local module = {}
module.acctable = "accounts"
module.oop = {}

function module.init ()
    assert(module.connection, "MySql подключение не существует")

    module.check_table ('db', module.acctable, [[(
            `id` int(11) NOT NULL AUTO_INCREMENT,
            `vkid` int(11) NOT NULL,
            PRIMARY KEY (`id`)
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8;]]
    );
end

function module.start()
    -- OOP
    function module.oop:set (field, value)
        self[field] = value
        module("UPDATE `%s` SET `%s`='%s' WHERE `vkid`=%i", module.acctable, field, value, self.vkid)
    end

    function module.oop:add (field, value)
        self[field] = self[field] + value
        module("UPDATE `%s` SET `%s`=`%s`+'%s' WHERE `vkid`=%i", module.acctable, field, field, value, self.vkid)
    end

    -- Modules tools
    if botcmd then
        botcmd.arg_types['U'] = function (args, arg, offset)
            if arg:find("%[(.-)|.-%]") then arg = arg:gsub("%[(.-)|.-%]", "%1") end
            return ca (module.get_user(getId(arg)), "пользователь не найден")
        end
    end
end
module.CheckInstall = module.init -- TOREMOVE

function module.find_table (table_name)
    local index = "Tables_in_"..db.settings.database
    local tables = module("SHOW TABLES")
    for i = 1,#tables do
        if tables[i][index] == table_name then
            return tables[i][index]
        end
    end
end,

function moduke.find_column (table_name, column_name)
    local columns = module("SHOW COLUMNS FROM `%s`", table_name)
    for i = 1, #columns do
        if columns[i].Field == column_name then
            return columns[i]
        end
    end
end

function module.check_column (module_name, table_name, column_name, args)
    if module.find_column(table_name, column_name) then return true end
    console.log(module_name, "Создаю поле %s в %s...", column_name, table_name)
    module("ALTER TABLE `%s` ADD `%s` %s", table_name, column_name, args)
    console.log(module_name, "Поле %s в было успешно создано.", column_name)
end

function module.check_table (module_name, table_name, command)
    if module.find_table(table_name) then return true end
    console.log(module_name, "Таблица %s не найдена.", table_name)
    console.log(module_name, "Создание таблицы %s...", table_name)
    module("CREATE TABLE `%s` " .. command, table_name)
    console.log(module_name, "Таблица %s успешно создана!", table_name)
    relua()
end

function module.connect(ip, username, password, database)
    module.connection = mysql(ip, username, password, database)
    module("SET NAMES utf8mb4")
    module.settings = { ip = ip, username = username, password = password, database = database }
end

function module.get_user_safe(vkid)
    if not vkid then return end
    local user = module('SELECT * FROM `%s` WHERE vkid=%i', module.acctable, vkid)[1]
    if not user then return false end
    setmetatable(user, { __index = module.oop })
    return user
end

function module.get_user_from_url(url)
    if not url then return end
    if url:find("%[(.-)|.-%]") then url = url:gsub("%[(.-)|.-%]", "%1") end
    return url and module.get_user_safe(getId(url))
end

function module.get_user(vkid)
    if not vkid then return end
    local user = module.get_user_safe(vkid)
    if not user then
        module("INSERT INTO `%s` (`vkid`) VALUES (%i)", module.acctable, vkid)
        user = module.get_user_safe(vkid)
    end
    return user;
end

function db.select(what, table, where, ...)
    return module.mc("SELECT %s FROM `%s` " .. (where and "WHERE "..where or ''), what, table, ...)
end

function db.select_one(what, table, where, ...)
    return module.mc("SELECT %s FROM `%s` " .. (where and "WHERE "..where or ''), what, table, ...)[1]
end

function db.get_count(table, where, ...)
    return module.mc("SELECT COUNT(id) FROM `%s` " .. (where and "WHERE "..where or ''), table, ...)[1]['COUNT(id)']
end

setmetatable(module, { __call = function (_, query, ...) return module.connection(query, ...) end })
return module