--[[
	diag_shellparts.luau -- dump the actual part inventory of hatch_junk and
	hyper_x. diag_nosecue2 found no headlight/taillight/seat on either, so the
	naming convention must differ. Read-only: list what IS there, plus a purely
	geometric asymmetry cue that needs no naming at all.

	Geometric cue (naming-independent): on a car, the passenger cabin /
	windscreen sits BEHIND the nose, so the mass distribution along the
	longitudinal axis is asymmetric. Cars are also taller at the cabin than at
	the nose. Reporting mean height per Z-half lets the shape itself indicate
	which end is the bonnet -- the tall half is the cabin/rear-biased end.
]]

local RS = game:GetService("ReplicatedStorage")
local SSS = game:GetService("ServerScriptService")
local SS = game:GetService("ServerStorage")

local TARGETS = { hatch_junk = true, hyper_x = true, rx7_fc = true }

local out = {}
local function log(s)
	table.insert(out, s)
end

local shells = {}
for _, root in ipairs({ RS, SSS, SS, workspace }) do
	for _, d in ipairs(root:GetDescendants()) do
		if d:IsA("Model") and TARGETS[d.Name] and d:FindFirstChild("Wheels") and not shells[d.Name] then
			shells[d.Name] = d
		end
	end
end

for _, name in ipairs({ "rx7_fc", "hatch_junk", "hyper_x" }) do
	local shell = shells[name]
	if not shell then
		log(name .. ": NOT FOUND")
		continue
	end
	local pivotInv = shell:GetPivot():Inverse()

	log("=== " .. name .. " ===")

	-- Part names outside the Wheels folder, with local Z, sorted front-to-back.
	local rows = {}
	for _, d in ipairs(shell:GetDescendants()) do
		if d:IsA("BasePart") and not d:IsDescendantOf(shell.Wheels) then
			local p = pivotInv * d.Position
			table.insert(rows, { name = d.Name, z = p.Z, y = p.Y, cls = d.ClassName })
		end
	end
	table.sort(rows, function(a, b)
		return a.z < b.z
	end)

	log(string.format("  %d non-wheel parts (sorted by local Z, -Z first):", #rows))
	local shown = 0
	for _, r in ipairs(rows) do
		if shown < 24 then
			log(string.format("    z=%+7.2f  y=%+6.2f  %-28s %s", r.z, r.y, r.name, r.cls))
			shown += 1
		end
	end
	if #rows > 24 then
		log(string.format("    ... %d more", #rows - 24))
	end

	-- Naming-independent shape cue: mean height of parts in each Z half.
	local negY, negN, posY, posN = 0, 0, 0, 0
	local minZ, maxZ
	for _, r in ipairs(rows) do
		minZ = minZ and math.min(minZ, r.z) or r.z
		maxZ = maxZ and math.max(maxZ, r.z) or r.z
	end
	local midZ = (minZ and maxZ) and ((minZ + maxZ) / 2) or 0
	for _, r in ipairs(rows) do
		if r.z < midZ then
			negY, negN = negY + r.y, negN + 1
		else
			posY, posN = posY + r.y, posN + 1
		end
	end
	if negN > 0 and posN > 0 then
		local negMean, posMean = negY / negN, posY / posN
		log(
			string.format(
				"  shape cue: mean height  -Z half = %+.2f (n=%d)   +Z half = %+.2f (n=%d)",
				negMean,
				negN,
				posMean,
				posN
			)
		)
		local tallEnd = (negMean > posMean) and "-Z" or "+Z"
		log(
			string.format(
				"             taller (cabin) end = %s  => nose is likely %s",
				tallEnd,
				(tallEnd == "-Z") and "+Z" or "-Z"
			)
		)
	else
		log("  shape cue: unavailable")
	end
	log("")
end

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