function insertIndex(i, buffer)
    table.insert(buffer, "[")
    if type(i) == "string" then
        table.insert(buffer, '"')
        table.insert(buffer, i)
        table.insert(buffer, '"')
    elseif type(i) == "number" then
        table.insert(buffer, tostring(i))
    end
    table.insert(buffer, "] = ")
end

function indexToStr(i, v, buffer)
    local tp = type(v)
    local itp = type(i)
    if itp ~= "number" and itp ~= "string" then
        print("Invalid index to serialize: " .. type(i))
    else
        if tp == "table" then
            insertIndex(i, buffer)
            serializeTable(v, buffer)
            table.insert(buffer, ",")
        elseif tp == "number" then
            insertIndex(i, buffer)
            table.insert(buffer, tostring(v))
            table.insert(buffer, ",")
        elseif tp == "string" then
            insertIndex(i, buffer)
            table.insert(buffer, '"')
            table.insert(buffer, v)
            table.insert(buffer, '",')
        elseif tp == "boolean" then
            insertIndex(i, buffer)
            table.insert(buffer, v == true and "true" or "false")
            table.insert(buffer, ",")
        else
            print("Invalid type to serialize: " .. tp .. ", index: " .. i)
        end
    end
end

function serializeTable(t, buffer)
    local buffer = buffer or {}
    table.insert(buffer, "{")
    for i, x in pairs(t) do
        indexToStr(i, x, buffer)
    end
    table.insert(buffer, "}")
    return table.concat(buffer)
end

function table.copy(t, out)
    out = out or {}
    if type(t) ~= "table" then
        return false
    end

    for i, x in pairs(t) do
        if type(x) == "table" then
            out[i] = {}
            table.copy(t[i], out[i])
        else
            out[i] = x
        end
    end
    return out
end

function unserializeTable(str, out)
    local tmp = loadstring("return " .. str)
    if tmp then
        tmp = tmp()
    else
        print("Unserialization error: " .. str)
        return false
    end
    return table.copy(tmp, out)
end

local function setTableIndexes(t, i, v, ...)
    if i and v then
        t[i] = v
        return setTableIndexes(t, ...)
    end
end

local function getTableIndexes(t, i, ...)
    if i then
        return t[i], getTableIndexes(t, ...)
    end
end

function unpack2(tab, i)
    local i, v = next(tab, i)
    if next(tab, i) then
        return i, v, unpack2(tab, i)
    else
        return i, v
    end
end

function pack(t, ...)
    for i = 1, select("#", ...) do
        local tmp = select(i, ...)
        t[i] = tmp
    end
    return t
end

function Item:setSpecialAttribute(...)
    local tmp
    if self:hasAttribute(ITEM_ATTRIBUTE_SPECIAL) then
        tmp = self:getAttribute(ITEM_ATTRIBUTE_SPECIAL)
    else
        tmp = "{}"
    end

    local tab = unserializeTable(tmp)
    if tab then
        setTableIndexes(tab, ...)
        tmp = serializeTable(tab)
        self:setAttribute(ITEM_ATTRIBUTE_SPECIAL, tmp)
        return true
    end
end

function Item:getSpecialAttribute(...)
    local tmp
    if self:hasAttribute(ITEM_ATTRIBUTE_SPECIAL) then
        tmp = self:getAttribute(ITEM_ATTRIBUTE_SPECIAL)
    else
        tmp = "{}"
    end

    local tab = unserializeTable(tmp)
    if tab then
        return getTableIndexes(tab, ...)
    end
end

if not PLAYER_STORAGE then
    PLAYER_STORAGE = {}
end

function Player:setSpecialStorage(storage, value)
    if not PLAYER_STORAGE[self:getGuid()] then
        self:loadSpecialStorage()
    end

    PLAYER_STORAGE[self:getGuid()][storage] = value
end

function Player:getSpecialStorage(storage)
    if not PLAYER_STORAGE[self:getGuid()] then
        self:loadSpecialStorage()
    end

    return PLAYER_STORAGE[self:getGuid()][storage]
end

function Player:loadSpecialStorage()
    if not PLAYER_STORAGE then
        PLAYER_STORAGE = {}
    end

    PLAYER_STORAGE[self:getGuid()] = {}
    local resultId = db.storeQuery("SELECT * FROM `player_misc` WHERE `player_id` = " .. self:getGuid())
    if resultId then
        local info = result.getStream(resultId , "info") or "{}"
        unserializeTable(info, PLAYER_STORAGE[self:getGuid()])
    end
end

function Player:saveSpecialStorage()
    if PLAYER_STORAGE and PLAYER_STORAGE[self:getGuid()] then
        local tmp = serializeTable(PLAYER_STORAGE[self:getGuid()])
        db.query("DELETE FROM `player_misc` WHERE `player_id` = " .. self:getGuid())
        db.query(string.format("INSERT INTO `player_misc` (`player_id`, `info`) VALUES (%d, %s)", self:getGuid(), db.escapeBlob(tmp, #tmp)))
    end
end