-- @preconditions: vec should be a unit vector, and 0 < rayLength <= 1000
function RayCast(startPos, vec, rayLength)
	local hitObject, hitPos = game.Workspace:FindPartOnRay(Ray.new(startPos + (vec * .01), vec * rayLength), Handle)
	if hitObject and hitPos then
		local distance = rayLength - (hitPos - startPos).magnitude
		if RayIgnoreCheck(hitObject, hitPos) and distance > 0 then
			-- there is a chance here for potential infinite recursion
			return RayCast(hitPos, vec, distance)
		end
	end
	return hitObject, hitPos
end



function TagHumanoid(humanoid, player)
	-- Add more tags here to customize what tags are available.
	while humanoid:FindFirstChild('creator') do
		humanoid:FindFirstChild('creator'):Destroy()
	end 
	local creatorTag = Instance.new("ObjectValue")
	creatorTag.Value = player
	creatorTag.Name = "creator"
	creatorTag.Parent = humanoid
	DebrisService:AddItem(creatorTag, 1.5)

	local weaponIconTag = Instance.new("StringValue")
	weaponIconTag.Value = IconURL
	weaponIconTag.Name = "icon"
	weaponIconTag.Parent = creatorTag
end

local function CreateFlash()
	if FlashHolder then
		local flash = Instance.new('Fire', FlashHolder)
		flash.Color = Color3.new(0, 145 / 255, 255)
		flash.SecondaryColor = Color3.new(1, 0, 0)
		flash.Size = 0.3
		DebrisService:AddItem(flash, FireRate / 1.5)
	else
		FlashHolder = Instance.new("Part", Tool)
		FlashHolder.Transparency = 1
		FlashHolder.CanCollide= false
		FlashHolder.Size = Vector3.new(1, 1, 1)
		FlashHolder.Position = Tool.Handle.Position
		local Weld = Instance.new("ManualWeld")
		Weld.C0 = CFrame.new(0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1)
		Weld.C1 = CFrame.new(0, 2.2, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0)
		Weld.Part0 = FlashHolder
		Weld.Part1 = Tool.Handle
		Weld.Parent = FlashHolder
	end
end

local function CreateBullet(bulletPos)
	local bullet = Instance.new('Part', Workspace)
	bullet.FormFactor = Enum.FormFactor.Custom
	bullet.Size = Vector3.new(0.1, 0.1, 0.1)
	bullet.BrickColor = MyPlayer.TeamColor
	bullet.Shape = Enum.PartType.Ball
	bullet.CanCollide = false
	bullet.CFrame = CFrame.new(bulletPos)
	bullet.Anchored = true
	bullet.TopSurface = Enum.SurfaceType.Smooth
	bullet.BottomSurface = Enum.SurfaceType.Smooth
	bullet.Name = 'Bullet'
	DebrisService:AddItem(bullet, 2.5)
	local fire = Instance.new("Fire", bullet)
	fire.Color = Color3.new(MyPlayer.TeamColor.r, MyPlayer.TeamColor.g, MyPlayer.TeamColor.b)
	fire.SecondaryColor = Color3.new(MyPlayer.TeamColor.r, MyPlayer.TeamColor.g, MyPlayer.TeamColor.b)
	fire.Size = 5
	fire.Heat = 0
	DebrisService:AddItem(fire, 0.2)
	return bullet
end

local function Reload()
	if not Reloading then
		Reloading = true
		-- Don't reload if you are already full or have no extra ammo
		if AmmoInClip ~= ClipSize and SpareAmmo > 0 then
			if RecoilTrack then
				RecoilTrack:Stop()
			end
			if WeaponGui and WeaponGui:FindFirstChild('Crosshair') then
				if WeaponGui.Crosshair:FindFirstChild('ReloadingLabel') then
					WeaponGui.Crosshair.ReloadingLabel.Visible = true
				end
			end
			wait(ReloadTime)
			-- Only use as much ammo as you have
			local ammoToUse = math.min(ClipSize - AmmoInClip, SpareAmmo)
			AmmoInClip = AmmoInClip + ammoToUse
			SpareAmmo = SpareAmmo - ammoToUse
			UpdateAmmo(AmmoInClip)
		end
		Reloading = false
	end
end

function OnFire()
	if IsShooting then return end
	if MyHumanoid and MyHumanoid.Health > 0 then
		if RecoilTrack and AmmoInClip > 0 then
			RecoilTrack:Play()
		end
		IsShooting = true
		while LeftButtonDown and AmmoInClip > 0 and not Reloading do
			if Spread and not DecreasedAimLastShot then
				Spread = math.min(MaxSpread, Spread + AimInaccuracyStepAmount)
				UpdateCrosshair(Spread)
			end
			DecreasedAimLastShot = not DecreasedAimLastShot
			if Handle:FindFirstChild('FireSound') then
				Handle.FireSound:Play()
			end
			CreateFlash()
			if MyMouse then
				local targetPoint = MyMouse.Hit.p
				local shootDirection = (targetPoint - Handle.Position).unit
				-- Adjust the shoot direction randomly off by a little bit to account for recoil
				shootDirection = CFrame.Angles((0.5 - math.random()) * 2 * Spread,
																(0.5 - math.random()) * 2 * Spread,
																(0.5 - math.random()) * 2 * Spread) * shootDirection
				local hitObject, bulletPos = RayCast(Handle.Position, shootDirection, Range)
				local bullet
				-- Create a bullet here
				if hitObject then
					bullet = CreateBullet(bulletPos)
				end
				if hitObject and hitObject.Parent then
					local hitHumanoid = hitObject.Parent:FindFirstChild("Humanoid")
					if hitHumanoid then
						local hitPlayer = game.Players:GetPlayerFromCharacter(hitHumanoid.Parent)
						if MyPlayer.Neutral or (hitPlayer and hitPlayer.TeamColor ~= MyPlayer.TeamColor) then
							TagHumanoid(hitHumanoid, MyPlayer)
							hitHumanoid:TakeDamage(Damage)
							if bullet then
								bullet:Destroy()
								bullet = nil
								--bullet.Transparency = 1
							end
							Spawn(UpdateTargetHit)
						end
					end
				end
	
				AmmoInClip = AmmoInClip - 1
				UpdateAmmo(AmmoInClip)
			end
			wait(FireRate)
		end		
		IsShooting = false
		if AmmoInClip == 0 then
			Reload()
		end
		if RecoilTrack then
			RecoilTrack:Stop()
		end
	end
end

local TargetHits = 0
function UpdateTargetHit()
	TargetHits = TargetHits + 1
	if WeaponGui and WeaponGui:FindFirstChild('Crosshair') and WeaponGui.Crosshair:FindFirstChild('TargetHitImage') then
		WeaponGui.Crosshair.TargetHitImage.Visible = true
	end
	wait(0.5)
	TargetHits = TargetHits - 1
	if TargetHits == 0 and WeaponGui and WeaponGui:FindFirstChild('Crosshair') and WeaponGui.Crosshair:FindFirstChild('TargetHitImage') then
		WeaponGui.Crosshair.TargetHitImage.Visible = false
	end
end

function UpdateCrosshair(value, mouse)
	if WeaponGui then
		local absoluteY = 650
		WeaponGui.Crosshair:TweenSize(
			UDim2.new(0, value * absoluteY * 2 + 23, 0, value * absoluteY * 2 + 23),
			Enum.EasingDirection.Out,
			Enum.EasingStyle.Linear,
			0.33)
	end
end

function UpdateAmmo(value)
	if WeaponGui and WeaponGui:FindFirstChild('AmmoHud') and WeaponGui.AmmoHud:FindFirstChild('ClipAmmo') then
		WeaponGui.AmmoHud.ClipAmmo.Text = AmmoInClip
		if value > 0 and WeaponGui:FindFirstChild('Crosshair') and WeaponGui.Crosshair:FindFirstChild('ReloadingLabel') then
			WeaponGui.Crosshair.ReloadingLabel.Visible = false
		end
	end
	if WeaponGui and WeaponGui:FindFirstChild('AmmoHud') and WeaponGui.AmmoHud:FindFirstChild('TotalAmmo') then
		WeaponGui.AmmoHud.TotalAmmo.Text = SpareAmmo
	end
end


function OnMouseDown()
	LeftButtonDown = true
	OnFire()
end

function OnMouseUp()
	LeftButtonDown = false
end

function OnKeyDown(key)
	if string.lower(key) == 'r' then
		Reload()
	end
end


function OnEquipped(mouse)
	RecoilAnim = WaitForChild(Tool, 'Recoil')
	FireSound  = WaitForChild(Handle, 'FireSound')

	MyCharacter = Tool.Parent
	MyPlayer = game:GetService('Players'):GetPlayerFromCharacter(MyCharacter)
	MyHumanoid = MyCharacter:FindFirstChild('Humanoid')
	MyTorso = MyCharacter:FindFirstChild('Torso')
	MyMouse = mouse
	WeaponGui = WaitForChild(Tool, 'WeaponHud'):Clone()
	if WeaponGui and MyPlayer then
		WeaponGui.Parent = MyPlayer.PlayerGui
		UpdateAmmo(AmmoInClip)
	end
	if RecoilAnim then
		RecoilTrack = MyHumanoid:LoadAnimation(RecoilAnim)
	end

	if MyMouse then
		-- Disable mouse icon
		MyMouse.Icon = "http://www.roblox.com/asset/?id=18662154"
		MyMouse.Button1Down:connect(OnMouseDown)
		MyMouse.Button1Up:connect(OnMouseUp)
		MyMouse.KeyDown:connect(OnKeyDown)
	end
end