<?php

declare(strict_types=1);

namespace UserAccessManager\Setup\Update;

class DatabaseUpdate1 extends DatabaseUpdate
{
    public function getVersion(): string
    {
        return '1.0';
    }

    private function updateToUserGroupTableUpdate(string $userGroupTable): bool
    {
        $alterQuery = "ALTER TABLE `{$userGroupTable}`
            ADD `read_access` TINYTEXT NOT NULL DEFAULT '',
            ADD `write_access` TINYTEXT NOT NULL DEFAULT '',
            ADD `ip_range` MEDIUMTEXT NULL DEFAULT ''";

        $this->database->query($alterQuery);

        $updateQuery = "UPDATE `$userGroupTable` SET `read_access` = 'group', `write_access` = 'group'";
        $success = $this->database->query($updateQuery) !== false;

        $selectQuery = "SHOW COLUMNS FROM `$userGroupTable` LIKE 'ip_range'";
        $dbIpRange = (string) $this->database->getVariable($selectQuery);

        if ($dbIpRange !== 'ip_range') {
            $alterQuery = "ALTER TABLE `$userGroupTable` ADD `ip_range` MEDIUMTEXT NULL DEFAULT ''";
            $success = $this->database->query($alterQuery) !== false;
        }

        return $success;
    }

    /**
     * @param string[] $legacyTables Legacy per-object-type tables, keyed by object type.
     */
    private function getObjectSelectQuery(string $objectType, array $legacyTables): ?string
    {
        if ($this->objectHandler->isPostType($objectType) === true) {
            $source = '`' . $legacyTables['post'] . '`, `' . $this->database->getPostsTable() . '`';

            return "SELECT `post_id` AS `id`, `group_id` AS `groupId` FROM $source"
                . " WHERE `post_id` = `ID` AND `post_type` = '$objectType'";
        }

        $idColumns = [
            'category' => 'category_id',
            'user' => 'user_id',
            'role' => 'role_name'
        ];

        if (isset($idColumns[$objectType]) === false) {
            return null;
        }

        return "SELECT `{$idColumns[$objectType]}` AS `id`, `group_id` AS `groupId`
            FROM `{$legacyTables[$objectType]}`";
    }

    /**
     * The object types whose assignments the legacy tables can hold. getObjectTypes() only
     * knows post types and taxonomies, so the user and role types have to be added for
     * their own legacy tables, whose rows would otherwise be dropped unmigrated.
     *
     * @return string[]
     */
    private function getMigratableObjectTypes(): array
    {
        return array_merge($this->objectHandler->getObjectTypes(), ['user', 'role']);
    }

    private function updateToUserGroupToObjectTableUpdate(): bool
    {
        $prefix = $this->database->getPrefix();
        $charsetCollate = $this->database->getColumnCharset();
        $userGroupToObject = $prefix . 'uam_accessgroup_to_object';
        $legacyTables = [
            'post' => $prefix . 'uam_accessgroup_to_post',
            'user' => $prefix . 'uam_accessgroup_to_user',
            'category' => $prefix . 'uam_accessgroup_to_category',
            'role' => $prefix . 'uam_accessgroup_to_role'
        ];

        $alterQuery = "ALTER TABLE `$userGroupToObject`
            CHANGE `object_id` `object_id` VARCHAR(64) $charsetCollate";
        $success = $this->database->query($alterQuery) !== false;

        if ($success === false) {
            return false;
        }

        foreach ($this->getMigratableObjectTypes() as $objectType) {
            $query = $this->getObjectSelectQuery($objectType, $legacyTables);

            if ($query === null) {
                continue;
            }

            $dbObjects = (array) $this->database->getResults($query);

            foreach ($dbObjects as $dbObject) {
                $insert = $this->database->insert(
                    $userGroupToObject,
                    [
                        'group_id' => $dbObject->groupId,
                        'object_id' => $dbObject->id,
                        'object_type' => $objectType
                    ],
                    // All three are strings, roles carry their name as the object id.
                    [
                        '%s',
                        '%s',
                        '%s'
                    ]
                );
                $success = $success && $insert !== false;
            }
        }

        $dropQuery = 'DROP TABLE IF EXISTS `' . implode('`, `', $legacyTables) . '`';

        return $success && $this->database->query($dropQuery) !== false;
    }

    public function update(): bool
    {
        $success = true;
        $userGroupTable = $this->database->getUserGroupTable();
        $dbUserGroup = $this->database->getVariable("SHOW TABLES LIKE '$userGroupTable'");

        if ($dbUserGroup === $userGroupTable) {
            $success = $this->updateToUserGroupTableUpdate($userGroupTable);
        }

        return $success && $this->updateToUserGroupToObjectTableUpdate();
    }
}