// Copyright (C) 2019 Nicola Murino
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, version 3.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

//go:build !nomysql
// +build !nomysql

package dataprovider

import (
	"context"
	"crypto/tls"
	"crypto/x509"
	"database/sql"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/go-sql-driver/mysql"

	"github.com/drakkan/sftpgo/v2/internal/logger"
	"github.com/drakkan/sftpgo/v2/internal/util"
	"github.com/drakkan/sftpgo/v2/internal/version"
	"github.com/drakkan/sftpgo/v2/internal/vfs"
)

const (
	mysqlResetSQL = "DROP TABLE IF EXISTS `{{api_keys}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{folders_mapping}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{users_folders_mapping}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{users_groups_mapping}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{admins_groups_mapping}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{groups_folders_mapping}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{admins}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{folders}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{shares}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{users}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{groups}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{defender_events}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{defender_hosts}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{active_transfers}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{shared_sessions}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{rules_actions_mapping}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{events_actions}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{events_rules}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{tasks}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{nodes}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{roles}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{ip_lists}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{configs}}` CASCADE;" +
		"DROP TABLE IF EXISTS `{{schema_version}}` CASCADE;"
	mysqlInitialSQL = "CREATE TABLE `{{schema_version}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `version` integer NOT NULL);" +
		"CREATE TABLE `{{admins}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `username` varchar(255) NOT NULL UNIQUE, " +
		"`description` varchar(512) NULL, `password` varchar(255) NOT NULL, `email` varchar(255) NULL, `status` integer NOT NULL, " +
		"`permissions` longtext NOT NULL, `filters` longtext NULL, `additional_info` longtext NULL, `last_login` bigint NOT NULL, " +
		"`role_id` integer NULL, `created_at` bigint NOT NULL, `updated_at` bigint NOT NULL);" +
		"CREATE TABLE `{{active_transfers}}` (`id` bigint AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`connection_id` varchar(100) NOT NULL, `transfer_id` bigint NOT NULL, `transfer_type` integer NOT NULL, " +
		"`username` varchar(255) NOT NULL, `folder_name` varchar(255) NULL, `ip` varchar(50) NOT NULL, " +
		"`truncated_size` bigint NOT NULL, `current_ul_size` bigint NOT NULL, `current_dl_size` bigint NOT NULL, " +
		"`created_at` bigint NOT NULL, `updated_at` bigint NOT NULL);" +
		"CREATE TABLE `{{defender_hosts}}` (`id` bigint AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`ip` varchar(50) NOT NULL UNIQUE, `ban_time` bigint NOT NULL, `updated_at` bigint NOT NULL);" +
		"CREATE TABLE `{{defender_events}}` (`id` bigint AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`date_time` bigint NOT NULL, `score` integer NOT NULL, `host_id` bigint NOT NULL);" +
		"ALTER TABLE `{{defender_events}}` ADD CONSTRAINT `{{prefix}}defender_events_host_id_fk_defender_hosts_id` " +
		"FOREIGN KEY (`host_id`) REFERENCES `{{defender_hosts}}` (`id`) ON DELETE CASCADE;" +
		"CREATE TABLE `{{folders}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `name` varchar(255) NOT NULL UNIQUE, " +
		"`description` varchar(512) NULL, `path` longtext NULL, `used_quota_size` bigint NOT NULL, " +
		"`used_quota_files` integer NOT NULL, `last_quota_update` bigint NOT NULL, `filesystem` longtext NULL);" +
		"CREATE TABLE `{{groups}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`name` varchar(255) NOT NULL UNIQUE, `description` varchar(512) NULL, `created_at` bigint NOT NULL, " +
		"`updated_at` bigint NOT NULL, `user_settings` longtext NULL);" +
		"CREATE TABLE `{{shared_sessions}}` (`key` varchar(128) NOT NULL PRIMARY KEY, " +
		"`data` longtext NOT NULL, `type` integer NOT NULL, `timestamp` bigint NOT NULL);" +
		"CREATE TABLE `{{users}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `username` varchar(255) NOT NULL UNIQUE, " +
		"`status` integer NOT NULL, `expiration_date` bigint NOT NULL, `description` varchar(512) NULL, `password` longtext NULL, " +
		"`public_keys` longtext NULL, `home_dir` longtext NOT NULL, `uid` bigint NOT NULL, `gid` bigint NOT NULL, " +
		"`max_sessions` integer NOT NULL, `quota_size` bigint NOT NULL, `quota_files` integer NOT NULL, " +
		"`permissions` longtext NOT NULL, `used_quota_size` bigint NOT NULL, `used_quota_files` integer NOT NULL, " +
		"`last_quota_update` bigint NOT NULL, `upload_bandwidth` integer NOT NULL, `download_bandwidth` integer NOT NULL, " +
		"`last_login` bigint NOT NULL, `filters` longtext NULL, `filesystem` longtext NULL, `additional_info` longtext NULL, " +
		"`created_at` bigint NOT NULL, `updated_at` bigint NOT NULL, `email` varchar(255) NULL, " +
		"`upload_data_transfer` integer NOT NULL, `download_data_transfer` integer NOT NULL, " +
		"`total_data_transfer` integer NOT NULL, `used_upload_data_transfer` integer NOT NULL, " +
		"`used_download_data_transfer` integer NOT NULL, `deleted_at` bigint NOT NULL, `first_download` bigint NOT NULL, " +
		"`first_upload` bigint NOT NULL, `last_password_change` bigint NOT NULL, `role_id` integer NULL);" +
		"CREATE TABLE `{{groups_folders_mapping}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`group_id` integer NOT NULL, `folder_id` integer NOT NULL, " +
		"`virtual_path` longtext NOT NULL, `quota_size` bigint NOT NULL, `quota_files` integer NOT NULL);" +
		"CREATE TABLE `{{users_groups_mapping}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`user_id` integer NOT NULL, `group_id` integer NOT NULL, `group_type` integer NOT NULL);" +
		"CREATE TABLE `{{users_folders_mapping}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `virtual_path` longtext NOT NULL, " +
		"`quota_size` bigint NOT NULL, `quota_files` integer NOT NULL, `folder_id` integer NOT NULL, `user_id` integer NOT NULL);" +
		"ALTER TABLE `{{users_folders_mapping}}` ADD CONSTRAINT `{{prefix}}unique_user_folder_mapping` " +
		"UNIQUE (`user_id`, `folder_id`);" +
		"ALTER TABLE `{{users_folders_mapping}}` ADD CONSTRAINT `{{prefix}}users_folders_mapping_user_id_fk_users_id` " +
		"FOREIGN KEY (`user_id`) REFERENCES `{{users}}` (`id`) ON DELETE CASCADE;" +
		"ALTER TABLE `{{users_folders_mapping}}` ADD CONSTRAINT `{{prefix}}users_folders_mapping_folder_id_fk_folders_id` " +
		"FOREIGN KEY (`folder_id`) REFERENCES `{{folders}}` (`id`) ON DELETE CASCADE;" +
		"ALTER TABLE `{{users_groups_mapping}}` ADD CONSTRAINT `{{prefix}}unique_user_group_mapping` UNIQUE (`user_id`, `group_id`);" +
		"ALTER TABLE `{{groups_folders_mapping}}` ADD CONSTRAINT `{{prefix}}unique_group_folder_mapping` UNIQUE (`group_id`, `folder_id`);" +
		"ALTER TABLE `{{users_groups_mapping}}` ADD CONSTRAINT `{{prefix}}users_groups_mapping_group_id_fk_groups_id` " +
		"FOREIGN KEY (`group_id`) REFERENCES `{{groups}}` (`id`) ON DELETE NO ACTION;" +
		"ALTER TABLE `{{users_groups_mapping}}` ADD CONSTRAINT `{{prefix}}users_groups_mapping_user_id_fk_users_id` " +
		"FOREIGN KEY (`user_id`) REFERENCES `{{users}}` (`id`) ON DELETE CASCADE; " +
		"ALTER TABLE `{{groups_folders_mapping}}` ADD CONSTRAINT `{{prefix}}groups_folders_mapping_folder_id_fk_folders_id` " +
		"FOREIGN KEY (`folder_id`) REFERENCES `{{folders}}` (`id`) ON DELETE CASCADE;" +
		"ALTER TABLE `{{groups_folders_mapping}}` ADD CONSTRAINT `{{prefix}}groups_folders_mapping_group_id_fk_groups_id` " +
		"FOREIGN KEY (`group_id`) REFERENCES `{{groups}}` (`id`) ON DELETE CASCADE;" +
		"CREATE TABLE `{{shares}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`share_id` varchar(60) NOT NULL UNIQUE, `name` varchar(255) NOT NULL, `description` varchar(512) NULL, " +
		"`scope` integer NOT NULL, `paths` longtext NOT NULL, `created_at` bigint NOT NULL, " +
		"`updated_at` bigint NOT NULL, `last_use_at` bigint NOT NULL, `expires_at` bigint NOT NULL, " +
		"`password` longtext NULL, `max_tokens` integer NOT NULL, `used_tokens` integer NOT NULL, " +
		"`allow_from` longtext NULL, `user_id` integer NOT NULL);" +
		"ALTER TABLE `{{shares}}` ADD CONSTRAINT `{{prefix}}shares_user_id_fk_users_id` " +
		"FOREIGN KEY (`user_id`) REFERENCES `{{users}}` (`id`) ON DELETE CASCADE;" +
		"CREATE TABLE `{{api_keys}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `name` varchar(255) NOT NULL, `key_id` varchar(50) NOT NULL UNIQUE," +
		"`api_key` varchar(255) NOT NULL UNIQUE, `scope` integer NOT NULL, `created_at` bigint NOT NULL, `updated_at` bigint NOT NULL, `last_use_at` bigint NOT NULL, " +
		"`expires_at` bigint NOT NULL, `description` longtext NULL, `admin_id` integer NULL, `user_id` integer NULL);" +
		"ALTER TABLE `{{api_keys}}` ADD CONSTRAINT `{{prefix}}api_keys_admin_id_fk_admins_id` FOREIGN KEY (`admin_id`) REFERENCES `{{admins}}` (`id`) ON DELETE CASCADE;" +
		"ALTER TABLE `{{api_keys}}` ADD CONSTRAINT `{{prefix}}api_keys_user_id_fk_users_id` FOREIGN KEY (`user_id`) REFERENCES `{{users}}` (`id`) ON DELETE CASCADE;" +
		"CREATE TABLE `{{events_rules}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`name` varchar(255) NOT NULL UNIQUE, `status` integer NOT NULL, `description` varchar(512) NULL, `created_at` bigint NOT NULL, " +
		"`updated_at` bigint NOT NULL, `trigger` integer NOT NULL, `conditions` longtext NOT NULL, `deleted_at` bigint NOT NULL);" +
		"CREATE TABLE `{{events_actions}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`name` varchar(255) NOT NULL UNIQUE, `description` varchar(512) NULL, `type` integer NOT NULL, " +
		"`options` longtext NOT NULL);" +
		"CREATE TABLE `{{rules_actions_mapping}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`rule_id` integer NOT NULL, `action_id` integer NOT NULL, `order` integer NOT NULL, `options` longtext NOT NULL);" +
		"CREATE TABLE `{{tasks}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `name` varchar(255) NOT NULL UNIQUE, " +
		"`updated_at` bigint NOT NULL, `version` bigint NOT NULL);" +
		"ALTER TABLE `{{rules_actions_mapping}}` ADD CONSTRAINT `{{prefix}}unique_rule_action_mapping` UNIQUE (`rule_id`, `action_id`);" +
		"ALTER TABLE `{{rules_actions_mapping}}` ADD CONSTRAINT `{{prefix}}rules_actions_mapping_rule_id_fk_events_rules_id` " +
		"FOREIGN KEY (`rule_id`) REFERENCES `{{events_rules}}` (`id`) ON DELETE CASCADE;" +
		"ALTER TABLE `{{rules_actions_mapping}}` ADD CONSTRAINT `{{prefix}}rules_actions_mapping_action_id_fk_events_targets_id` " +
		"FOREIGN KEY (`action_id`) REFERENCES `{{events_actions}}` (`id`) ON DELETE NO ACTION;" +
		"CREATE TABLE `{{admins_groups_mapping}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		" `admin_id` integer NOT NULL, `group_id` integer NOT NULL, `options` longtext NOT NULL);" +
		"ALTER TABLE `{{admins_groups_mapping}}` ADD CONSTRAINT `{{prefix}}unique_admin_group_mapping` " +
		"UNIQUE (`admin_id`, `group_id`);" +
		"ALTER TABLE `{{admins_groups_mapping}}` ADD CONSTRAINT `{{prefix}}admins_groups_mapping_admin_id_fk_admins_id` " +
		"FOREIGN KEY (`admin_id`) REFERENCES `{{admins}}` (`id`) ON DELETE CASCADE;" +
		"ALTER TABLE `{{admins_groups_mapping}}` ADD CONSTRAINT `{{prefix}}admins_groups_mapping_group_id_fk_groups_id` " +
		"FOREIGN KEY (`group_id`) REFERENCES `{{groups}}` (`id`) ON DELETE CASCADE;" +
		"CREATE TABLE `{{nodes}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, " +
		"`name` varchar(255) NOT NULL UNIQUE, `data` longtext NOT NULL, `created_at` bigint NOT NULL, " +
		"`updated_at` bigint NOT NULL);" +
		"CREATE TABLE `{{roles}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `name` varchar(255) NOT NULL UNIQUE, " +
		"`description` varchar(512) NULL, `created_at` bigint NOT NULL, `updated_at` bigint NOT NULL);" +
		"ALTER TABLE `{{admins}}` ADD CONSTRAINT `{{prefix}}admins_role_id_fk_roles_id` FOREIGN KEY (`role_id`) " +
		"REFERENCES `{{roles}}`(`id`) ON DELETE NO ACTION;" +
		"ALTER TABLE `{{users}}` ADD CONSTRAINT `{{prefix}}users_role_id_fk_roles_id` FOREIGN KEY (`role_id`) " +
		"REFERENCES `{{roles}}`(`id`) ON DELETE SET NULL;" +
		"CREATE TABLE `{{ip_lists}}` (`id` bigint AUTO_INCREMENT NOT NULL PRIMARY KEY, `type` integer NOT NULL, " +
		"`ipornet` varchar(50) NOT NULL, `mode` integer NOT NULL, `description` varchar(512) NULL, " +
		"`first` VARBINARY(16) NOT NULL, `last` VARBINARY(16) NOT NULL, `ip_type` integer NOT NULL, `protocols` integer NOT NULL, " +
		"`created_at` bigint NOT NULL, `updated_at` bigint NOT NULL, `deleted_at` bigint NOT NULL);" +
		"ALTER TABLE `{{ip_lists}}` ADD CONSTRAINT `{{prefix}}unique_ipornet_type_mapping` UNIQUE (`type`, `ipornet`);" +
		"CREATE TABLE `{{configs}}` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `configs` longtext NOT NULL);" +
		"INSERT INTO {{configs}} (configs) VALUES ('{}');" +
		"CREATE INDEX `{{prefix}}users_updated_at_idx` ON `{{users}}` (`updated_at`);" +
		"CREATE INDEX `{{prefix}}users_deleted_at_idx` ON `{{users}}` (`deleted_at`);" +
		"CREATE INDEX `{{prefix}}defender_hosts_updated_at_idx` ON `{{defender_hosts}}` (`updated_at`);" +
		"CREATE INDEX `{{prefix}}defender_hosts_ban_time_idx` ON `{{defender_hosts}}` (`ban_time`);" +
		"CREATE INDEX `{{prefix}}defender_events_date_time_idx` ON `{{defender_events}}` (`date_time`);" +
		"CREATE INDEX `{{prefix}}active_transfers_connection_id_idx` ON `{{active_transfers}}` (`connection_id`);" +
		"CREATE INDEX `{{prefix}}active_transfers_transfer_id_idx` ON `{{active_transfers}}` (`transfer_id`);" +
		"CREATE INDEX `{{prefix}}active_transfers_updated_at_idx` ON `{{active_transfers}}` (`updated_at`);" +
		"CREATE INDEX `{{prefix}}shared_sessions_type_idx` ON `{{shared_sessions}}` (`type`);" +
		"CREATE INDEX `{{prefix}}shared_sessions_timestamp_idx` ON `{{shared_sessions}}` (`timestamp`);" +
		"CREATE INDEX `{{prefix}}events_rules_updated_at_idx` ON `{{events_rules}}` (`updated_at`);" +
		"CREATE INDEX `{{prefix}}events_rules_deleted_at_idx` ON `{{events_rules}}` (`deleted_at`);" +
		"CREATE INDEX `{{prefix}}events_rules_trigger_idx` ON `{{events_rules}}` (`trigger`);" +
		"CREATE INDEX `{{prefix}}rules_actions_mapping_order_idx` ON `{{rules_actions_mapping}}` (`order`);" +
		"CREATE INDEX `{{prefix}}ip_lists_type_idx` ON `{{ip_lists}}` (`type`);" +
		"CREATE INDEX `{{prefix}}ip_lists_ipornet_idx` ON `{{ip_lists}}` (`ipornet`);" +
		"CREATE INDEX `{{prefix}}ip_lists_ip_type_idx` ON `{{ip_lists}}` (`ip_type`);" +
		"CREATE INDEX `{{prefix}}ip_lists_updated_at_idx` ON `{{ip_lists}}` (`updated_at`);" +
		"CREATE INDEX `{{prefix}}ip_lists_deleted_at_idx` ON `{{ip_lists}}` (`deleted_at`);" +
		"CREATE INDEX `{{prefix}}ip_lists_first_last_idx` ON `{{ip_lists}}` (`first`, `last`);" +
		"INSERT INTO {{schema_version}} (version) VALUES (28);"
	mysqlV29SQL = "ALTER TABLE `{{users}}` MODIFY `used_download_data_transfer` bigint NOT NULL;" +
		"ALTER TABLE `{{users}}` MODIFY `used_upload_data_transfer` bigint NOT NULL;"
	mysqlV29DownSQL = "ALTER TABLE `{{users}}` MODIFY `used_upload_data_transfer` integer NOT NULL;" +
		"ALTER TABLE `{{users}}` MODIFY `used_download_data_transfer` integer NOT NULL;"
)

// MySQLProvider defines the auth provider for MySQL/MariaDB database
type MySQLProvider struct {
	dbHandle *sql.DB
}

func init() {
	version.AddFeature("+mysql")
}

func initializeMySQLProvider() error {
	connString, err := getMySQLConnectionString(false)
	if err != nil {
		return err
	}
	redactedConnString, err := getMySQLConnectionString(true)
	if err != nil {
		return err
	}
	dbHandle, err := sql.Open("mysql", connString)
	if err != nil {
		providerLog(logger.LevelError, "error creating mysql database handler, connection string: %q, error: %v",
			redactedConnString, err)
		return err
	}
	providerLog(logger.LevelDebug, "mysql database handle created, connection string: %q, pool size: %v",
		redactedConnString, config.PoolSize)
	dbHandle.SetMaxOpenConns(config.PoolSize)
	if config.PoolSize > 0 {
		dbHandle.SetMaxIdleConns(config.PoolSize)
	} else {
		dbHandle.SetMaxIdleConns(2)
	}
	dbHandle.SetConnMaxLifetime(240 * time.Second)
	dbHandle.SetConnMaxIdleTime(120 * time.Second)
	provider = &MySQLProvider{dbHandle: dbHandle}

	ctx, cancel := context.WithTimeout(context.Background(), defaultSQLQueryTimeout)
	defer cancel()

	return dbHandle.PingContext(ctx)
}
func getMySQLConnectionString(redactedPwd bool) (string, error) {
	var connectionString string
	if config.ConnectionString == "" {
		password := config.Password
		if redactedPwd && password != "" {
			password = "[redacted]"
		}
		sslMode := getSSLMode()
		if sslMode == "custom" && !redactedPwd {
			if err := registerMySQLCustomTLSConfig(); err != nil {
				return "", err
			}
		}
		connectionString = fmt.Sprintf("%s:%s@tcp([%s]:%d)/%s?collation=utf8mb4_unicode_ci&interpolateParams=true&timeout=10s&parseTime=true&clientFoundRows=true&tls=%s&writeTimeout=60s&readTimeout=60s",
			config.Username, password, config.Host, config.Port, config.Name, sslMode)
	} else {
		connectionString = config.ConnectionString
	}
	return connectionString, nil
}

func registerMySQLCustomTLSConfig() error {
	tlsConfig := &tls.Config{}
	if config.RootCert != "" {
		rootCAs, err := x509.SystemCertPool()
		if err != nil {
			rootCAs = x509.NewCertPool()
		}
		rootCrt, err := os.ReadFile(config.RootCert)
		if err != nil {
			return fmt.Errorf("unable to load root certificate %q: %v", config.RootCert, err)
		}
		if !rootCAs.AppendCertsFromPEM(rootCrt) {
			return fmt.Errorf("unable to parse root certificate %q", config.RootCert)
		}
		tlsConfig.RootCAs = rootCAs
	}
	if config.ClientCert != "" && config.ClientKey != "" {
		clientCert := make([]tls.Certificate, 0, 1)
		tlsCert, err := tls.LoadX509KeyPair(config.ClientCert, config.ClientKey)
		if err != nil {
			return fmt.Errorf("unable to load key pair %q, %q: %v", config.ClientCert, config.ClientKey, err)
		}
		clientCert = append(clientCert, tlsCert)
		tlsConfig.Certificates = clientCert
	}
	if config.SSLMode == 2 || config.SSLMode == 3 {
		tlsConfig.InsecureSkipVerify = true
	}
	if !filepath.IsAbs(config.Host) && !config.DisableSNI {
		tlsConfig.ServerName = config.Host
	}
	providerLog(logger.LevelInfo, "registering custom TLS config, root cert %q, client cert %q, client key %q, disable SNI? %v",
		config.RootCert, config.ClientCert, config.ClientKey, config.DisableSNI)
	if err := mysql.RegisterTLSConfig("custom", tlsConfig); err != nil {
		return fmt.Errorf("unable to register tls config: %v", err)
	}
	return nil
}

func (p *MySQLProvider) checkAvailability() error {
	return sqlCommonCheckAvailability(p.dbHandle)
}

func (p *MySQLProvider) validateUserAndPass(username, password, ip, protocol string) (User, error) {
	return sqlCommonValidateUserAndPass(username, password, ip, protocol, p.dbHandle)
}

func (p *MySQLProvider) validateUserAndTLSCert(username, protocol string, tlsCert *x509.Certificate) (User, error) {
	return sqlCommonValidateUserAndTLSCertificate(username, protocol, tlsCert, p.dbHandle)
}

func (p *MySQLProvider) validateUserAndPubKey(username string, publicKey []byte, isSSHCert bool) (User, string, error) {
	return sqlCommonValidateUserAndPubKey(username, publicKey, isSSHCert, p.dbHandle)
}

func (p *MySQLProvider) updateTransferQuota(username string, uploadSize, downloadSize int64, reset bool) error {
	return sqlCommonUpdateTransferQuota(username, uploadSize, downloadSize, reset, p.dbHandle)
}

func (p *MySQLProvider) updateQuota(username string, filesAdd int, sizeAdd int64, reset bool) error {
	return sqlCommonUpdateQuota(username, filesAdd, sizeAdd, reset, p.dbHandle)
}

func (p *MySQLProvider) getUsedQuota(username string) (int, int64, int64, int64, error) {
	return sqlCommonGetUsedQuota(username, p.dbHandle)
}

func (p *MySQLProvider) setUpdatedAt(username string) {
	sqlCommonSetUpdatedAt(username, p.dbHandle)
}

func (p *MySQLProvider) updateLastLogin(username string) error {
	return sqlCommonUpdateLastLogin(username, p.dbHandle)
}

func (p *MySQLProvider) updateAdminLastLogin(username string) error {
	return sqlCommonUpdateAdminLastLogin(username, p.dbHandle)
}

func (p *MySQLProvider) userExists(username, role string) (User, error) {
	return sqlCommonGetUserByUsername(username, role, p.dbHandle)
}

func (p *MySQLProvider) addUser(user *User) error {
	return p.normalizeError(sqlCommonAddUser(user, p.dbHandle), fieldUsername)
}

func (p *MySQLProvider) updateUser(user *User) error {
	return p.normalizeError(sqlCommonUpdateUser(user, p.dbHandle), -1)
}

func (p *MySQLProvider) deleteUser(user User, softDelete bool) error {
	return sqlCommonDeleteUser(user, softDelete, p.dbHandle)
}

func (p *MySQLProvider) updateUserPassword(username, password string) error {
	return sqlCommonUpdateUserPassword(username, password, p.dbHandle)
}

func (p *MySQLProvider) dumpUsers() ([]User, error) {
	return sqlCommonDumpUsers(p.dbHandle)
}

func (p *MySQLProvider) getRecentlyUpdatedUsers(after int64) ([]User, error) {
	return sqlCommonGetRecentlyUpdatedUsers(after, p.dbHandle)
}

func (p *MySQLProvider) getUsers(limit int, offset int, order, role string) ([]User, error) {
	return sqlCommonGetUsers(limit, offset, order, role, p.dbHandle)
}

func (p *MySQLProvider) getUsersForQuotaCheck(toFetch map[string]bool) ([]User, error) {
	return sqlCommonGetUsersForQuotaCheck(toFetch, p.dbHandle)
}

func (p *MySQLProvider) dumpFolders() ([]vfs.BaseVirtualFolder, error) {
	return sqlCommonDumpFolders(p.dbHandle)
}

func (p *MySQLProvider) getFolders(limit, offset int, order string, minimal bool) ([]vfs.BaseVirtualFolder, error) {
	return sqlCommonGetFolders(limit, offset, order, minimal, p.dbHandle)
}

func (p *MySQLProvider) getFolderByName(name string) (vfs.BaseVirtualFolder, error) {
	ctx, cancel := context.WithTimeout(context.Background(), defaultSQLQueryTimeout)
	defer cancel()
	return sqlCommonGetFolderByName(ctx, name, p.dbHandle)
}

func (p *MySQLProvider) addFolder(folder *vfs.BaseVirtualFolder) error {
	return p.normalizeError(sqlCommonAddFolder(folder, p.dbHandle), fieldName)
}

func (p *MySQLProvider) updateFolder(folder *vfs.BaseVirtualFolder) error {
	return sqlCommonUpdateFolder(folder, p.dbHandle)
}

func (p *MySQLProvider) deleteFolder(folder vfs.BaseVirtualFolder) error {
	return sqlCommonDeleteFolder(folder, p.dbHandle)
}

func (p *MySQLProvider) updateFolderQuota(name string, filesAdd int, sizeAdd int64, reset bool) error {
	return sqlCommonUpdateFolderQuota(name, filesAdd, sizeAdd, reset, p.dbHandle)
}

func (p *MySQLProvider) getUsedFolderQuota(name string) (int, int64, error) {
	return sqlCommonGetFolderUsedQuota(name, p.dbHandle)
}

func (p *MySQLProvider) getGroups(limit, offset int, order string, minimal bool) ([]Group, error) {
	return sqlCommonGetGroups(limit, offset, order, minimal, p.dbHandle)
}

func (p *MySQLProvider) getGroupsWithNames(names []string) ([]Group, error) {
	return sqlCommonGetGroupsWithNames(names, p.dbHandle)
}

func (p *MySQLProvider) getUsersInGroups(names []string) ([]string, error) {
	return sqlCommonGetUsersInGroups(names, p.dbHandle)
}

func (p *MySQLProvider) groupExists(name string) (Group, error) {
	return sqlCommonGetGroupByName(name, p.dbHandle)
}

func (p *MySQLProvider) addGroup(group *Group) error {
	return p.normalizeError(sqlCommonAddGroup(group, p.dbHandle), fieldName)
}

func (p *MySQLProvider) updateGroup(group *Group) error {
	return sqlCommonUpdateGroup(group, p.dbHandle)
}

func (p *MySQLProvider) deleteGroup(group Group) error {
	return sqlCommonDeleteGroup(group, p.dbHandle)
}

func (p *MySQLProvider) dumpGroups() ([]Group, error) {
	return sqlCommonDumpGroups(p.dbHandle)
}

func (p *MySQLProvider) adminExists(username string) (Admin, error) {
	return sqlCommonGetAdminByUsername(username, p.dbHandle)
}

func (p *MySQLProvider) addAdmin(admin *Admin) error {
	return p.normalizeError(sqlCommonAddAdmin(admin, p.dbHandle), fieldUsername)
}

func (p *MySQLProvider) updateAdmin(admin *Admin) error {
	return p.normalizeError(sqlCommonUpdateAdmin(admin, p.dbHandle), -1)
}

func (p *MySQLProvider) deleteAdmin(admin Admin) error {
	return sqlCommonDeleteAdmin(admin, p.dbHandle)
}

func (p *MySQLProvider) getAdmins(limit int, offset int, order string) ([]Admin, error) {
	return sqlCommonGetAdmins(limit, offset, order, p.dbHandle)
}

func (p *MySQLProvider) dumpAdmins() ([]Admin, error) {
	return sqlCommonDumpAdmins(p.dbHandle)
}

func (p *MySQLProvider) validateAdminAndPass(username, password, ip string) (Admin, error) {
	return sqlCommonValidateAdminAndPass(username, password, ip, p.dbHandle)
}

func (p *MySQLProvider) apiKeyExists(keyID string) (APIKey, error) {
	return sqlCommonGetAPIKeyByID(keyID, p.dbHandle)
}

func (p *MySQLProvider) addAPIKey(apiKey *APIKey) error {
	return p.normalizeError(sqlCommonAddAPIKey(apiKey, p.dbHandle), -1)
}

func (p *MySQLProvider) updateAPIKey(apiKey *APIKey) error {
	return p.normalizeError(sqlCommonUpdateAPIKey(apiKey, p.dbHandle), -1)
}

func (p *MySQLProvider) deleteAPIKey(apiKey APIKey) error {
	return sqlCommonDeleteAPIKey(apiKey, p.dbHandle)
}

func (p *MySQLProvider) getAPIKeys(limit int, offset int, order string) ([]APIKey, error) {
	return sqlCommonGetAPIKeys(limit, offset, order, p.dbHandle)
}

func (p *MySQLProvider) dumpAPIKeys() ([]APIKey, error) {
	return sqlCommonDumpAPIKeys(p.dbHandle)
}

func (p *MySQLProvider) updateAPIKeyLastUse(keyID string) error {
	return sqlCommonUpdateAPIKeyLastUse(keyID, p.dbHandle)
}

func (p *MySQLProvider) shareExists(shareID, username string) (Share, error) {
	return sqlCommonGetShareByID(shareID, username, p.dbHandle)
}

func (p *MySQLProvider) addShare(share *Share) error {
	return p.normalizeError(sqlCommonAddShare(share, p.dbHandle), fieldName)
}

func (p *MySQLProvider) updateShare(share *Share) error {
	return p.normalizeError(sqlCommonUpdateShare(share, p.dbHandle), -1)
}

func (p *MySQLProvider) deleteShare(share Share) error {
	return sqlCommonDeleteShare(share, p.dbHandle)
}

func (p *MySQLProvider) getShares(limit int, offset int, order, username string) ([]Share, error) {
	return sqlCommonGetShares(limit, offset, order, username, p.dbHandle)
}

func (p *MySQLProvider) dumpShares() ([]Share, error) {
	return sqlCommonDumpShares(p.dbHandle)
}

func (p *MySQLProvider) updateShareLastUse(shareID string, numTokens int) error {
	return sqlCommonUpdateShareLastUse(shareID, numTokens, p.dbHandle)
}

func (p *MySQLProvider) getDefenderHosts(from int64, limit int) ([]DefenderEntry, error) {
	return sqlCommonGetDefenderHosts(from, limit, p.dbHandle)
}

func (p *MySQLProvider) getDefenderHostByIP(ip string, from int64) (DefenderEntry, error) {
	return sqlCommonGetDefenderHostByIP(ip, from, p.dbHandle)
}

func (p *MySQLProvider) isDefenderHostBanned(ip string) (DefenderEntry, error) {
	return sqlCommonIsDefenderHostBanned(ip, p.dbHandle)
}

func (p *MySQLProvider) updateDefenderBanTime(ip string, minutes int) error {
	return sqlCommonDefenderIncrementBanTime(ip, minutes, p.dbHandle)
}

func (p *MySQLProvider) deleteDefenderHost(ip string) error {
	return sqlCommonDeleteDefenderHost(ip, p.dbHandle)
}

func (p *MySQLProvider) addDefenderEvent(ip string, score int) error {
	return sqlCommonAddDefenderHostAndEvent(ip, score, p.dbHandle)
}

func (p *MySQLProvider) setDefenderBanTime(ip string, banTime int64) error {
	return sqlCommonSetDefenderBanTime(ip, banTime, p.dbHandle)
}

func (p *MySQLProvider) cleanupDefender(from int64) error {
	return sqlCommonDefenderCleanup(from, p.dbHandle)
}

func (p *MySQLProvider) addActiveTransfer(transfer ActiveTransfer) error {
	return sqlCommonAddActiveTransfer(transfer, p.dbHandle)
}

func (p *MySQLProvider) updateActiveTransferSizes(ulSize, dlSize, transferID int64, connectionID string) error {
	return sqlCommonUpdateActiveTransferSizes(ulSize, dlSize, transferID, connectionID, p.dbHandle)
}

func (p *MySQLProvider) removeActiveTransfer(transferID int64, connectionID string) error {
	return sqlCommonRemoveActiveTransfer(transferID, connectionID, p.dbHandle)
}

func (p *MySQLProvider) cleanupActiveTransfers(before time.Time) error {
	return sqlCommonCleanupActiveTransfers(before, p.dbHandle)
}

func (p *MySQLProvider) getActiveTransfers(from time.Time) ([]ActiveTransfer, error) {
	return sqlCommonGetActiveTransfers(from, p.dbHandle)
}

func (p *MySQLProvider) addSharedSession(session Session) error {
	return sqlCommonAddSession(session, p.dbHandle)
}

func (p *MySQLProvider) deleteSharedSession(key string) error {
	return sqlCommonDeleteSession(key, p.dbHandle)
}

func (p *MySQLProvider) getSharedSession(key string) (Session, error) {
	return sqlCommonGetSession(key, p.dbHandle)
}

func (p *MySQLProvider) cleanupSharedSessions(sessionType SessionType, before int64) error {
	return sqlCommonCleanupSessions(sessionType, before, p.dbHandle)
}

func (p *MySQLProvider) getEventActions(limit, offset int, order string, minimal bool) ([]BaseEventAction, error) {
	return sqlCommonGetEventActions(limit, offset, order, minimal, p.dbHandle)
}

func (p *MySQLProvider) dumpEventActions() ([]BaseEventAction, error) {
	return sqlCommonDumpEventActions(p.dbHandle)
}

func (p *MySQLProvider) eventActionExists(name string) (BaseEventAction, error) {
	return sqlCommonGetEventActionByName(name, p.dbHandle)
}

func (p *MySQLProvider) addEventAction(action *BaseEventAction) error {
	return p.normalizeError(sqlCommonAddEventAction(action, p.dbHandle), fieldName)
}

func (p *MySQLProvider) updateEventAction(action *BaseEventAction) error {
	return sqlCommonUpdateEventAction(action, p.dbHandle)
}

func (p *MySQLProvider) deleteEventAction(action BaseEventAction) error {
	return sqlCommonDeleteEventAction(action, p.dbHandle)
}

func (p *MySQLProvider) getEventRules(limit, offset int, order string) ([]EventRule, error) {
	return sqlCommonGetEventRules(limit, offset, order, p.dbHandle)
}

func (p *MySQLProvider) dumpEventRules() ([]EventRule, error) {
	return sqlCommonDumpEventRules(p.dbHandle)
}

func (p *MySQLProvider) getRecentlyUpdatedRules(after int64) ([]EventRule, error) {
	return sqlCommonGetRecentlyUpdatedRules(after, p.dbHandle)
}

func (p *MySQLProvider) eventRuleExists(name string) (EventRule, error) {
	return sqlCommonGetEventRuleByName(name, p.dbHandle)
}

func (p *MySQLProvider) addEventRule(rule *EventRule) error {
	return p.normalizeError(sqlCommonAddEventRule(rule, p.dbHandle), fieldName)
}

func (p *MySQLProvider) updateEventRule(rule *EventRule) error {
	return sqlCommonUpdateEventRule(rule, p.dbHandle)
}

func (p *MySQLProvider) deleteEventRule(rule EventRule, softDelete bool) error {
	return sqlCommonDeleteEventRule(rule, softDelete, p.dbHandle)
}

func (p *MySQLProvider) getTaskByName(name string) (Task, error) {
	return sqlCommonGetTaskByName(name, p.dbHandle)
}

func (p *MySQLProvider) addTask(name string) error {
	return sqlCommonAddTask(name, p.dbHandle)
}

func (p *MySQLProvider) updateTask(name string, version int64) error {
	return sqlCommonUpdateTask(name, version, p.dbHandle)
}

func (p *MySQLProvider) updateTaskTimestamp(name string) error {
	return sqlCommonUpdateTaskTimestamp(name, p.dbHandle)
}

func (p *MySQLProvider) addNode() error {
	return sqlCommonAddNode(p.dbHandle)
}

func (p *MySQLProvider) getNodeByName(name string) (Node, error) {
	return sqlCommonGetNodeByName(name, p.dbHandle)
}

func (p *MySQLProvider) getNodes() ([]Node, error) {
	return sqlCommonGetNodes(p.dbHandle)
}

func (p *MySQLProvider) updateNodeTimestamp() error {
	return sqlCommonUpdateNodeTimestamp(p.dbHandle)
}

func (p *MySQLProvider) cleanupNodes() error {
	return sqlCommonCleanupNodes(p.dbHandle)
}

func (p *MySQLProvider) roleExists(name string) (Role, error) {
	return sqlCommonGetRoleByName(name, p.dbHandle)
}

func (p *MySQLProvider) addRole(role *Role) error {
	return p.normalizeError(sqlCommonAddRole(role, p.dbHandle), fieldName)
}

func (p *MySQLProvider) updateRole(role *Role) error {
	return sqlCommonUpdateRole(role, p.dbHandle)
}

func (p *MySQLProvider) deleteRole(role Role) error {
	return sqlCommonDeleteRole(role, p.dbHandle)
}

func (p *MySQLProvider) getRoles(limit int, offset int, order string, minimal bool) ([]Role, error) {
	return sqlCommonGetRoles(limit, offset, order, minimal, p.dbHandle)
}

func (p *MySQLProvider) dumpRoles() ([]Role, error) {
	return sqlCommonDumpRoles(p.dbHandle)
}

func (p *MySQLProvider) ipListEntryExists(ipOrNet string, listType IPListType) (IPListEntry, error) {
	return sqlCommonGetIPListEntry(ipOrNet, listType, p.dbHandle)
}

func (p *MySQLProvider) addIPListEntry(entry *IPListEntry) error {
	return p.normalizeError(sqlCommonAddIPListEntry(entry, p.dbHandle), fieldIPNet)
}

func (p *MySQLProvider) updateIPListEntry(entry *IPListEntry) error {
	return sqlCommonUpdateIPListEntry(entry, p.dbHandle)
}

func (p *MySQLProvider) deleteIPListEntry(entry IPListEntry, softDelete bool) error {
	return sqlCommonDeleteIPListEntry(entry, softDelete, p.dbHandle)
}

func (p *MySQLProvider) getIPListEntries(listType IPListType, filter, from, order string, limit int) ([]IPListEntry, error) {
	return sqlCommonGetIPListEntries(listType, filter, from, order, limit, p.dbHandle)
}

func (p *MySQLProvider) getRecentlyUpdatedIPListEntries(after int64) ([]IPListEntry, error) {
	return sqlCommonGetRecentlyUpdatedIPListEntries(after, p.dbHandle)
}

func (p *MySQLProvider) dumpIPListEntries() ([]IPListEntry, error) {
	return sqlCommonDumpIPListEntries(p.dbHandle)
}

func (p *MySQLProvider) countIPListEntries(listType IPListType) (int64, error) {
	return sqlCommonCountIPListEntries(listType, p.dbHandle)
}

func (p *MySQLProvider) getListEntriesForIP(ip string, listType IPListType) ([]IPListEntry, error) {
	return sqlCommonGetListEntriesForIP(ip, listType, p.dbHandle)
}

func (p *MySQLProvider) getConfigs() (Configs, error) {
	return sqlCommonGetConfigs(p.dbHandle)
}

func (p *MySQLProvider) setConfigs(configs *Configs) error {
	return sqlCommonSetConfigs(configs, p.dbHandle)
}

func (p *MySQLProvider) setFirstDownloadTimestamp(username string) error {
	return sqlCommonSetFirstDownloadTimestamp(username, p.dbHandle)
}

func (p *MySQLProvider) setFirstUploadTimestamp(username string) error {
	return sqlCommonSetFirstUploadTimestamp(username, p.dbHandle)
}

func (p *MySQLProvider) close() error {
	return p.dbHandle.Close()
}

func (p *MySQLProvider) reloadConfig() error {
	return nil
}

// initializeDatabase creates the initial database structure
func (p *MySQLProvider) initializeDatabase() error {
	dbVersion, err := sqlCommonGetDatabaseVersion(p.dbHandle, false)
	if err == nil && dbVersion.Version > 0 {
		return ErrNoInitRequired
	}
	if errors.Is(err, sql.ErrNoRows) {
		return errSchemaVersionEmpty
	}
	logger.InfoToConsole("creating initial database schema, version 28")
	providerLog(logger.LevelInfo, "creating initial database schema, version 28")
	initialSQL := sqlReplaceAll(mysqlInitialSQL)

	return sqlCommonExecSQLAndUpdateDBVersion(p.dbHandle, strings.Split(initialSQL, ";"), 28, true)
}

func (p *MySQLProvider) migrateDatabase() error {
	dbVersion, err := sqlCommonGetDatabaseVersion(p.dbHandle, true)
	if err != nil {
		return err
	}

	switch version := dbVersion.Version; {
	case version == sqlDatabaseVersion:
		providerLog(logger.LevelDebug, "sql database is up to date, current version: %d", version)
		return ErrNoInitRequired
	case version < 28:
		err = fmt.Errorf("database schema version %d is too old, please see the upgrading docs", version)
		providerLog(logger.LevelError, "%v", err)
		logger.ErrorToConsole("%v", err)
		return err
	case version == 28:
		return updateMySQLDatabaseFrom28To29(p.dbHandle)
	default:
		if version > sqlDatabaseVersion {
			providerLog(logger.LevelError, "database schema version %d is newer than the supported one: %d", version,
				sqlDatabaseVersion)
			logger.WarnToConsole("database schema version %d is newer than the supported one: %d", version,
				sqlDatabaseVersion)
			return nil
		}
		return fmt.Errorf("database schema version not handled: %d", version)
	}
}

func (p *MySQLProvider) revertDatabase(targetVersion int) error {
	dbVersion, err := sqlCommonGetDatabaseVersion(p.dbHandle, true)
	if err != nil {
		return err
	}
	if dbVersion.Version == targetVersion {
		return errors.New("current version match target version, nothing to do")
	}

	switch dbVersion.Version {
	case 29:
		return downgradeMySQLDatabaseFrom29To28(p.dbHandle)
	default:
		return fmt.Errorf("database schema version not handled: %d", dbVersion.Version)
	}
}

func (p *MySQLProvider) resetDatabase() error {
	sql := sqlReplaceAll(mysqlResetSQL)
	return sqlCommonExecSQLAndUpdateDBVersion(p.dbHandle, strings.Split(sql, ";"), 0, false)
}

func (p *MySQLProvider) normalizeError(err error, fieldType int) error {
	if err == nil {
		return nil
	}
	var mysqlErr *mysql.MySQLError
	if errors.As(err, &mysqlErr) {
		switch mysqlErr.Number {
		case 1062:
			var message string
			switch fieldType {
			case fieldUsername:
				message = util.I18nErrorDuplicatedUsername
			case fieldIPNet:
				message = util.I18nErrorDuplicatedIPNet
			default:
				message = util.I18nErrorDuplicatedName
			}
			return util.NewI18nError(
				fmt.Errorf("%w: %s", ErrDuplicatedKey, err.Error()),
				message,
			)
		case 1452:
			return fmt.Errorf("%w: %s", ErrForeignKeyViolated, err.Error())
		}
	}
	return err
}

func updateMySQLDatabaseFrom28To29(dbHandle *sql.DB) error {
	logger.InfoToConsole("updating database schema version: 28 -> 29")
	providerLog(logger.LevelInfo, "updating database schema version: 28 -> 29")

	sql := strings.ReplaceAll(mysqlV29SQL, "{{users}}", sqlTableUsers)
	return sqlCommonExecSQLAndUpdateDBVersion(dbHandle, strings.Split(sql, ";"), 29, true)
}

func downgradeMySQLDatabaseFrom29To28(dbHandle *sql.DB) error {
	logger.InfoToConsole("downgrading database schema version: 29 -> 28")
	providerLog(logger.LevelInfo, "downgrading database schema version: 29 -> 28")

	sql := strings.ReplaceAll(mysqlV29DownSQL, "{{users}}", sqlTableUsers)
	return sqlCommonExecSQLAndUpdateDBVersion(dbHandle, strings.Split(sql, ";"), 28, false)
}
