--!strict
-- Verify the rebuilt Daikoku PA junction IN-ENGINE, after MapBuilder has run.
--
-- MEASURE FIRST (project rule): ray tests and code reasoning both mislead;
-- actual part positions are ground truth. This reads the built parts back out
-- of Workspace rather than trusting the source that generated them.
--
-- Checks:
--   1. No PA ring/parapet part intrudes into the mainline carriageway.
--   2. Mainline deck clears the ring/apron by a usable height.
--   3. Both ramps form a continuous, climbable chain (no cliff, no gap).
--   4. The old PARingPillar parts are gone.
local ws = workspace

local function findFirst(name: string): Instance?
	return ws:FindFirstChild(name, true)
end

local out = {}
local function say(s: string)
	table.insert(out, s)
end

-- Locate the PA + road containers -------------------------------------------
local pa = findFirst("ParkingArea") or findFirst("PA") or findFirst("DaikokuPA")
local road = findFirst("Road")
local struct = findFirst("Structure") or findFirst("Struct")

say("== CONTAINERS ==")
say(("pa=%s road=%s struct=%s"):format(
	pa and pa:GetFullName() or "NIL",
	road and road:GetFullName() or "NIL",
	struct and struct:GetFullName() or "NIL"
))

-- Gather parts by name pattern anywhere under Workspace ----------------------
local buckets: { [string]: { BasePart } } = {}
local function bucket(key: string, p: BasePart)
	buckets[key] = buckets[key] or {}
	table.insert(buckets[key], p)
end

for _, d in ipairs(ws:GetDescendants()) do
	if d:IsA("BasePart") then
		local n = d.Name
		if n:match("^PARingWall") or n:match("^PARingRail") then
			bucket("ringwall", d)
		elseif n:match("^PARingPillar") then
			bucket("ringpillar", d)
		elseif n:match("^PARamp") and n:match("Pillar") then
			bucket("ramppillar", d)
		elseif n:match("^PARampKerb") then
			bucket("rampkerb", d)
		elseif n:match("^PAOnRamp") then
			bucket("entryramp", d)
		elseif n:match("^PAOffRamp") then
			bucket("exitramp", d)
		elseif n:match("^Road_") then
			bucket("roaddeck", d)
		end
	end
end

say("")
say("== PART COUNTS ==")
for _, k in ipairs({ "roaddeck", "ringwall", "ringpillar", "entryramp", "exitramp", "ramppillar", "rampkerb" }) do
	say(("%-12s %d"):format(k, buckets[k] and #buckets[k] or 0))
end

-- 4. Old ring pillars must be gone ------------------------------------------
say("")
say("== CHECK: legacy ring pillars removed ==")
local rp = buckets["ringpillar"]
if rp and #rp > 0 then
	say(("FAIL: %d PARingPillar parts still present (ring should be ground-level)"):format(#rp))
else
	say("PASS: no PARingPillar parts (ring is ground-level)")
end

-- 1 + 2. Ring structures vs mainline carriageway -----------------------------
say("")
say("== CHECK: ring walls do not intrude into the carriageway ==")
local decks = buckets["roaddeck"] or {}
local walls = buckets["ringwall"] or {}
local worstGap, worstDesc = math.huge, "n/a"
local intrusions = 0
for _, w in ipairs(walls) do
	local wTop = w.Position.Y + w.Size.Y / 2
	for _, dk in ipairs(decks) do
		local dxz = (Vector3.new(dk.Position.X, 0, dk.Position.Z) - Vector3.new(w.Position.X, 0, w.Position.Z)).Magnitude
		-- Only decks whose footprint actually overlaps this wall matter.
		if dxz < (dk.Size.X / 2 + w.Size.X / 2 + 30) then
			local deckBottom = dk.Position.Y - dk.Size.Y / 2
			local gap = deckBottom - wTop
			if gap < worstGap then
				worstGap = gap
				worstDesc = ("%s vs %s dxz=%.1f"):format(dk.Name, w.Name, dxz)
			end
			if gap < 0 then
				intrusions += 1
			end
		end
	end
end
if worstGap == math.huge then
	say("PASS: no ring wall shares a footprint with any mainline deck")
else
	say(("closest ring-wall/deck pair: %s"):format(worstDesc))
	say(("vertical gap = %.1f studs"):format(worstGap))
	if intrusions > 0 then
		say(("FAIL: %d wall/deck pairs overlap vertically -- wall in the road"):format(intrusions))
	else
		say("PASS: every overlapping ring wall passes UNDER the deck")
	end
end

-- 3. Ramp continuity ---------------------------------------------------------
local function checkRamp(key: string, label: string)
	say("")
	say(("== CHECK: %s continuity =="):format(label))
	local segs = buckets[key]
	if not segs or #segs == 0 then
		say("FAIL: no segments found")
		return
	end
	table.sort(segs, function(a, b)
		local ai = tonumber(a.Name:match("_(%d+)$")) or 0
		local bi = tonumber(b.Name:match("_(%d+)$")) or 0
		return ai < bi
	end)
	local loY = segs[1].Position.Y
	local hiY = segs[#segs].Position.Y
	say(("%d segments, Y from %.1f to %.1f (rise %.1f)"):format(#segs, loY, hiY, hiY - loY))
	local maxStep, maxGap = 0, 0
	for i = 2, #segs do
		local a, b = segs[i - 1], segs[i]
		local step = math.abs(b.Position.Y - a.Position.Y)
		local horiz = (Vector3.new(a.Position.X, 0, a.Position.Z) - Vector3.new(b.Position.X, 0, b.Position.Z)).Magnitude
		-- gap = horizontal distance minus the two half-lengths that face
		-- each other; negative means the segments overlap (good).
		local gap = horiz - (a.Size.Z / 2 + b.Size.Z / 2)
		maxStep = math.max(maxStep, step)
		maxGap = math.max(maxGap, gap)
	end
	say(("max vertical step between segments = %.2f studs"):format(maxStep))
	say(("max horizontal gap between segments = %.2f studs (negative = overlap)"):format(maxGap))
	if maxStep > 6 then
		say("FAIL: a step that large is a cliff a car cannot climb")
	elseif maxGap > 0.5 then
		say("FAIL: segments do not meet -- wheels will drop into the seam")
	else
		say("PASS: ramp is continuous and climbable")
	end
end

checkRamp("entryramp", "entry ramp")
checkRamp("exitramp", "exit ramp")

return table.concat(out, "\n")