<?php
/**
 * Copy folders from other media folder plugins into Image Manager folders. Read-only towards the other plugin: its
 * tables and terms are never written. Formats as read in each plugin's own code on WordPress.org (20 Oct 2026).
 *
 * @package AffStackDevImageManager
 */

namespace AffStackDev\ImageManager;

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

/**
 * Folder import from other media-folder plugins: their folder trees made as Image Manager folders and their files
 * placed in them, in steps; the other plugin's data is only read.
 */
final class Folder_Import {
	public const OPTION      = 'afsd_im_folder_import';
	public const MAX_FOLDERS = 5000;
	private const CHUNK      = 500;

	/** Supported plugins. Table plugins keep their own tables; the others use ordinary WordPress terms. */
	public static function sources(): array {
		return array(
			'filebird'   => array(
				'name' => 'FileBird',
				'kind' => 'filebird',
			),
			'rml'        => array(
				'name' => 'Real Media Library',
				'kind' => 'rml',
			),
			'happyfiles' => array(
				'name'     => 'HappyFiles',
				'kind'     => 'taxonomy',
				'taxonomy' => 'happyfiles_category',
			),
			'eml'        => array(
				'name'     => 'Enhanced Media Library',
				'kind'     => 'taxonomy',
				'taxonomy' => 'media_category',
			),
			'folders'    => array(
				'name'     => 'Folders (Premio)',
				'kind'     => 'taxonomy',
				'taxonomy' => 'media_folder',
			),
		);
	}
	/**
	 * Whether a database table exists (another plugin's own table).
	 *
	 * @param string $table The table's full name.
	 * @return bool True when it does.
	 */
	private static function table_exists( string $table ): bool {
		global $wpdb;
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only check whether another plugin's own table exists; no WordPress API covers it.
		return $table === $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table ) ) );
	}
	/**
	 * Folders of one source: id => name, parent (0 = top), owner (FileBird's per-user folders).
	 *
	 * @param string $key The source plugin's key.
	 * @return array Folder ID => name, parent and owner.
	 */
	public static function folders( string $key ): array {
		global $wpdb;
		$src = self::sources()[ $key ] ?? null;
		if ( ! $src ) {
			return array();
		}
		$out = array();
		if ( 'filebird' === $src['kind'] ) {
			if ( ! self::table_exists( $wpdb->prefix . 'fbv' ) ) {
				return array();
			}
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only read of FileBird's own folder table (type 0 = media folders), bounded.
			$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT id, name, parent, created_by FROM %i WHERE type = 0 ORDER BY id LIMIT %d', $wpdb->prefix . 'fbv', self::MAX_FOLDERS + 1 ), ARRAY_A );
			foreach ( (array) $rows as  $r ) {
				$out[ (int) $r['id'] ] = array(
					'name'   => (string) $r['name'],
					'parent' => max( 0, (int) $r['parent'] ),
					'owner'  => max( 0, (int) $r['created_by'] ),
				);
			}
		} elseif ( 'rml' === $src['kind'] ) {
			if ( ! self::table_exists( $wpdb->prefix . 'realmedialibrary' ) ) {
				return array();
			}
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only read of Real Media Library's own folder table (top level = parent -1), bounded.
			$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT id, name, parent FROM %i ORDER BY id LIMIT %d', $wpdb->prefix . 'realmedialibrary', self::MAX_FOLDERS + 1 ), ARRAY_A );
			foreach ( (array) $rows as  $r ) {
				$out[ (int) $r['id'] ] = array(
					'name'   => (string) $r['name'],
					'parent' => max( 0, (int) $r['parent'] ),
					'owner'  => 0,
				);
			}
		} else {
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only read of another plugin's terms; its taxonomy may not be registered while it is inactive, so get_terms() cannot be used.
			$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT t.term_id AS id, t.name, tt.parent FROM %i t INNER JOIN %i tt ON tt.term_id = t.term_id WHERE tt.taxonomy = %s ORDER BY t.term_id LIMIT %d', $wpdb->terms, $wpdb->term_taxonomy, $src['taxonomy'], self::MAX_FOLDERS + 1 ), ARRAY_A );
			foreach ( (array) $rows as  $r ) {
				$out[ (int) $r['id'] ] = array(
					'name'   => (string) $r['name'],
					'parent' => max( 0, (int) $r['parent'] ),
					'owner'  => 0,
				);
			}
		}
		return $out;
	}
	/**
	 * Folder-file pairs, in a stable order, from an offset. Each pair: [source folder id, attachment id].
	 *
	 * @param string $key    The source plugin's key.
	 * @param int    $offset Where to start.
	 * @param int    $limit  How many pairs.
	 * @return array Pairs of source folder ID and attachment ID.
	 */
	private static function pairs( string $key, int $offset, int $limit ): array {
		global $wpdb;
		$src = self::sources()[ $key ];
		if ( 'filebird' === $src['kind'] ) {
			if ( ! self::table_exists( $wpdb->prefix . 'fbv_attachment_folder' ) ) {
				return array();
			}
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only page of FileBird's folder relationships.
			$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT folder_id AS f, attachment_id AS a FROM %i ORDER BY folder_id, attachment_id LIMIT %d OFFSET %d', $wpdb->prefix . 'fbv_attachment_folder', $limit, $offset ), ARRAY_A );
		} elseif ( 'rml' === $src['kind'] ) {
			if ( ! self::table_exists( $wpdb->prefix . 'realmedialibrary_posts' ) ) {
				return array();
			}
			// A shortcut is its own attachment whose isShortcut holds the original's ID: the original goes into that folder too.
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only page of Real Media Library's folder relationships.
			$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT fid AS f, IF(isShortcut > 0, isShortcut, attachment) AS a FROM %i WHERE fid > 0 ORDER BY attachment, isShortcut LIMIT %d OFFSET %d', $wpdb->prefix . 'realmedialibrary_posts', $limit, $offset ), ARRAY_A );
		} else {
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only page of another plugin's term relationships (its taxonomy may be unregistered).
			$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT tt.term_id AS f, tr.object_id AS a FROM %i tr INNER JOIN %i tt ON tt.term_taxonomy_id = tr.term_taxonomy_id WHERE tt.taxonomy = %s ORDER BY tr.object_id, tt.term_id LIMIT %d OFFSET %d', $wpdb->term_relationships, $wpdb->term_taxonomy, $src['taxonomy'], $limit, $offset ), ARRAY_A );
		}
		return array_map( static fn( $r ) =>  array( (int) $r['f'], (int) $r['a'] ), (array) $rows );
	}
	/**
	 * How many folder-file pairs a source has.
	 *
	 * @param string $key The source plugin's key.
	 * @return int The count.
	 */
	public static function pair_count( string $key ): int {
		global $wpdb;
		$src = self::sources()[ $key ];
		if ( 'filebird' === $src['kind'] ) {
			if ( ! self::table_exists( $wpdb->prefix . 'fbv_attachment_folder' ) ) {
				return 0;
			}
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only count for the import preview.
			return (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM %i', $wpdb->prefix . 'fbv_attachment_folder' ) );
		}
		if ( 'rml' === $src['kind'] ) {
			if ( ! self::table_exists( $wpdb->prefix . 'realmedialibrary_posts' ) ) {
				return 0;
			}
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only count for the import preview.
			return (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM %i WHERE fid > 0', $wpdb->prefix . 'realmedialibrary_posts' ) );
		}
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Read-only count for the import preview.
		return (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM %i tr INNER JOIN %i tt ON tt.term_taxonomy_id = tr.term_taxonomy_id WHERE tt.taxonomy = %s', $wpdb->term_relationships, $wpdb->term_taxonomy, $src['taxonomy'] ) );
	}
	/** What the Library shows before anything is copied. */
	public static function found(): array {
		$out = array();
		foreach ( self::sources() as  $key => $src ) {
			$folders = self::folders( $key );
			if ( $folders ) {
				$out[ $key ] = array(
					'name'     => $src['name'],
					'folders'  => count( $folders ),
					'pairs'    => self::pair_count( $key ),
					'too_many' => count( $folders ) > self::MAX_FOLDERS,
				);
			}
		}
		return $out;
	}
	/**
	 * The saved import.
	 *
	 * @return array The import, or an empty array.
	 */
	public static function state(): array {
		$s = Settings::fresh_option( self::OPTION, array() );
		return is_array( $s ) && 1 === ( $s['v'] ?? 0 ) ? $s : array();
	}
	/**
	 * A source folder's name made safe as plain text, at most 120 characters (a folder without a name is named after its
	 * number).
	 *
	 * @param string $name The name in the other plugin.
	 * @param int    $id   Its number there.
	 * @return string The name.
	 */
	private static function clean_name( string $name, int $id ): string {
		$name = trim( sanitize_text_field( html_entity_decode( $name, ENT_QUOTES | ENT_HTML5, 'UTF-8' ) ) );
		if ( function_exists( 'mb_substr' ) ) {
			$name = mb_substr( $name, 0, 120 );
		} else {
			$name = substr( $name, 0, 120 );
		}
		/* translators: %d: the folder's number in the other plugin. */
		return '' !== $name ? $name : sprintf( __( 'Folder %d', 'affstackdev-image-manager' ), $id );
	}
	/**
	 * One Image Manager folder for a slug, reusing a folder of the same name under the same parent.
	 *
	 * @param string $slug   The folder's slug (import-<source>-<id>).
	 * @param string $name   Its name.
	 * @param int    $parent Its parent folder (0 for the top).
	 * @param array  $counts Folders made and reused so far, changed in place.
	 * @return int The folder's term ID.
	 * @throws \RuntimeException With a reason code as its message when the step cannot be done.
	 */
	private static function folder( string $slug, string $name, int $parent, array &$counts ): int {
		$term = get_term_by( 'slug', $slug, Library::FOLDER );
		if ( $term && ! is_wp_error( $term ) ) {
			++$counts['reused'];
			return (int) $term->term_id;
		}
		$made = Reviewed_Store::wp_insert_term(
			$name,
			Library::FOLDER,
			array(
				'slug'   => $slug,
				'parent' => $parent,
			)
		);
		if ( is_wp_error( $made ) ) {
			$existing = (int) $made->get_error_data( 'term_exists' );
			if ( 'term_exists' === $made->get_error_code() && $existing ) {
				++$counts['reused'];
				return $existing;
			}
			throw new \RuntimeException( 'folder_import_failed' );
		}
		++$counts['created'];
		return (int) $made['term_id'];
	}
	/**
	 * Creates the whole tree, parents first. A folder whose parent is missing goes to the top level.
	 *
	 * @param string $key     The source plugin's key.
	 * @param array  $folders Its folders (folders()).
	 * @return array Source folder ID => Image Manager folder ID, and the counts made and reused.
	 */
	private static function tree( string $key, array $folders ): array {
		$map    = array();
		$counts = array(
			'created' => 0,
			'reused'  => 0,
		);
		$users  = array();
		$depth  = static function ( int $id ) use ( $folders ): int {
			$d    = 0;
			$seen = array();
			while ( $id && isset( $folders[ $id ] ) && ! isset( $seen[ $id ] ) && $d < 64 ) {
				$seen[ $id ] = true;
				$id          = $folders[ $id ]['parent'];
				++$d;
			} return $d;
		};
		$order  = array_keys( $folders );
		usort( $order, static fn( $a, $b ) =>  $depth( $a ) <=> $depth( $b ) ?: $a <=> $b );
		foreach ( $order as  $id ) {
			$f      = $folders[ $id ];
			$parent = 0;
			if ( $f['parent'] && isset( $map[ $f['parent'] ] ) ) {
				$parent = $map[ $f['parent'] ];
			} elseif ( $f['owner'] ) {
				if ( ! isset( $users[ $f['owner'] ] ) ) {
					$user = get_userdata( $f['owner'] );
					/* translators: %s: name of the person whose own FileBird folders these were. */
					$users[ $f['owner'] ] = self::folder( 'import-' . $key . '-user-' . $f['owner'], self::clean_name( sprintf( __( '%s (FileBird)', 'affstackdev-image-manager' ), $user ? $user->display_name : '#' . $f['owner'] ), 0 ), 0, $counts );
				}
				$parent = $users[ $f['owner'] ];
			}
			$map[ $id ] = self::folder( 'import-' . $key . '-' . $id, self::clean_name( $f['name'], $id ), $parent, $counts );
		}
		Library::clear_terms();
		return array( $map, $counts );
	}
	/**
	 * Start (confirmed) or continue an import. Each request works for a few seconds and saves its position.
	 *
	 * @param string $key       The source plugin's key.
	 * @param bool   $start     True to start the import.
	 * @param bool   $confirmed The owner's confirmation (needed to start).
	 * @return array The import.
	 * @throws \RuntimeException With a reason code as its message when the step cannot be done.
	 */
	public static function step( string $key, bool $start, bool $confirmed ): array {
		$im_reviewed_owner_lock = Reviewed_Store::enter();
		try {
			if ( ! current_user_can( 'manage_options' ) || ! current_user_can( 'upload_files' ) ) {
				throw new \RuntimeException( 'folder_import_access' );
			}
			if ( ! isset( self::sources()[ $key ] ) ) {
				throw new \RuntimeException( 'folder_import_source' );
			}
			$token = Repository::acquire( 'folder_import', 300 );
			if ( ! $token ) {
				throw new \RuntimeException( 'folder_import_busy' );
			}
			try {
				$state = self::state();
				if ( $start ) {
					if ( ! $confirmed ) {
						throw new \RuntimeException( 'folder_import_confirm' );
					}
					if ( $state && 'more' === $state['status'] && $state['source'] !== $key ) {
						throw new \RuntimeException( 'folder_import_other' );
					}
					$folders = self::folders( $key );
					if ( ! $folders ) {
						throw new \RuntimeException( 'folder_import_source' );
					}
					if ( count( $folders ) > self::MAX_FOLDERS ) {
						throw new \RuntimeException( 'folder_import_too_many' );
					}
					list( $map, $counts ) = self::tree( $key, $folders );
					$state                = array(
						'v'       => 1,
						'source'  => $key,
						'actor'   => get_current_user_id(),
						'started' => time(),
						'updated' => time(),
						'map'     => $map,
						'created' => $counts['created'],
						'reused'  => $counts['reused'],
						'cursor'  => 0,
						'total'   => self::pair_count( $key ),
						'placed'  => 0,
						'missing' => 0,
						'status'  => 'more',
					);
				} elseif ( ! $state || $state['source'] !== $key || 'more' !== $state['status'] ) {
					throw new \RuntimeException( 'folder_import_stale' );
				}
				$until = microtime( true ) + 8;
				do {
					$pairs   = self::pairs( $key, (int) $state['cursor'], self::CHUNK );
					$by_file = array();
					foreach ( $pairs as  list( $f, $a ) ) {
						if ( isset( $state['map'][ $f ] ) && $a > 0 ) {
							$by_file[ $a ][] = (int) $state['map'][ $f ];
						} else {
							++$state['missing'];
						}
					}
					foreach ( $by_file as  $a => $terms ) {
						if ( 'attachment' !== get_post_type( $a ) || ! current_user_can( 'edit_post', $a ) ) {
							$state['missing'] += count( $terms );
							continue;
						}
						// Added to the folder, never taken out of one it is already in.
						$set = Reviewed_Store::wp_set_object_terms( $a, array_values( array_unique( $terms ) ), Library::FOLDER, true );
						if ( is_wp_error( $set ) ) {
							throw new \RuntimeException( 'folder_import_failed' );
						}
						$state['placed'] += count( $terms );
					}
					$state['cursor'] += count( $pairs );
					$state['updated'] = time();
					if ( count( $pairs ) < self::CHUNK ) {
						$state['status'] = 'done';
						break;
					}
					if ( ! Repository::owns( $token, 'folder_import' ) ) {
						throw new \RuntimeException( 'folder_import_busy' );
					}
					Reviewed_Store::update_option( self::OPTION, $state, false );
				} while ( microtime( true ) < $until );
				Reviewed_Store::update_option( self::OPTION, $state, false );
				return $state;
			} finally {
				Repository::release( $token, 'folder_import' );
			}
		} finally {
			Reviewed_Store::leave( $im_reviewed_owner_lock );
		}
	}
	/**
	 * What an import did, in words: folders made, folders already there and file placements done.
	 *
	 * @param array $s The import.
	 * @return string The translated words.
	 */
	public static function message( array $s ): string {
		$name = self::sources()[ $s['source'] ]['name'] ?? '';
		/* translators: %d: folders made by this import. */
		$made = sprintf( _n( '%d folder made', '%d folders made', (int) $s['created'], 'affstackdev-image-manager' ), (int) $s['created'] );
		/* translators: %d: folders this import found already there. */
		$there = sprintf( __( '%d already there', 'affstackdev-image-manager' ), (int) $s['reused'] );
		/* translators: 1: file placements done; 2: placements in total. */
		$done = sprintf( _n( '%1$d of %2$d file placement done', '%1$d of %2$d file placements done', (int) $s['total'], 'affstackdev-image-manager' ), (int) $s['placed'], (int) $s['total'] );
		/* translators: 1: other plugin's name; 2: folders made, such as "3 folders made"; 3: folders already there; 4: placements done, such as "40 of 40 file placements done". */
		$text = sprintf( __( 'Import from %1$s: %2$s, %3$s; %4$s.', 'affstackdev-image-manager' ), $name, $made, $there, $done );
		if ( $s['missing'] ) {
			/* translators: %d: placements whose file or folder no longer exists. */
			$text .= ' ' . sprintf( _n( '%d placement was skipped because its file or folder no longer exists.', '%d placements were skipped because their file or folder no longer exists.', (int) $s['missing'], 'affstackdev-image-manager' ), (int) $s['missing'] );
		}
		$text .= ' ' . ( 'done' === $s['status'] ? __( 'The import is finished. The other plugin’s folders are unchanged.', 'affstackdev-image-manager' ) : __( 'More remains: choose Continue import.', 'affstackdev-image-manager' ) );
		return $text;
	}
	/**
	 * The words for an import's reason code.
	 *
	 * @param string $code The reason code.
	 * @return string The translated words.
	 */
	public static function human_error( string $code ): string {
		$m = array(
			'folder_import_access'   => __( 'You cannot organize site media.', 'affstackdev-image-manager' ),
			'folder_import_source'   => __( 'No folders were found in that plugin. Reload the library.', 'affstackdev-image-manager' ),
			'folder_import_confirm'  => __( 'Tick the confirmation box, then import again. Nothing was changed.', 'affstackdev-image-manager' ),
			'folder_import_busy'     => __( 'An import is still working. Reload the library in a moment.', 'affstackdev-image-manager' ),
			'folder_import_other'    => __( 'Another import is not finished. Continue it first.', 'affstackdev-image-manager' ),
			'folder_import_stale'    => __( 'This import finished or changed in another window. Reload the library.', 'affstackdev-image-manager' ),
			'folder_import_too_many' => __( 'That plugin has more than 5,000 folders, more than one import takes. Nothing was changed.', 'affstackdev-image-manager' ),
			'folder_import_failed'   => __( 'A folder could not be made or filled. What was done so far is kept; reload the library and continue.', 'affstackdev-image-manager' ),
		);
		return $m[ $code ] ?? __( 'The import could not finish. What was done so far is kept; reload the library.', 'affstackdev-image-manager' );
	}
}