-- Cool Modular GUI + Modules in one file

local Players = game:GetService("Players")
local RunService = game:GetService("RunService")
local LocalPlayer = Players.LocalPlayer
local UserInputService = game:GetService("UserInputService")
local camera = workspace.CurrentCamera

-- Simple GUI Library
local Library = {}
Library.__index = Library

function Library:CreateWindow(title, gradientType)
    local screenGui = Instance.new("ScreenGui")
    screenGui.Name = "CoolGUIHub"
    screenGui.ResetOnSpawn = false
    screenGui.Parent = game:GetService("CoreGui")

    local frame = Instance.new("Frame")
    frame.Size = UDim2.new(0, 400, 0, 500)
    frame.Position = UDim2.new(0.5, -200, 0.5, -250)
    frame.BackgroundColor3 = Color3.new(0, 0, 0)
    frame.BackgroundTransparency = 0
    frame.BorderSizePixel = 0
    frame.Parent = screenGui
    frame.ClipsDescendants = true

    -- Add UICorner to frame
    local uicorner = Instance.new("UICorner")
    uicorner.CornerRadius = UDim.new(0, 8)
    uicorner.Parent = frame

    -- Gradient background
    local bgGradient = Instance.new("UIGradient")
    bgGradient.Parent = frame
    bgGradient.Rotation = 90

    local gradients = {
        ["Red & Black"] = {
            ColorSequence = ColorSequence.new{ColorSequenceKeypoint.new(0, Color3.fromRGB(255,0,0)), ColorSequenceKeypoint.new(1, Color3.fromRGB(0,0,0))},
            TransparencySequence = NumberSequence.new{NumberSequenceKeypoint.new(0, 0), NumberSequenceKeypoint.new(1, 0.6)},
            Rotation = 180
        },
        ["Blue & Black"] = {
            ColorSequence = ColorSequence.new{ColorSequenceKeypoint.new(0, Color3.fromRGB(0,85,255)), ColorSequenceKeypoint.new(1, Color3.fromRGB(0,0,0))},
            TransparencySequence = NumberSequence.new{NumberSequenceKeypoint.new(0, 0), NumberSequenceKeypoint.new(1, 0.7)},
            Rotation = 180
        },
        ["Purple & Black"] = {
            ColorSequence = ColorSequence.new{ColorSequenceKeypoint.new(0, Color3.fromRGB(170,0,255)), ColorSequenceKeypoint.new(1, Color3.fromRGB(0,0,0))},
            TransparencySequence = NumberSequence.new{NumberSequenceKeypoint.new(0, 0), NumberSequenceKeypoint.new(1, 0.6)},
            Rotation = 180
        },
        ["Green & Black"] = {
            ColorSequence = ColorSequence.new{ColorSequenceKeypoint.new(0, Color3.fromRGB(0,255,85)), ColorSequenceKeypoint.new(1, Color3.fromRGB(0,0,0))},
            TransparencySequence = NumberSequence.new{NumberSequenceKeypoint.new(0, 0), NumberSequenceKeypoint.new(1, 0.7)},
            Rotation = 180
        }
    }

    local chosenGradient = gradients[gradientType] or gradients["Red & Black"]
    bgGradient.Color = chosenGradient.ColorSequence
    bgGradient.Transparency = chosenGradient.TransparencySequence
    bgGradient.Rotation = chosenGradient.Rotation

    -- Title bar
    local titleBar = Instance.new("Frame")
    titleBar.Size = UDim2.new(1, 0, 0, 40)
    titleBar.BackgroundTransparency = 1
    titleBar.Parent = frame

    -- Add UICorner to titleBar for smooth edges
    local titleBarCorner = Instance.new("UICorner")
    titleBarCorner.CornerRadius = UDim.new(0, 8)
    titleBarCorner.Parent = titleBar

    local titleLabel = Instance.new("TextLabel")
    titleLabel.Text = title or "Cool GUI Hub"
    titleLabel.Size = UDim2.new(1, -40, 1, 0)
    titleLabel.Position = UDim2.new(0, 10, 0, 0)
    titleLabel.BackgroundTransparency = 1
    titleLabel.TextColor3 = Color3.new(1,1,1)
    titleLabel.TextXAlignment = Enum.TextXAlignment.Left
    titleLabel.Font = Enum.Font.GothamBold
    titleLabel.TextSize = 20
    titleLabel.Parent = titleBar

    -- Close button
    local closeButton = Instance.new("TextButton")
    closeButton.Text = "X"
    closeButton.Size = UDim2.new(0, 30, 0, 30)
    closeButton.Position = UDim2.new(1, -35, 0, 5)
    closeButton.BackgroundColor3 = Color3.fromRGB(255, 50, 50)
    closeButton.TextColor3 = Color3.new(1,1,1)
    closeButton.Font = Enum.Font.GothamBold
    closeButton.TextSize = 18
    closeButton.Parent = titleBar
    closeButton.AutoButtonColor = true
    closeButton.MouseButton1Click:Connect(function()
        screenGui:Destroy()
    end)

    -- Container for controls
    local content = Instance.new("ScrollingFrame")
    content.Size = UDim2.new(1, -20, 1, -50)
    content.Position = UDim2.new(0, 10, 0, 45)
    content.BackgroundTransparency = 1
    content.ScrollBarThickness = 5
    content.Parent = frame

    -- UIListLayout for stacking controls
    local layout = Instance.new("UIListLayout")
    layout.Parent = content
    layout.SortOrder = Enum.SortOrder.LayoutOrder
    layout.Padding = UDim.new(0, 8)

    -- Store last added control to handle size
    self._content = content
    self._layout = layout
    self._screenGui = screenGui
    self._controlsCount = 0

    -- Helper to add new controls and update canvas size
    function self:AddControl(control)
        control.Parent = content
        self._controlsCount = self._controlsCount + 1
        content.CanvasSize = UDim2.new(0, 0, 0, layout.AbsoluteContentSize.Y + 20)
    end

    -- === DRAG LOGIC START ===
    local dragging = false
    local dragInput = nil
    local dragStart = nil
    local startPos = nil

    local function clampPosition(pos, size)
        local viewportSize = camera.ViewportSize
        local x = math.clamp(pos.X, 0, viewportSize.X - size.X)
        local y = math.clamp(pos.Y, 0, viewportSize.Y - size.Y)
        return Vector2.new(x, y)
    end

    titleBar.InputBegan:Connect(function(input)
        if input.UserInputType == Enum.UserInputType.MouseButton1 or
           input.UserInputType == Enum.UserInputType.Touch then
            dragging = true
            dragInput = input
            dragStart = input.Position
            startPos = frame.AbsolutePosition
            input.Changed:Connect(function()
                if input.UserInputState == Enum.UserInputState.End then
                    dragging = false
                    dragInput = nil
                end
            end)
        end
    end)

    titleBar.InputChanged:Connect(function(input)
        if input == dragInput then
            -- handled in UserInputService.InputChanged below
        end
    end)

    UserInputService.InputChanged:Connect(function(input)
        if input == dragInput and dragging then
            local delta = input.Position - dragStart
            local newPos = startPos + delta

            -- Clamp position so frame stays inside screen
            local clampedPos = clampPosition(newPos, frame.AbsoluteSize)

            local viewportSize = camera.ViewportSize
            local posX = clampedPos.X / viewportSize.X
            local posY = clampedPos.Y / viewportSize.Y

            frame.Position = UDim2.new(posX, 0, posY, 0)
        end
    end)
    -- === DRAG LOGIC END ===

    return self
end

function Library:AddLabel(text)
    local label = Instance.new("TextLabel")
    label.Text = text or "Label"
    label.Size = UDim2.new(1, 0, 0, 25)
    label.BackgroundTransparency = 1
    label.TextColor3 = Color3.new(1,1,1)
    label.Font = Enum.Font.Gotham
    label.TextSize = 18
    label.TextXAlignment = Enum.TextXAlignment.Left

    self:AddControl(label)
    return label
end

function Library:AddToggle(text, callback)
    local frame = Instance.new("Frame")
    frame.Size = UDim2.new(1, 0, 0, 30)
    frame.BackgroundTransparency = 1

    local label = Instance.new("TextLabel")
    label.Text = text
    label.Size = UDim2.new(1, -40, 1, 0)
    label.BackgroundTransparency = 1
    label.TextColor3 = Color3.new(1,1,1)
    label.Font = Enum.Font.Gotham
    label.TextSize = 18
    label.TextXAlignment = Enum.TextXAlignment.Left
    label.Parent = frame

    local toggle = Instance.new("TextButton")
    toggle.Text = "OFF"
    toggle.Size = UDim2.new(0, 40, 1, 0)
    toggle.Position = UDim2.new(1, -40, 0, 0)
    toggle.BackgroundColor3 = Color3.fromRGB(180, 0, 0)
    toggle.TextColor3 = Color3.new(1,1,1)
    toggle.Font = Enum.Font.GothamBold
    toggle.TextSize = 16
    toggle.Parent = frame

    local enabled = false
    toggle.MouseButton1Click:Connect(function()
        enabled = not enabled
        if enabled then
            toggle.Text = "ON"
            toggle.BackgroundColor3 = Color3.fromRGB(0, 180, 0)
        else
            toggle.Text = "OFF"
            toggle.BackgroundColor3 = Color3.fromRGB(180, 0, 0)
        end
        if callback then
            callback(enabled)
        end
    end)

    self:AddControl(frame)
    return frame
end

-- Usage Example:

local myGui = setmetatable({}, Library):CreateWindow("My Cool GUI", "Purple & Black")

myGui:AddLabel("Welcome to the GUI!")
myGui:AddToggle("Enable Feature", function(state)
    print("Toggle state:", state)
end)

return Library