<?php
/**
 * @file
 * @ingroup Maintenance
 */
$IP = getenv( 'MW_INSTALL_PATH' );
if ( $IP === false ) {
	$IP = __DIR__ . '/../../..';
}
require_once "$IP/maintenance/Maintenance.php";

/**
 * Run automatically with update.php
 *
 * @since January 2020
 */
class MigrateOldAJAXPollUserColumnsToActor extends LoggedUpdateMaintenance {
	public function __construct() {
		parent::__construct();
		$this->addDescription( 'Migrates data from old poll_user column in the ajaxpoll_vote table ' .
			'to the new actor column.' );
	}

	/**
	 * Get the update key name to go in the update log table
	 *
	 * @return string
	 */
	protected function getUpdateKey() {
		return __CLASS__;
	}

	/**
	 * Message to show that the update was done already and was just skipped
	 *
	 * @return string
	 */
	protected function updateSkippedMessage() {
		return 'ajaxpoll_vote has already been migrated to use the actor column.';
	}

	/**
	 * Do the actual work.
	 *
	 * @return bool True to log the update as done
	 */
	protected function doDBUpdates() {
		$dbw = $this->getDB( DB_PRIMARY );

		if ( $dbw->fieldExists( 'ajaxpoll_vote', 'poll_vote_id', __METHOD__ ) ) {
			return true;
		}

		$dbw->sourceFile( __DIR__ . '/../sql/drop-primary-key.sql' );
		$dbw->sourceFile( __DIR__ . '/../sql/add-new-primary-key.sql' );

		// Find missing anonymous actors and insert them to the actor table
		// Do not attempt doing it with an insertSelect, it's apparently incompatible with postgres
		$res = $dbw->select(
			[
				'ajaxpoll_vote',
				'actor'
			],
			[ 'poll_ip' ],
			[
				'poll_ip = poll_user',
				'actor_id IS NULL'
			],
			__METHOD__,
			[ 'DISTINCT' ],
			[
				'actor' => [
					'LEFT JOIN',
					[ 'actor_name = poll_user' ]
				]
			]
		);

		$toInsert = [];

		foreach ( $res as $row ) {
			$toInsert[] = [ 'actor_name' => $row->poll_ip ];
		}

		if ( !empty( $toInsert ) ) {
			$dbw->insert(
				'actor',
				$toInsert,
				__METHOD__
			);
		}

		// Find corresponding actors for votes
		$dbw->query(
			"UPDATE {$dbw->tableName( 'ajaxpoll_vote' )} " .
			"SET poll_actor=(SELECT actor_id FROM {$dbw->tableName( 'actor' )} WHERE actor_name=poll_user)",
			__METHOD__
		);

		// After the update we can create a unique key
		$dbw->sourceFile( __DIR__ . '/../sql/create-unique-index-poll_id_actor.sql' );

		return true;
	}
}

$maintClass = MigrateOldAJAXPollUserColumnsToActor::class;
require_once RUN_MAINTENANCE_IF_MAIN;