while not game do
	wait()
end

local ChangeHistoryService = game:GetService "ChangeHistoryService"
local CoreGui = game:GetService "CoreGui"
local New = require("../Modules/New").New

-- local CreateStandardLabel = require "../Modules/Terrain/CreateStandardLabel"

---------------
--PLUGIN SETUP-
---------------
local loaded = false
local on = false

local On, Off

local this = PluginManager():CreatePlugin() :: Plugin

local toolbar = this:CreateToolbar "Terrain" :: Toolbar
local toolbarbutton =
	toolbar:CreateButton("Brush", "Brush", "brush.png") :: Button
toolbarbutton.Click:connect(function()
	if on then
		Off()
	elseif loaded then
		On()
	end
end)

game:WaitForChild "Workspace"
workspace:WaitForChild "Terrain"

-- Local function definitions
local c = workspace.Terrain
local GetCell = c.GetCell
local SetCells = c.SetCells
local AutowedgeCells = c.AutowedgeCells
local WorldToCellPreferSolid = c.WorldToCellPreferSolid
local CellCenterToWorld = c.CellCenterToWorld

local buildTerrainMode = "Add"
local removeTerrainMode = "Remove"

-----------------
--DEFAULT VALUES-
-----------------
local radius = 5
local depth = 0
local mousedown = false
local mousemoving = false
local brushheight
local material = 1
local lastMousePos = Vector2.new(-1, -1)
local lastCellFillTime = 0
local maxYExtents = math.min(c.MaxExtents.Max.Y, 512)

-- Which mode (build/remove) it is.
local mode = buildTerrainMode

-- Height and depth to use for the different modes.
local buildTerrainHeight = 5
local removeTerrainDepth = -5

local mouse = this:GetMouse()
mouse.Button1Down:connect(function()
	buttonDown()
end)
mouse.Button1Up:connect(function()
	mousedown = false
	brushheight = nil
	enablePreview()
	updatePreviewSelection(mouse.Hit)
	ChangeHistoryService:SetWaypoint "Brush"
end)
mouse.Move:connect(function()
	mouseMoved()
end)
local selectionPart = New "Part" {
	Name = "SelectionPart",
	Archivable = false,
	Transparency = 1,
	Anchored = true,
	Locked = true,
	CanCollide = false,
	FormFactor = Enum.FormFactor.Custom,
}

local selectionBox = New "SelectionBox" {
	Archivable = false,
	Color = BrickColor.new "Lime green",
	Adornee = selectionPart,
}
mouse.TargetFilter = selectionPart

function disablePreview()
	selectionBox.Parent = nil
end

function enablePreview()
	selectionBox.Parent = workspace
end

-----------------------
--FUNCTION DEFINITIONS-
-----------------------

-- searches the y depth of a particular cell position to find the lowest y that is empty
function findLowestEmptyCell(x, y, z)
	local cellMat = GetCell(c, x, y, z)
	local lowestY = y

	while cellMat == Enum.CellMaterial.Empty do
		lowestY = y
		if y > 0 then
			y = y - 1
			cellMat = GetCell(c, x, y, z)
		else
			lowestY = 0
			cellMat = nil
		end
	end
	return lowestY
end

-- finds the lowest cell that is not filled in the radius that is currently specified
local function findLowPoint(x, y, z)
	local lowestPoint = maxYExtents + 1
	for i = -radius, radius do
		local zPos = z + i
		for _ = -radius, radius do
			local xPos = x + i
			local cellMat = GetCell(c, xPos, y, zPos)
			if cellMat == Enum.CellMaterial.Empty then
				local emptyDepth = findLowestEmptyCell(xPos, y, zPos)
				if emptyDepth < lowestPoint then
					lowestPoint = emptyDepth
				end
			end
		end
	end
	return lowestPoint
end

-- Do a line/plane intersection.  The line starts at the camera.  The plane is at y == 0, normal(0, 1, 0)
--
-- vectorPos - End point of the line.
--
-- Return:
-- success      - Value is true if there was a plane intersection, false if not.
-- intersection - Value is the terrain cell intersection point if there is one, vectorPos if there isn't.
local function PlaneIntersection(vectorPos)
	local currCamera = workspace.CurrentCamera
	local startPos = Vector3.new(
		currCamera.CoordinateFrame.p.X,
		currCamera.CoordinateFrame.p.Y,
		currCamera.CoordinateFrame.p.Z
	)
	local endPos = Vector3.new(vectorPos.X, vectorPos.Y, vectorPos.Z)
	local normal = Vector3.new(0, 1, 0)
	local p3 = Vector3.new(0, 0, 0)
	local startEndDot = normal:Dot(endPos - startPos)
	local cellPos = vectorPos
	local success = false
	if startEndDot ~= 0 then
		local t = normal:Dot(p3 - startPos) / startEndDot
		if t >= 0 and t <= 1 then
			local intersection = ((endPos - startPos) * t) + startPos
			cellPos = c:WorldToCell(intersection)
			success = true
		end
	end

	return success, cellPos
end

-- brushes terrain at point (x, y, z) in cluster c
local function brush(x, y, z)
	if depth == 0 then
		return
	elseif depth > 0 then
		local findY = findLowPoint(x, y + depth, z)
		local yWithDepth = y + depth

		local lowY
		if findY < yWithDepth then
			lowY = findY
		else
			lowY = yWithDepth
		end

		local lowVec = Vector3int16.new(x - radius, lowY, z - radius)
		local highVec = Vector3int16.new(x + radius, yWithDepth, z + radius)
		local regionToFill = Region3int16.new(lowVec, highVec)

		SetCells(c, regionToFill, material, 0, 0)
		AutowedgeCells(c, regionToFill)
	else
		local lowVec = Vector3int16.new(x - radius, y + depth + 1, z - radius)
		local highVec = Vector3int16.new(x + radius, maxYExtents, z + radius)
		local regionToEmpty = Region3int16.new(lowVec, highVec)
		SetCells(c, regionToEmpty, Enum.CellMaterial.Empty, 0, 0)
	end
end

function updatePreviewSelection(position)
	if not position then
		return
	elseif depth == 0 then -- or not mouse.Target
		disablePreview()
		return
	end

	local vectorPos = Vector3.new(position.x, position.y, position.z)
	local cellPos = WorldToCellPreferSolid(c, vectorPos)
	local solidCell = WorldToCellPreferSolid(c, vectorPos)

	-- If nothing was hit, do the plane intersection.
	if 0 == GetCell(c, solidCell.X, solidCell.Y, solidCell.Z).Value then
		local success = false
		success, cellPos = PlaneIntersection(vectorPos)
		if not success then
			if mouse.Target then
				cellPos = solidCell
			else
				return
			end
		end
	end

	local regionToSelect
	if depth > 0 then
		local yWithDepth
		if brushheight then
			yWithDepth = brushheight + depth
		else
			yWithDepth = cellPos.y + depth
		end

		local lowY
		if brushheight then
			lowY = brushheight + 1
		else
			local findY = findLowPoint(cellPos.x, yWithDepth, cellPos.z)
			if findY < yWithDepth then
				lowY = findY
			else
				lowY = yWithDepth
			end
		end

		local lowVec = CellCenterToWorld(
			c,
			cellPos.x - radius,
			lowY - 1,
			cellPos.z - radius
		)
		local highVec = CellCenterToWorld(
			c,
			cellPos.x + radius,
			yWithDepth + 1,
			cellPos.z + radius
		)
		selectionBox.Color = BrickColor.new "Lime green"
		regionToSelect = Region3.new(lowVec, highVec)
	else
		local yPos = cellPos.y + depth
		if brushheight then
			yPos = brushheight + depth
		end

		local lowVec =
			CellCenterToWorld(c, cellPos.x - radius, yPos, cellPos.z - radius)
		local highVec = CellCenterToWorld(
			c,
			cellPos.x + radius,
			maxYExtents,
			cellPos.z + radius
		)
		selectionBox.Color = BrickColor.new "Really red"
		regionToSelect = Region3.new(lowVec, highVec)
	end

	selectionPart.Size = regionToSelect.Size - Vector3.new(-4, 4, -4)
	selectionPart.CFrame = regionToSelect.CFrame

	enablePreview()
end

function doFillCells(position, mouseDrag, needsCellPos)
	if mouseDrag then
		local timeBetweenFills = tick() - lastCellFillTime
		local totalDragPixels = math.abs(mouseDrag.x) + math.abs(mouseDrag.y)
		local editDistance = (
			(workspace.CurrentCamera :: Camera).CoordinateFrame.p
			- Vector3.new(position.x, position.y, position.z)
		).Magnitude

		if timeBetweenFills <= 0.05 then
			if editDistance * totalDragPixels < 450 then
				lastCellFillTime = tick()
				return
			end
		end
	end

	local x = position.x
	local y = position.y
	local z = position.z

	if needsCellPos then
		local cellPos = WorldToCellPreferSolid(c, Vector3.new(x, y, z))

		local solidCell = WorldToCellPreferSolid(c, Vector3.new(x, y, z))

		-- If nothing was hit, do the plane intersection.
		if 0 == GetCell(c, solidCell.X, solidCell.Y, solidCell.Z).Value then
			local success = false
			success, cellPos = PlaneIntersection(Vector3.new(x, y, z))
			if not success then
				if mouse.Target then
					cellPos = solidCell
				else
					return
				end
			end
		end

		x = cellPos.x
		y = cellPos.y
		z = cellPos.z
	end

	if brushheight == nil then
		brushheight = y
	end

	brush(x, brushheight, z)
	lastCellFillTime = tick()
end

function mouseMoved()
	if not on then
		return
	elseif mousedown == true then
		if mousemoving then
			return
		end

		mousemoving = true
		local currMousePos = Vector2.new(mouse.X, mouse.Y)
		local mouseDrag = currMousePos - lastMousePos
		doFillCells(mouse.Hit, mouseDrag, true)
		lastMousePos = currMousePos
		mousemoving = false
	end
	updatePreviewSelection(mouse.Hit)
end

function buttonDown()
	if on then
		local firstCellPos = WorldToCellPreferSolid(
			c,
			Vector3.new(mouse.Hit.x, mouse.Hit.y, mouse.Hit.z)
		)
		local solidCell = WorldToCellPreferSolid(
			c,
			Vector3.new(mouse.Hit.x, mouse.Hit.y, mouse.Hit.z)
		)

		-- If nothing was hit, do the plane intersection.
		if 0 == GetCell(c, solidCell.X, solidCell.Y, solidCell.Z).Value then
			local success = false
			success, firstCellPos = PlaneIntersection(
				Vector3.new(mouse.Hit.x, mouse.Hit.y, mouse.Hit.z)
			)
			if not success then
				if not mouse.Target then
					return
				end
				firstCellPos = solidCell
			end
		end

		local celMat =
			GetCell(c, firstCellPos.x, firstCellPos.y, firstCellPos.z)
		if celMat.Value > 0 then
			material = celMat.Value
		else
			if 0 == material then
				-- It was nothing, give it a default type and the plane intersection.
				material = 1
			end
		end

		brushheight = firstCellPos.y
		lastMousePos = Vector2.new(mouse.X, mouse.Y)
		doFillCells(firstCellPos)

		mousedown = true
	end
end

local brushDragBar

function On()
	if not c then
		return
	elseif this then
		this:Activate(true)
	end
	if toolbarbutton then
		toolbarbutton:SetActive(true)
	end
	if enablePreview then
		enablePreview()
	end
	if brushDragBar then
		brushDragBar.Visible = true
	end
	on = true
end

function Off()
	if toolbarbutton then
		toolbarbutton:SetActive(false)
	end
	if disablePreview then
		disablePreview()
	end
	if brushDragBar then
		brushDragBar.Visible = false
	end
	on = false
end

------
--GUI-
------

--load library for with sliders
local RbxGui = LoadLibrary "RbxGui"

-- Create a standard dropdown.  Use this for all dropdowns in the popup so it is easy to standardize.
-- name - What to set the text label name as.
-- pos    	 	 - Where to position the label.  Should be of type UDim2.
-- values    	 - A table of the values that will be in the dropbox, in the order they are to be shown.
-- initValue	 - Initial value the dropdown should be set to.
-- funcOnChange  - Function to run when a dropdown selection is made.
-- parent 	 	 - What to set the parent as.
-- Return:
-- dropdown 	   - The dropdown gui.
-- updateSelection - Object to use to change the current dropdown.
function CreateStandardDropdown(
	name,
	pos,
	values,
	initValue,
	funcOnChange,
	parent
)
	-- Create a dropdown selection for the modes to fill in a river
	local dropdown, updateSelection =
		RbxGui.CreateDropDownMenu(values, funcOnChange)
	dropdown.Name = name
	dropdown.Position = pos
	dropdown.Active = true
	dropdown.Size = UDim2.new(0, 150, 0, 32)
	dropdown.Parent = parent

	updateSelection(initValue)

	return dropdown, updateSelection
end

-- Create a standardized slider.
-- name  - Name to use for the slider.
-- pos   - Position to display the slider at.
-- steps - How many steps there are in the slider.
-- funcOnChange - Function to call when the slider changes.
-- initValue    - Initial value to set the slider to.  If nil the slider stays at the default.
-- parent       - What to set as the parent.
-- Return:
-- sliderGui      - Slider gui object.
-- sliderPosition - Object that can set the slider value.
-- function CreateStandardSlider(
-- 	name,
-- 	pos,
-- 	lengthBarPos,
-- 	steps,
-- 	funcOnChange,
-- 	initValue,
-- 	parent
-- )
-- 	local sliderGui, sliderPosition =
-- 		RbxGui.CreateSlider(steps, 0, UDim2.new(0, 0, 0, 0))

-- 	sliderGui.Name = name
-- 	sliderGui.Parent = parent
-- 	sliderGui.Position = pos
-- 	sliderGui.Size = UDim2.new(0, 160, 0, 20)
-- 	local lengthBar = sliderGui:FindFirstChild "Bar"
-- 	lengthBar.Size = UDim2.new(1, -20, 0, 5)
-- 	lengthBar.Position = lengthBarPos

-- 	if nil ~= funcOnChange then
-- 		sliderPosition.Changed:connect(function()
-- 			funcOnChange(sliderPosition)
-- 		end)
-- 	end

-- 	if nil ~= initValue then
-- 		sliderPosition.Value = initValue
-- 	end

-- 	return sliderGui, sliderPosition
-- end

--screengui
local g = New "ScreenGui" {
	Name = "TerrainBrushGui",
	Parent = CoreGui,
}

local elevationFrame, elevationHelpFrame, elevationCloseEvent
brushDragBar, elevationFrame, elevationHelpFrame, elevationCloseEvent =
	RbxGui.CreatePluginFrame(
		"Terrain Brush",
		UDim2.new(0, 151, 0, 160),
		UDim2.new(0, 0, 0, 0),
		false,
		g
	)
brushDragBar.Visible = false
elevationCloseEvent.Event:connect(function()
	Off()
end)

elevationHelpFrame.Size = UDim2.new(0, 200, 0, 210)

local helpText =
	[[Drag the mouse by holding the left mouse button to either create or destroy terrain defined by the selection box.

Radius:
Half of the width of the selection box to be used.

Height:
How tall to make terrain from the mouse location.  If this value is negative, the brush will remove terrain instead of creating terrain (indicated by the red selection box).
]]

New "TextLabel" {
	Font = Enum.Font.ArialBold,
	FontSize = Enum.FontSize.Size12,
	TextColor3 = Color3.new(1, 1, 1),
	BackgroundTransparency = 1,
	TextWrapped = true,
	Size = UDim2.new(1, -10, 1, -10),
	Position = UDim2.new(0, 5, 0, 5),
	TextXAlignment = Enum.TextXAlignment.Left,
	Text = helpText,
	Parent = elevationHelpFrame,
}

-- current radius display label
local radl = New "TextLabel" {
	Position = UDim2.new(0, 0, 0, 70),
	Size = UDim2.new(1, 0, 0, 14),
	Text = "",
	BackgroundColor3 = Color3.new(0.4, 0.4, 0.4),
	TextColor3 = Color3.new(0.95, 0.95, 0.95),
	Font = Enum.Font.ArialBold,
	FontSize = Enum.FontSize.Size14,
	TextXAlignment = Enum.TextXAlignment.Left,
	BorderColor3 = Color3.new(0, 0, 0),
	BackgroundTransparency = 1,
	Parent = elevationFrame,
}

--radius slider
local radSliderGui, radSliderPosition =
	RbxGui.CreateSlider(5, 0, UDim2.new(0, 10, 0, 92))
radSliderGui.Parent = elevationFrame
local radBar = radSliderGui:FindFirstChild "Bar"
radBar.Size = UDim2.new(1, -20, 0, 5)
radSliderPosition.Changed:connect(function()
	radius = radSliderPosition.Value + 1
	radl.Text = " Radius: " .. radius
end)
radSliderPosition.Value = radius - 1

--current depth factor display label
local dfl = New "TextLabel" {
	Position = UDim2.new(0, 0, 0, 110),
	Size = UDim2.new(1, 0, 0, 14),
	Text = "",
	BackgroundColor3 = Color3.new(0.4, 0.4, 0.4),
	TextColor3 = Color3.new(0.95, 0.95, 0.95),
	Font = Enum.Font.ArialBold,
	FontSize = Enum.FontSize.Size14,
	BorderColor3 = Color3.new(0, 0, 0),
	TextXAlignment = Enum.TextXAlignment.Left,
	BackgroundTransparency = 1,
	Parent = elevationFrame,
}

--depth factor slider
local addSliderGui, addSliderPosition =
	RbxGui.CreateSlider(31, 0, UDim2.new(0, 10, 0, 132))
addSliderGui.Parent = elevationFrame
local dfBar = addSliderGui:FindFirstChild "Bar"
dfBar.Size = UDim2.new(1, -20, 0, 5)
addSliderPosition.Changed:connect(function()
	depth = addSliderPosition.Value
	dfl.Text = " Height: " .. depth
end)
addSliderPosition.Value = buildTerrainHeight

--depth factor slider
local removeSliderGui, removeSliderPosition =
	RbxGui.CreateSlider(31, 0, UDim2.new(0, 10, 0, 132))
removeSliderGui.Parent = elevationFrame
dfBar = removeSliderGui:FindFirstChild "Bar"
dfBar.Size = UDim2.new(1, -20, 0, 5)
removeSliderPosition.Changed:connect(function()
	depth = -removeSliderPosition.Value
	dfl.Text = " Height: " .. depth
end)
removeSliderPosition.Value = removeTerrainDepth

-- Set which mode is to be used.  Show/hide as needed.
--
-- mode - Which build mode to run.
function SetMode(setmode)
	if setmode == buildTerrainMode then
		addSliderGui.Visible = true
		local hold = addSliderPosition.Value
		addSliderPosition.Value = 0
		addSliderPosition.Value = hold
		removeSliderGui.Visible = false
	elseif setmode == removeTerrainMode then
		addSliderGui.Visible = false
		removeSliderGui.Visible = true
		local hold = removeSliderPosition.Value
		removeSliderPosition.Value = 0
		removeSliderPosition.Value = hold
	end
end

-- Create/Remove mode
-- Create the build mode gui.
-- local buildModeLabel = CreateStandardLabel(
-- 	"BuildModeLabel",
-- 	UDim2.new(0, 8, 0, 10),
-- 	UDim2.new(0, 67, 0, 14),
-- 	"Build Mode:",
-- 	elevationFrame
-- )
local _, buildModeSet = CreateStandardDropdown(
	"BuildModeDropdown",
	UDim2.new(0, 1, 0, 26),
	{ buildTerrainMode, removeTerrainMode },
	buildMode,
	function(value)
		if "Add" == value then
			SetMode(buildTerrainMode)
		elseif "Remove" == value then
			SetMode(removeTerrainMode)
		end
	end,
	elevationFrame
)
--[[							
	buildModeSet(buildTerrainMode)
	buildModeSet(removeTerrainMode)
--]]
buildModeSet(mode)
SetMode(mode)

this.Deactivation:connect(function()
	Off()
end)

--------------------------
--SUCCESSFUL LOAD MESSAGE-
--------------------------

loaded = true