local object = {}
local select = ""

local callback = function() end --catch the error of 'callback is a nil value'

local getBy = function(parent, check, by, extra)
    local iterate;
    iterate = function(parent, check, by, extra)
        for index, value in pairs(parent:GetChildren()) do
            if by == "class" then
                if value.ClassName:lower() == check:lower() then
                    table.insert(object, value)
                end
            elseif by == "name" then
                if value.Name:lower() == check:lower() then
                    table.insert(object, value)
                end
            elseif by == "property" then
                if pcall(function() return value[check] end) then
                    local kind = type(value[check])
                    if value[check] == (kind == "string" and tostring(extra) or kind == "number" and tonumber(extra) or extra) then
                        table.insert(object, value)
                    end
                end
            elseif by == "all" then
                table.insert(object, value)
            end
            iterate(value, check, by, extra)
        end
    end
    iterate(parent, check, by, extra)
end

local loop = function(lqCallback, userCallback, ...)
    for index, value in pairs(object) do
        if lqCallback then
            lqCallback(index, value)
        end
        if userCallback then
            userCallback(index, value, ...)
        end
    end
    return lq
end

local removeElement = function(array, element)
    for index, value in ipairs(array) do
        if value == element then
            table.remove(array, index)
        end
    end
end

local warn = function(warning, selector)
    return "WARNING: " .. warning .. " ( " .. selector .. " ) "
end

local lq;
lq = {
    each = function(callback)
        return loop(nil, callback)
    end,
    dest = function(callback)
        return loop(function(_, value) value:Destroy() end, callback)
    end,
    val = function(key)
        if not key and #object == 1 and object[1]:FindFirstChild("LQ_SAVE_KEY") then
            return object[1]["LQ_SAVE_KEY"].Value
        elseif not key then
            return warn("Cannot get the value of multiple items!", select)
        end
        return loop(function(_, value)
            if value:FindFirstChild("LQ_SAVE_KEY") then
                value["LQ_SAVE_KEY"].Value = key
            else
                local save = Instance.new("StringValue", value)
                save.Name = "LQ_SAVE_KEY"
                save.Value = key
            end
        end)
    end,
    color = function(color)
        local colors = {
            blue = "Bright blue",
            red = "Bright red",
            green = "Bright green",
            orange = "Bright orange",
            yellow = "Bright yellow",
            purple = "Bright purple",
            white = "White",
            black = "Black"
        }
        return loop(function(_, value)
            if value:IsA("BasePart") then
                value.BrickColor = BrickColor.new(colors[color:lower()] or color)
            end
        end)
    end,
    attr = function(property, set)
        if type(property) == "table" then
            return loop(function(_, value)
                for property, apply in pairs(property) do
                    pcall(function() value[property] = apply end)
                end
            end)
        elseif set then
            return loop(function(_, value)
                pcall(function() value[property] = set end)
            end)
        elseif pcall(function() return object[1][property] and not object[1]:FindFirstChild(property) end) then
            return object[1][property]
        end
    end,
    listen = function(event, callback)
        local events = {
            change = "Changed", newplayer = "PlayerAdded"
        }
        return loop(function(_, value)
            pcall(function() value[events[event:lower()] or event]:connect(callback) end)
        end)
    end,
    rand = function()
        return object[math.random(#object)]
    end,
    indexOf = function(search)
        local ret = false
        if type(object) == "string" then
            ret = object:find(search)
        else
            loop(function(index, value)
                if value == search then
                    ret = index
                end
            end)
        end
        return ret
    end,
    insert = function(...)
        for _, value in ipairs({...}) do
            table.insert(object, value)
        end
        return lq
    end,
    rid = function(...)
        for index, value in ipairs(object) do
            for _, check in ipairs({...}) do
                if check == value then
                    table.remove(object, index)
                end
            end
        end
        return lq
    end,
    concat = function(split)
        return table.concat(object, split)
    end,
    greatest = function()
        return math.max(unpack(object))
    end,
    least = function()
        return math.min(unpack(object))
    end,
    raw = function()
        return object
    end
}

local ret = function(selector, parent)
    object = {}
    select = selector
    parent = parent or Workspace
    if type(selector) == "string" then
        local matched;
        selector:gsub("%.(.-)/", function(pattern)
            matched = true
            getBy(parent, pattern, "class")
        end):gsub("#(.-)/", function(pattern)
            matched = true
            getBy(parent, pattern, "name")
        end):gsub("%?([%a%d]+)=(.-)/", function(patternOne, patternTwo)
            matched = true
            getBy(parent, patternOne, "property", patternTwo)
        end):gsub("&(.-)/", function(pattern)
            matched = true
            if pattern:lower() == "direct" then
                for _, v in ipairs(parent:GetChildren()) do
                    table.insert(object, v)
                end
            elseif pattern:lower() == "all" then
                getBy(parent, nil, "all")
            end
        end):gsub("%?([%a%d]+)!=(.-)/", function(patternOne, patternTwo)
            matched = true
            for _, v in pairs(object) do
                pcall(function()
                    if v[patternOne] == patternTwo then
                        removeElement(object, v)
                    end
                end)
            end
        end)
        if not matched then
            object = selector
        end
    elseif type(selector) == "table" then
        object = selector
    else
        object = {selector}
    end
    return lq
end

return ret