<?php
/**
 * Lists everything on this site, grouped by sync class.
 *
 * @package WonderfulSync
 */

namespace WonderfulPlugins\WonderfulSync;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Builds the inventory shown on the admin page and by `wp wsync inventory`.
 */
class Inventory {

	/**
	 * Classifier used for every object.
	 *
	 * @var Classifier
	 */
	private $classifier;

	/**
	 * Option prefix => plugin name, built from the installed plugins.
	 *
	 * @var array<string, string>|null
	 */
	private $owner_prefixes = null;

	/**
	 * Installed plugin slug => plugin name.
	 *
	 * @var array<string, string>
	 */
	private $installed_slugs = array();

	/**
	 * Constructor.
	 *
	 * @param Classifier $classifier Classifier.
	 */
	public function __construct( Classifier $classifier ) {
		$this->classifier = $classifier;
	}

	/**
	 * Returns the inventory as class => list of rows.
	 *
	 * Each row: kind (theme, plugin, post_type, option, table), name, count, detail.
	 *
	 * @return array<string, array<int, array<string, mixed>>>
	 */
	public function build(): array {
		$groups = array_fill_keys( array_keys( Classifier::labels() ), array() );

		foreach ( $this->code_rows() as $row ) {
			$groups[ $row['class'] ][] = $row;
		}
		foreach ( $this->post_type_rows() as $row ) {
			$groups[ $row['class'] ][] = $row;
		}
		foreach ( $this->option_rows() as $row ) {
			$groups[ $row['class'] ][] = $row;
		}
		foreach ( $this->table_rows() as $row ) {
			$groups[ $row['class'] ][] = $row;
		}

		// Unassigned rows are a to-do list: group them by owning plugin, unknown ones last.
		usort(
			$groups[ Classifier::UNASSIGNED ],
			function ( $a, $b ) {
				return array( '' === $a['detail'], $a['detail'], $a['name'] ) <=> array( '' === $b['detail'], $b['detail'], $b['name'] );
			}
		);

		return $groups;
	}

	/**
	 * Themes and plugins. The active theme, its parent and active plugins are marked.
	 *
	 * @return array<int, array<string, mixed>>
	 */
	private function code_rows(): array {
		$rows       = array();
		$stylesheet = get_stylesheet();
		$template   = get_template();

		foreach ( wp_get_themes() as $slug => $theme ) {
			$state  = $slug === $stylesheet ? __( 'active', 'wonderful-sync' ) : ( $slug === $template ? __( 'parent of active theme', 'wonderful-sync' ) : __( 'inactive', 'wonderful-sync' ) );
			$rows[] = array(
				'class'  => Classifier::CODE,
				'kind'   => 'theme',
				'name'   => (string) $slug,
				'count'  => 1,
				'detail' => sprintf( '%s %s, %s', $theme->get( 'Name' ), $theme->get( 'Version' ), $state ),
			);
		}

		if ( ! function_exists( 'get_plugins' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}
		foreach ( get_plugins() as $file => $data ) {
			$rows[] = array(
				'class'  => Classifier::CODE,
				'kind'   => 'plugin',
				'name'   => (string) $file,
				'count'  => 1,
				'detail' => sprintf( '%s %s, %s', $data['Name'], $data['Version'], is_plugin_active( $file ) ? __( 'active', 'wonderful-sync' ) : __( 'inactive', 'wonderful-sync' ) ),
			);
		}

		foreach ( get_mu_plugins() as $file => $data ) {
			$rows[] = array(
				'class'  => $this->classifier->mu_plugin( (string) $file ),
				'kind'   => 'mu_plugin',
				'name'   => (string) $file,
				'count'  => 1,
				'detail' => sprintf( '%s %s', $data['Name'], $data['Version'] ),
			);
		}

		return $rows;
	}

	/**
	 * One row per post type with the number of posts.
	 *
	 * @return array<int, array<string, mixed>>
	 */
	private function post_type_rows(): array {
		global $wpdb;

		$rows   = array();
		$counts = $wpdb->get_results( "SELECT post_type, COUNT(*) AS n FROM {$wpdb->posts} WHERE post_status <> 'auto-draft' GROUP BY post_type ORDER BY post_type" ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery -- read-only inventory, no cache needed.
		foreach ( (array) $counts as $row ) {
			$rows[] = array(
				'class'  => $this->classifier->post_type( (string) $row->post_type ),
				'kind'   => 'post_type',
				'name'   => (string) $row->post_type,
				'count'  => (int) $row->n,
				'detail' => '',
			);
		}

		return $rows;
	}

	/**
	 * One row per option. Transients are folded into a single row each.
	 *
	 * @return array<int, array<string, mixed>>
	 */
	private function option_rows(): array {
		global $wpdb;

		$rows       = array();
		$transients = 0;
		$names      = $wpdb->get_col( "SELECT option_name FROM {$wpdb->options} ORDER BY option_name" ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery -- read-only inventory, no cache needed.
		foreach ( (array) $names as $name ) {
			$name = (string) $name;
			if ( 0 === strpos( $name, '_transient_' ) || 0 === strpos( $name, '_site_transient_' ) ) {
				++$transients;
				continue;
			}
			$rows[] = array(
				'class'  => $this->classifier->option( $name ),
				'kind'   => 'option',
				'name'   => $name,
				'count'  => 1,
				'detail' => $this->owner( $name ),
			);
		}

		if ( $transients > 0 ) {
			$rows[] = array(
				'class'  => Classifier::CACHE,
				'kind'   => 'option',
				'name'   => '_transient_*',
				'count'  => $transients,
				'detail' => '',
			);
		}

		return $rows;
	}

	/**
	 * One row per table that is not part of the core post/option tables already listed.
	 *
	 * @return array<int, array<string, mixed>>
	 */
	private function table_rows(): array {
		global $wpdb;

		$rows   = array();
		$tables = $wpdb->get_col( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $wpdb->prefix ) . '%' ) ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery -- read-only inventory, no cache needed.
		$skip   = array( 'options', 'posts', 'postmeta' );
		foreach ( (array) $tables as $table ) {
			$table = (string) $table;
			if ( in_array( substr( $table, strlen( $wpdb->prefix ) ), $skip, true ) ) {
				continue;
			}
			$rows[] = array(
				'class'  => $this->classifier->table( $table, $wpdb->prefix ),
				'kind'   => 'table',
				'name'   => $table,
				'count'  => 1,
				'detail' => $this->owner( substr( $table, strlen( $wpdb->prefix ) ) ),
			);
		}

		return $rows;
	}

	/**
	 * Guesses which installed plugin an option or table belongs to.
	 *
	 * Most plugins prefix their options with their slug, an underscore form of it
	 * or its first word (updraft_, cmplz_ for Complianz needs a rule, rcb- for Real
	 * Cookie Banner does not). The guess only labels rows; it never changes the class.
	 *
	 * @param string $name Option name or table name without the database prefix.
	 * @return string Plugin name, or '' when no plugin matches.
	 */
	public function owner( string $name ): string {
		if ( null === $this->owner_prefixes ) {
			$this->owner_prefixes = $this->build_owner_prefixes();
		}

		$best = '';
		foreach ( array_keys( $this->owner_prefixes ) as $prefix ) {
			if ( 0 === stripos( $name, $prefix ) && strlen( $prefix ) > strlen( $best ) ) {
				$best = (string) $prefix;
			}
		}

		if ( '' !== $best ) {
			return $this->owner_prefixes[ $best ];
		}

		$known = $this->classifier->known_plugin( $name );
		if ( ! $known ) {
			return '';
		}
		if ( isset( $this->installed_slugs[ $known[2] ] ) ) {
			return $this->installed_slugs[ $known[2] ];
		}

		/* translators: %s: plugin name. */
		return sprintf( __( '%s (not installed)', 'wonderful-sync' ), $known[0] );
	}

	/**
	 * Derives option prefixes from every installed plugin.
	 *
	 * @return array<string, string> Prefix => plugin name.
	 */
	private function build_owner_prefixes(): array {
		if ( ! function_exists( 'get_plugins' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}

		$prefixes = array();
		foreach ( get_plugins() as $file => $data ) {
			$slug  = strtolower( dirname( $file ) );
			$slug  = '.' === $slug ? strtolower( basename( $file, '.php' ) ) : $slug;
			$this->installed_slugs[ $slug ] = (string) $data['Name'];
			$words = preg_split( '/[-_]/', $slug );
			$cands = array( $slug . '_', $slug . '-', str_replace( '-', '_', $slug ) . '_' );
			if ( ! empty( $data['TextDomain'] ) ) {
				$cands[] = str_replace( '-', '_', strtolower( $data['TextDomain'] ) ) . '_';
			}
			// First word only when it is distinctive enough ("updraft", not "wp").
			if ( isset( $words[0] ) && strlen( $words[0] ) >= 5 ) {
				$cands[] = $words[0] . '_';
				$cands[] = $words[0] . '-';
			}
			// Initials of multi-word slugs: real-cookie-banner => rcb-, rcb_.
			if ( count( $words ) >= 3 ) {
				$initials = implode( '', array_map( function ( $w ) {
					return substr( $w, 0, 1 );
				}, $words ) );
				$cands[] = $initials . '-';
				$cands[] = $initials . '_';
			}

			/**
			 * Filters the option prefixes that identify a plugin in the inventory.
			 *
			 * @param string[] $cands Prefixes.
			 * @param string   $file  Plugin file.
			 */
			foreach ( (array) apply_filters( 'wonderful_sync_owner_prefixes', $cands, $file ) as $prefix ) {
				if ( strlen( (string) $prefix ) >= 3 && ! isset( $prefixes[ $prefix ] ) ) {
					$prefixes[ (string) $prefix ] = (string) $data['Name'];
				}
			}
		}

		return $prefixes;
	}
}