<?php
/** Storage and context boundaries. @package ThreeTaskPostOrder */
namespace ThreeTask\PostOrder;

use WP_Error;

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

final class Store {
	public static function table( string $name ): string {
		global $wpdb;

		return $wpdb->prefix . 'threepo_' . $name;
	}

	public static function install( bool $network_wide = false ): void {
		if ( $network_wide ) {
			wp_die( esc_html__( 'Activate Post Order separately on each site.', '3task-post-order' ) );
		}

		global $wpdb;

		require_once ABSPATH . 'wp-admin/includes/upgrade.php';

		$charset = $wpdb->get_charset_collate();
		$table   = self::table( 'contexts' );
		dbDelta(
			"CREATE TABLE $table (
   id bigint unsigned NOT NULL AUTO_INCREMENT,
   context_key varchar(191) NOT NULL,
   kind varchar(8) NOT NULL,
   object_type varchar(32) NOT NULL,
   taxonomy varchar(32) NOT NULL DEFAULT '',
   term_id bigint unsigned NOT NULL DEFAULT 0,
   parent_id bigint unsigned NOT NULL DEFAULT 0,
   label varchar(120) NOT NULL,
   scope varchar(12) NOT NULL DEFAULT 'backend',
   revision bigint unsigned NOT NULL DEFAULT 0,
   import_id bigint unsigned NOT NULL DEFAULT 0,
   PRIMARY KEY (id),
   UNIQUE KEY context_key (context_key)
  ) ENGINE=InnoDB $charset;"
		);
		$table = self::table( 'entries' );
		dbDelta(
			"CREATE TABLE $table (
   context_id bigint unsigned NOT NULL,
   object_id bigint unsigned NOT NULL,
   rank_value bigint NOT NULL,
   PRIMARY KEY (context_id,object_id),
   KEY ordered (context_id,rank_value,object_id)
  ) ENGINE=InnoDB $charset;"
		);
		$table = self::table( 'history' );
		dbDelta(
			"CREATE TABLE $table (
   id bigint unsigned NOT NULL AUTO_INCREMENT,
   context_id bigint unsigned NOT NULL,
   operation varchar(36) NOT NULL,
   fingerprint varchar(64) NOT NULL,
   actor bigint unsigned NOT NULL,
   revision bigint unsigned NOT NULL,
   action varchar(12) NOT NULL,
   object_id bigint unsigned NOT NULL DEFAULT 0,
   previous_id bigint unsigned NOT NULL DEFAULT 0,
   next_id bigint unsigned NOT NULL DEFAULT 0,
   created datetime NOT NULL,
   PRIMARY KEY (id),
   UNIQUE KEY operation (context_id,operation),
   KEY recent (context_id,revision)
  ) ENGINE=InnoDB $charset;"
		);
		$table = self::table( 'imports' );
		dbDelta(
			"CREATE TABLE $table (
   id bigint unsigned NOT NULL AUTO_INCREMENT,
   status varchar(24) NOT NULL,
   source_hash varchar(64) NOT NULL,
   plan longtext NOT NULL,
   cursor_index bigint unsigned NOT NULL DEFAULT 0,
   cursor_offset bigint unsigned NOT NULL DEFAULT 0,
   was_active tinyint NOT NULL DEFAULT 0,
   created datetime NOT NULL,
   PRIMARY KEY (id)
  ) ENGINE=InnoDB $charset;"
		);
		$table = self::table( 'snapshots' );
		dbDelta(
			"CREATE TABLE $table (
         context_id bigint unsigned NOT NULL,
         revision bigint unsigned NOT NULL,
         object_id bigint unsigned NOT NULL,
         rank_value bigint NOT NULL,
         PRIMARY KEY (context_id,revision,object_id)
        ) ENGINE=InnoDB $charset;"
		);
		update_option( 'threepo_schema', 5, true );
	}

	public static function error( string $code, string $message, int $status = 400 ): WP_Error {
		return new WP_Error( 'threepo_' . $code, $message, array( 'status' => $status ) );
	}

	/**
	 * @return array<string,mixed>|null
	 */
	public static function get( int $id ): ?array {
		global $wpdb;

		$row = $wpdb->get_row( $wpdb->prepare( 'SELECT * FROM %i WHERE id=%d', self::table( 'contexts' ), $id ), ARRAY_A );

		return $row ? self::cast( $row ) : null;
	}

	/**
	 * @param array<string,mixed> $row Validated values.
	 * @return array<string,mixed>
	 */
	public static function cast( array $row ): array {
		foreach ( array( 'id', 'term_id', 'parent_id', 'revision', 'import_id' ) as $key ) {
			$row[ $key ] = (int) $row[ $key ];
		}
		return $row;
	}

	/**
	 * @param array<string,mixed> $context Validated values.
	 */
	public static function allowed( array $context ): bool {
		if ( 'term' === $context['kind'] ) {
			$tax = get_taxonomy( $context['object_type'] );

			return $tax && current_user_can( $tax->cap->manage_terms );
		}

		$type = get_post_type_object( $context['object_type'] );

		return $type && current_user_can( $type->cap->edit_others_posts );
	}

	/**
	 * @param array<string,mixed> $data Validated values.
	 * @return array<string,mixed>|\WP_Error
	 */
	public static function create( array $data ) {
		global $wpdb;

		if ( ! current_user_can( 'manage_options' ) ) {
			return self::error( 'forbidden', __( 'You cannot create an ordering context.', '3task-post-order' ), 403 );
		}

		if ( defined( 'ICL_SITEPRESS_VERSION' ) || function_exists( 'pll_languages_list' ) ) {
			return self::error( 'language', __( 'Multilingual ordering is not supported in this version.', '3task-post-order' ) );
		}

		if ( ! self::allowed( $data ) ) {
			return self::error( 'forbidden', __( 'You cannot manage this content type.', '3task-post-order' ), 403 );
		}

		$kind   = $data['kind'];
		$type   = $data['object_type'];
		$tax    = $data['taxonomy'];
		$term   = $data['term_id'];
		$parent = $data['parent_id'];
		$object = 'post' === $kind ? get_post_type_object( $type ) : get_taxonomy( $type );

		if ( ! $object || ! $object->show_ui || ( 'post' === $kind && 'attachment' === $type ) ) {
			return self::error( 'type', __( 'Choose a supported content type.', '3task-post-order' ) );
		}

		if ( $tax && ( 'post' !== $kind || ! is_object_in_taxonomy( $type, $tax ) || ! $term || ! term_exists( $term, $tax ) ) ) {
			return self::error( 'taxonomy', __( 'The category does not belong to this content type.', '3task-post-order' ) );
		}

		if ( ! $tax && $term ) {
			return self::error( 'taxonomy', __( 'Choose the taxonomy for this term.', '3task-post-order' ) );
		}

		if ( $parent ) {
			$p = 'post' === $kind ? get_post( $parent ) : get_term( $parent, $type );

			if ( ! $p || is_wp_error( $p ) || ! $object->hierarchical || ( 'post' === $kind && ( $p->post_type !== $type || ! current_user_can( 'edit_post', $parent ) ) ) ) {
				return self::error( 'parent', __( 'The parent is not available in this context.', '3task-post-order' ) );
			}
		}

		$key = implode( ':', array( $kind, $type, $tax, $term, $parent ) );
		$old = $wpdb->get_var( $wpdb->prepare( 'SELECT id FROM %i WHERE context_key=%s', self::table( 'contexts' ), $key ) );

		if ( $old ) {
			return self::get( (int) $old );
		}

		$row = array(
			'context_key' => $key,
			'kind'        => $kind,
			'object_type' => $type,
			'taxonomy'    => $tax,
			'term_id'     => $term,
			'parent_id'   => $parent,
			'label'       => $data['label'],
		);

		if ( false === $wpdb->insert( self::table( 'contexts' ), $row ) ) {
			return self::error( 'database', __( 'The context could not be saved.', '3task-post-order' ), 503 );
		}

		return self::get( (int) $wpdb->insert_id );
	}

	/**
	 * Delete one order and its history. Content and legacy ranks stay untouched.
	 *
	 * @return array<string,mixed>|\WP_Error
	 */
	public static function delete( int $id ) {
		global $wpdb;

		try {
			Order::begin();
		} catch ( \RuntimeException $error ) {
			// No transaction of ours is open here, so nothing may be rolled back.
			return self::error( 'database', __( 'The order could not be deleted. Reload and try again.', '3task-post-order' ), 503 );
		}

		try {
			$c = $wpdb->get_row( $wpdb->prepare( 'SELECT * FROM %i WHERE id=%d FOR UPDATE', self::table( 'contexts' ), $id ), ARRAY_A );

			if ( ! $c ) {
				$wpdb->query( 'ROLLBACK' );

				return self::error( 'missing', __( 'This order no longer exists.', '3task-post-order' ), 404 );
			}

			if ( 'importing' === $c['scope'] ) {
				$wpdb->query( 'ROLLBACK' );

				return self::error( 'importing', __( 'This order belongs to an unfinished import. Discard the import instead.', '3task-post-order' ), 409 );
			}

			foreach ( array( 'entries', 'history', 'snapshots' ) as $table ) {
				Order::check( $wpdb->delete( self::table( $table ), array( 'context_id' => $id ) ) );
			}

			Order::check( $wpdb->delete( self::table( 'contexts' ), array( 'id' => $id ) ) );
			Order::check( $wpdb->query( 'COMMIT' ) );
		} catch ( \RuntimeException $error ) {
			$wpdb->query( 'ROLLBACK' );

			return self::error( 'database', __( 'The order could not be deleted. Reload and try again.', '3task-post-order' ), 503 );
		}

		do_action( 'threepo_order_changed', $id, 0, 0 );

		return array(
			'deleted' => true,
			'id'      => $id,
		);
	}

	/**
	 * @return list<array<string,mixed>>
	 */
	public static function contexts(): array {
		global $wpdb;

		$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT * FROM %i ORDER BY label,id LIMIT 500', self::table( 'contexts' ) ), ARRAY_A );

		return array_values( array_filter( array_map( array( self::class, 'cast' ), $rows ), array( self::class, 'allowed' ) ) );
	}
}