local running = false

local function strip_qty(itemstring)
	return string.match(itemstring,"(.*) .*")
end

local function compare_shaped_crafts(a,b)
	if a.output == b.output then return false end
	if minetest.registered_aliases[a.output] == b.output
		or minetest.registered_aliases[b.output] == a.output then
		return false
	end
	for i=1,9,1 do
		if a.items[i] ~= b.items[i] then
			return false
		end
	end
	return true
end

local function table_contains(tbl,search)
	for i,item in pairs(tbl) do
		if item == search then
			return i
		end
	end
end

local function compare_shapeless_crafts(a,b)
	if a.output == b.output then return false end
	if minetest.registered_aliases[a.output] == b.output
		or minetest.registered_aliases[b.output] == a.output then
		return false
	end
	local a_items = {}
	for _,item in pairs(a.items) do
		table.insert(a_items,item)
	end
	local b_items = {}
	for _,item in pairs(b.items) do
		table.insert(b_items,item)
	end
	for _,item in pairs(a_items) do
		local b_idx = table_contains(b_items,item)
		if not b_idx then return false end
		b_items[b_idx] = nil
	end
	for _ in pairs(b_items) do return false end
	return true
end

local function run()
	if running then return end
	running = true
	print()
	print()
	print("Craft analysis started")
	print()
	print("Building list of crafts...")
	local crafts = {}
	crafts.shaped = {}
	crafts.shapeless = {}
	for name in pairs(minetest.registered_items) do
		local crafts_for_name = minetest.get_all_craft_recipes(name)
		if crafts_for_name then
			for _,craft in pairs(crafts_for_name) do
				craft.output = strip_qty(craft.output)
				if craft.type == "normal" and craft.width > 0 then
					table.insert(crafts.shaped,craft)
				elseif craft.type == "normal" and craft.width == 0 then
					table.insert(crafts.shapeless,craft)
				end
			end
		end
	end
	print(#crafts.shaped.." shaped recipes")
	print(#crafts.shapeless.." shapeless recipes")
	print()
	local conflicts = {}
	print("Searching for shaped <-> shaped conflicts...")
	conflicts.shaped_shaped = {}
	print("0/"..#crafts.shaped.." crafts scanned")
	for src=1,(#crafts.shaped-1),1 do
		if src % 1000 == 0 then
			print(src.."/"..#crafts.shaped.." crafts scanned")
		end
		for dst=(src+1),#crafts.shaped,1 do
			local conflict = compare_shaped_crafts(crafts.shaped[src],crafts.shaped[dst])
			if conflict then
				local conflictdef = {}
				conflictdef[1] = crafts.shaped[src].output
				conflictdef[2] = crafts.shaped[dst].output
				table.insert(conflicts.shaped_shaped,conflictdef)
			end
		end
	end
	print(#crafts.shaped.."/"..#crafts.shaped.." crafts scanned")
	print(#conflicts.shaped_shaped.." found")
	print()
	print("Searching for shapeless <-> shapeless conflicts...")
	conflicts.shapeless_shapeless = {}
	print("0/"..#crafts.shapeless.." crafts scanned")
	for src=1,(#crafts.shapeless-1),1 do
		if src % 1000 == 0 then
			print(src.."/"..#crafts.shapeless.." crafts scanned")
		end
		for dst=(src+1),#crafts.shapeless,1 do
			local conflict = compare_shapeless_crafts(crafts.shapeless[src],crafts.shapeless[dst])
			if conflict then
				local conflictdef = {}
				conflictdef[1] = crafts.shapeless[src].output
				conflictdef[2] = crafts.shapeless[dst].output
				table.insert(conflicts.shapeless_shapeless,conflictdef)
			end
		end
	end
	print(#crafts.shapeless.."/"..#crafts.shapeless.." crafts scanned")
	print(#conflicts.shapeless_shapeless.." found")
	print()
	print("Searching for shaped <-> shapeless conflicts...")
	conflicts.shaped_shapeless = {}
	print("0/"..#crafts.shapeless.." crafts scanned")
	for src=1,#crafts.shapeless,1 do
		if src % 1000 == 0 then
			print(src.."/"..#crafts.shapeless.." crafts scanned")
		end
		for dst=1,#crafts.shaped,1 do
			local conflict = compare_shapeless_crafts(crafts.shapeless[src],crafts.shaped[dst])
			if conflict then
				local conflictdef = {}
				conflictdef[1] = crafts.shaped[src].output
				conflictdef[2] = crafts.shapeless[dst].output
				table.insert(conflicts.shaped_shapeless,conflictdef)
			end
		end
	end
	print(#crafts.shapeless.."/"..#crafts.shapeless.." crafts scanned")
	print(#conflicts.shaped_shapeless.." found")
	print()
	print()
	print("=== SHAPED <-> SHAPED CRAFT CONFLICTS ===")
	if #conflicts.shaped_shaped == 0 then
		print("None found!")
	else
		for _,conflictdef in pairs(conflicts.shaped_shaped) do
			print(string.format("%s <-> %s",conflictdef[1],conflictdef[2]))
		end
	end
	print()
	print()
	print("=== SHAPELESS <-> SHAPELESS CRAFT CONFLICTS ===")
	if #conflicts.shapeless_shapeless == 0 then
		print("None found!")
	else
		for _,conflictdef in pairs(conflicts.shapeless_shapeless) do
			print(string.format("%s <-> %s",conflictdef[1],conflictdef[2]))
		end
	end
	print()
	print()
	print("=== SHAPED <-> SHAPELESS CRAFT CONFLICTS ===")
	if #conflicts.shaped_shapeless == 0 then
		print("None found!")
	else
		for _,conflictdef in pairs(conflicts.shaped_shapeless) do
			print(string.format("%s <-> %s",conflictdef[1],conflictdef[2]))
		end
	end
	print()
	print()
	print("Craft analysis complete, shutting down server")
	minetest.request_shutdown("Craft conflict detection finished - see terminal for results")
end
minetest.after(1,run)