return 'attributes';
	}

	/**
	 * {@inheritDoc}
	 */
	public function get_label() {
		return __( 'Normalize attributes', 'agentictrack-agent-readiness-for-woocommerce' );
	}

	/**
	 * {@inheritDoc}
	 */
	public function get_description() {
		return __( 'Cleans up the naming, casing and spacing of your existing custom attributes so agents read consistent facts. Does not invent values.', 'agentictrack-agent-readiness-for-woocommerce' );
	}

	/**
	 * {@inheritDoc}
	 */
	public function preview( WC_Product $product ) {
		$proposals = array();

		$attributes = $product->get_attributes();
		if ( empty( $attributes ) ) {
			return $proposals;
		}

		foreach ( $attributes as $key => $attribute ) {
			if ( ! $attribute instanceof WC_Product_Attribute ) {
				continue;
			}
			// Only custom/local attributes have a normalizable text name + options.
			if ( $attribute->is_taxonomy() ) {
				continue;
			}

			$old_name = (string) $attribute->get_name();
			$new_name = $this->normalize_name( $old_name );

			$old_options = array_map( 'strval', (array) $attribute->get_options() );
			$new_options = $this->normalize_options( $old_options );

			$name_changed   = ( $new_name !== $old_name );
			$option_changed = ( $new_options !== $old_options );

			if ( ! $name_changed && ! $option_changed ) {
				continue;
			}

			$proposals[] = array(
				'field'       => (string) $key,
				'label'       => $old_name,
				'before'      => $old_name . ': ' . implode( ' | ', $old_options ),
				'after'       => $new_name . ': ' . implode( ' | ', $new_options ),
				'needs_input' => false,
				'auto'        => true,
				'note'        => '',
			);
		}

		return $proposals;
	}

	/**
	 * {@inheritDoc}
	 */
	public function apply( WC_Product $product, array $input ) {
		unset( $input );
		$result = $this->result();

		$attributes = $product->get_attributes();
		if ( empty( $attributes ) ) {
			return $result;
		}

		$changed = false;
		foreach ( $attributes as $key => $attribute ) {
			if ( ! $attribute instanceof WC_Product_Attribute || $attribute->is_taxonomy() ) {
				continue;
			}

			$old_name = (string) $attribute->get_name();
			$new_name = $this->normalize_name( $old_name );

			$old_options = array_map( 'strval', (array) $attribute->get_options() );
			$new_options = $this->normalize_options( $old_options );

			if ( $new_name === $old_name && $new_options === $old_options ) {
				continue;
			}

			$attribute->set_name( $new_name );
			$attribute->set_options( $new_options );
			$attributes[ $key ] = $attribute;
			$changed            = true;

			$result->add_change(
				(string) $key,
				$old_name,
				$old_name . ': ' . implode( ' | ', $old_options ),
				$new_name . ': ' . implode( ' | ', $new_options )
			);
		}

		if ( $changed ) {
			$product->set_attributes( $attributes );
			$product->save();
		}

		return $result;
	}

	/**
	 * Normalize a custom attribute display name: trim, collapse spaces, Title Case.
	 *
	 * @param string $name Raw name.
	 * @return string
	 */
	protected function normalize_name( $name ) {
		$name = trim( preg_replace( '/\s+/', ' ', (string) $name ) );
		if ( '' === $name ) {
			return $name;
		}
		if ( function_exists( 'mb_convert_case' ) ) {
			return mb_convert_case( $name, MB_CASE_TITLE, 'UTF-8' );
		}
		return ucwords( strtolower( $name ) );
	}

	/**
	 * Normalize a list of attribute option values: trim, collapse whitespace,
	 * drop empties, de-duplicate (case-insensitively, keeping first spelling).
	 *
	 * @param string[] $options Raw options.
	 * @return string[]
	 */
	protected function normalize_options( array $options ) {
		$clean = array();
		$seen  = array();
		foreach ( $options as $value ) {
			$value = trim( preg_replace( '/\s+/', ' ', (string) $value ) );
			if ( '' === $value ) {
				continue;
			}
			$fold = function_exists( 'mb_strtolower' ) ? mb_strtolower( $value, 'UTF-8' ) : strtolower( $value );
			if ( isset( $seen[ $fold ] ) ) {
				continue;
			}
			$seen[ $fold ] = true;
			$clean[]       = $value;
		}
		return $clean;
	}
}