Sal's Roblox Dialogue System

-- CODE BREAKDOWN & HOW TO SET-UP: https://youtu.be/BZrsNgzfMm4

--Settings:
local InteractKeyCode = Enum.KeyCode.E
local CameraTweenInfo = TweenInfo.new(1, Enum.EasingStyle.Cubic, Enum.EasingDirection.InOut)

-- Services:

local RS = game:GetService("ReplicatedStorage")
local RunService = game:GetService("RunService")
local TweenService = game:GetService("TweenService")
local UIS = game:GetService("UserInputService")
-- Player/Char Stuff:

local Player = game.Players.LocalPlayer
repeat wait() until Player.Character
local Character = Player.Character
local Humanoid = Character:WaitForChild("Humanoid")
local HumanoidRootPart = Character:WaitForChild("HumanoidRootPart")

-- Objects:

local NpcFolder = workspace:WaitForChild("Npc's")
local CurrentCamera = workspace.CurrentCamera
CurrentCamera.CameraType = Enum.CameraType.Custom
CurrentCamera.CameraSubject = Humanoid

-- Elements:

local DialougeUI = script.Parent
local HolderUI = DialougeUI:WaitForChild("Holder")
local ChoicesUI = HolderUI:WaitForChild("Choices")
local Text = HolderUI:WaitForChild("Text")

--\\-- FX & Extra UI --//--

local ObjectsFolder = script:WaitForChild("Objects")
local DialogFX = ObjectsFolder:WaitForChild("DialogFX")
local ParticleEmitter = DialogFX:WaitForChild("ParticleEmitter")
local BillboardGui = DialogFX:WaitForChild("BillboardGui")
local BasicTextFont = ObjectsFolder:WaitForChild("BasicTextFont")

-- Variables
local CurrentDialog = nil
local InDialog = false

-- Functions:
function SearchForDialouges()
    local DialogTable = {}

    for index, value in ipairs(NpcFolder:GetDescendants()) do
        if value:IsA("Dialog") and value.Parent:IsA("BoolValue") and value.Parent.Value == true then
            table.insert(DialogTable, table.getn(DialogTable) + 1, value)
        end
    end

    return DialogTable
end

function FindClosestDialog(DialogTable)
    local Closest
    local PlayerPosition = Character.PrimaryPart.Position

    for i, v in pairs(DialogTable) do

        if Closest == nil then
            Closest = v
        else
            if (PlayerPosition - v.Parent.Parent.Position).magnitude < (Closest.Parent.Parent.Position - PlayerPosition).magnitude then
                Closest = v
            end
        end

    end
    return Closest
end

function CreateChoices(Dialog)
    local SelectedChoice = false
    local Choices = {}

    for i, v in ipairs(Dialog:GetChildren()) do
        if v:IsA("DialogChoice") then
            table.insert(Choices, table.getn(Choices) + 1, v)
        end
    end

    for i, v in pairs(Choices) do

        local OffSet = 1/table.getn(Choices)
        local Clone = BasicTextFont:Clone()
        Clone.Parent = ChoicesUI
        Clone.Text = tostring(v.UserDialog)
        Clone.Size = UDim2.new(OffSet,0,1,0)
        Clone.Position = UDim2.new(OffSet*(i - 1),0,0,0)

        Clone.MouseButton1Click:Connect(function()
            SelectedChoice = v
        end)

    end
    repeat wait() until SelectedChoice ~= false or table.getn(Choices) <= 0
    return SelectedChoice
end

function StartDialog()
    if CurrentDialog ~= nil and CurrentCamera.CameraType ~= Enum.CameraType.Scriptable and InDialog == false then
        local HostPart = CurrentDialog.Parent.Parent
        InDialog = true
        CurrentCamera.CameraType = Enum.CameraType.Scriptable
        local CamCF = CFrame.lookAt(CurrentCamera.CFrame.Position, HostPart.Position)
        local CameraTween = TweenService:Create(CurrentCamera, CameraTweenInfo, {CFrame = CamCF})
        local TextTransparencyTweenDark = TweenService:Create(Text, TweenInfo.new(1), {BackgroundTransparency = 0.5})
        TextTransparencyTweenDark:Play()
        CameraTween:Play()

        local DialogSelected = CurrentDialog
        Text.Text = DialogSelected.InitialPrompt

        if DialogSelected:FindFirstChildWhichIsA("DialogChoice") ~= nil then
            local Choice = CreateChoices(DialogSelected)
            if Choice:FindFirstChildWhichIsA("DialogChoice") ~= nil then
                repeat wait() until Choice
                ChoicesUI:ClearAllChildren()
                DialogSelected = Choice
                Text.Text = DialogSelected.ResponseDialog

                repeat

                    local Choice = CreateChoices(DialogSelected)
                    repeat wait() until Choice
                    if Choice ~= false then
                        ChoicesUI:ClearAllChildren()
                        DialogSelected = Choice
                        Text.Text = DialogSelected.ResponseDialog
                    end
                until DialogSelected:FindFirstChildWhichIsA("DialogChoice") == nil or Choice == false

            else -- No other choices.
                Text.Text = Choice.ResponseDialog
            end
        end
        ChoicesUI:ClearAllChildren()
        wait(1)
        Text.Text = ""
        Text.BackgroundTransparency = 1
        CurrentCamera.CameraType = Enum.CameraType.Custom
        CurrentCamera.CameraSubject = Humanoid
        InDialog = false
    end
end


-- Running:
local Dialouges = SearchForDialouges()

RunService.Stepped:Connect(function()
    local ClosestDialog = FindClosestDialog(Dialouges)
    local HostPart = ClosestDialog.Parent.Parent
    local Magnitude = (HumanoidRootPart.Position - ClosestDialog.Parent.Parent.Position).Magnitude

    if Magnitude <= ClosestDialog.ConversationDistance then
        DialogFX.Parent = workspace
        DialogFX.Position = HostPart.Position
        BillboardGui.Enabled = true
        ParticleEmitter.Enabled = true
        CurrentDialog = ClosestDialog
    else
        ParticleEmitter.Enabled = false
        BillboardGui.Enabled = false
        DialogFX.Parent = ObjectsFolder
        CurrentDialog = nil
    end

end)

UIS.InputBegan:Connect(function(input)
    if input.UserInputType == Enum.UserInputType.Keyboard then
        if input.KeyCode == InteractKeyCode then
            StartDialog()
        end
    end
end)