-- Diagnose the raycast outlier: report WHICH parts the rays hit.
-- The v3 raycast filtered on the whole map, so overhead geometry (overpass
-- decks, girders, gantries, tunnel ceilings) can be hit before the road.
local sss = game:GetService("ServerScriptService")
local orig = sss:FindFirstChild("MapBuilder", true)
local clone = orig:Clone()
clone.Name = "MapBuilder_Diag"
clone.Parent = orig.Parent
local MB = require(clone)
local map = MB.build()
local Circuit = require(game:GetService("ReplicatedStorage"):FindFirstChild("Circuit", true))
local samples = Circuit.samples
local n = #samples

local rp = RaycastParams.new()
rp.FilterType = Enum.RaycastFilterType.Include
rp.FilterDescendantsInstances = { map }

local out = {}
-- Road-only params: what the driver actually touches.
local roadOnly = RaycastParams.new()
roadOnly.FilterType = Enum.RaycastFilterType.Include
roadOnly.FilterDescendantsInstances = { map:FindFirstChild("Expressway") }

local worstAll, worstRoad, atAll, atRoad = 0, 0, -1, -1
local hits = {}
for i = 1, n do
	local j = (i % n) + 1
	local p = samples[j].pos
	local fwd = (samples[(j % n) + 1].pos - samples[i].pos)
	fwd = Vector3.new(fwd.X, 0, fwd.Z)
	if fwd.Magnitude > 0.01 then
		fwd = fwd.Unit
		local o1 = p - fwd * 3 + Vector3.new(0, 40, 0)
		local o2 = p + fwd * 3 + Vector3.new(0, 40, 0)
		local a1 = workspace:Raycast(o1, Vector3.new(0, -120, 0), rp)
		local a2 = workspace:Raycast(o2, Vector3.new(0, -120, 0), rp)
		if a1 and a2 then
			local d = math.abs(a1.Position.Y - a2.Position.Y)
			if d > worstAll then
				worstAll, atAll = d, i
			end
			if d > 1 then
				hits[#hits + 1] = ("i=%d(%s) d=%.2f hitA=%s hitB=%s"):format(
					i, samples[i].piece, d, a1.Instance.Name, a2.Instance.Name)
			end
		end
		local b1 = workspace:Raycast(o1, Vector3.new(0, -120, 0), roadOnly)
		local b2 = workspace:Raycast(o2, Vector3.new(0, -120, 0), roadOnly)
		if b1 and b2 then
			local d = math.abs(b1.Position.Y - b2.Position.Y)
			if d > worstRoad then
				worstRoad, atRoad = d, i
			end
		end
	end
end

out[#out + 1] = ("ALL-GEOMETRY worst=%.3f at i=%d"):format(worstAll, atAll)
out[#out + 1] = ("ROAD-ONLY  worst=%.3f at i=%d -> %s"):format(
	worstRoad, atRoad, worstRoad <= 0.60 and "PASS" or "FAIL")
out[#out + 1] = ("outlier samples (d>1), first 12 of %d:"):format(#hits)
for k = 1, math.min(12, #hits) do
	out[#out + 1] = "  " .. hits[k]
end

map:Destroy()
clone:Destroy()
return table.concat(out, "\n")