-- Headless verification of the four C1 fidelity fixes.
-- Asserts NUMBERS the build produced, not "the build ran".
local sss = game:GetService("ServerScriptService")
local orig = sss:FindFirstChild("MapBuilder", true)
if not orig then return "FAIL: MapBuilder not found" end

-- Freshness gate: prove we are measuring the NEW source before trusting anything.
local fresh = {}
for _, tok in ipairs({ "WIDE_ROAD_WIDTH", "BridgeGirder", "GinzaOverpass", "isJctSample", "GIRDER_H" }) do
	fresh[#fresh + 1] = tok .. "=" .. tostring(orig.Source:find(tok, 1, true) ~= nil)
end

-- Fresh-require so Studio's module cache cannot serve a stale copy.
local clone = orig:Clone()
clone.Name = "MapBuilder_Verify"
clone.Parent = orig.Parent
local okM, MB = pcall(require, clone)
if not okM then
	clone:Destroy()
	return "FAIL require: " .. tostring(MB)
end

local okB, map = pcall(MB.build)
if not okB then
	clone:Destroy()
	return "FAIL build: " .. tostring(map)
end

local Circuit = require(game:GetService("ReplicatedStorage"):FindFirstChild("Circuit", true))

local counts = {}
local decks = {}
for _, d in ipairs(map:GetDescendants()) do
	if d:IsA("BasePart") then
		counts[d.Name] = (counts[d.Name] or 0) + 1
		local idx = d.Name:match("^Road_(%d+)$")
		if idx then
			decks[tonumber(idx)] = d
		end
	end
end

local out = {}
local function line(s)
	out[#out + 1] = s
end
line("FRESHNESS: " .. table.concat(fresh, " "))

-- FIX 1: bridge flag wired up ------------------------------------------------
local nBridgeSamples = 0
for _, s in ipairs(Circuit.samples) do
	if s.bridge then
		nBridgeSamples += 1
	end
end
local girders = counts["BridgeGirder"] or 0
line(("FIX1 bridge flag: samples=%d girders=%d piercaps=%d piercols=%d -> %s"):format(
	nBridgeSamples, girders, counts["PierCap"] or 0, counts["PierColumn"] or 0,
	(girders >= nBridgeSamples * 0.5 and girders > 0) and "PASS" or "FAIL"))

-- FIX 2: Ginza overpasses with piers between the carriageways ----------------
local ov, pier = counts["GinzaOverpass"] or 0, counts["OverpassPier"] or 0
line(("FIX2 Ginza 跨道橋: overpass=%d pier=%d parapet=%d -> %s"):format(
	ov, pier, counts["OverpassParapet"] or 0, (ov > 0 and pier == ov) and "PASS" or "FAIL"))

-- Piers must actually sit BETWEEN the carriageways (near the centreline),
-- not off to one side -- that is the whole point of the fix.
local worstPier = 0
for _, d in ipairs(map:GetDescendants()) do
	if d.Name == "OverpassPier" then
		local best = math.huge
		for i, s in ipairs(Circuit.samples) do
			if s.piece == "Ginza" then
				local dd = (Vector3.new(s.pos.X, 0, s.pos.Z) - Vector3.new(d.Position.X, 0, d.Position.Z)).Magnitude
				best = math.min(best, dd)
				local _ = i
			end
		end
		worstPier = math.max(worstPier, best)
	end
end
line(("FIX2 pier centreline offset: worst=%.2f studs -> %s"):format(
	worstPier, worstPier < 6 and "PASS" or "FAIL"))

-- FIX 3: 40 km/h plates in junctions ----------------------------------------
local n40, n50 = 0, 0
for _, d in ipairs(map:GetDescendants()) do
	if d.Name == "SpeedLimitSign" then
		for _, g in ipairs(d:GetDescendants()) do
			if g:IsA("TextLabel") then
				if g.Text == "40" then
					n40 += 1
				elseif g.Text == "50" then
					n50 += 1
				end
				break
			end
		end
	end
end
line(("FIX3 speed plates: 40kmh=%d 50kmh=%d -> %s"):format(
	n40, n50, (n40 > 0 and n50 > 0) and "PASS" or "FAIL"))

-- FIX 4: Shiodome 3+3 widening ----------------------------------------------
local shioW, baseW, shioN, baseN = 0, 0, 0, 0
for i, s in ipairs(Circuit.samples) do
	local d = decks[i]
	if d then
		if s.piece == "Shiodome" then
			shioW += d.Size.X
			shioN += 1
		elseif s.piece == "Kasumigaseki" then
			baseW += d.Size.X
			baseN += 1
		end
	end
end
shioW = shioN > 0 and shioW / shioN or 0
baseW = baseN > 0 and baseW / baseN or 0
line(("FIX4 deck width: Shiodome avg=%.1f  Kasumigaseki avg=%.1f -> %s"):format(
	shioW, baseW, (shioW > baseW + 8) and "PASS" or "FAIL"))

-- Lane boundary count: 3 lanes per side needs 2 boundary lines per side.
local function boundariesNear(zone)
	local best, bestI = math.huge, nil
	for i, s in ipairs(Circuit.samples) do
		if s.piece == zone then
			bestI = bestI or i
			best = 0
		end
	end
	local _ = best
	return bestI
end
local si = boundariesNear("Shiodome")
local nLines = 0
if si and decks[si] then
	local c = decks[si].Position
	for _, d in ipairs(map:GetDescendants()) do
		if (d.Name == "LaneLine" or d.Name == "Dash") and (d.Position - c).Magnitude < 40 then
			nLines += 1
		end
	end
end
line(("FIX4 lane boundaries near Shiodome sample %s: %d markings"):format(tostring(si), nLines))

-- REGRESSION: no holes in the deck, seam lips still within tolerance --------
local holes, maxLip = 0, 0
local n = #Circuit.samples
for i = 1, n do
	local a, b = decks[i], decks[(i % n) + 1]
	if a and b then
		local lip = math.abs((a.Position.Y + a.Size.Y / 2) - (b.Position.Y + b.Size.Y / 2))
		maxLip = math.max(maxLip, lip)
	elseif not a then
		holes += 1
	end
end
line(("REGRESSION decks=%d holes=%d maxSeamLip=%.3f -> %s"):format(
	n, holes, maxLip, (holes == 0 and maxLip <= 0.30) and "PASS" or "FAIL"))

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