local max_depth = 31000
local cells = 10
local cell_size = 60 / cells


dofile(fun_caves.path .. "/trophies.lua")
dofile(fun_caves.path .. "/tesseract.lua")


-- dungeon floor, basic
newnode = fun_caves.clone_node("default:stone")
newnode.description = "Dungeon Stone"
newnode.legacy_mineral = false
newnode.groups = {fortress = 1}
minetest.register_node("fun_caves:dungeon_floor_1", newnode)

-- dungeon walls, basic
newnode = fun_caves.clone_node("default:sandstone")
newnode.description = "Dungeon Stone"
newnode.groups = {fortress = 1}
minetest.register_node("fun_caves:dungeon_wall_1", newnode)

-- dungeon walls, type 2
newnode = fun_caves.clone_node("default:desert_stone")
newnode.description = "Dungeon Stone"
newnode.groups = {fortress = 1}
minetest.register_node("fun_caves:dungeon_wall_2", newnode)

newnode = fun_caves.clone_node("default:glass")
newnode.description = "Dungeon Stone"
newnode.groups = {fortress = 1}
minetest.register_node("fun_caves:dungeon_wall_transparent", newnode)

newnode = fun_caves.clone_node("default:glass")
newnode.description = "Dungeon Stone"
newnode.groups = {fortress = 1}
newnode.tiles = {'fun_caves_blank.png'}
newnode.pointable = false
minetest.register_node("fun_caves:dungeon_wall_invisible", newnode)

newnode = fun_caves.clone_node("default:meselamp")
newnode.description = "Dungeon Light"
newnode.light_source = 10
newnode.groups = {fortress = 1}
minetest.register_node("fun_caves:dungeon_light", newnode)


local treasures = {
	{'fun_caves:aquamarine', 'fun_caves:garnet', 'fun_caves:zoisite', 'fun_caves:coral_gem', 'fun_caves:moonstone', 'fun_caves:pure_copper', 'fun_caves:sky_iron', 'fun_caves:sky_iron', 'fun_caves:sky_iron', 'fun_caves:sky_iron', 'default:obsidian'},
	{'fun_caves:aquamarine', 'fun_caves:garnet', 'fun_caves:zoisite', 'fun_caves:coral_gem', 'fun_caves:moonstone', 'fun_caves:pure_copper', 'fun_caves:metallic_ice', 'fun_caves:metallic_ice', 'fun_caves:metallic_ice', 'fun_caves:metallic_ice', 'default:obsidian'},
	{'fun_caves:aquamarine', 'fun_caves:garnet', 'fun_caves:zoisite', 'fun_caves:coral_gem', 'fun_caves:moonstone', 'default:obsidian'},
	{'fun_caves:aquamarine', 'fun_caves:garnet', 'fun_caves:zoisite', 'fun_caves:coral_gem', 'fun_caves:moonstone', 'default:obsidian'},
	{'fun_caves:aquamarine', 'fun_caves:garnet', 'fun_caves:zoisite', 'fun_caves:coral_gem', 'fun_caves:moonstone', 'default:obsidian'},
	{'fun_caves:aquamarine', 'fun_caves:garnet', 'fun_caves:zoisite', 'fun_caves:coral_gem', 'fun_caves:moonstone', 'default:obsidian'},
}

local filler = {'default:apple 50', 'default:coal_lump 99', 'default:wood 99', 'default:obsidian_shard', 'default:steel_ingot 10', 'default:mese_crystal', 'default:copper_ingot 10', 'default:bronze_ingot 10', 'default:diamond 10', 'fun_caves:silver_ingot 10', 'default:gold_ingot 10', 'fun_caves:moon_glass 25', 'fun_caves:moon_juice 50', 'default:sword_mese', 'default:pick_mese', 'default:sword_diamond', 'default:pick_diamond', 'fun_caves:constant_flame'}

if minetest.registered_entities['mobs_monster:stone_monster'] then
	filler[#filler+1] = 'mobs_monster:stone_monster'
end

if minetest.registered_entities['mobs_monster:dungeon_master'] then
	filler[#filler+1] = 'mobs_monster:dungeon_master'
end

local trophies = {
	{'fun_caves:unobtainium', 'fun_caves:philosophers_stone'},
	{'fun_caves:unobtainium', 'fun_caves:philosophers_stone'},
	{'fun_caves:unobtainium', 'fun_caves:philosophers_stone'},
	{'fun_caves:unobtainium', 'fun_caves:philosophers_stone'},
	{'fun_caves:unobtainium', 'fun_caves:philosophers_stone'},
	{'fun_caves:unobtainium', 'fun_caves:philosophers_stone'},
}
local chest_formspec =
	"size[8,9]" ..
	default.gui_bg ..
	default.gui_bg_img ..
	default.gui_slots ..
	"list[current_name;main;0,0.3;8,4;]" ..
	"list[current_player;main;0,4.85;8,1;]" ..
	"list[current_player;main;0,6.08;8,3;8]" ..
	"listring[current_name;main]" ..
	"listring[current_player;main]" ..
	default.get_hotbar_bg(0,4.85)

local newnode = fun_caves.clone_node("default:chest")
newnode.description = "Treasure Chest"
newnode.on_construct = nil
newnode.drop = 'default:chest'
newnode.on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
	if not pos then
		return
	end

	local meta = minetest.get_meta(pos)
	if not meta then
		return
	end

	local ready = meta:get_string('formspec')
	if ready == '' then
		local level = math.max(6, math.ceil(pos.y / math.floor(max_depth / 6)))
		local big_item = treasures[level][math.random(#treasures[level])]
		meta:set_string("formspec", chest_formspec)
		local inv = meta:get_inventory()
		inv:set_size("main", 8*4)
		inv:add_item('main', big_item)
		for i = 1, math.random(12) do
			inv:add_item('main', filler[math.random(#filler)])
		end
		if math.random(20) == 1 then
			inv:add_item('main', trophies[level][math.random(#trophies[level])])
		end
	end
end
minetest.register_node("fun_caves:coffer", newnode)


-- All arrays in the maze functions are zero-based.
local floor_noise_1 = {offset = 0, scale = 1, seed = 1587, spread = {x = 30, y = 30, z = 30}, octaves = 3, persist = 1, lacunarity = 2}

function table.shuffle(self)
	local j
	local t = self

	for i = #t, 1, -1 do
		j = math.random(0, i)
		t[i], t[j] = t[j], t[i]
	end
end

function unionfind(max)
	if not (max and type(max) == 'number') then
		return
	end

	local u = { _parent = {}, _rank = {} }

	for i = 0, max-1 do
		u._parent[i] = i
		u._rank[i] = 0
	end

	u.find = function(self, i)
		local p = self._parent[i]
		if i == p then
			return i
		end
		self._parent[i] = self:find(p)
		return self._parent[i]
	end

	u.union = function(self, i, j)
		i = i or 0
		j = j or 0
		local root1 = self:find(i)
		local root2 = self:find(j)

		if root1 == root2 then
			return
		end

		if self._rank[root1] > self._rank[root2] then
			self._parent[root2] = root1
		elseif self._rank[root2] > self._rank[root1] then
			self._parent[root1] = root2
		else
			self._parent[root2] = root1
			self._rank[root1] = self._rank[root1] + 1
		end
	end

	return u
end


local function maze_floor(y2, minp, maxp, data, area, node)
	if not (y2 and minp and maxp and data and area and node and type(y2) == 'number' and type(data) == 'table') then
		return
	end

	-- walls is zero-based.
	local walls = {}
	for i = 0, 2 * cells * cells - 1 do
		walls[i] = i
	end
	table.shuffle(walls)

	local set = unionfind(cells * cells)

	-- Remove walls in a continuous path.
	for m = 0, #walls-1 do
		local c = walls[m]
		local a = math.floor(c / 2)
		local i = a % cells
		local j = math.floor(a / cells)
		local u = c % 2 == 0 and 1 or 0
		local v = c % 2 == 1 and 1 or 0
		local b = a + u + cells * v
		if i < cells - u and j < cells - v and set:find(a) ~= set:find(b) then
			set:union(a, b)
			local x = (i + u) * cell_size + minp.x
			local y = minp.y + y2 * cell_size
			local z = (j + v) * cell_size + minp.z

			for z1 = z + (1-v), z + (1-v) * (cell_size - 1) do
				for y1 = y + 1, y + (cell_size - 1) do
					local ivm = area:index(x + (1-u), y1, z1)
					for x1 = x + (1-u), x + (1-u) * (cell_size - 1) do
						if x1 < maxp.x and z1 < maxp.z and x1 > minp.x and z1 > minp.z then
							data[ivm] = node["air"]
						end
						ivm = ivm + 1
					end
				end
			end
		end
	end
end


local designs = {
	{
		{0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,0,0},
		{0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,1,0,1,0,0,0,1,0,1,0},
		{1,1,1,1,0,1,1,1,1,1,0,1,1,1,0,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0},
		{1,1,0,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,0},
		{0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0},
		{0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0},
		{0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,1,0},
		{1,1,1,1,0,1,0,1,1,1,0,1,1,1,1,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0},
		{1,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,0},
		{0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0},
		{0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0},
		{0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,0,0,1,0},
		{0,1,1,1,0,1,1,1,0,1,0,1,1,1,1,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0},
		{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
	},
	{
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,1,0,1,0,1,1,1,1,1,1,1,1,1,0,1,0,1,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,1,0,1,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,0,0,1,0,1,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,1,0,1,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,1,0,1,0,1,1,1,1,1,1,1,1,1,0,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
	},
	{
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,1,1,1,1,1,0,0,0,1,1,1,1,1,1,1,1,1,0},
		{0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0},
		{0,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,0},
		{0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,1,0,1,0},
		{0,1,0,1,0,1,1,1,1,1,0,0,0,1,0,1,0,1,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,1,0,1,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,1,0,1,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,1,0,1,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,1,0,1,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,1,0,1,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,1,0,1,0},
		{0,1,0,1,0,1,0,0,0,0,0,0,0,1,0,1,0,1,0},
		{0,1,0,1,0,1,1,1,1,1,1,1,1,1,0,1,0,1,0},
		{0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,1,0,1,0},
		{0,1,0,1,1,1,0,0,0,1,1,1,1,1,1,1,0,1,0},
		{0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0},
		{0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
	},
	{
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{1,1,0,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,1},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,0,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,0,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,0,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,0,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{1,1,0,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,1},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
	},
}

local function design_floor(y2, minp, maxp, data, area, node)
	if not (y2 and minp and maxp and data and area and node and type(y2) == 'number' and type(data) == 'table') then
		return
	end

	local design = designs[math.random(#designs)]

	local py = minp.y + y2 * cell_size
	for z = 1, 10 do
		for x = 1, 9 do
			if design[z * 2 - 1][x * 2] == 0 then
				local px = minp.x + x * cell_size
				local pz = minp.z + (z - 1) * cell_size
				for z1 = pz + 1, pz + cell_size - 1 do
					local ivm = area:index(px, py + 1, z1)
					for y1 = py + 1, py + cell_size - 1 do
						data[ivm] = node['air']
						ivm = ivm + area.ystride
					end
				end
			end
		end
	end
	for z = 1, 9 do
		for x = 1, 10 do
			if design[z * 2][x * 2 - 1] == 0 then
				local px = minp.x + (x - 1) * cell_size
				local pz = minp.z + z * cell_size
				for x1 = px + 1, px + cell_size - 1 do
					local ivm = area:index(x1, py + 1, pz)
					for y1 = py + 1, py + cell_size - 1 do
						data[ivm] = node['air']
						ivm = ivm + area.ystride
					end
				end
			end
		end
	end
	for z = 1, 9 do
		for x = 1, 9 do
			if design[z * 2][x * 2] == 0 then
				local px = minp.x + x * cell_size
				local pz = minp.z + z * cell_size
				local ivm = area:index(px, py + 1, pz)
				for y1 = py + 1, py + cell_size - 1 do
					data[ivm] = node['air']
					ivm = ivm + area.ystride
				end
			end
		end
	end
end


fun_caves.fortress = function(minp_in, maxp_in, data, area, node)
	if not (minp_in and maxp_in and data and area and node and type(data) == 'table') then
		return
	end

	-- hungry maze
	-- chests (w traps)
	-- step traps (math based)
	-- hidden doors/downs
	-- hot/ice floors
	-- torches
	--
	local minp = vector.add(minp_in, 10)
	local maxp = vector.subtract(maxp_in, 9)
	local level = math.min(6, math.ceil(maxp.y / math.floor(max_depth / -6)))
	local inner_floor = node['fun_caves:dungeon_floor_1']
	local outer_wall = node['fun_caves:dungeon_wall_2']
	local inner_wall = node['fun_caves:dungeon_wall_1']
	local treasure_count = 0
	local csize = vector.add(vector.subtract(maxp_in, minp_in), 1)
	local floor_1 = minetest.get_perlin_map(floor_noise_1, {x=csize.x, y=csize.z}):get2dMap_flat({x=minp_in.x, y=minp_in.z})
	if not floor_1 then
		return
	end

	for y2 = 0, cells-1 do
		local floor_type = math.random(20)

		local dox, doz = math.random(0, cells-1), math.random(0, cells-1)
		for z = minp.z, maxp.z do
			for y = minp.y + y2 * cell_size, minp.y + y2 * cell_size + (cell_size - 1) do
				local ivm = area:index(minp.x, y, z)
				for x = minp.x, maxp.x do
					if x == minp.x or z == minp.z or x == maxp.x or z == maxp.z then
						data[ivm] = outer_wall
					elseif (y - minp.y) % cell_size == 0 then
						if math.floor((z - minp.z) / cell_size) == doz and math.floor((x - minp.x) / cell_size) == dox and (z - minp.z) % cell_size ~= 0 and (x - minp.x) % cell_size ~= 0 and y ~= minp.y then
							data[ivm] = node["air"]
						else
							data[ivm] = inner_floor
						end
					elseif floor_type ~= 3 and ((z - minp.z) % cell_size == 0 or (x - minp.x) % cell_size == 0) then
						if y == minp.y + y2 * cell_size + 3 and ((z - minp.z) % cell_size == 3 or (x - minp.x) % cell_size == 3) and math.random(5) == 1 then
							data[ivm] = node['fun_caves:dungeon_light']
						elseif floor_type == 1 and level > 3 then
							data[ivm] = node['fun_caves:dungeon_wall_invisible']
						elseif floor_type == 1 then
							data[ivm] = node['fun_caves:dungeon_wall_transparent']
						elseif floor_type ~= 3 then
							data[ivm] = inner_wall
						end
					else
						if y2 == 0 and y == minp.y + y2 * cell_size + 1 and data[ivm - area.ystride] ~= node['air'] and math.random(700) == 1 then
							treasure_count = treasure_count + 1
							data[ivm] = node['fun_caves:coffer']
						else
							data[ivm] = node["air"]
						end
					end
					ivm = ivm + 1
				end
			end
		end

		if floor_type ~= 3 then
			local wall_type = math.random(#designs + 1)

			if wall_type == 1 then
				maze_floor(y2, minp, maxp, data, area, node)
			else
				design_floor(y2, minp, maxp, data, area, node)
			end
		end

		local index = 0
		for z = minp.z + 1, maxp.z - 1 do
			for x = minp.x + 1, maxp.x - 1 do
				local ivm = area:index(x, minp.y + y2 * cell_size, z)

				if floor_type == 2 then
					if data[ivm] ~= node['air'] and data[ivm + area.ystride] == node['air'] then
						if level > 3 then
							data[ivm + area.ystride] = node['default:lava_source']
						else
							data[ivm + area.ystride] = node['fun_caves:hot_cobble']
						end
					end
				elseif floor_type == 3 then
					if (y2 < 9 or (z - minp_in.z) > 16 or (x - minp_in.x) > 16) and data[ivm] ~= node['air'] then
						local index = (z - minp_in.z) * csize.x + x - minp_in.x
						for i = 1, math.min((cell_size - 1), math.floor((cell_size - 1) * math.abs(floor_1[index]))) do
							if data[ivm + area.ystride * i] == node['air'] then
								data[ivm + area.ystride * i] = node['default:dirt']
							end
						end
					end
				elseif floor_type == 4 then
					for i = 1, (cell_size - 1) do
						if data[ivm + area.ystride * i] == node['air'] then
							data[ivm + area.ystride * i] = node['default:water_source']
						end
					end
				end
			end
		end
	end
end