<?php
/**
 * Keep the post overview list tables readable.
 *
 * Yoast SEO (+ Premium), Post Expirator, Duplicate Post and friends each bolt
 * extra columns onto the post overviews. WordPress core gives
 * author/categories/tags/date percentage widths and those plugins give their
 * columns fixed em widths, so with `table-layout: fixed` there is nothing left
 * for the auto-width title column: it collapses to ~10px on a 1280px laptop and
 * the headers wrap letter by letter. A large monitor has enough width to spare,
 * which is why the problem only shows up on laptops.
 *
 * @package Acato\Readable_List_Tables
 */

declare( strict_types=1 );

namespace Acato\Readable_List_Tables;

defined( 'ABSPATH' ) || exit;

/**
 * Sizes the columns of the post overviews and makes the table scroll sideways.
 */
class List_Table {

	/**
	 * Handle of the stylesheet and the script.
	 *
	 * @var string
	 */
	private const HANDLE = 'acato-readable-list-tables';

	/**
	 * Hook the list table changes into WordPress.
	 *
	 * @return void
	 */
	public function register(): void {
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_assets' ) );
	}

	/**
	 * Whether the plugin should do anything on the current screen.
	 *
	 * @return bool True when the columns should be sized.
	 */
	private function is_enabled(): bool {
		$screen = function_exists( 'get_current_screen' ) ? get_current_screen() : null;

		/**
		 * Filter whether to size the columns on the current screen.
		 *
		 * @since 1.0.0
		 *
		 * @param bool            $enabled Whether the plugin is active here.
		 * @param \WP_Screen|null $screen  The screen being rendered.
		 */
		return (bool) apply_filters( 'acato_readable_list_tables_enabled', true, $screen );
	}

	/**
	 * Explicit width per column, in pixels.
	 *
	 * Any column not listed here falls back to the default width, so columns
	 * from plugins this list does not know about are covered too.
	 *
	 * @return array<string, int> Column slug => width in pixels.
	 */
	private function column_widths(): array {
		/**
		 * Filter the per-column widths.
		 *
		 * @since 1.0.0
		 *
		 * @param array<string, int> $widths Column slug => width in pixels.
		 */
		return (array) apply_filters(
			'acato_readable_list_tables_column_widths',
			array(
				'title'                        => 260,
				'author'                       => 115,
				'categories'                   => 120,
				'tags'                         => 95,
				'date'                         => 130,
				// Post Expirator.
				'expirationdate'               => 130,
				// Duplicate Post.
				'duplicate_post_original_item' => 130,
				// Yoast SEO.
				'wpseo-title'                  => 170,
				'wpseo-metadesc'               => 190,
				'wpseo-focuskw'                => 130,
			)
		);
	}

	/**
	 * Width for columns that have no explicit width of their own.
	 *
	 * `min-width` cannot do this job: `table-layout: fixed` ignores it on cells,
	 * so an unsized column still collapses to ~20px and drags its header into a
	 * letter-per-line stack.
	 *
	 * @return int Width in pixels.
	 */
	private function default_width(): int {
		/**
		 * Filter the fallback width for unrecognised columns.
		 *
		 * @since 1.0.0
		 *
		 * @param int $width Width in pixels.
		 */
		return (int) apply_filters( 'acato_readable_list_tables_default_width', 130 );
	}

	/**
	 * Column classes that must keep the width their own stylesheet gives them.
	 *
	 * These are the deliberately narrow ones: the checkbox, the comment bubble
	 * and the Yoast score icons. Widening them to the default would waste a lot
	 * of horizontal space.
	 *
	 * @return string[] CSS class names, without the leading dot.
	 */
	private function narrow_columns(): array {
		/**
		 * Filter the columns that keep their own width.
		 *
		 * @since 1.0.0
		 *
		 * @param string[] $classes CSS class names, without the leading dot.
		 */
		return (array) apply_filters(
			'acato_readable_list_tables_narrow_columns',
			array(
				'check-column',
				'column-comments',
				'column-wpseo-score',
				'column-wpseo-score-readability',
				'column-wpseo-links',
				'column-wpseo-linked',
				'column-wpseo-cornerstone',
				'column-wpseo-inclusive-language',
			)
		);
	}

	/**
	 * Whether to pin the checkbox and title columns while scrolling sideways.
	 *
	 * @return bool True to pin them.
	 */
	private function sticky_enabled(): bool {
		/**
		 * Filter whether the identity columns are pinned.
		 *
		 * @since 1.0.0
		 *
		 * @param bool $sticky Whether to pin the checkbox and title columns.
		 */
		return (bool) apply_filters( 'acato_readable_list_tables_sticky_columns', true );
	}

	/**
	 * Register and enqueue the stylesheet and script.
	 *
	 * Every column that would otherwise be auto-width gets a pixel width. A
	 * fixed table is as wide as its columns demand, so the table grows past its
	 * container rather than squeezing the title column down to nothing; the
	 * scroll container takes care of the overflow. Columns an editor hides are
	 * `display: none` and drop out of that sum, so switching a few off through
	 * Screen Options is enough to make it fit without scrolling. Any leftover
	 * space on wider screens is divided over the columns by the browser.
	 *
	 * Left untyped on purpose: this is an action callback in a file under
	 * strict_types, so a loosely typed value from a third party would otherwise
	 * be fatal.
	 *
	 * @param mixed $hook_suffix The current admin page.
	 *
	 * @return void
	 */
	public function enqueue_assets( $hook_suffix ): void {
		if ( 'edit.php' !== $hook_suffix || ! $this->is_enabled() ) {
			return;
		}

		wp_enqueue_style(
			self::HANDLE,
			plugins_url( 'assets/css/list-tables.css', ACATO_READABLE_LIST_TABLES_PLUGIN_FILE ),
			array(),
			ACATO_READABLE_LIST_TABLES_VERSION
		);

		wp_add_inline_style( self::HANDLE, $this->column_css() );

		wp_enqueue_script(
			self::HANDLE,
			plugins_url( 'assets/js/list-tables.js', ACATO_READABLE_LIST_TABLES_PLUGIN_FILE ),
			array(),
			ACATO_READABLE_LIST_TABLES_VERSION,
			true
		);

		wp_add_inline_script(
			self::HANDLE,
			'window.acatoReadableListTables = ' . wp_json_encode(
				array(
					'label'  => __( 'Post list, scrolls horizontally', 'acato-readable-list-tables' ),
					'sticky' => $this->sticky_enabled(),
				)
			) . ';',
			'before'
		);
	}

	/**
	 * Build the filterable part of the stylesheet.
	 *
	 * @return string CSS.
	 */
	private function column_css(): string {
		$narrow = array_filter( array_map( 'sanitize_html_class', $this->narrow_columns() ) );
		$css    = '';

		if ( $narrow ) {
			/*
			 * Everything except the deliberately narrow columns.
			 *
			 * box-sizing, because wp-admin cells are content-box and the 10px
			 * cell padding would otherwise be added on top of every width.
			 *
			 * width, as a floor for any column not sized explicitly, including
			 * columns from plugins this one does not know about. The specific
			 * widths after it have the same specificity and come later, so they
			 * win. `:where()` keeps the exclusion list at zero specificity.
			 */
			$css .= sprintf(
				".fixed .manage-column:not(:where(.%s)){box-sizing:border-box;width:%dpx}\n",
				implode( ', .', $narrow ),
				absint( $this->default_width() )
			);
		}

		foreach ( $this->column_widths() as $column => $width ) {
			$column = sanitize_html_class( (string) $column );

			if ( '' === $column || ! $width ) {
				continue;
			}

			$css .= sprintf( ".fixed .column-%s{width:%dpx}\n", $column, absint( $width ) );
		}

		return $css;
	}
}