<?php
/**
 * Cost column + COGS filter on WooCommerce Products list.
 *
 * @package Kayvandra\MarginBeacon
 */

declare(strict_types=1);

namespace Kayvandra\MarginBeacon\Admin\Products;

use Kayvandra\MarginBeacon\Application\Cost\CanonicalCostSource;
use Kayvandra\MarginBeacon\Application\Cost\CostResolver;
use Kayvandra\MarginBeacon\Support\Constants;

/**
 * Products → All Products: resolved canonical cost for the current page only.
 *
 * WooCommerce versions differ: some expose a native `cogs_value` list column when
 * COGS is enabled; older builds may enable the feature without registering that
 * column. Detect the real column key in the filtered columns array — never assume
 * a feature flag or WC version guarantees the native column.
 */
final class ProductListCostColumn {

	const COLUMN_KEY = 'aksmb_cogs';
	const FILTER_KEY = 'aksmb_cogs_filter';

	/**
	 * WooCommerce native Cost column key when the list table registers it.
	 */
	const NATIVE_COLUMN_KEY = 'cogs_value';

	/**
	 * Visible character budget for the amount cell (ellipsis + title holds the rest).
	 */
	const DISPLAY_MAX_CHARS = 14;

	/**
	 * @var array<int,array{display:string,full:string,source_label:string}>
	 */
	private $page_cache = array();

	/**
	 * Register hooks once (Free owns this surface).
	 *
	 * @return void
	 */
	public function register() {
		// Runs after WP_List_Table priority 0 → get_columns() → manage_product_posts_columns
		// (where Woo may inject cogs_value), so native presence is observable here.
		add_filter( 'manage_edit-product_columns', array( $this, 'add_column' ), 20 );
		add_action( 'manage_product_posts_custom_column', array( $this, 'render_column' ), 10, 2 );
		add_action( 'restrict_manage_posts', array( $this, 'render_filter' ), 20, 2 );
		add_action( 'pre_get_posts', array( $this, 'apply_filter' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_styles' ) );
	}

	/**
	 * Keep the COGS column readable on the dense product list table.
	 *
	 * CSS is enqueued whenever this screen can show the MarginBeacon column.
	 * Column presence is decided later on manage_edit-product_columns; unused
	 * selectors are harmless when the native Woo column is used alone.
	 *
	 * @param string $hook Current admin page hook.
	 * @return void
	 */
	public function enqueue_styles( $hook ) {
		if ( 'edit.php' !== $hook ) {
			return;
		}
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Screen detection only.
		$post_type = isset( $_GET['post_type'] ) ? sanitize_key( wp_unslash( $_GET['post_type'] ) ) : '';
		if ( 'product' !== $post_type || ! $this->user_can_view() ) {
			return;
		}

		$css = '
			.wp-list-table.widefat .column-' . self::COLUMN_KEY . ' {
				width: 8.5em;
				min-width: 8.5em;
				max-width: 8.5em;
				vertical-align: middle;
			}
			.wp-list-table.widefat .column-' . self::COLUMN_KEY . ' .aksmb-cogs-cell {
				display: block;
				max-width: 100%;
				line-height: 1.35;
				overflow: hidden;
			}
			.wp-list-table.widefat .column-' . self::COLUMN_KEY . ' .aksmb-cogs-cell__amount {
				display: block;
				max-width: 100%;
				overflow: hidden;
				text-overflow: ellipsis;
				white-space: nowrap;
				font-variant-numeric: tabular-nums;
			}
			.wp-list-table.widefat .column-' . self::COLUMN_KEY . ' .aksmb-cogs-cell__source {
				display: block;
				max-width: 100%;
				margin-top: 2px;
				color: #646970;
				font-size: 11px;
				line-height: 1.3;
				overflow: hidden;
				text-overflow: ellipsis;
				white-space: nowrap;
			}
		';
		wp_register_style( 'aksmb-product-list-cogs', false, array(), AKSMB_VERSION );
		wp_enqueue_style( 'aksmb-product-list-cogs' );
		wp_add_inline_style( 'aksmb-product-list-cogs', preg_replace( '/\s+/', ' ', trim( $css ) ) );
	}

	/**
	 * Whether the WooCommerce native Cost column is already in the column map.
	 *
	 * @param array $columns Columns.
	 * @return bool
	 */
	public function columns_include_native_cogs( $columns ) {
		return is_array( $columns ) && array_key_exists( self::NATIVE_COLUMN_KEY, $columns );
	}

	/**
	 * Whether MarginBeacon should register its fallback/primary COGS column.
	 *
	 * @param array $columns Columns after Woo (and earlier filters) have run.
	 * @return bool
	 */
	public function should_register_marginbeacon_column( $columns ) {
		if ( ! $this->user_can_view() ) {
			return false;
		}
		$canonical = new CanonicalCostSource();
		if ( $canonical->is_woocommerce() && $this->columns_include_native_cogs( $columns ) ) {
			return false;
		}
		return true;
	}

	/**
	 * @param array $columns Columns.
	 * @return array
	 */
	public function add_column( $columns ) {
		if ( ! is_array( $columns ) ) {
			return $columns;
		}
		if ( ! $this->should_register_marginbeacon_column( $columns ) ) {
			return $columns;
		}

		$new = array();
		foreach ( $columns as $key => $label ) {
			$new[ $key ] = $label;
			if ( 'price' === $key ) {
				$new[ self::COLUMN_KEY ] = __( 'COGS', 'marginbeacon' );
			}
		}
		if ( ! isset( $new[ self::COLUMN_KEY ] ) ) {
			$new[ self::COLUMN_KEY ] = __( 'COGS', 'marginbeacon' );
		}
		return $new;
	}

	/**
	 * @param string $column  Column key.
	 * @param int    $post_id Product ID.
	 * @return void
	 */
	public function render_column( $column, $post_id ) {
		if ( self::COLUMN_KEY !== $column || ! $this->user_can_view() ) {
			return;
		}
		$row = $this->resolve_row( (int) $post_id );
		echo '<span class="aksmb-cogs-cell">';
		printf(
			'<span class="aksmb-cogs-cell__amount" title="%s">%s</span>',
			esc_attr( $row['full'] ),
			esc_html( $row['display'] )
		);
		if ( '' !== $row['source_label'] && __( 'Missing', 'marginbeacon' ) !== $row['full'] ) {
			echo '<span class="aksmb-cogs-cell__source">' . esc_html( $row['source_label'] ) . '</span>';
		}
		echo '</span>';
	}

	/**
	 * @param string $post_type Post type.
	 * @param string $which     Top/bottom.
	 * @return void
	 */
	public function render_filter( $post_type, $which = '' ) {
		unset( $which );
		if ( 'product' !== $post_type || ! $this->user_can_view() ) {
			return;
		}
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$current = isset( $_GET[ self::FILTER_KEY ] ) ? sanitize_key( wp_unslash( $_GET[ self::FILTER_KEY ] ) ) : '';
		?>
		<select name="<?php echo esc_attr( self::FILTER_KEY ); ?>" id="aksmb_cogs_filter">
			<option value=""><?php echo esc_html__( 'COGS: All', 'marginbeacon' ); ?></option>
			<option value="missing" <?php selected( $current, 'missing' ); ?>><?php echo esc_html__( 'Missing COGS', 'marginbeacon' ); ?></option>
			<option value="has" <?php selected( $current, 'has' ); ?>><?php echo esc_html__( 'Has COGS', 'marginbeacon' ); ?></option>
		</select>
		<?php
	}

	/**
	 * Meta filter against the active canonical store only.
	 *
	 * @param \WP_Query $query Query.
	 * @return void
	 */
	public function apply_filter( $query ) {
		if ( ! is_admin() || ! $query->is_main_query() || ! $this->user_can_view() ) {
			return;
		}
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$post_type = isset( $_GET['post_type'] ) ? sanitize_key( wp_unslash( $_GET['post_type'] ) ) : '';
		if ( 'product' !== $post_type ) {
			return;
		}
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$filter = isset( $_GET[ self::FILTER_KEY ] ) ? sanitize_key( wp_unslash( $_GET[ self::FILTER_KEY ] ) ) : '';
		if ( ! in_array( $filter, array( 'missing', 'has' ), true ) ) {
			return;
		}

		$canonical = new CanonicalCostSource();
		$meta_key  = $canonical->is_woocommerce() ? '_cogs_total_value' : Constants::META_MANUAL_COST;

		$meta_query = (array) $query->get( 'meta_query' );
		if ( 'has' === $filter ) {
			$meta_query[] = array(
				'key'     => $meta_key,
				'compare' => 'EXISTS',
			);
			$meta_query[] = array(
				'key'     => $meta_key,
				'value'   => '',
				'compare' => '!=',
			);
		} else {
			$meta_query[] = array(
				'relation' => 'OR',
				array(
					'key'     => $meta_key,
					'compare' => 'NOT EXISTS',
				),
				array(
					'key'     => $meta_key,
					'value'   => '',
					'compare' => '=',
				),
			);
		}
		$query->set( 'meta_query', $meta_query );
	}

	/**
	 * @param int $post_id Product ID.
	 * @return array{display:string,full:string,source_label:string}
	 */
	private function resolve_row( $post_id ) {
		if ( isset( $this->page_cache[ $post_id ] ) ) {
			return $this->page_cache[ $post_id ];
		}

		$canonical = new CanonicalCostSource();
		$resolver  = new CostResolver();
		$resolved  = $resolver->resolve_catalog( $post_id, 0 );

		if ( ! $resolved->is_resolved() || ! $resolved->amount() ) {
			$missing = __( 'Missing', 'marginbeacon' );
			$row     = array(
				'display'      => $missing,
				'full'         => $missing,
				'source_label' => '',
			);
		} else {
			$full    = $this->format_amount( $resolved->amount()->to_decimal_string() );
			$display = $this->truncate_display( $full );
			$row     = array(
				'display'      => $display,
				'full'         => $full,
				'source_label' => $canonical->label(),
			);
		}

		$this->page_cache[ $post_id ] = $row;
		return $row;
	}

	/**
	 * Format a decimal cost for list display without float overflow.
	 *
	 * Casting extreme DECIMAL values through (float) produces garbage currency
	 * strings that blow up the products table layout.
	 *
	 * @param string $decimal Tax-exclusive unit cost.
	 * @return string
	 */
	private function format_amount( $decimal ) {
		$decimal        = (string) $decimal;
		$safe_for_float = function_exists( 'bccomp' )
			? bccomp( $decimal, '0', 6 ) >= 0 && bccomp( $decimal, '1000000000', 6 ) < 0
			: (bool) preg_match( '/^\d{1,9}(?:\.\d+)?$/', $decimal );

		if ( $safe_for_float && function_exists( 'wc_price' ) ) {
			return wp_strip_all_tags( wc_price( (float) $decimal ) );
		}

		$symbol = function_exists( 'get_woocommerce_currency_symbol' )
			? html_entity_decode( (string) get_woocommerce_currency_symbol(), ENT_QUOTES, 'UTF-8' )
			: '';
		return $symbol . $decimal;
	}

	/**
	 * Cap visible characters; full value remains available via title tooltip.
	 *
	 * @param string $text Display text.
	 * @return string
	 */
	private function truncate_display( $text ) {
		$text = (string) $text;
		$max  = self::DISPLAY_MAX_CHARS;
		if ( function_exists( 'mb_strlen' ) && function_exists( 'mb_substr' ) ) {
			if ( mb_strlen( $text ) <= $max ) {
				return $text;
			}
			return mb_substr( $text, 0, $max - 1 ) . '…';
		}
		if ( strlen( $text ) <= $max ) {
			return $text;
		}
		return substr( $text, 0, $max - 1 ) . '…';
	}

	/**
	 * Capability-based: anyone who can edit products.
	 *
	 * @return bool
	 */
	private function user_can_view() {
		return current_user_can( 'edit_products' );
	}
}